Honeywell Heating System EN2H 0221GE51 R0808 User Manual

Smile SDC heating and  
district heating controller  
SERVICE MANUAL  
EN2H-0221GE51 R0808  
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SDC / DHC  
Contents  
Contents  
1
2
Software version..........................................................................................................11  
Safety instructions.......................................................................................................11  
2.1  
2.2  
Intended use .....................................................................................................11  
Requirements for start-up..................................................................................11  
2.2.1 Power supply........................................................................................12  
2.2.2 Connection conditions ..........................................................................12  
2.2.3 Cable cross-sections ............................................................................12  
2.2.4 Maximum cable lengths........................................................................12  
2.2.5 Cable installation ..................................................................................12  
2.2.6 Grounding and zeroing.........................................................................13  
Hot-water temperature greater than 60 °C ........................................................13  
Connection of accessory parts..........................................................................14  
Maintenance and cleaning ................................................................................14  
Safety precautions for EMC-compliant installation............................................15  
2.3  
2.4  
2.5  
2.6  
3
4
5
Overview.......................................................................................................................20  
Abbreviations...............................................................................................................21  
Operation......................................................................................................................22  
5.1  
Display and operating elements........................................................................22  
5.1.1 Display (basic display)..........................................................................23  
5.1.2 Operating elements ..............................................................................24  
5.1.2.1 Input button (press / turn)........................................................24  
5.1.2.2 "Daytime room temperature" button........................................24  
5.1.2.3 "Night-time room temperature" button.....................................25  
5.1.2.4 "Daytime hot-water temperature" button .................................25  
5.1.2.5 "Operating mode" button (basic display).................................26  
5.1.2.6 "Switching time programs / Holiday programs" button ............33  
5.1.2.7 "System information" button....................................................35  
5.1.2.8 "Manual mode" / "Emission measurement" button..................44  
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Contents  
SDC / DHC  
5.1.2.9 Access to the technician / OEM area ......................................46  
5.1.2.10Heating curve..........................................................................47  
Menu-selection level..........................................................................................48  
5.2.1 "Time - Date" menu ..............................................................................54  
5.2.2 "Timeprograms" menu..........................................................................55  
5.2.2.1 Selection of the control circuit .................................................56  
5.2.2.2 Selection of the program.........................................................56  
5.2.2.3 Selection of day of the week and cycle ...................................56  
5.2.2.4 Programming switching times and cycle temperatures ...........57  
5.2.3 "System Parameters" menu..................................................................72  
5.2.3.1 Language selection.................................................................72  
5.2.3.2 Time program..........................................................................73  
5.2.3.3 Operating mode ......................................................................74  
5.2.3.4 Parameter reset ......................................................................76  
5.2.3.5 Complete reset........................................................................77  
5.2.4 "DHW" menu ........................................................................................77  
5.2.4.1 Night-time hot-water temperature............................................78  
5.2.4.2 Legionella protection day ........................................................78  
5.2  
5.2.5 "Direct Heating Circuit" / "Mixed Heating Circuit 1" / "Mixed  
Heating Circuit 2" menu........................................................................78  
5.2.5.1 Reduced operation..................................................................79  
5.2.5.2 Heating system .......................................................................80  
Error messages.................................................................................................80  
Parameter settings............................................................................................81  
5.4.1 "Hydraulics" menu (HYDRAULIC) ........................................................81  
5.4.2 "System parameters" menu (SYSTEM)................................................85  
5.4.3 "Hot-water circuit" menu (DHW) ...........................................................89  
5.4.4 "Direct heating circuit" menu (UNMIXED CIRC)...................................92  
5.3  
5.4  
5.4.5 "Mixed heating circuit 1 / 2" (MIX.VALVE - 1 / MIX.VALVE - 2)  
menus ...................................................................................................95  
5.4.6 "Heat generator" menu (HEAT GENER................................................99  
4
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Contents  
5.4.7 "District hot water" menu (DIST.HEATING)........................................104  
5.4.8 "Return increase" menu (RETURN CONTR)......................................105  
5.4.9 "Solar" menu (SOLAR) .......................................................................106  
5.4.10 "Solid" menu (SOLID FUEL)...............................................................107  
5.4.11 "Buffer" menu (BUFFER)....................................................................108  
5.4.12 "Total flow regulation" menu (MAIN SUPPLY)....................................109  
5.4.13 "Cascading" menu (CASCADE) .........................................................110  
5.4.14 "Data bus" menu (BUS)......................................................................111  
5.4.15 "Relay test" menu (RELAY TEST )....................................................111  
5.4.16 "Error messages" menu (ALARM)......................................................112  
5.4.17 "Error messages 2" menu (ALARM 2) ................................................113  
5.4.18 "Sensor calibration" menu (SENSOR ADJ.) .......................................113  
6
Control Functions......................................................................................................114  
6.1  
Variable adjustment of the hydraulic parameters (variable inputs and  
outputs) ...........................................................................................................114  
6.1.1 Connection and settings table ............................................................116  
Switching time program enabling ....................................................................117  
Suppressing the cycle temperature on time program level..............................118  
Enabling "Separate Control Mode"..................................................................118  
Switching from SDC to DHC ...........................................................................119  
Selection of hydraulic parameter presettings ..................................................119  
The variable inputs and outputs of device series SDC/DHC 43 ......................119  
General functions and their operation .............................................................120  
6.8.1 Outside temperature sensing..............................................................120  
6.8.1.1 Building type .........................................................................120  
6.2  
6.3  
6.4  
6.5  
6.6  
6.7  
6.8  
6.8.2 Heating circuit outside temperature assignment.................................121  
6.8.3 Outside temperature emergency operation value...............................121  
6.8.4 Outside temperature disable...............................................................122  
6.8.5 Climate zone.......................................................................................122  
6.8.6 Design temperature............................................................................122  
6.8.7 Summer switch-off..............................................................................123  
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SDC / DHC  
6.8.8 System frost protection.......................................................................124  
6.8.9 Pump forced operation .......................................................................127  
7
Hydraulic Components..............................................................................................128  
7.1  
Heat generator: Boiler .....................................................................................128  
7.1.1 Heat generator start-up protection......................................................128  
7.1.2 Heat generator minimum temperature limit.........................................129  
7.1.3 Maximum temperature limit heat generator ........................................130  
7.1.4 Heating circuits minimum temperature limit........................................130  
7.1.5 Heat generator sensor control mode ..................................................130  
7.1.6 Minimum burner runtime.....................................................................131  
7.1.7 Switching: Multi-stage heat generator/Switching differential...............131  
7.1.8 Operation for modulating burners.......................................................136  
7.1.9 Modulation of P part (Xp)....................................................................137  
7.1.10 Modulation of sample time Ta.............................................................137  
7.1.11 Modulation of integral action time Tn..................................................138  
7.1.12 Modulation of runtime.........................................................................138  
7.1.13 Modulation of start time ......................................................................138  
7.1.14 Modulation of start power ...................................................................139  
7.1.15 OpenTherm ........................................................................................140  
7.1.16 Use of boiler sensor 2.........................................................................141  
7.1.17 External heat generator cut-off ...........................................................141  
7.1.18 Heat generator forced discharge ........................................................141  
7.1.19 Exhaust gas temperature monitoring..................................................142  
7.1.20 Burner counter mode..........................................................................143  
Heat generation, heat exchanger, district heating...........................................144  
7.2.1 On/Off operation of the district heating valve......................................145  
7.2.2 Continuous heat exchanger valve control...........................................145  
7.2.3 District heating return temperature limit..............................................147  
7.2.4 Return temperature limit for hot-water loading....................................149  
7.2.5 Hot-water pre-regulator with district heating systems.........................150  
7.2.6 Mode of operation: Hot-water pre-control ...........................................151  
7.2  
6
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7.2.7 Quick hot-water control.......................................................................152  
7.2.8 Mode of operation of hot-water control mode "external  
operation" ...........................................................................................154  
7.2.9 Conditional parallel operation for mixed heating circuits.....................155  
7.2.10 Circulation pump control mode...........................................................155  
7.2.11 Switch-off of district heating control....................................................156  
7.2.12 Return interval flushing.......................................................................156  
7.2.13 Heat meter for additional limitation according to the volume flow  
or thermal output ................................................................................156  
7.2.14 Charging pump (CHP) ........................................................................157  
7.2.15 Primary pump .....................................................................................158  
7.2.16 Boiler circuit pump..............................................................................158  
7.2.17 Return increase ..................................................................................159  
7.2.17.1Bypass pump (RBP)..............................................................160  
7.2.17.2Return maintenance through controlled feed water  
addition160  
7.2.17.3Indirect return increase .........................................................161  
Heating circuit .................................................................................................161  
7.3.1 General heating circuit functions ........................................................161  
7.3.1.1 Heating curve........................................................................161  
7.3.1.2 Heating curve setting (heating curve)....................................162  
7.3.1.3 Reduced operation................................................................164  
7.3.1.4 Heating system .....................................................................164  
7.3.1.5 Heating circuit temperature limit............................................164  
7.3.1.6 Heating circuit temperature offset .........................................165  
7.3.1.7 Heating circuit pump extended running time.........................165  
7.3.1.8 Screed function .....................................................................165  
7.3.2 Heating circuit constant temperature control ......................................168  
7.3.3 Fixed-value control .............................................................................168  
7.3.4 Consideration of the room temperature/room influence......................169  
7.3.4.1 Heating circuit room connection............................................169  
7.3.4.2 Heating circuit room factor ....................................................170  
7.3  
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SDC / DHC  
7.3.4.3 Heating circuit room controller ..............................................171  
7.3.4.4 Switch-on/switch-off optimisation ..........................................171  
7.3.4.5 Room setpoint ramp..............................................................175  
7.3.4.6 Heating limit function.............................................................175  
7.3.4.7 Heating circuit room frost protection limit ..............................177  
7.3.4.8 Mixed heating circuits cooling switch-over ............................177  
7.3.4.9 Heating circuit name .............................................................180  
7.3.4.10Room thermostat function (maximum room  
temperature limit) ..................................................................181  
7.3.5 Hot-water production ..........................................................................187  
7.3.5.1 Hot-water tank loading (SLP)................................................187  
7.3.5.2 Circulation pump (CIR.).........................................................194  
7.3.6 Solar/Solid fuel/Buffer.........................................................................196  
7.3.6.1 Solar function........................................................................196  
7.3.6.2 Buffer tank function ...............................................................199  
7.3.6.3 Solid fuel function..................................................................212  
7.3.7 Tank loading switch-over....................................................................213  
7.3.8 Hydraulic buffer relief (HBR)...............................................................215  
7.3.9 Easy enabling and disabling of a heating pump .................................216  
7.3.10 Other system components..................................................................217  
7.3.10.1Global fault message input....................................................217  
7.3.10.2Global fault message output .................................................217  
7.3.10.3Timer 217  
7.3.10.4External switching modem ....................................................218  
7.3.10.5External information ..............................................................219  
7.3.10.6Demand contact....................................................................219  
7.3.11 Bus communication ............................................................................221  
7.3.11.1Bus address of central device...............................................221  
7.3.11.2Control functions via the data bus.........................................222  
7.3.11.3Operation of wall devices......................................................227  
7.3.12 Cascading of heat generators in the bus system................................232  
8
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Contents  
7.3.12.1General description of cascading of control devices .............232  
7.3.12.2Function of the cascade parameters.....................................233  
7.3.12.3Mode of operation of cascade control ...................................234  
7.3.13 Commissioning, maintenance and troubleshooting help ....................237  
7.3.13.1Automatic set function...........................................................237  
7.3.13.2Emission measurement (not for DHC 43) .............................238  
7.3.13.3Relay/function test.................................................................239  
Error messages...............................................................................................243  
7.4.1 Basic display/fault stack fault messages ............................................248  
7.4.1.1 Sensor calibration .................................................................249  
7.4.1.2 Full controller reset................................................................249  
7.4.1.3 Controller time correction......................................................249  
7.4  
8
Technical data............................................................................................................250  
8.1  
General ...........................................................................................................250  
8.1.1 Installation recommendations.............................................................251  
Sensor resistance values ................................................................................251  
8.2.1 NTC 20 ...............................................................................................251  
8.2.2 PT 1000..............................................................................................252  
Sensor measurement ranges..........................................................................252  
Digital inputs....................................................................................................253  
8.2  
8.3  
8.4  
9
Log ..............................................................................................................................254  
Index....................................................................................................................................255  
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Contents  
SDC / DHC  
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SDC / DHC  
Software version  
1 Software version  
This documentation is valid for software version V 3.0 of your  
control device. The software version is displayed after switch-on  
for approx. 8 s. If you are using an older software version, please  
contact your heating technician.  
2 Safety instructions  
2.1 Intended use  
The SDC / DHC Smile family of controllers was designed for the  
sole purpose of regulating and controlling hot-water, heating and  
district heating systems (including hot-water production) that do  
not exceed a maximum flow temperature of 120 °C.  
2.2 Requirements for start-up  
ATTENTION  
The heating system must be complete and filled with water  
so that the pumps do not run dry and the heating boiler is not  
damaged.  
The control equipment must be installed in accordance with  
the installation instructions.  
All electrical connections (voltage supply, burner, mixer  
motor, pumps, sensor wiring etc.) must be carried out by the  
technician in accordance with the applicable VDE regulations  
and correspond with the circuit diagrams.  
If floor heating is connected, a limiting thermostat must also  
be installed in the flow line after the heating circuit pump.  
This switches off the pumps at excessive flow temperatures.  
Before starting up the controller, have the heating technician  
check all requirements listed above.  
NOTE The current time and date are already set at the factory and are  
backed up by a battery.  
The time switch functions based on a basic program and the  
control functions are preset for common heating systems with low-  
temperature boilers.  
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Safety instructions  
SDC / DHC  
2.2.1 Power supply  
Do not disconnect the controller from the mains supply!  
The battery for saving all individualised data is otherwise  
unnecessarily strained. The frost-protection function of the  
controller is deactivated.  
2.2.2 Connection conditions  
All electrical connection work may only be carried out by qualified  
personnel!  
2.2.3 Cable cross-sections  
1.5 mm2 for all cables carrying 230 V (power supply, burner,  
pumps, actuator).  
0.6 mm2 for bus cables (recommended type J-Y(St)Y 2 x 0.6).  
0.5 mm2 for sensors, selectors and analog signal cables.  
2.2.4 Maximum cable lengths  
Sensor, selector and analog inputs  
We recommend using cables no longer than 200 m. Longer  
connection lines could be used, but increase the risk of  
interference.  
Relay outputs  
Unlimited cable length.  
Bus connections  
Max. length of 100 m from the first bus subscriber to the last one  
(incl. wall modules).  
2.2.5 Cable installation  
Install cables for sensors apart from the cables carrying 230 V!  
Branch boxes in the sensor cable must be avoided!  
12  
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Safety instructions  
2.2.6 Grounding and zeroing  
Local regulations on the connection of equipment must be  
observed!  
2.3 Hot-water temperature greater than 60 °C  
ATTENTION  
Note that there is a danger of scalding at all hot-water draw-  
off points (kitchen, bathroom etc.) in the following cases.  
Add sufficient cold water in these cases.  
Automatic anti- When the automatic anti-legionella mechanism is activated, the  
legionella mechanism hot water is automatically heated to the anti-legionella  
temperature (65 °C at the factory) on the selected day and at the  
selected time to kill any legionella bacteria found in the hot-water  
tank.  
Manual mode / In the manual mode / emission measurement operating mode, the  
Emission hot water is heated up to the highest possible boiler temperature,  
measurement as the burner and all pumps are switched on and the mixer is  
opened fully. There is an acute danger of scalding at all  
connected hot-water draw-off points! Add sufficient cold water or  
switch off the hot-water loading pump (at the switch of the pump,  
if present). Heating and hot water are in unregulated continuous  
operation. This operating mode is for special use by the chimney  
sweep for emission measurement or if the controller is defective.  
The high hot-water temperatures can be prevented, however, by  
setting the boiler thermostat to a max. boiler temperature of  
approx. 60 °C.  
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Safety instructions  
SDC / DHC  
2.4 Connection of accessory parts  
WARNING  
According to VDE 0730, a separator for each mains terminal  
is to be provided in the voltage supply to the control  
equipment. Observe the local regulations regarding  
grounding and zeroing.  
As soon as the mains voltage is applied to terminals 21, 22,  
2, 6, 12 and 18, headers X3 and X4 can also carry mains  
voltage.  
If the heating circuit and hot-water loading pumps do not  
have an On / Off switch, but manual switch-on and switch-off  
capability is still desired, the appropriate switches must be  
installed by the customer. All accessory parts (sensors,  
selectors etc.) are to be connected to the respective circuit  
diagram.  
2.5 Maintenance and cleaning  
The controller is maintenance-free. The device can be cleaned  
externally with a moist (not wet) cloth.  
14  
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SDC / DHC  
Safety instructions  
2.6 Safety precautions for EMC-compliant installation  
Mains lines and sensor/data bus lines must be installed separate  
from each other. A minimum of 2 cm space must be present  
between the lines. It is permissible to cross lines.  
ç
é
æ
a
b
Mains 230 V AC  
x
y
15 cm  
2 cm  
Data bus line 12 V AC  
For control devices with their own mains connection, separate  
installation of mains and sensor/bus lines must absolutely be  
ensured. If cable ducts are used, they are to be provided with cut-  
off bridges.  
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Safety instructions  
SDC / DHC  
When installing control or wall devices, a minimum spacing of  
40 cm to other electrical equipment with electromagnetic  
emissions, e.g. relays, motors, transformers, dimmers, microwave  
ovens and televisions, audio speakers, computers, cordless  
telephones etc., is to be ensured.  
ç
é
æ
x 40 cm  
A minimum spacing of 40 cm is to be ensured between wall  
devices and central devices. Multiple central devices in the data  
bus system can be mounted directly next to one another.  
16  
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Safety instructions  
The mains connection of the heating system (boiler – panel –  
control equipment) must be designed as a separate circuit.  
Neither fluorescent lamps nor any machines which are potential  
sources of interference may be connected/connectable.  
a
c
b
ç
é
d
æ
ç
é
æ
e
a
b
c
Safety fuse 16 A  
Boiler room emergency switch  
Connect boiler room lighting and electrical outlets to  
separate circuits only!  
d
e
Wall devices  
Heat generator  
Shielded cables must be used for the data bus lines.  
For a recommended layout, see 8 Technical data, pg. 250  
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Safety instructions  
SDC / DHC  
The earth connection of the cable shielding must occur on one  
side at the protective conductor connection, e.g. at the cladding  
plate of the heat generator, protective conductor terminal etc.  
Multiple earth connections of a single cable are not permissible  
(buzzing loop).  
ç
é
æ
a
b
ç
é
æ
PE  
a No earth connection here!  
b Central device  
18  
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SDC / DHC  
Safety instructions  
With star-topology data bus systems, double earth connections  
may not be made. The earth connection must be made on one  
side of the star!  
a
c
Shielding  
b
d
Two-lead data bus line  
Branch box  
Distributor terminal  
The outside sensor may not be installed near transmitters or  
receivers (e.g. on garage walls near garage door opener  
receivers, amateur radio antennas, radio alarm systems or directly  
next to large transmission equipment etc.).  
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Overview  
SDC / DHC  
3 Overview  
The modular SDC / DHC control device is available in an  
installable switch cabinet version and a surface-mounted wall  
version with the following equipment features:  
Type  
3
3
7
x
x
x
SDC 3-10  
SDC 3-40  
SDC 7-21 1)  
x
x
x
x
x
x
x
x
x
7
x
x
x
+ two  
variable  
relays  
SDC 9-21 2)  
10  
x
x
x
x
x
x
x
x
+ two  
variable  
relays  
SDC 12-31 3)  
1) DHC 43-1  
2) DHC 43-2  
3) DHC 43-3  
20  
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Abbreviations  
4 Abbreviations  
The following abbreviations are used in this documentation/in the  
display of the control device:  
RED  
Lowering operation  
Outside sensor  
BS 2  
BLP  
RBP  
RP  
Buffer sensor 2 (bottom)  
Buffer loading pump  
Return bypass pump  
Return pump  
OS  
OS2  
FGS  
OT  
Outside sensor 2  
Flue gas sensor  
Outside temperature  
System data bus  
SD I  
SD II  
Switching differential I  
Switching differential II  
Tank sensor  
BUS  
OC1  
Burner stage 1 operating hour TS  
counter  
OC2  
Burner stage 2 operating hour TLP  
counter  
Tank loading pump  
DC  
Direct heating circuit  
Direct heating circuit pump  
Switch-off operation  
Electric heating rod  
Solid fuel boiler sensor  
Solid fuel buffer sensor  
Fixed-value control  
Solid fuel pump  
SLS  
SLSS  
SFD  
SLP  
STL  
VO  
Solar loading switch-over  
Solar loading switch-over sensor  
Solar forced dissipation  
Solar loading pump  
Stratified tank loading pump  
Variable output (general)  
Variable output 1  
DCP  
ECO  
EHR  
SFB  
SFR  
FC  
VO1  
VO2  
VI  
SFP  
PI  
Variable output 2  
Pulse input  
Variable input (general)  
Variable input 1  
BP  
Boiler circuit pump  
Constant control  
VI1  
CC  
VI2  
Variable input 2  
CRS  
Collector return sensor  
VI3  
Variable input 3  
CTBS Collector tank/buffer sensor  
FM1  
Flow sensor of mixed heating  
circuit 1  
CFS  
Collector flow sensor  
FM2  
Flow sensor of mixed heating  
circuit 2  
MM  
MC  
MHP  
P1  
Mixer motor  
PHE  
HG  
Parallel heat generator enable  
Heat generator  
Mixed heating circuit  
Mixed heating circuit pump  
Switching time program  
HGS  
WD  
Heat generator sensor  
Wall device for room temperature  
sensing  
P2  
P3  
BS  
Switching time program  
Switching time program  
Buffer sensor (top)  
HW  
CIR  
CHP  
Hot water  
Circulation pump  
Charging pump  
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Operation  
SDC / DHC  
5 Operation  
5.1 Display and operating elements  
5
1
6
7
8
9
2
3
4
11  
10  
1 "Manual mode" / "Emission measurement" button (not on  
district heating controllers)  
2 "Operating modes" button (basic display)  
3 "Switching time programs" / "Holiday programs" button  
4 "System information" button  
5 Display  
6 Cover clip for service socket  
7 "Daytime room temperature" button  
8 "Night-time room temperature" button  
9 "Daytime hot-water temperature" button  
10 Input button (press / turn)  
11 Operating mode symbols (heating programs)  
22  
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SDC / DHC  
Operation  
5.1.1 Display (basic display)  
1
C
5
2
3
4
1
2
3
Day of the week / Date  
Time  
4
5
Operating mode symbols  
Heat generator temperature  
Active operating mode  
The illumination of the display is switched on by pressing any  
button or using the input button îand switches off automatically  
if no buttons are pressed for a longer period of time.  
During start-up of the unit and after a power failure, a segment  
test with automatic fault diagnosis is carried out. The respective  
device type and the software version number then appear briefly.  
The basic display that then appears shows the day of the week,  
the date, the time and the heat generator temperature in  
automatic mode. Different values appear in the basic display  
depending on the set operating mode (AUTOMATIC, PARTY  
etc.). Thus, for example, in the ABSENT operating mode, the  
indication ABSENT TIL appears instead of the date and the return  
date instead of the temperature. Active summer deactivation is  
indicated by a beach umbrella symbol À, and active frost  
protection is indicated by a snowflake symbol Á.  
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Operation  
SDC / DHC  
5.1.2 Operating elements  
5.1.2.1 Input button (press / turn)  
By pressing once, you can:  
ð
Confirm input / values  
By pressing and holding (approx. 3 s), you can:  
Switch to the menu-selection level  
Move up one menu level  
By turning the input button î, you can:  
Change values (clockwise increases called-up values,  
anticlockwise decreases them)  
Navigate through menus  
5.1.2.2 "Daytime room temperature" button  
Sets the desired room temperature (room setpoint) in automatic  
¥
mode during the heating cycles and in the PARTY and HEATING  
operating modes. In operating mode 1, the set value for all  
heating circuits is the same. In operating mode 2, the set value  
applies for the respective heating circuit. To set the operating  
mode, see 5.2.3.3 Operating mode, pg. 74.  
Setting  
Press ¥button.  
Set flashing room temperature specification to the desired  
value by turning the input button î.  
C
Confirm set value by pressing the ¥button or the input  
button î.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Factory setting 20 °C  
Setting range 5 ... 30 °C  
24  
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SDC / DHC  
Operation  
5.1.2.3 "Night-time room temperature" button  
Sets the lowered room temperature in automatic mode between  
the heating cycles and in the ABSENT and RED. HEATING  
operating modes.  
¦
In operating mode 1, the set value for all heating circuits is the  
same. In operating mode 2, the set value applies for the  
respective heating circuit. To set the operating mode, see  
5.2.3.3 Operating mode, pg. 74.  
Setting  
Press ¦button.  
Set flashing room temperature specification to the desired  
value by turning the input button î.  
C
Confirm set value by pressing the ¦button or the input  
button î.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Factory setting 16 °C  
Setting range 5 ... 30 °C  
5.1.2.4 "Daytime hot-water temperature" button  
Sets the daytime hot-water temperature during the hot-water  
operational-readiness times in automatic mode and in the PARTY  
and HEATING operating modes. This set value also applies for  
exclusively hot-water operation (manual summer operation).  
§
Setting  
Press §button.  
Set flashing hot-water temperature to the desired value by  
turning the input button î.  
C
Confirm set value by pressing the §button or the input  
button î.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Factory setting 50 °C  
EN2H-0221GE51 R0808  
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Operation  
SDC / DHC  
Setting range 5 °C (hot-water economy temperature) ... Maximum hot-water  
heater temperature limit (service setting)  
One-time hot-water  
circuit loading  
Pressing and holding (approx. 3 s) the §button brings you to  
the reload function, where the reload time can be set in minutes.  
With a reload time of 0 minutes, loading is started once and the  
hot-water tank is loaded to the daytime setpoint. The time for this  
superimposed hot-water circuit loading can be set between 0 and  
240 minutes. The current week program is superimposed here.  
5.1.2.5 "Operating mode" button (basic display)  
Sets the operating mode and returns to the basic display from  
every operating level.  
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SDC / DHC  
Operation  
Overview of the operating modes  
Operating mode Display  
Symbol  
Setting  
ABSENT  
P1 (P2, P3)*, return  
date  
ç
PARTY  
P1 (P2, P3)*,  
party end time  
è
é
AUTOMATIC  
SUMMER  
HEATING  
RED. HEATING  
STANDBY  
P1 (P2, P3)*  
P1(P2, P3)*  
C
C
C
C
C
ê
ë
ì
í
* P2 and P3 only after enabling, see "System Parameters"  
menu, parameter 2 = P1 to P3  
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Operation  
SDC / DHC  
The selected operating mode appears in plain text, whereby a  
marking at the bottom edge of the display points to the respective  
operating mode symbol at the same time. In operating mode 1,  
the set value for all heating circuits is the same. In operating  
mode 2, the set value applies for the respective heating circuit. To  
set the operating mode, see 5.2.3.3 Operating mode, pg. 74.  
Setting  
Press  
button.  
Select operating mode by turning the input button î. The  
marking is located above the corresponding operating mode  
symbol.  
Confirm set operating mode by pressing the  
input button î.  
button or the  
With short-term operating modes (ABSENT, PARTY), set the  
desired value by turning the input button îand confirm with  
the  
button or the input button î.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Return to the basic  
display  
Press the  
button for approx. 3 s to return to the basic display  
from any operating level.  
NOTE Holiday mode is set via the "Switching time programs / Holiday  
programs" button (see 5.1.2.6 "Switching time programs / Holiday  
programs" button, pg. 33).  
5.1.2.5.1 Absence mode (short-term program)  
With the ABSENT operating mode, heating operation is  
temporarily deactivated and protected from frost during brief  
absences. During the absence, all heating circuits are adjusted to  
the specified lowered room temperature. Once the set time  
expires, the heating circuits automatically return to the operating  
mode that was active before the switch to the absence operation.  
Short-term programs such as PARTY or ABSENT are skipped  
here.  
Setting See 5.1.2.5 "Operating mode" button (basic display) , pg. 26  
Application Short absence while heating operation is active.  
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SDC / DHC  
Operation  
Cancellation An active absence program can be cancelled in case of early  
return.  
Press  
button.  
Turn input button îand switch to automatic operation.  
The active absence program has been cancelled.  
Factory setting P1 as from activation  
Setting range P1 (P2, P3) / 0.5 to 24 h to the current time  
P1 (P2, P3)  
Program-controlled resumption of heating operation. After  
activation of the absence program, heating operation is  
interrupted until the following switch-on time of the current  
automatic program P1 (or P2 or P3, if enabled).  
0,5 ... 24 h  
The set value is added on to the current time and represents the  
return time. When the absence program is called up again, the  
last set value is saved and suggested as the initial value.  
Display An active absence program appears in the basic display with  
information on the return time.  
5.1.2.5.2 Party mode (short-term program)  
Party mode causes one-time intermediate heating of all heating  
circuits up to a specified point in time and bridges an upcoming or  
already active absence cycle totally or partially. Once the set time  
expires, the heating circuits automatically return to the operating  
mode that was active before the party program. Short-term  
programs such as ABSENT or PARTY are skipped here.  
Setting See 5.1.2.5 "Operating mode" button (basic display) , pg. 26  
Application One-time extension of heating operation or intermediate heating  
during lowering operation outside the schedule.  
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Operation  
SDC / DHC  
Cancellation An active party program can be cancelled early.  
Press button.  
Turn input button îand switch to automatic mode.  
The active party program has been cancelled.  
Factory setting P1 as from activation  
Setting range P1 (P2, P3) / 0.5 to 24 h to the current time P1  
P1 (P2, P3)  
Program-controlled resumption of heating operation. After  
activation of the party program, heating operation is continued  
until the following switch-on time of the current automatic program  
P1 (or P2 or P3, if enabled)  
0,5 ... 24 h  
The set value is added on to the current time and represents the  
end of the party time. When the party program is called up again,  
the last set value is saved and suggested as the initial value.  
Display An active party program appears in the basic display with  
information on the party end time.  
5.1.2.5.3 Automatic mode  
In automatic operation, max. three time programs with different  
heating operation times are available. They are called up during  
C
start-up as factory-set and unlosable default programs P1, P2 or  
P3 and can, if necessary, be overwritten with their own switching  
times in the "Timeprograms" menu (see 5.2.2 "Timeprograms"  
menu, pg. 55).  
NOTE Default programs P2 and P3 cannot be selected until the  
PROGRAM = P1 to P3 parameter is enabled in the "System  
Parameters" menu. Without enabling, only program P1 is active.  
Setting See 5.1.2.5 "Operating mode" button (basic display) , pg. 26  
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SDC / DHC  
Operation  
Disabling / enabling default program P2 to P3  
Disabling  
"System Parameters" menu, program parameter = P1. All heating  
circuits and the hot-water circuit solely refer to the default /  
individually programmed switching times in the program P1  
parameter. Program P1 does not appear in the display in this  
operating mode (see 5.2.2 "Timeprograms" menu, pg. 55 and  
5.2.3.2 Time program, pg. 73).  
C
Enabling  
"System Parameters" menu, program parameter = P1 to P3 (see  
5.2.2 "Timeprograms" menu, pg. 55 and 5.2.3.2 Time program,  
pg. 73).  
C
Display An active automatic program appears in the basic display with the  
current date and time. If default programs P2 and P3 were  
enabled, the corresponding symbol, Â,Ãor Ä, is also  
displayed depending on the selected program. The symbols are  
only displayed with the time program P1 to P3 active.  
5.1.2.5.4 Manual summer operation (excluding heating operation)  
With manual summer operation, only the hot-water circuit remains  
operation and controls the heat generator temperature based on  
C
the specified hot-water temperature and the specified hot-water  
switching time program. Heating operation is stopped, and  
protection from frost is provided. This feature is only available  
when control mode is set to 1.  
Setting See 5.1.2.5 "Operating mode" button (basic display) , pg. 26  
Disabling / enabling default programs P2 to P3  
Disabling  
"System Parameters" menu, program parameter = P1. All heating  
circuits and the hot-water circuit solely refer to the default /  
C
individually programmed switching times in the time program = P1  
parameter. Program P1 does not appear in the display in this  
operating mode (see 5.2.2.1 Selection of the control circuit, pg. 56  
and 5.2.3.2 Time program, pg. 73).  
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Operation  
SDC / DHC  
Enabling  
"System Parameters" menu, program parameter = P1 to P3 (see  
5.2.2.1 Selection of the control circuit, pg. 56 and 5.2.3.2 Time  
program, pg. 73).  
C
Display Manual summer operation appears in the basic display with the  
information SUMMER. If default programs P2 and P3 were  
enabled, the corresponding symbol, Â, Ãor Ä, is also  
displayed depending on the selected program. The symbols are  
only displayed with the time program P1 to P3 active.  
5.1.2.5.5 Continuous heating operation  
The HEATING operating mode ensures continuous heating  
operation without time limitations based on the specified daytime  
C
room temperature. Hot-water production occurs continuously  
based on the specified daytime hot-water temperature.  
NOTE The HEATING operating mode remains active until another  
operating mode is activated.  
Display Activated continuous heating operation appears in the basic  
display with the information HEATING.  
5.1.2.5.6 Continuous lowering operation  
The RED. HEATING operating mode causes continuously  
reduced heating operation based on the specified lowered room  
C
temperature. On the heating circuit levels, the reduced operating  
mode ECO (frost-protected deactivation mode) or RED (lowering  
mode) is set accordingly. The minimum temperature limit of the  
respective heating circuit must be taken into account.  
See the "Direct Circuit" or "Mixed Heating Circuit 1" / "Mixed  
Heating Circuit 2" menu, reduced parameter = reduced operation  
and 12 parameter = minimum temperature limit.  
Hot-water production occurs continuously based on the specified  
hot-water economy temperature (see "DHW" menu, hot water  
parameter = hot water at night).  
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SDC / DHC  
Operation  
NOTE The RED. HEATING operating mode remains active until another  
operating mode is activated.  
Display Activated continuous lowering operation appears in the basic  
display with the information RED. HEATING.  
In standby mode, the entire system is switched off and protected  
from frost (all frost-protection functions active).  
C
Hot-water production is disabled and protected from frost. At  
storage temperatures below 5 °C, a reload to up to 8 °C takes  
place.  
Application Total deactivation of heating and hot water with full building  
protection.  
NOTE The heat generator and hot-water production remain in operation  
in case of external demand or demand by other heating circuits  
on the bus network. The heating circuit pumps are switched on  
briefly every day (pump anti-blocking protection).  
The standby mode remains active until another operating mode is  
activated.  
Display Activated continuous standby mode appears in the basic display  
with the information STANDBY.  
5.1.2.6 "Switching time programs / Holiday programs" button  
Using this button, you can create individualised switching time  
programs for heating and hot-water operation and set holiday  
mode.  
See 5.1.2.6.1 Holiday mode, pg. 34 and 5.2.2 "Timeprograms"  
menu, pg. 55.  
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Operation  
SDC / DHC  
5.1.2.6.1 Holiday mode  
In holiday mode, the heating circuits can be switched off and  
protected from frost or operated based on the settings for the RED.  
HEATING operating mode for the duration of the holiday based on  
the presetting ("Direct circuit" or "Mixed heating circuit 1" / "Mixed  
heating circuit 2" menu, parameter 25 = holiday operating mode).  
Setting  
Press  
button.  
The menu-selection level Switching time programs / Holiday  
programs appears in the display.  
Turn input button îto the left.  
HOLIDAY appears in the display.  
Press input button î.  
HOLIDAY 01 appears in the display.  
Press input button î.  
The year flashes in the display.  
Set year with the input button î.  
Press input button î.  
The day on which the holiday is to begin flashes in the display.  
Set the day the holiday will begin with the input button î.  
Press input button î.  
TIL - - appears in the display.  
Set the day you will return from holiday with the input  
button î.  
Press input button î.  
The desired holiday timeframe is saved.  
You can now enter additional holiday timeframes (up to 15 holiday  
blocks).  
Application Longer absence while heating operation is active.  
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SDC / DHC  
Operation  
Control during At outside temperatures below the frost-protection limit (see  
holidays 5.2.3 "System Parameters" menu, pg. 72) the heating circuits are  
controlled as follows:  
Without wall devices: Based on a lowered room temperature  
specification of 3 °C.  
With wall devices: Based on the room frost-protection limit of  
the respective heating circuit of 10 °C (see "Direct Heating  
Circuit" or "Mixed Heating Circuit 1", "Mixed heating circuit 2"  
menu, parameter 08 = room frost-protection limit).  
Cancellation An active holiday program can be cancelled in case of early  
return.  
Press and hold the  
button for approx. 3 seconds until the  
following appears in the display: "Holiday off".  
Factory setting Current date  
Setting range Current date... (current date + 250 days)  
Display An active holiday program appears in the basic display with  
information on the return date.  
5.1.2.7 "System information" button  
Calls up system information, such as temperatures and counter  
¤
data.  
The information on the outside temperature appears first after the  
¤button is pressed. Turning the input button îcauses the  
system temperatures and the counter and consumption states  
and operating states of the connected system components to  
appear. Pressing the input button îcauses the respective  
setpoint values to appear.  
Exceptions  
Collector flow temperature: No setpoint  
Solar tank temperature:  
Outside temperature:  
No setpoint  
Averaged value  
NOTE The displayed information (see the following example) is  
independent of the installed or enabled system components and  
control circuits.  
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Operation  
SDC / DHC  
Operating overview  
Press  
button  
Turn input button to the left  
Turn input button to the right  
Average/current outside  
temperature value  
Program/operating mode  
Outside temperature  
direct heating circuit/pump status  
min. to max. (0:00 to 24:00 hours)  
Program/operating mode  
mixed heating circuit 1/pump status  
Heat generator temperature  
setpoint/actual value  
Actuator of  
mixed heating circuit 1/status  
Hot-water temperature  
setpoint/actual value  
Program/operating mode  
Flow temperature  
mixed heating circuit 2/pump status  
setpoint/actual value  
Actuator of  
mixed heating circuit 2/status  
Flow temp of mixed heating circuit 1  
setpoint/actual value  
Program/operating mode  
hot-water circuit/pump status  
Flow temp of mixed heating circuit 2  
setpoint/actual value  
Heat generator  
status  
Variable input 1  
setpoint/actual value  
Direct heating circuit  
pump function/status  
Variable input 2  
setpoint/actual value  
Variable output 1  
Variable input 2  
function/operating state  
setpoint/actual value  
Variable output 2  
function/operating state  
Operating hours  
Activations of heat generator  
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SDC / DHC  
Operation  
Setting time for  
automatic return  
If the ¤button is pressed and held for approx. 3 s, the INFO  
TIME parameter appears.  
With this parameter, the time it takes for automatic return to the  
basic display can be specified.  
Setting range OFF  
No return. The last selected information display  
continuously remains in the basic display until the  
next change.  
1 ... 10 min Automatic return from the information level after the  
specified time (in 0.5 minute increments).  
Factory setting OFF  
5.1.2.7.1 Temperature displays  
Information  
Display  
Condition  
Remarks  
Outside  
temperature (1)  
Determined  
value/Current  
value  
Outside  
Min./max. value Outside sensor  
temperature (1)  
(0:00 to 24:00  
hours)  
connected and no fault  
message  
Outside  
temperature (2)  
Determined  
value/Current  
value  
Variable input  
configured as OS2  
Connection OS2 to variable  
input VI1, VI2 or VI3  
Outside  
Min./max. value OS2 connected, no fault  
temperature (2)  
(0:00 to 24:00  
hours)  
message  
EM-SET (energy "EM-SET"  
management  
setpoint)  
Highest hot-water setpoint  
and highest heating circuit  
setpoint in the system  
Heat generator  
temperature (1)  
Setpoint/Actual Heat generator  
value specified  
Setpoint/Actual Variable input  
value configured as BS2  
Code 1 only appears if BS2  
is present  
Heat generator  
temperature (2)  
Connection BS2 to variable  
input VI1, VI2 or VI3  
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Operation  
SDC / DHC  
Information  
Display  
Condition  
Remarks  
Return  
temperature  
Setpoint/Actual Return sensor  
Connection of return sensor  
to associated variable input  
value  
connected and one of  
the functions for return 1 or 2, VI can no longer be  
increase is active  
called up  
Flow sensor of  
district heating  
valve VF1  
Setpoint/Actual  
value  
With district heating  
controllers  
Return sensor of Setpoint/Actual  
With district heating  
controllers  
district heating  
valve VFB  
value  
External heat  
Disabled mode External heat generator External contact to variable  
generator disable ON/OFF  
disable (VI1-VI3)  
specified  
input VI1, VI2 or VI3  
Flue gas  
temperature  
Limit signal  
value/Actual  
value  
Variable input  
configured as AGF  
Connection only to variable  
input VI1  
Water heater  
temperature (1)  
Setpoint/Actual If hot-water circuit is  
value present  
Setpoint/Actual Variable input  
value configured as SF2  
Code 1 only appears if SF2  
is present  
Water heater  
temperature (2)  
Connection to variable input  
VI1, VI2 or VI3  
Water heater  
temperature  
controller  
Load condition Thermostat mode  
ON/OFF  
Thermostat instead of sensor  
(SF1 only)  
Demand via  
switching contact ON/OFF  
(VI1)  
Demand  
VI configured as  
demand contact  
External contact to variable  
input VI1, VI2 or VI3  
Demand via  
switching contact ON/OFF  
(VI2)  
Demand  
VI configured as  
demand contact  
External contact to variable  
input VI1, VI2 or VI3  
Demand via  
switching contact ON/OFF  
(VI3)  
Demand  
VI configured as  
demand contact  
External contact to variable  
input VI1, VI2 or VI3  
Mixed heating  
circuit 1 flow  
temperature  
Setpoint/Actual Mixed heating circuit 1  
value  
specified  
Mixed heating  
circuit 1 return  
temperature  
Actual value  
Return temperature with  
return maximum limit  
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SDC / DHC  
Operation  
Information  
Display  
Condition  
Remarks  
Mixed heating  
circuit 2 flow  
temperature  
Setpoint/Actual Mixed heating circuit 2  
value  
specified  
Mixed heating  
circuit 2 return  
temperature  
Actual value  
Return temperature with  
return maximum limit  
Direct heating  
circuit room  
temperature  
Setpoint/Actual Direct heating circuit  
value specified  
Setpoint inquiry without room  
temperature sensing:  
Current room setpoint of  
direct heating circuit  
Mixed heating  
circuit 1 room  
temperature  
Setpoint/Actual Mixed heating circuit 1  
value specified  
Setpoint inquiry without room  
temperature sensing:  
Current room setpoint of  
mixer heating circuit 1  
Mixed heating  
circuit 2 room  
temperature  
Setpoint/Actual Mixed heating circuit 2  
Setpoint inquiry without room  
temperature sensing:  
Current room setpoint of  
mixed heating circuit 2  
value  
specified  
Direct heating  
circuit thermostat THERMOSTAT specified  
function  
DC  
Thermostat function  
OFF = temperature limit  
exceeded  
Mixed heating  
circuit 1  
MC1  
Thermostat function  
OFF = temperature limit  
exceeded  
THERMOSTAT specified  
thermostat  
function  
Mixed heating  
circuit 2  
MC2  
Thermostat function  
OFF = temperature limit  
exceeded  
THERMOSTAT specified  
thermostat  
function  
Solid fuel boiler  
temperature  
Actual value  
Actual value  
VO1/2 configured as  
Connection of FSKF to  
solid fuel loading pump associated variable input 1  
or 2, VI can no longer be  
called up  
Solid fuel boiler  
buffer  
temperature  
Solid fuel loading pump at  
variable output, corresponds  
to KSPF or FPF, depending  
on configuration  
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Operation  
SDC / DHC  
Information  
Display  
Condition  
Remarks  
Buffer tank  
temperature at  
top  
Setpoint/Actual VO1/2 configured as  
Connection of PF1 to  
associated variable input 1  
or 2, VI can no longer be  
called up  
value  
buffer tank loading  
pump  
Buffer tank  
temperature at  
bottom  
Setpoint/Actual VO1/2 configured as  
Connection of PF2 to  
variable input VI1, VI2 or VI3  
value  
buffer tank loading  
pump  
Solar collector  
flow temperature  
Actual value  
Actual value  
Actual value  
VO1/2 configured as  
solar tank loading pump  
Special sensor  
Solar tank  
temperature  
VO1/2 configured as  
solar tank loading pump  
Solar collector  
return  
VO1/2 configured as  
solar tank loading pump variable input VI1, VI2 or VI3  
Connection of KRLF to  
temperature  
Solar tank switch- Actual value  
over temperature  
Solar loading valve activated  
5.1.2.7.2 Operating states  
An operating state inquiry occurs after the information menu is  
called up by turning the input button anti-clockwise. The following  
displays appear only under the specified conditions and may not  
be available (depends on device version).  
Information  
Display  
Condition  
Remarks  
Direct heating  
circuit operating  
status  
Direct heating circuit  
specified  
Heating program: Holiday,  
Absent Til, Party Til, Auto,  
Summer, Heating, Red.  
Heating, Standby  
Switching time program:  
P1 (P2, P3) control mode:  
Day, RED, ECO  
Mixed heating  
circuit 1 operating  
status  
Mixed heating circuit 1  
specified  
Heating program: Holiday,  
Absent Til, Party Til, Auto,  
Summer, Heating, Red.  
Heating, Standby  
Switching time program:  
P1 (P2, P3) control mode:  
Day, RED, ECO  
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SDC / DHC  
Operation  
Information  
Display  
Condition  
Remarks  
MC1 actuator  
operating status  
Mixed heating circuit 1  
specified  
Mixed heating circuit 1  
opens, closes or does not  
move  
Mixed heating  
circuit 2 operating  
status  
Mixed heating circuit 2  
specified  
Heating program: Holiday,  
Absent Til, Party Til, Auto,  
Summer, Heating, Red.  
Heating, Standby  
Switching time program:  
P1 (P2, P3) control mode:  
Day, RED, ECO  
MC2 actuator  
operating status  
Mixed heating circuit 2  
specified  
Mixed heating circuit 2  
opens, closes or does not  
move  
District heating  
valve operating  
status  
District heating valve  
opens, closes or does  
not move  
With district heating  
controllers  
Heat generator  
operating status  
(st. 1)  
Heat generator specified Information on the switching  
state of the multi-stage heat  
generator  
Heat generator  
operating status  
(st. 2)  
Multi-stage heat  
generator specified  
Information on the switching  
state of the second stage of  
the heat generator  
Operating status  
of modulating  
Modulating burner  
specified  
If a single-stage modulating  
heat generator is set,  
heat generator  
display of actual value and  
setpoint occurs in %  
Hot-water circuit  
operating status  
Hot-water circuit  
specified  
Hot-water program: Holiday,  
Absent Til, Party Til, Auto,  
Summer, Heating, Red.  
Heating, Standby  
Switching time program:  
P1 (P2, P3) control mode:  
Day, RED, ECO  
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Operation  
SDC / DHC  
Information  
Display  
Condition  
Remarks  
Function and  
status of direct  
heating circuit  
pump  
Outputs specified  
Solar (SOP), circulation  
(CIR), electric heating rod  
(ELH), feeder (CHP), boiler  
circuit (KKP1, KKP2), fault  
message (SMA), return  
(RLP), buffer (PLP), solid  
fuel (FSP), heating circuit  
(HKP), constant (KP), timer  
(CLOCK)  
based on function  
Function and  
status of variable  
output 1  
Outputs specified  
based on function  
Solar (SOP), circulation  
(CIR), electric heating rod  
(ELH), feeder (CHP), boiler  
circuit (KKP1, KKP2), fault  
message (SMA), return  
(RLP), buffer (PLP), solid  
fuel (FSP), heating circuit  
(HKP), constant (KP), timer  
(CLOCK)  
Function and  
status of variable  
output 2  
Outputs specified  
based on function  
Solar (SOP), circulation  
(CIR), electric heating rod  
(ELH), feeder (CHP), boiler  
circuit (KKP1, KKP2), fault  
message (SMA), return  
(RLP), buffer (PLP), solid  
fuel (FSP), heating circuit  
(HKP), constant (KP), timer  
(CLOCK)  
District heating  
valve volume flow  
Heat generator specified With district heating  
controllers  
District heating  
valve capacity  
Heat generator specified With district heating  
controllers  
Heat generator  
(1) start-ups  
Heat generator specified Information on the number  
of heat generator switch-ons  
(burner start-ups) of the  
multi-stage heat generator.  
Operating hours  
of heat generator  
(1)  
Heat generator specified Information on the number  
of heat generator operating  
hours of the multi-stage heat  
generator.  
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SDC / DHC  
Operation  
Information  
Display  
Condition  
Remarks  
Heat generator  
switch-ons stage  
2
Multi-stage heat  
generator specified  
Information on the number  
of heat generator switch-ons  
(burner start-ups) of the  
second stage.  
Heat generator  
operating hours  
stage 2  
Multi-stage heat  
generator specified  
Information on the number  
of heat generator operating  
hours of the second stage.  
Test temperature  
for measurement  
purposes  
KVT sensor connected Controller-independent test  
and VI configured.  
temperature, sensor  
connection to variable input  
VI1, VI2 or VI3  
Operating status  
of ext. switching  
modem  
VI configured as  
switching modem  
Control modes based on the  
switching state of the  
modem: AUTO (automatic)  
STBY (standby), HEAT  
(continuous heating), RED  
(continuously reduced).  
Solar heating  
capacity  
VO1/2 configured as  
solar tank loading pump variable output  
Solar loading pump at  
Solar heat  
balance  
VO1/2 configured as  
solar tank loading pump variable output  
Solar loading pump at  
Switch-ons  
VO1/2 configured as  
Solar loading pump at  
solar tank loading pump variable output  
Solar loading  
pump  
Operating hours  
VO1/2 configured as  
Solar loading pump at  
solar tank loading pump variable output  
Solar loading  
pump  
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Operation  
SDC / DHC  
5.1.2.8 "Manual mode" / "Emission measurement" button  
5.1.2.8.1 Manual mode  
If this button is pressed and held longer than 5 s in the basic  
display, the controller is switched to manual mode. In this  
operating mode, the required heat generator temperature is  
specified manually with the input button îaccording to the  
respective heating need.  
A controller set to manual mode has no effect in heat circuit  
expansion.  
The heat generator setpoint is set between the minimum and  
maximum heat generator temperatures and appears flashing at  
the bottom left-hand side. The current heat generator temperature  
appears statically on the right-hand side in the basic display. The  
set switching differential corresponds to the value of automatic  
control and is symmetrical to the set value.  
C
C
Application Controller malfunctions (emergency operation), errors  
NOTE The maximum heat generator temperature limit is paramount to  
the heat generator switching differential and stops the heat  
generator in case of exceedance.  
With control devices operated purely as a heating circuit  
expansion, the setting of the temperature has no effect.  
The last value to which the control device adjusted the heat  
generator temperature appears as a recommendation.  
Cancellation  
Press  
button or  
button, to return to the last selected  
operating mode.  
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SDC / DHC  
Operation  
5.1.2.8.2 Emission measurement (not with district heating controllers)  
ATTENTION  
Emission measurements may only be carried out by the  
chimney sweep.  
Pressing the  
button controls the heat generator for a duration  
of 20 min based on the set maximum temperature limit. The  
remaining time is displayed and counted down.  
With two-stage heat generators, both stages are in operation  
(measurement at nominal output).  
Function The heat generator is adjusted to the maximum heat generator  
temperature. All heating circuits and the hot-water production  
adjust their setpoint to the respective maximum temperature.  
ATTENTION  
There is a danger of scalding by hot water, as the hot-water  
temperature can exceed the set setpoint temperature.  
Application Emission measurement by the chimney sweep.  
Cancellation  
Emission measurement can be cancelled at any time with the  
or button.  
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Operation  
SDC / DHC  
5.1.2.9 Access to the technician / OEM area  
Entering a technician or OEM code enables additional setting  
options in the parameter menu. The technician code is: 1234  
For access to the OEM area, please ask your field-service contact  
partner.  
Procedure:  
Press the  
and  
buttons simultaneously. The first  
number of the 4-digit code flashes.  
Set the first code number by turning the input button.  
Press the input button. The second number flashes.  
Enter all remaining code numbers as described in Steps 2 and  
3. After entering the last code number, the controller is  
enabled for the respective area (technician or OEM).  
Press and hold the rotary button longer than 3 seconds. You  
reach the menu-selection level and can enter / modify  
parameters.  
Pressing the  
Pressing the  
button jumps back to the previous selection.  
button, pressing and holding the input button  
longer than 3 seconds or waiting until the set info time expires  
causes a jump back to the basic display.  
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SDC / DHC  
Operation  
5.1.2.10 Heating curve  
Determines the heating curve for the heating circuits.  
The heating curve describes the relationship of the flow  
C
temperature change to the outside temperature change. With a  
larger heating surface, such as with floor heaters, the heating  
curve has a less extreme slope than with a smaller heating  
surface (e.g. radiators).  
The set value refers to the lowest outside temperature used for  
heat demand calculation.  
ATTENTION  
This parameter must be set by the technician and should no  
longer be changed.  
Setting  
Press and hold input button îfor 3 s.  
Turn the input button îto select the desired heating circuit (HC,  
MC-1 or MC-2) and confirm it by pressing the input button î.  
The design temperature (system) appears at the bottom right-  
hand side of the display.  
Press input button î.  
The slope of the heating curve appears at the bottom left-hand  
side of the display.  
Set the flashing heating curve value by turning the input button  
î(design temperature also flashes and is changed  
automatically depending on the slope of the heating curve).  
Confirm by pressing the input button î.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Press  
Setting range 0,2 ... 3,5  
button to return to the basic display.  
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Operation  
SDC / DHC  
Factory setting Direct heating circuit (HC) = 1,5  
Mixed heating circuit 1  
(MC-1)  
= 1  
= 1  
Mixed heating circuit 2  
(MC-2)  
x
y
a
x
y
a
Boiler / flow temperature [°C]  
Outside temperature [°C]  
Troom [°C]  
5.2 Menu-selection level  
The control device contains a menu-selection level that is  
structured differently, depending on the respective device version.  
Access  
Press and hold input button îfor approx. 3 seconds.  
The menu selection always begins with the TIME – DATE  
menu.  
Turn input button îto select additional menus.  
Press input button îto confirm the selected menu.  
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SDC / DHC  
Operation  
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Operation  
SDC / DHC  
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SDC / DHC  
Operation  
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Operation  
SDC / DHC  
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SDC / DHC  
Operation  
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Operation  
SDC / DHC  
5.2.1 "Time - Date" menu  
The following current calendar values can be specified in this  
menu:  
Time  
Year  
Day - Month  
Time change mode (summer / winter time)  
NOTE All listed daytime values are set at the factory and generally do  
not need to be updated.  
An internal, pre-programmed calendar ensures automatic time  
change on the annually recurring summer / winter time switchover  
dates. If necessary, the automatic time change can be  
deactivated. The current weekday, Mo to Su is determined from  
the calendar date and does not need to be set.  
Application Corrections for rare fault cases  
Access See 5.2 Menu-selection level, pg. 48  
Setting  
Turn input button îand select the "Time - Date" menu.  
Turn input button îand select the desired calendar value  
(time, year, day - month, change).  
Press input button îand change the corresponding value by  
turning the input button î.  
Press input button îto confirm the set value.  
Turn input button îto select and change additional calendar  
values.  
Returning  
Returning to the basic display takes place by pressing the  
button or automatically after the set information time (see  
5.1.2.7 "System information" button, pg. 35).  
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SDC / DHC  
Operation  
5.2.2 "Timeprograms" menu  
Individualised switching time programs for heating and hot-water  
operation can be created in this menu. Here, the factory-set  
default programs P1 (and, if enabled, P2 and P3 as well) of each  
heating circuit and the hot-water circuit are overwritten by  
individualised switching times and temperature specifications.  
This is especially advantageous if correspondingly adapted  
heating programs are to be created in case of periodically  
recurring assignments with different assignment times (e.g. shift  
work). Max. three heating cycles, each with a switch-on and  
switch-off time, are available for each day of the week for  
programming switching times. Each heating cycle can also be  
combined with a freely-selectable temperature specification.  
NOTE The default programs are not lost when overwritten by individually  
created programs. Individualised programs, however, are deleted  
when default programs are reloaded and must be recreated. For  
this reason, individualised switch-on / switch-off times and  
temperature specifications should always be entered in the tables  
provided for this purpose (see 9 Log, pg. 254).  
Access  
Press  
button.  
Returning  
Returning to the basic display takes place by pressing the  
button or automatically after the set information time (see  
5.1.2.7 "System information" button, pg. 35).  
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Operation  
SDC / DHC  
5.2.2.1 Selection of the control circuit  
After accessing the "Timeprograms" menu, the desired control  
circuits can be selected with the input button îin the following  
sequence:  
Direct heating circuit (HC)  
Mixed heating circuit 1 (MC-1)  
Mixed heating circuit 2 (MC-2)  
Hot-water circuit (DHW)  
Press input button îto access the selected circuit.  
5.2.2.2 Selection of the program  
If the switching time programs P2 and P3 have been enabled (see  
"System Parameter" menu, program parameter = P1 to P3), the  
program selection appears.  
If switching time programs P2 and P3 are disabled, program  
selection is automatically skipped (see "System Parameters"  
menu, program parameter = P1).  
5.2.2.3 Selection of day of the week and cycle  
Once the program is selected, the first cycle of the first day of the  
week (MO 1) and the relevant section in the top time bar flash.  
The other cycles are selected by turning the input button îand  
confirmed by pressing the input button î.  
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SDC / DHC  
Operation  
5.2.2.4 Programming switching times and cycle temperatures  
5.2.2.4.1 Switch-on time  
The switch-on time is the start of heating or, with enabled switch-  
on optimisation, the start of assignment.  
After selecting the day of the week and the corresponding cycle,  
the respective switch-on time appears flashing and can be set  
with the input button î. The time bar in the top part of the display  
provides an overview of all programmed cycles between 0:00 and  
24:00 hours on the selected day of the week.  
NOTE The switch-on time cannot be set below the switch-off time of a  
previous cycle or below 0:00 hours of the selected day of the  
week.  
If the switch-on time is changed, the corresponding time bar  
display is adjusted to the left-hand side.  
If the switch-on time is made equal to the switch-off time, the  
corresponding cycle is deleted. A subsequent cycle is  
automatically shifted to the position of the deleted cycle upon  
acceptance.  
With subsequent insertion of a cycle that has been bumped up,  
the corresponding day of the week must be reprogrammed.  
A flashing switch-on time is accepted by pressing the input button î.  
5.2.2.4.2 Switch-off time  
The switch-off time is the end of heating or, with enabled switch-  
off optimisation, the end of assignment.  
Once the switch-on time is accepted, the associated switch-off time  
appears flashing and can be changed with the input button î. The  
time bar in the top part of the display provides an overview of all  
programmed cycles between 0:00 and 24:00 hours on the  
selected day of the week.  
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Operation  
SDC / DHC  
NOTE The switch-off time cannot be set higher than the switch-on time  
of a subsequent cycle.  
If the switch-on time is changed, the corresponding time bar  
display is adjusted to the right-hand side.  
If the switch-off time is made equal to the switch-on time, the  
corresponding cycle is deleted. A subsequent cycle is  
automatically shifted to the position of the deleted cycle upon  
acceptance.  
With subsequent insertion of a cycle that has been bumped up,  
the corresponding day of the week must be reprogrammed.  
A flashing switch-off time is accepted by pressing the input button î.  
5.2.2.4.3 Cycle temperature  
Once the switch-off time is accepted, the associated cycle  
temperature appears flashing and can be changed immediately  
with the input button î. With heating circuits, the displayed cycle  
temperature is always based on the desired room temperature;  
with the hot-water circuit, it is based on the desired normal hot-  
water temperature in the selected cycle.  
A flashing cycle temperature is accepted by pressing the input  
button î.  
At the same time, the last called-up cycle appears flashing so that  
it may be monitored; additional cycles can then be selected  
directly and edited in the same way in the order: switch-on time,  
switch-off time, cycle temperature.  
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SDC / DHC  
Operation  
Switching time programming (programs P2 and P3 disabled)  
Upon accessing the menu-selection level, the "Timeprograms"  
menu always appears first.  
Enabling of programs P2 and P3 in the "System Parameters"  
menu (see 5.2 Menu-selection level, pg. 48 ).  
Select  
heating circuit:  
Default  
time  
Copy  
circuit  
HC  
MC -1  
MC -2  
DHW  
We  
Th  
Fr  
Select day  
and cycle:  
Tu-  
Hcy-1  
Copy  
day  
Mo-  
Hcy-1  
Mo-  
Hcy-2  
Mo-  
Hcy-3  
Su-  
Hcy-3  
Sa  
Change:  
Change:  
Only appears if there are switching  
times in the second heating cycle.  
Start of  
heating  
End of  
heating  
Monitoring  
Return:  
3 s  
Change:  
Temperature  
Return to the basic display:  
HC  
Direct heating circuit  
MC-1  
MC-2  
DHW  
Hcy  
Mixed heating circuit 1  
Mixed heating circuit 2  
Hot-water heating circuit  
Heating cycle  
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Operation  
SDC / DHC  
Default switching time program (P1) for heating and hot  
water  
Uniform, continuous heating and hot-water operation on all days  
of the week  
Default program P1  
Heating circuit  
Day  
Heating operation  
from  
6:00  
to  
Heat generator heating  
circuit  
Mo to Su  
Mo to Su  
22:00  
Hot-water circuit  
5:00  
6:00  
22:00  
22:00  
Mixed heating circuit 1 / 2 Mo to Su  
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SDC / DHC  
Operation  
Switching time programming (program P2 and P3 enabled)  
Upon accessing the menu-selection level, the "Timeprograms"  
menu always appears first. Enabling of programs P2 and P3 in  
the "System Parameters" menu (see 5.2 Menu-selection level, pg.  
48 ).  
Select  
heating circuit:  
Default  
time  
Copy  
circuit  
HC  
P1  
MC -1  
P2  
MC -2  
P3  
DHW  
Select  
program:  
We  
Th  
Fr  
Select day  
and cycle:  
Mo-  
Hcy-1  
Mo-  
Hcy-2  
Mo-  
Hcy-3  
Tu-  
Hcy-1  
Su-  
Hcy-3  
Copy day  
Sa  
Change:  
Change:  
Start of  
heating  
Only appears if there are switching  
times in the second heating cycle  
End of  
heating  
Monitoring  
Return:  
3 s  
Change:  
Temperature  
Return to the basic display:  
HC  
Direct heating circuit  
MC-1  
MC-2  
DHW  
Hcy  
Mixed heating circuit 1  
Mixed heating circuit 2  
Hot-water heating circuit  
Heating cycle  
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Operation  
SDC / DHC  
Default program P1  
Heating circuit  
Day  
Heating operation  
from  
6:00  
to  
Heat generator heat- Mo to Su  
ing circuit  
22:00  
Hot-water circuit  
Mo to Su  
Mo to Su  
5:00  
6:00  
22:00  
22:00  
Mixed heating  
circuit 1 / 2  
Default program P2  
Heating circuit  
Day  
Heating operation  
from to from to  
Mo to Th  
Fr  
6:00  
6:00  
6:00  
5:00  
5:00  
6:00  
6:00  
6:00  
7:00  
8:00  
16:00 22:00  
13:00 22:00  
Boiler heating circuit  
Hot-water circuit  
8:00  
Sa to Su  
Mo to Th  
Fr  
22:00  
8:00  
15:30 22:00  
12:30 22:00  
8:00  
Sa to Su  
Mo to Th  
Fr  
23:00  
8:00  
16:00 22:00  
13:00 22:00  
Mixed heating  
circuit 1 / 2  
8:00  
Sa to Su  
23:00  
Default program P3  
Heating circuit  
Day  
Heating operation  
from  
to  
Heat generator heat- Mo to Fr  
7:00  
18:00  
ing circuit  
Sa to Su  
Reduced  
6:00  
Hot-water circuit  
Mo to Su  
Sa to Su  
Mo to Su  
Sa to Su  
18:00  
18:00  
Reduced  
7:00  
Mixed heating  
circuit 1 / 2  
Reduced  
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SDC / DHC  
Operation  
5.2.2.4.3.1 Copying switching time programs (days)  
Block programming enables the switching times and cycle  
temperatures of any day of the week to be copied  
1 – To any days within the week (Mo, Tu, We, ..., Su)  
2 – To all weekdays (Mo to Fr)  
3 – To the weekend (Sa to Su)  
4 – To the entire week (Mo to Su)  
Calling up the copy function (days)  
See flowcharts on pg. 65  
Source day  
Press input button îto confirm the copy function.  
Turn input button îto select the source day (MO to SU) to be  
copied.  
The respective automatic program P1 (P2, P3) of the source  
day is copied in the display with the time switch symbol and  
the program index.  
Target day  
Press input button îto confirm the source day.  
The source day appears flashing.  
Turn input button îto select the following setting values and  
confirm by pressing the input button î:  
The following target days (Mo to Su) individually  
All days of the week (1 to 7) as a week block  
All weekdays (1 to 5) as a weekday block  
The weekend days (6 to 7) as a weekend block  
Acceptance is confirmed by acknowledging DAY COPY OK.  
After acknowledgement, the following target days appear one  
after another automatically with each additional press of the input  
button îand can be skipped and accepted if necessary.  
Pressing the  
display.  
button causes an immediate return to the basic  
NOTE Only complete days with all cycles and temperature specifications  
and the respective program can be copied.  
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Operation  
SDC / DHC  
5.2.2.4.3.2 Copying switching time programs (heating circuits)  
Block programming also enables the copying of all switching  
times and temperature specifications of a heating circuit to  
another heating circuit.  
Calling up the copy function (heating circuits)  
See flowcharts on pg. 65  
Source circuit  
Press input button îto confirm the copy function.  
Turn input button îto select the source circuit to be copied  
(HC, MC-1, MC-2, DHW).  
If automatic program P1, P2 or P3 (see "System Parameter"  
menu, PROGRAM parameter = P1 to P3) was enabled, the  
desired switching time program P1, P2 or P3 of the source  
circuit can be selected. If not enabled, program selection is  
skipped.  
Target circuit  
Press input button î, to confirm the source circuit.  
Based on the same chart, the desired target circuit and, if  
enabled, the desired program can be selected and accepted.  
Acceptance is confirmed by acknowledging COPY OK. The copy  
function is then called up again to copy additional circuits, if  
necessary.  
NOTE Heating circuits cannot be copied to hot-water circuits or the re-  
verse due to the different temperature specifications. If a heating  
circuit (HC, MC-1, MC-2) is selected as the source circuit, the hot-  
water circuit (DHW) switches off as the target circuit.  
A hot-water circuit as the source circuit is also the target circuit. In  
this case, only switching time programs P1 to P3 are copied  
among one another.  
Pressing the  
display.  
button causes an immediate return to the basic  
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SDC / DHC  
Operation  
Block programming  
The copy function enables a source day to be copied to any target  
days or to all days of the week (week programming). All cycles of  
the source day are copied. Individual heating cycles cannot be  
copied.  
ö
Select  
heating circuit:  
Default  
time  
Copy  
circuit  
HC  
MC -1  
P2  
MC -2  
P3  
DHW  
ö
î
Select program:  
1)  
P1  
ö
î
We  
Th  
Fr  
Select  
copy function:  
Mo  
Hcy-1  
Mo  
Hcy-2  
Mo  
Hcy-3  
Tu  
Hcy-1  
Su  
Hcy-3  
Copy day  
Sa  
HC  
Direct heating circuit  
MC-1  
MC-2  
DHW  
1)  
Mixed heating circuit 1  
Mixed heating circuit 2  
Hot-water heating circuit  
Program selection for source and target circuits are  
skipped if programs P2 and P3 are disabled in the  
"System Parameter" menu.  
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Operation  
SDC / DHC  
Copy day  
Select  
source day:  
Example: Monday  
Copy  
from  
Mo  
Mo ... Su  
Source day  
Select  
first target day:  
Example: Tuesday  
Copy Mo  
to  
Tu  
1 target day or  
1-7 (Mo ... Su) or  
1-5 (Mo ... Fr) or  
6-7 (Sa ... Su)  
Copy source day  
to first target day:  
Acknowledge:  
Copy  
day  
OK  
Tuesday as with Monday  
Source day  
Select  
second target day:  
Example: Wednesday  
Copy Mo  
to  
We  
Second target day  
Copy source day  
to second target day  
Acknowledge:  
Copy  
day  
OK  
Wednesday as with Monday  
Select and copy other  
target days if necessary  
Return to the basic display:  
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SDC / DHC  
Operation  
Copying heating circuits  
NOTE Heating circuits cannot be copied to hot-water circuits since they  
have different cycle temperatures: If a heating circuit is selected  
as the source circuit, the hot-water circuit can no longer be called  
up as the target circuit. The hot-water circuit as the source circuit  
is also the target circuit. In this case, only programs of the hot-  
water circuit are copied among one another if they were enabled  
in the "System Parameter" menu.  
Select  
copy function:  
Default  
time  
Copy  
circuit  
HC  
MC-1  
MC-2  
DHW  
Select  
source circuit:  
Source circuit Source circuit Source circuit  
HC  
MC -1  
MC -2  
Select  
source circuit  
program:  
Source circuit Source circuit Source circuit  
1)  
HC  
P1 MC -1  
P2 MC -2  
P3  
Select  
target circuit:  
Target circuit  
HC  
Target circuit  
MC -1  
Target circuit  
MC -2  
Select  
target circuit  
program:  
Target circuit  
Target circuit Target circuit  
1)  
MC -2  
P1 MC -2 P2 MC -2 P3  
Copy:  
Acknowledge:  
Program P1 (direct heating circuit) =  
Program P2 (mixed heating circuit 2)  
Copy  
-OK-  
Copy additional heating circuits  
if necessary  
Exit:  
Basic display  
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Operation  
SDC / DHC  
HC  
Direct heating circuit  
Mixed heating circuit 1  
Mixed heating circuit 2  
Hot-water heating circuit  
MC-1  
MC-2  
DHW  
1)  
Program selection for source and target circuits are  
skipped if programs P2 and P3 are disabled in the  
"System Parameter" menu.  
5.2.2.4.4 Reloading default programs  
See flowchart on pg. 70  
Individually created switching time program P1, P2 or P3 can be  
overwritten with the original default switching time program P1, P2  
or P3.  
For this purpose, select the DEFAULT-TIME function within the  
heating circuit selection after accessing the "Timeprograms"  
menu.  
After confirming by pressing the input button î, the circuit  
dedicated to reloading appears flashing (HC, MC-1, MC-2, ALL).  
If the automatic programs P1, P2 and P3 (see "System  
Parameter" menu, program parameter = P1 to P3) were enabled,  
the desired switching time program P1, P2 or P3 of the heating  
circuit affected by the reload can be selected. If not enabled,  
program selection is skipped.  
Resetting Resetting then occurs by pressing and holding the input button  
approx. 5 s until acknowledgement appears in the display.  
Resetting is confirmed by acknowledging COPY OK.  
The DEFAULT-TIME function is then called up again to replace  
other circuits with their default programs if necessary.  
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SDC / DHC  
Operation  
ATTENTION  
With the setting value ALL, all heating circuits and the hot-  
water circuit are overwritten with their default switching  
times with regard to the selected program.  
When overwriting occurs, individually created switching time  
programs are permanently lost and must be recreated from  
scratch.  
Pressing the  
display.  
button causes an immediate return to the basic  
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Operation  
SDC / DHC  
Reloading default programs  
Switching time programs P2 and P3 disabled  
HC  
Direct heating circuit  
MC-1 Mixed heating circuit 1  
MC-2 Mixed heating circuit 2  
DHW Hot-water heating circuit  
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SDC / DHC  
Operation  
Reloading default programs  
Switching time programs P2 and P3 enabled  
DHW  
HC  
Direct heating circuit  
MC-1 Mixed heating circuit 1  
MC-2 Mixed heating circuit 2  
DHW Hot-water heating circuit  
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Operation  
SDC / DHC  
5.2.3 "System Parameters" menu  
The system parameters refer to general limiting parameters and  
specification values within the heating system.  
Access See 5.2 Menu-selection level, pg. 48  
Returning  
Returning to the basic display takes place by pressing the  
button or automatically after the set information time (see  
5.1.2.7 "System information" button, pg. 35).  
5.2.3.1 Language selection  
Several languages can be selected for all information that  
appears in the display.  
After selecting the language and confirming it by pressing the  
input button î, additional communication takes place in the  
respective language.  
Setting values  
DE  
GB  
FR  
IT  
German  
English  
French  
Italian  
NL  
ES  
PT  
HU  
CZ  
PL  
RO  
RU  
TR  
S
Dutch  
Spanish  
Portuguese  
Hungarian  
Czech  
Polish  
Romanian  
Russian  
Turkish  
Swedish  
Norwegian  
N
Factory setting German  
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SDC / DHC  
Operation  
5.2.3.2 Time program  
This parameter specifies enabling of the switching time programs  
for program selection and for individualised switching time  
programming. In the state of delivery, only one switching time  
program is enabled. This achieves simplification of operation with  
a large portion of applications for which only one switching time  
program is used.  
Set values  
P1  
Program 1 = enabled, programs 2 and 3 = disabled  
All three programs enabled  
P1 to P3  
Factory setting P1  
Effects In contrast to the previous description, the following setting  
options are available when programs P1 to P3 are enabled:  
Operating mode selection: In the AUTOMATIC and SUMMER  
operating modes, switching time program P1, P2 or P3 can be  
selected.  
Switching time programming: With switching time pro-  
gramming, the three switching time programs, P1 to P3, can  
be selected for each heating circuit.  
5.2.3.2.1 Control mode selection  
In the AUTOMATIC and SUMMER control modes, switching time  
program P1, P2 or P3 can be selected.  
5.2.3.2.2 Switching time programming  
With switching time programming, the three switching time  
programs, P1 ... P3 can be selected.  
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Operation  
SDC / DHC  
5.2.3.3 Operating mode  
Two operating modes can be selected. They determine whether  
the operating mode, the daytime temperature and the night-time  
temperature apply for all heating circuits or can be specified  
individually for each heating circuit.  
Setting range 1, 2  
Set values  
1 The selected setting applies for all heating circuits together.  
2 Each heating circuit can be assigned an individualised set-  
ting.  
Factory setting  
1
5.2.3.3.1 Individualised daytime room temperature for each heating  
circuit  
Setting  
Press ¥button.  
Select desired heating circuit (HC, MC-1 or MC-2) by turning  
the input button î.  
C
Confirm selected circuit by pressing the input button î.  
Set flashing room temperature specification to the desired  
value by turning the input button î.  
Confirm set value by pressing the ¥button.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Setting range 5 ... 30 °C  
Factory setting 20 °C  
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Operation  
5.2.3.3.2 Individualised night-time room temperature for each heating  
circuit  
Setting  
Press ¦button.  
Select desired heating circuit (HC, MC-1 or MC-2) by turning  
the input button î.  
C
Confirm selected circuit by pressing the input button î.  
Set flashing room temperature specification to the desired  
value by turning the input button î.  
Confirm set value by pressing the ¦button.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
Setting range 5 ... 30 °C  
Factory setting 16 °C  
5.2.3.3.3 Individualised operating mode for each heating circuit  
Each heating circuit can be assigned an individualised operating  
mode.  
Setting  
Press  
button.  
Select desired heating circuit (HC, MC-1 or MC-2) by turning  
the input button î.  
C
Confirm selected circuit by pressing the input button î.  
Select flashing operating mode by turning the input button î.  
Confirm set operating mode by pressing the  
input button î.  
button or the  
With short-term operating modes (ABSENT, PARTY), set  
desired target value by turning the input button îand confirm  
set value by pressing the input button î.  
Alternative: Automatic acceptance of the value after the set  
information time (see 5.1.2.7 "System information" button, pg. 35).  
This parameter specifies the end of heating operation depending  
on the outside temperature based on the following criteria:  
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Operation  
SDC / DHC  
Quick increase in outside temperature  
If the averaged outside temperature is below the set value and  
the current outside temperature is 2 K above the set value,  
heating operation is interrupted.  
Slow increase in outside temperature  
Deactivation is also initiated when the averaged and current  
outside temperature exceeds the set value.  
Undoing deactivation  
Deactivation is undone when the averaged and current outside  
temperature exceeds the set value by 1 K.  
The summer deactivation function is undone:  
In case of an outside sensor defect  
In case frost protection is active  
NOTE During deactivation phases (standby mode, manual summer  
operation, summer deactivation) lasting longer than 24 hours all  
pumps are switched on for approx. 20 s and the mixers are  
temporarily opened during this time to protect against blocking by  
corrosion.  
In connection with a second outside sensor, the current averaged  
outside temperature is accepted for summer deactivation if the  
average value of both sensors is specified during outside sensor  
assignment.  
Active summer deactivation is represented by a beach umbrella  
symbol in the basic display.  
Only active in the AUTOMATIC operating mode.  
Factory setting 20 °C  
Setting range OFF, set value of system frost protection to 40 °C  
5.2.3.4 Parameter reset  
With the reset parameter, it is possible to reset any inadvertently  
made changes in the parameter menu to the factory setting.  
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Operation  
ATTENTION  
A reset should only be carried out if all individually entered  
values are to be replaced by the values specified at the  
factory.  
Setting When the PARAM. RESETdisplay flashes, press the input  
button î.  
SET flashes in the display.  
Press and hold the input button îfor 5 s.  
If a reset is carried out, the RESET OK confirmation appears  
briefly. Verification is then started with a call-up of the first  
parameter in the respective menu once again.  
After the parameter values are reset, a return to the first  
parameter in the "System Parameter" menu occurs.  
5.2.3.5 Complete reset  
To reset all settings, a complete reset of the device can be carried  
out.  
A complete reset is initiated when the  
, ¥, ¦and §keys  
are pressed simultaneously until the controller restarts.  
5.2.4 "DHW" menu  
This menu contains all parameters required to program the hot-  
water circuit, except the hot-water switching time programs.  
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Operation  
SDC / DHC  
5.2.4.1 Night-time hot-water temperature  
This parameter specifies the temperature in the hot-water  
generator between the operational-readiness times in automatic  
mode.  
Factory setting 40 °C  
Setting range 5 °C to set normal hot-water temperature value  
NOTE If a hot-water thermostat (see parameter 05 = transducer for hot-  
water circuit) is used to detect the hot-water temperature, this  
parameter is skipped.  
5.2.4.2 Legionella protection day  
Factory setting OFF  
Setting range OFF, MO to SU, ALL  
Set values  
OFF  
The legionella protection function is not active.  
MO to SU  
Legionella protection is activated on the selected  
day of the week at the legionella protection time set  
in the following parameter.  
ALL  
The legionella protection function is activated daily  
at the legionella protection time set in the next  
parameter.  
NOTE If a hot-water thermostat (see 05 parameter = transducer for hot-  
water circuit) is used to detect the hot-water temperature, these  
parameters are skipped.  
5.2.5 "Direct Heating Circuit" / "Mixed Heating Circuit 1" / "Mixed  
Heating Circuit 2" menu  
These menus contain all parameters required to program the  
heating circuit, except the switch time programs. Max. one direct  
heating circuit and two mixed heating circuits (mixed heating  
circuit 1 and mixed heating circuit 2) are available as heating  
circuits.  
The following described heating circuit parameters are available  
separately for setting for each heating circuit.  
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SDC / DHC  
Operation  
5.2.5.1 Reduced operation  
During reduced operation, you can select between two operating  
modes.  
Factory setting ECO  
Setting range ECO, RED  
Set values RED (lowering operation)  
The heating circuit pump of the direct heating circuit continues  
functioning during reduced operation (see 5.2.3.2 Time program,  
pg. 73). The flow temperature is determined based on the lowered  
room temperature from the associated reduced heating curve.  
The set maximum temperature is not undershot.  
Application Building with minimal insulation values and high cooling loss.  
ECO (switch-off operation)  
During reduced operation, the direct heating circuit is switched off  
completely with outside temperatures above the set frost-  
protection limit. The maximum heat generator temperature is not  
functional. The heating circuit pump is switched off after a delay to  
avoid safety deactivation by reheating the heat generator (pump  
follow-up).  
If the outside temperature is or becomes lower than the specified  
outside temperature frost-protection limit, the controller switches  
from deactivated (deactivation mode) to lowered lowering  
operation and controls the heating circuit temperature based on  
the set lowering curve taking the set minimum heat generator  
specification into account.  
Application Building with high insulation values (full heating protection).  
NOTE The mode set here also applies for the ABSENT and RED.  
HEATING operating modes.  
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Operation  
SDC / DHC  
5.2.5.2 Heating system  
This parameter refers to the type of the heating system (floor,  
radiator or convector heating) and can be matched to the  
exponent of the respective heat distributor. Using its progressive  
characteristics, the set value determines the curve characteristics  
of the heating curve of the direct heating circuit and compensates  
for the losses in output in the low-temperature range with it.  
The following settings are recommend depending on the type of  
heating system:  
UFH  
Slightly progressive heating curves for floor or other  
area heating.  
RAD  
Progressive standard heating curves for all radiator  
heating with m-values between 1.25 and 1.35.  
CONV Progressive heating curves for convector and  
baseboard heating.  
Factory setting  
RAD  
UFH  
(radiator systems)  
(floor heating) with mixed heating circuits  
Setting range UFH, RAD, CONV  
5.3 Error messages  
ATTENTION  
Inform the heating technician whenever any fault messages  
are output.  
The control device contains substantial error-notification logic.  
The error messages appear in continuous alteration with the basic  
display. Multiple errors that occur at the same time appear one  
after another in the order in which they occurred. The following  
types of error message exist:  
Sensor error Sensor measured values that do not lie in the measurement  
messages range are evaluated as an interruption or short-circuit. They  
appear depending on the type and allocation with fault code 10 to  
20 and index 0 for short-circuit or 1 for interruption.  
Heat generator error These error messages evaluate the respective switching status.  
messages They appear depending on the type and allocation with fault code  
30 to 40 and index 0, 1 or 2.  
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SDC / DHC  
Operation  
Logical error These error messages evaluate the control result to be expected.  
messages They appear depending on the type and allocation with fault code  
50 to 60 and index 0, 1 or 2.  
Bus error messages These error messages refer to address faults such as double  
issuance or non-recognition of address settings on the data bus.  
They appear with fault code 70 and index 0 or 1, depending on  
the type and assignment.  
5.4 Parameter settings  
5.4.1 "Hydraulics" menu (HYDRAULIC)  
The parameters in this menu refer to the general system  
hydraulics and the functions and configuration of the  
programmable inputs and outputs for the respective system  
components. Representative of many individual settings, the  
applications are only defined by the 1st parameter of this setting  
table.  
Example: The controller is to cover system No 0202. Provided  
that the controller features enough relays, parameter 01 must be  
set to value 0202.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
Hydraulic  
schematic  
0, 0101, 0102, ... n  
0
02  
Hot-water charging OFF  
No function  
1
pump output  
1
Hot-water charging  
pump  
4
5
Circulating pump  
Electric heating rod  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
03  
Mixed heating  
circuit 1 output  
OFF  
2
No function  
3
Direct heating circuit  
controlled by weather  
conditions  
3
Mixed heating circuit  
controlled by weather  
conditions  
6
Constant regulator  
Fixed-value regulator  
Return maintenance  
7
8
30  
Mixed heating circuit as  
continuous hot-water  
pre-regulator (district  
heating)  
39  
Hot-water pre-regulator  
(district heating)  
04  
05  
Mixed heating  
circuit 2 output  
For setting values, see parameter 3  
03  
Direct heating  
OFF  
2
No function  
2
circuit pump output  
Direct heating circuit  
pump  
4
Circulating pump  
Electric heating element  
Constant regulation  
Feeder pump  
5
6
10  
11  
12  
13  
14  
15  
25  
27  
Boiler circuit pump 1  
Boiler circuit pump 2  
Group alarm  
Time switch  
Solar charging pump  
Cooling switchover  
Hydraulic buffer relief  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
06  
Variable output 1  
OFF  
4
No function  
OFF  
Circulating pump  
5
Electrical heating circuit  
Bypass pump  
9
10  
11  
12  
13  
15  
16  
17  
18  
Feeder pump  
Boiler circuit pump 1  
Boiler circuit pump 2  
Group error message  
Solar charging pump  
Buffer charging pump  
Solid fuel charging pump  
Stratified tank charging  
pump (DHC)  
19  
Solar charging  
switchover  
25  
26  
27  
Cooling switchover  
Primary pump  
Hydraulic buffer relief  
07  
Variable output 2  
For setting values, see parameter OFF  
06  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
08  
Variable input 1  
OFF  
1
No function  
OFF  
Outside sensor 2  
2
3
4
5
6
Heat generator sensor 2  
Tank sensor 2  
Buffer sensor 2  
Request contact  
External error message  
input  
7
Return maximum limit of  
mixed heating circuit 1  
Return maximum limit of  
mixed heating circuit 2  
Return temperature  
sensor  
8
9
10  
11  
External heat generator  
cutoff  
External switching  
modem  
12  
13  
14  
15  
External information  
Total flow sensor  
Collector return sensor  
District hot-water strat-  
ified tank charge sensor  
Exhaust gas sensor  
16  
18  
19  
29  
30  
Solids buffer sensor  
Buffer sensor 1  
Hygrostatic switch-off  
Room sensor NTC 20 of  
direct heating circuit  
31  
32  
Room sensor NTC 20 of  
mixed heating circuit 1  
Room sensor NTC 20 of  
mixed heating circuit 2  
84  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
09  
Variable input 2  
For setting values, see parameter OFF  
08; does not include setting value  
16 (exhaust gas sensor),  
however  
10  
Variable input 3  
For setting values, see parameter OFF  
08; does not include setting value  
16 (exhaust gas sensor), limit  
sensor of district heating VFB,  
however  
11  
Indirect return lift-  
ing via mixed  
OFF, ON  
OFF  
heating circuit  
5.4.2 "System parameters" menu (SYSTEM)  
The parameters in this menu refer to general limit parameters and  
specification values in the heating system used.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
Lan-  
Language  
selection  
DE  
GB  
FR  
IT  
German  
English  
guage  
selec-  
tion**  
French  
Italian  
NL  
ES  
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EN2H-0221GE51 R0808  
85  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
Time  
Time program  
P1  
Only one switching time P1  
program  
program enabled  
P1 to  
P3  
Three switching time  
programs enabled  
Operat- Operating mode  
1
Common adjustment for  
all heating circuits  
1
ing  
mode  
2
Separate adjustment for  
the individual heating  
circuits  
Summe Summer switch-  
OFF, setting value of parameter  
05 to 30°C  
20  
3
r
off  
05  
System frost pro- OFF, –20°C to Setting value of  
tection  
summer parameter  
06  
Request contact  
module  
1
Direct heating circuit  
1
2
Mixed heating circuit 1  
Mixed heating circuit 2  
Hot-water circuit  
for variable  
input 1  
3
4
ALL  
All controllers  
07  
08  
Request contact  
module  
For setting values, see parameter 1  
06  
for variable  
input 2  
Request contact  
module  
For setting values, see parameter 1  
06  
for variable  
input 3  
09  
10  
Climate zone  
Building type  
–50 ... 0°C  
–12  
1
2
3
Light construction  
2
Medium construction  
Heavy construction  
86  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
11  
Automatic exit  
time  
OFF  
No automatic exit  
2
0,5 ... Automatic jump back to  
5 min  
the basic display occurs  
after the set time  
12  
Anti-blocking  
protection  
ON  
Anti-blocking protection ON  
active  
OFF  
Anti-blocking protection  
not active  
13  
Logical fault  
messages  
OFF, ON  
OFF, ON  
OFF, 0001 to 9999  
OFF  
14  
Automatic set  
function  
OFF  
1234  
Type  
ON  
15*  
16*  
18  
Locking code for  
heating technician  
Type code  
Controller type corresponding to  
type code table  
Cycle temperature OFF  
enable  
Cycle temperature  
disabled  
ON  
Cycle temperatures  
enabled  
19  
Frost-protection  
mode  
OFF  
Continuous frost  
protection as per  
parameter 05  
OFF  
0.5 to  
Cyclic operation  
60 min  
EN2H-0221GE51 R0808  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
21*  
Adjustment of the –10 ... 10 s  
real time clock  
0
(RTC)  
23  
25  
Locking code for  
operating level  
OFF, 0000 ... 9999  
OFF  
6
Cooling switch-on 2 ... 10 K  
temperature  
28  
Error memory 2  
OFF, ON  
OFF  
0
29*  
Characteristic  
curve for  
–50 to 30°C  
emergency  
operation without  
outside sensor  
Selec-  
tion of  
SDC/  
DHC  
Selection of  
SDC/DHC  
SDC, DHC  
SDC  
Para-  
meter  
reset  
Parameter reset  
SET by pressing the input button  
* OEM  
** Other controllers also allow other language variants.  
88  
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SDC / DHC  
Operation  
5.4.3 "Hot-water circuit" menu (DHW)  
This menu contains all parameters required to program the  
hot-water circuit, except the switch time programs.  
Para-  
meter  
Designation  
Hot water at night  
Legionella  
Setting range / Setting values  
Factory  
setting  
Setting  
Hot  
10°C to normal hot-water  
temperature  
40  
water  
Legio  
OFF  
No legionella protection OFF  
protect protection day  
ion day  
Mon to Legionella protection on  
Sun  
specified day of week  
ALL  
Legionella protection  
every day  
03  
04  
Legionella  
00:00 ... 23:00 hours  
02:00  
65  
protection time  
Legionella  
protection  
temperature  
10 °C to setting value of  
parameter 06  
05  
06  
Transducer for hot- 1  
water circuit  
Hot-water circuit  
1
temperature sensor  
2
Hot-water circuit  
temperature controller  
(thermostat)  
Maximum  
20°C to heat generator maximum 65  
temperature  
temperature limit  
for hot water circuit  
If parameter 07 = 7:  
20 to 90°C.  
In automatic mode, from hot-  
water circuit minimum  
temperature.  
EN2H-0221GE51 R0808  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
07  
Hot-water circuit  
operating mode  
1
2
3
4
Parallel operation  
Priority operation  
Conditional priority  
2
Parallel operation based  
on weather conditions  
5
Priority operation with  
intermediate heating  
6
7
8
Priority isolating circuit  
External operation  
Conditional parallel  
operation for mixed  
heating circuit (DHC  
only)  
08  
09  
Tank discharge  
protection  
OFF  
ON  
No discharge protection ON  
Discharge protection  
activated  
Temperature in-  
crease of heat  
generator with hot-  
water circuit  
0 ... 50 K  
15  
Difference between hot-water  
circuit charging temperature and  
hot-water circuit setpoint  
temperature  
charging  
10  
11  
Switching  
2 ... 20 K  
5
5
differential of hot-  
water circuit  
Value of hot-water circuit switch-  
ing differential. Symmetrical  
effect around the hot-water circuit  
setpoint  
Hot-water charging 0 ... 60 min  
pump follow-up  
time  
90  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
12  
Circulation pump  
switching time  
program  
AUTO Active hot-water circuit  
time program  
AUTO  
1
2
3
4
P1, direct heating circuit  
P2, direct heating circuit  
P3, direct heating circuit  
P1, mixed heating  
circuit 1  
5
6
7
8
9
P2, mixed heating  
circuit 1  
P3, mixed heating  
circuit 1  
P1, mixed heating  
circuit 2  
P2, mixed heating  
circuit 2  
P3, mixed heating  
circuit 2  
10  
11  
12  
P1, hot-water circuit  
P2, hot-water circuit  
P3, hot-water circuit  
13  
Economy interval  
pause of circu-  
lating pump  
0 ... setting value of parameter 14 5  
Switch-on interval while the  
circulating pump is running  
14  
16  
Economy interval  
cycle (period  
duration)  
1 ... 60 min  
20  
Circulating pump  
1
2
Normal operation  
1
Switched off during hot-  
water circuit charging  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
17  
Behaviour of heat  
generator during  
follow-up time  
AUTO Setpoint at heat gen-  
erator depending on  
demand  
AUTO  
OFF  
Heat generator off  
during follow-up time of  
solar charging pump  
5.4.4 "Direct heating circuit" menu (UNMIXED CIRC)  
This menu contains all parameters required to program the un-  
mixed heating circuits, except the switching time programs.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
Heat-  
ing  
Slope  
OFF, 0.02 to 3.50  
1.5  
curve  
Re-  
Reduced operation ECO  
RED  
Switch-off operation  
Lowering operation  
ECO  
RAD  
duced  
Heat-  
ing  
Heating system  
UFH Under floor heating  
RAD Radiator  
system  
CON Convector heater  
V
92  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
03  
Room connection  
(in conjunction  
OFF  
Display of heat  
OFF  
generator temperature,  
room sensor off,  
operation active  
with room sensor)  
1
2
Display of room  
temperature, room sensor  
active, operation active  
Display of room  
temperature, room sensor  
active, operation  
disabled  
3
Display of room  
temperature, room sensor  
off, operation active  
04  
Room factor  
Heating limit  
OFF  
OFF  
10 ... Influence active  
500  
%
RC  
Room controller active  
07  
08  
OFF, 0.5 to 40 K  
5 ... 30°C  
OFF  
10  
Room frost-  
protection limit  
09  
10  
Room thermostat  
function  
OFF, 0.5 to 5 K  
OFF  
0
Assignment of  
outside sensor  
0
Regulation to average  
value (outside sensor 1  
+ outside sensor 2)  
1
2
Regulation to outside  
sensor 1  
Regulation to outside  
sensor 2  
11  
Constant  
temperature  
setpoint  
10 ... 95°C  
20  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
12  
Minimum  
10°C to setting value of  
parameter 13  
20  
temperature limit  
13  
Maximum  
Setting value of parameter 12 to  
Setting value of parameter 30 in  
"Heat generator" menu (OEM  
maximum limit)  
75  
temperature limit  
14  
Temperature  
increase of heating  
circuit  
–5 ... 20 K  
Direct  
heating  
circuit = 0  
15  
16  
Extended pump  
over-run  
0 ... 60 min  
OFF  
5
Screed function  
OFF  
1
Functional heating  
2
Screed-drying heating  
23  
Room control  
C-factor (SDW 30  
only)  
1 ... 100  
8
24  
25  
Room control Tn  
(SDW 30 only)  
5 ... 240 min  
35  
Holiday operating  
mode  
STBY Standby  
STBY  
RED  
Lowering operation  
26  
41  
Room setpoint  
ramp  
OFF, 0.5 to 60 K/h  
OFF  
OFF  
Switch-on  
OFF  
optimisation  
1
2
3
Adaption off  
Adaption on  
Adaption restart  
42  
43  
Min. pre-heat time 0 ... setting value of parameter 43 0,5  
Max. pre-heat time Setting value of parameter 42 to  
30 h  
5
5
1
44  
45  
Min. jump back  
temperature  
0 ... 30°C  
Without room  
sensor  
0 ... 10°C  
94  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
46  
Pre-heat time at  
0°C  
0 ... 30 h  
1
47  
Lowering ramp  
0 ... 500 %  
100  
Heat-  
ing  
Heating circuit  
name  
00000 ... ZZZZZ  
circuit  
name  
5.4.5 "Mixed heating circuit 1 / 2" (MIX.VALVE - 1 / MIX.VALVE - 2)  
menus  
These menus contain all parameters required to program the  
mixed heating circuit, except the switching time programs.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
Heat-  
ing  
Slope  
OFF, 0.02 to 3.50  
1
curve  
Re-  
Reduced operation ECO  
RED  
Switch-off operation  
Lowering operation  
Floor heating  
ECO  
RAD  
duced  
Heat-  
ing  
Heating system  
UFH  
RAD  
CONV  
Radiator  
system  
Convector heater  
EN2H-0221GE51 R0808  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
03  
Room connection  
(in conjunction  
OFF  
Display of heat  
OFF  
generator temperature,  
room sensor off,  
operation active  
with room sensor)  
1
Display of room  
temperature, room  
sensor active, operation  
active  
2
Display of room  
temperature, room  
sensor active, operation  
disabled  
3
Display of room  
temperature, room  
sensor off, operation  
active  
04  
Room factor  
Heating limit  
OFF  
OFF  
10 ...  
Influence active  
500 %  
RC  
Room controller active  
07  
08  
OFF, 0.5 to 40 K  
OFF  
10  
Room frost-  
5 ... 30 °C  
protection limit  
09  
10  
Room thermostat  
function  
OFF, 0.5 to 5 K  
OFF  
0
Assignment of  
outside sensor  
0
Regulation to average  
value (outside sensor 1  
+ outside sensor 2)  
1
2
Regulation to outside  
sensor 1  
Regulation to outside  
sensor 2  
96  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
11  
Constant tem-  
perature setpoint  
(only if output was  
set to constant  
regulator)  
10 ... 95°C  
20  
12  
13  
Minimum  
10°C to setting value of  
parameter 13  
20  
75  
temperature limit  
Maximum  
Setting value of parameter 12 to  
Setting value of parameter 30 in  
"Heat generator" menu (OEM  
maximum limit)  
temperature limit  
14  
Temperature  
increase of heating  
circuit  
–5 ... 20 K  
Mixed  
heating  
circuit = 4  
15  
16  
Follow-up time of  
pump  
0 ... 60 min  
OFF  
5
Screed function  
OFF  
1
2
Functional heating  
Screed-drying heating  
17  
Return maximum  
temperature limit  
90  
10 ... 90 °C  
18*  
19*  
20*  
21*  
22*  
P part XP  
1 ... 50 %/K  
1 ... 600 s  
1 ... 600 s  
10 ... 600 s  
2
Sampling time Ts  
I part Tn  
20  
270  
120  
1
Actuator runtime  
Actuator end  
1
Continuous control  
position function  
signal in end position  
2
Control signal  
suppressed at end  
position (actuator de-  
energised)  
23  
Room control C-  
factor (SDW 30  
only)  
1 ... 100  
8
EN2H-0221GE51 R0808  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
24  
Room control Tn  
(SDW 30 only)  
5 ... 240 min  
35  
25  
Holiday operating  
mode  
STBY  
RED  
Standby  
STBY  
Lowering operation  
26  
28  
Room setpoint  
ramp  
OFF, 0.5 ... 60 K/h  
OFF  
OFF  
Cooling  
OFF, 18 to 24  
temperature of  
mixed heating  
circuit  
39  
40  
Spread of hot-  
water circuit pre-  
regulator  
2 ... 20 K  
5
0
Offset valve  
position of hot-  
water circuit pre-  
regulator  
0 ... 100 %  
41  
Switch-on op-  
timisation  
OFF  
OFF  
1
2
3
Adaptation off  
Adaptation on  
Adaptation restart  
42  
43  
44  
45  
46  
47  
Minimum pre-heat 0 ... setting value of parameter 43 0.5  
time  
Maximum pre-heat Setting value of parameter 42 to  
5
time  
30 h  
Min. jump back  
temperature  
0 ... 30 °C  
5
Without room  
sensor  
0 ... 10 °C  
0 ... 30 h  
1
Pre-heat time at  
0 °C  
1
Lowering ramp  
0 ... 500 %  
100  
98  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
Heat-  
ing  
Heating circuit  
name  
00000 ... ZZZZZ  
circuit  
name  
* OEM  
5.4.6 "Heat generator" menu (HEAT GENER.  
The parameters in this menu refer to the type of the respective  
heat generator and the associated specific control functions.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
Design  
OFF  
Without heat generator  
Oil/gas - one stage  
Oil/gas - two stages  
Oil/gas - 2 x one stage  
Modulating burner  
Open Therm  
1
1
2
3
4
5
02  
Start-up protection OFF  
No start-up protection  
1
(not if parameter  
1
Unlimited start-up  
protection  
01 = OFF)  
2
Start-up protection  
controlled by weather  
conditions  
3
Start-up protection  
disconnected  
03  
04  
Minimum tem-  
perature limit (not  
if parameter 01 =  
OFF)  
5°C to setting value of parameter 38 (5 with  
04  
automatic  
operation)  
Maximal  
Setting value of parameter 03 to  
setting value of parameter 30  
(OEM maximum limit)  
80  
temperature limit  
(not if parameter  
01 = OFF)  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
05  
Limit mode  
1
Minimum limit based on  
request  
1
minimum limit (not  
if parameter 01 =  
OFF)  
2
3
1
Limited minimum limit  
Unlimited minimum limit  
06  
Sensor operating  
mode  
Burner switch-off in case  
of defect  
1
2
3
External burner switch-  
off  
Burner enable in case of  
defect  
07  
08  
Minimum burner  
runtime  
0 ... 20 min  
2
6
Burner switching  
differential I  
One stage: 2 ... 30 K  
Two stages: 2 ... (setting value of  
parameter 09 – 0.5 K)  
09  
Burner switching  
(setting value of parameter 08 +  
8
differential II (not if 0.5) to 30 K  
parameter  
01 = 2)  
10  
11  
Connection delay  
stage II  
0 ... 60 min (0 = 10 s)  
0
2
Boiler start-up  
relief stage II  
1
2
1
Unlimited enable during  
start-up relief  
Time-out during start-up  
relief  
12  
Storage charge  
1–2 stages  
Two-stage hot-water  
circuit charge (with delay  
of full-load stage)  
1
2
3
Two-stage hot-water cir-  
cuit charge (unlimited)  
One-stage hot-water  
circuit charge (partial  
stage only)  
100  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
13  
Lead time of boiler 0 ... 10 min  
circuit pump or  
parallel heat  
0
generator enable  
(only with  
appropriate  
configuration in the  
"Hydraulics"  
menu)  
14  
Follow-up time of  
boiler circuit pump  
(only with  
0 ... 60 min  
2
2
appropriate  
configuration in the  
"Hydraulics"  
menu)  
15  
16  
Follow-up time of  
feeder pump (only  
with appropriate  
configuration in the  
"Hydraulics"  
0 ... 60 min  
menu)  
Exhaust gas  
temperature  
OFF  
Display of exhaust gas OFF  
temperature only  
monitoring (only  
with appropriate  
configuration in the  
"Hydraulics"  
0 ... 60  
min  
Heat generator lock if  
limit value is exceeded  
for set time  
SLT  
Heat generator lock if  
limit value is exceeded  
menu)  
17  
Exhaust gas limit  
value (only with  
appropriate  
50 ... 500°C  
200  
configuration in the  
"Hydraulics"  
menu)  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
19*  
Modulation of  
proportional range  
XP  
0.1 ... 50 %/K  
5
20*  
21*  
22*  
23*  
24*  
25  
Modulation of  
1 ... 600 s  
20  
sampling time Ts  
Modulation of  
180  
12  
1 ... 600 s / °C  
adjustment time Tn  
Modulation of  
runtime  
5 ... 600 s  
Modulation of start 0 ... 900 s  
time  
60  
Modulation of start 0 ... 100 %  
power  
70  
Outside tempera-  
ture lock (not if  
parameter 01 =  
OFF)  
OFF, –20 to +30 °C  
OFF  
26  
27  
Base load  
increase  
0 ... 60 K  
10  
Minimum  
5 °C to setting value of parameter 36  
03  
temperature limit  
of heating circuits  
(only if parameter  
02 = 3)  
28  
Switching  
2 ... 20 K  
4
differential of  
minimum  
temperature limit  
of heating  
circuits (only if  
parameter 02 = 3)  
102  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
29  
Heat generator  
OFF  
OFF  
forced discharge  
1
2
3
Discharge to process  
water tank  
Discharge to heating  
circuits  
Discharge to buffer tank  
30*  
31*  
34  
OEM maximum  
limit  
Setting value of parameter 03 to  
130 °C  
110  
Full-load  
OFF, 0.5 to 10  
OFF  
100  
regulation  
Power limit for  
heating  
50 ... 100 %  
35  
Power limit for hot 50 ... 100 %  
water  
100  
37  
Burner counter  
mode (counter of  
operating hours)  
AUTO  
AUTO  
1
2
Feedback only  
Free counter  
38  
Outside  
OFF, –20 to +30 °C  
OFF  
temperature  
lock, inverse  
RESET Resetting of burner SET by pressing the input button  
ST-1  
start counter and  
operating hours of  
stage 1 (not if  
parameter 01 =  
OFF)  
RESET Resetting of  
SET by pressing the input button  
ST-2  
burner start  
counter and  
operating hours of  
stage 2 (not if  
parameter 01 = 2  
or 01 = OFF)  
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Operation  
SDC / DHC  
* OEM  
5.4.7 "District hot water" menu (DIST.HEATING)  
The parameters in this menu refer to the type of the respective  
district hot-water station and the associated specific control  
functions.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
Increase  
OFF, –10 to 50 K  
0
Maximum limit of  
flow temperature  
setpoint  
90  
10 ... 130 °C  
03*  
04  
Minimum district  
heating valve  
stroke  
0 ... 50 %  
10  
5
Secondary flow  
boost  
0,1 ... 30 %/K  
0 ... 60 min  
05  
06  
Adjustment time  
3
Runtime of district 10 ... 1800 s  
heating valve 1  
120  
07*  
08*  
Runtime of district 10 ... 1800 s  
heating valve 2  
30  
90  
Maximum return  
temperature  
setpoint  
0 ... 100 °C  
09*  
10*  
Application point  
variable district  
heating return  
temperature  
OFF  
OFF, –40 to +10 °C  
Maximum return  
temperature  
setpoint with hot  
water circuit  
charge  
90  
0 ... 100 °C  
104  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
11*  
Return limit of  
district heating  
valve  
0
1
Temperature  
0
(parameters 12 through  
15 are not displayed)  
Volume flow and  
temperature (parameters  
12 through 14 are not  
displayed)  
2
Heat output and  
temperature (parameters  
13 through 15 are not  
displayed)  
12*  
13*  
14*  
15*  
Calibration of heat 1 ... 9999  
output  
1
Calibration of  
volume flow  
1 ... 9999  
1
Maximum heat  
output  
1 ... 9999 kW  
9999  
99.99  
Maximum volume  
flow  
0,01 ... 99.99 m3/h  
* OEM  
5.4.8 "Return increase" menu (RETURN CONTR)  
The parameters in this menu refer to special settings with regard  
to the increase in return temperature with heat generators.  
Enabling occurs only with corresponding activation in the  
"Hydraulics" menu.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
03  
Return temperature 10 ... 95°C  
setpoint  
20  
Switch-off  
differential  
1 ... 20 K  
2
Follow-up time of  
pump  
0 ... 60 min  
1
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Operation  
SDC / DHC  
5.4.9 "Solar" menu (SOLAR)  
The parameters in this menu refer to special settings with regard  
to the solar applications.  
Enabling occurs only with corresponding activation in the  
"Hydraulics" menu.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
03  
Switch-on  
differential  
(Setting value of parameter  
02 + 3 K) to 30 K  
10  
Switch-off  
differential  
2 K to (setting value of parameter 5  
01 – 3 K)  
Minimum runtime  
of solar charging  
pump  
0 ... 60 min  
3
04  
05  
06  
Collector maxi-  
OFF, 70 to 210°C  
20 ... 110°C  
210  
75  
mum temperature  
Buffer maximum  
temperature limit  
Operating mode  
1
2
3
Priority operation  
Parallel operation  
Priority operation of hot-  
water circuit  
4
Priority operation of  
buffer  
07  
Heat generator  
cycle inhibitor  
(only if parameter  
06 = 1)  
OFF, 0.5 to 24 h  
OFF  
08  
09  
Solar priority  
OFF, 1 to 30 K  
OFF  
OFF  
parallel switchover  
Heat balance  
OFF  
1
No heat balancing  
Heat balancing via flow-  
through calculation  
2
Heat balancing via pulse  
input  
106  
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SDC / DHC  
Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
SET by pressing the input button  
0 ... 30 L/min or L/pulse  
Factory  
setting  
Setting  
10  
Reset heat  
balance  
11  
12  
13  
Volume flow  
0
Density of medium 0.8 ... 1.2 kg/L  
1.05  
3.6  
Heat capacity of  
medium  
2 ... 5 KJ/kgK  
14  
15  
Final switch-off  
temperature  
OFF, 90 to 210 °C  
210  
10  
Test cycle of solar 1 ... 60 min  
charging  
switchover  
16  
Switchover tem-  
perature  
20 ... 110 °C  
75  
5.4.10 "Solid" menu (SOLID FUEL)  
The parameters in this menu refer to special settings with regard  
to solids regulation.  
Enabling occurs only with corresponding activation in the  
"Hydraulics" menu.  
Para-  
meter  
Designation  
Setting range / Setting values  
20 ... 80 °C  
Factory  
setting  
Setting  
01  
02  
03  
04  
05  
Minimum  
60  
90  
10  
temperature  
Maximum  
30 ... 100 °C  
temperature  
Switch-on  
differential  
(Setting value of parameter  
04 + 3 K) to 20 K  
Switch-off  
differential  
2 K to (setting value of parameter 5  
03 – 3 K)  
Heat generator  
cycle inhibitor  
OFF, 2 to 180 min  
OFF  
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Operation  
SDC / DHC  
5.4.11 "Buffer" menu (BUFFER)  
The parameters in this menu refer to special settings with regard  
to solids regulation.  
Enabling occurs only with corresponding activation in the  
"Hydraulics" menu.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
03  
04  
05  
Minimum  
5 °C to setting value of parameter 20  
02  
temperature  
Maximum  
Setting value of parameter  
01 to 95 °C  
80  
temperature  
Boiler temperature –10 to 80 K  
increase  
0
Buffer switching  
differential  
1 to 70 K  
2
Forced discharge  
OFF  
OFF  
1
2
In process water tank  
In heating circuits  
06  
07  
08  
Follow-up switch-  
on differential  
OFF, (setting value of parameter 10  
07 + 2 K) to 50 K  
Follow-up switch-  
off differential  
1 K to (setting value of parameter 5  
06 – 2 K)  
Buffer start-up  
protection  
OFF  
No start-up  
protection  
ON  
ON  
Start-up protection  
active  
09  
Buffer discharge  
protection  
OFF  
ON  
No discharge  
protection  
ON  
Discharge protection  
active  
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Operation  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
10  
Buffer operating  
mode  
1
2
Heating circuit  
1
charge regulation  
and hot-water circuit  
Heating circuit  
charge regulation  
without hot-water  
circuit  
3
4
Heating circuit and  
hot-water circuit  
discharge regulation  
Heating circuit  
discharge regulation  
without hot-water  
circuit  
5
Charge regulation  
with hot-water circuit  
switchover  
6
Discharge regulation  
for heat generator  
11  
Follow-up time of  
buffer charging  
pump  
0 ... 60 min  
3
5.4.12 "Total flow regulation" menu (MAIN SUPPLY)  
The parameters in this module refer to special settings with regard  
to total flow regulation.  
This selection is only available if a total flow sensor is configured  
on one of the variable inputs (see the "Hydraulics" menu,  
parameters 08, 09 or 10).  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
03  
Regulation  
Regulation  
0 ... 50 %/K  
1 ... 600 s  
5
180  
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SDC / DHC  
5.4.13 "Cascading" menu (CASCADE)  
The parameters in this menu refer solely to the parameters that  
are associated with the cascading of multiple heat generators.  
This selection is only available if multiple heat generators exist in  
the control system.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
Switching  
differential  
0.5... 30 K  
8
02  
03  
04  
Connection delay  
Switch-off delay  
0 ... 200 min  
0 ... 60 min  
0
0
Switchover power 10 ... 100 %  
of stage sequence  
65  
05  
06  
07  
Stage reversal  
Guidance stage  
Peak-load stage  
OFF, 1 to 250 h  
OFF  
1
1 ... maximum number of stages  
OFF, 2 ... maximum number of  
stages  
OFF  
All heat generators are numbered  
consecutively within the cascade.  
The total quantity determines the  
maximum number of stages.  
08  
09  
Switchover of base OFF, ON  
load with grouping  
OFF  
OFF  
Quick hot-water  
connection  
OFF, 1 ... maximum number of  
stages  
110  
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Operation  
5.4.14 "Data bus" menu (BUS)  
The parameters in this menu refer solely to the parameters that  
are associated with the data bus.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
Central device  
address  
10, 20, 30, 40, 50  
10  
02  
Bus authorisation  
SDW 30 of direct  
heating circuit  
1
2
1
2
1
2
Expanded access  
authorisation  
1
Simple access  
authorisation  
03  
04  
Bus authorisation  
SDW 30 of mixed  
heating circuit 1  
Expanded access  
authorisation  
1
1
Simple access  
authorisation  
Bus authorisation  
SDW 30 of mixed  
heating circuit 2  
Expanded access  
authorisation  
Simple access  
authorisation  
5.4.15 "Relay test" menu (RELAY TEST )  
In this menu, the relays contained within the central device can be  
selected via the input button and checked for operation.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
Heat generator test Different relay switching sequence –  
depending on the set heat  
generator  
02  
03  
Direct heating  
OFF-ON-OFF  
OFF  
OFF  
circuit pump test  
Mixed heating  
OFF-ON-OFF  
circuit pump 1 test  
04  
05  
Mixer motor 1 test STOP-OPEN-CLOS  
STOP  
OFF  
Mixed heating  
OFF-ON-OFF  
circuit pump 2 test  
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Operation  
SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
06  
07  
Mixer motor 2 test STOP-OPEN-CLOS  
STOP  
OFF  
Storage charging  
pump test  
OFF-ON-OFF  
OFF-ON-OFF  
OFF-ON-OFF  
08  
09  
10  
Variable output 1  
test  
OFF  
OFF  
Variable output 2  
test  
System  
Display of sensor value by  
pressing the input button  
5.4.16 "Error messages" menu (ALARM)  
Error messages that occur are displayed in this menu. The fault  
memory can hold max. 20 messages, which can be displayed  
individually.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
03  
04  
05  
...  
Error message 1  
Error message 2  
Error message 3  
Error message 4  
Error message 5  
Last error message  
"Display"  
"Display"  
"Display"  
"Display"  
"Display"  
Last error message but one  
Last error message but two  
Last error message but three  
Last error message but four  
20  
21*  
Error message 20 First error message  
"Display"  
Reset error  
messages  
SET by pressing the input button  
* OEM  
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Operation  
5.4.17 "Error messages 2" menu (ALARM 2)  
Only in conjunction with heat generator interface  
Error messages triggered by an automatic stoker are displayed in  
this menu. The fault memory can hold max. 20 messages, which  
can be displayed individually.  
For this purpose, parameter 28 in the "System parameters" menu  
must be set to ON.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
03  
04  
...  
Error message 1  
Error message 2  
Error message 3  
Error message 4  
Last error message  
"Display"  
"Display"  
"Display"  
"Display"  
Last error message but one  
Last error message but two  
Last error message but three  
20  
21*  
Error message 20 First error message  
"Display"  
Reset error  
messages  
SET by pressing the input button  
* OEM  
5.4.18 "Sensor calibration" menu (SENSOR ADJ.)  
In this menu, all sensors connected to the central device can be  
corrected by ±5 K based on the factory calibration value.  
Para-  
meter  
Designation  
Setting range / Setting values  
Factory  
setting  
Setting  
01  
02  
Outside sensor  
–5 ... +5 K  
–5 ... +5 K  
0
0
Heat generator  
sensor  
03  
04  
Hot-water sensor  
–5 ... +5 K  
–5 ... +5 K  
0
0
Flow sensor of  
mixed heating  
circuit 1  
05  
Flow sensor of  
mixed heating  
circuit 2  
–5 ... +5 K  
0
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SDC / DHC  
Para-  
meter  
Designation  
Setting range / Setting values  
–5 ... +5 K  
Factory  
setting  
Setting  
06  
07  
08  
09  
10  
11  
Collector flow  
sensor  
0
0
0
0
0
0
Buffer sensor of  
collector  
–5 ... +5 K  
Sensor of variable –5 ... +5 K  
input 1  
Sensor of variable –5 ... +5 K  
input 2  
Sensor of variable –5 ... +5 K  
input 3  
Room sensor SDW –5 ... +5 K  
10 of direct heating  
circuit  
12  
13  
Room sensor SDW –5 ... +5 K  
10 of mixed heating  
circuit 1  
0
0
Room sensor SDW –5 ... +5 K  
10 of mixed heating  
circuit 2  
6 Control Functions  
6.1 Variable adjustment of the hydraulic parameters (variable  
inputs and outputs)  
The hydraulic presetting of the inputs and outputs of the controller  
selected via the "Hydraulics" menu, Parameter 01 can be  
adjusted individually. The preset hydraulics parameters can be  
changed individually for this purpose.  
Thus hydraulics not covered by the automatic preconfiguration  
can also be implemented.  
ATTENTION  
The hydraulic parameters define the system. Changes can  
have far-reaching effects on the way the controller works.  
Parameter settings made elsewhere can be lost. Individual  
adjustments must therefore be made very carefully!  
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Control Functions  
Only those inputs and outputs that are actually present on the  
controller are available for setting in the "Hydraulics" menu.  
The function of the corresponding output is determined by the  
setting of the hydraulic parameter.  
Example:  
Parameter 05 defines the function assignment of the output for  
the direct heating circuit pump (DHCP). Ex works, this output is  
set to the corresponding setting for the direct heating circuit  
pump.  
If this output is assigned the "circulation pump" function, the direct  
heating circuit pump function is no longer available.  
A function can only be executed if the corresponding function is  
also available in the hydraulic system.  
Example:  
The parameters for setting the circulation pump are not  
accessible until the direct heating circuit pump output is assigned  
to the "circulation pump" function, for example.  
If a variable function requires an input value (sensor), then this  
sensor will be assigned to the matching variable input. This input  
can then no longer be changed manually.  
If individual settings were previously made for the associated  
input, they are overwritten and the corresponding functions are  
reset.  
Example:  
A second outside sensor is assigned to variable input 1. The  
"buffer loading pump" function is now assigned to variable output  
1. The variable input is now reset automatically (outside sensor 2  
no longer active). The buffer sensor is then assigned to it, as it is  
required for correction.  
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Control Functions  
SDC / DHC  
6.1.1 Connection and settings table  
Function  
Adjustable Inputs  
at output  
Comment  
Fixed  
Optional  
assign (VI 1/2)  
ment  
DHW loading  
SLP  
SF  
---  
---  
Fixed sensor input  
Direct heating circuit  
DKP, MK-1, ---  
controlled by weather MK-2  
conditions  
Mixed heating circuit  
controlled by weather  
conditions  
MK-1, MK-2 VF1,  
VF2  
---  
Fixed sensor input for respective  
mixed heating circuit  
Circulation pump  
Electric heating rod  
Constant control  
SLP, DKP, ---  
---  
---  
---  
---  
---  
VA1, VA2  
SLP, DKP, ---  
VA1, VA2  
DKP, MK-1, VF1,  
Sensor for connection to MK  
Sensor for connection to MK  
MK-2  
VF2  
Fixed-value control  
Boiler return control  
MK-1, MK-2 VF1,  
VF2  
MK-1, MK-2 VF1,  
VF2  
Bypass pump (..VV..) VA1, VA2  
---  
---  
---  
Charging pump  
DKP, VA1, ---  
VA2  
Boiler circuit pump 1  
Boiler circuit pump 2  
DKP, VA1, ---  
VA2  
---  
---  
---  
---  
DKP, VA1, ---  
VA2  
Global malfunction  
message  
DKP, VA1, ---  
VA2  
Timer  
DKP  
---  
Solar loading pump  
DKP, VA1, KVLF,  
KRLF  
(14)  
Return flow sensor option  
(SDC 8-21, SDC 9-21, VA2  
SDC 12-31,  
KSPF  
DHC 43-2)  
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Control Functions  
Function  
Adjustable Inputs  
Comment  
at output  
Fixed  
Optional  
assign (VI 1/2)  
ment  
Buffer loading pump  
(SDC 8-21, SDC 9-21,  
SDC 12-31,  
VA1, VA2  
VA1, VA2  
PF  
PF1 (19) Fixed assignment to VI if PLP is  
set to PF. Otherwise, PF1 can  
be adjusted at free VI (activation  
of buffer management)  
DHC 43-2)  
Solid-fuel loading  
pump  
FKF  
FPF (18) SFS in fixed assignment to  
corresponding VI; standard  
buffer sensor is KSPF; separate  
solid-fuel buffer tank sensor SFB  
can be configured (optional)  
Stratified tank loading VA1, VA2  
pump (DHC 43-2)  
SSLP  
SLVF  
---  
Solar loading valve  
VA1, VA2  
----  
SLVS in DHW storage; KSPF in  
buffer  
Solar forced  
VA1, VA2  
dissipation valve  
6.2 Switching time program enabling  
The modular Smile SDC/DHC 43 series of controllers features  
three switching time programs for each heating circuit that can be  
set separately.  
When supplied, only one switching time program is enabled. The  
use of only a single switching time program for a wide range of  
applications makes it possible to simplify operation.  
See also 5.2.3.2 Time program, Pg. 73  
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Control Functions  
SDC / DHC  
6.3 Suppressing the cycle temperature on time program level  
When programming switching times, the specialist can set a  
system parameter to suppress the respective room or DHW  
temperature for the cycle.  
Function Setting "ON" causes control of the respective circuit to be based  
on the cycle temperatures stored in the switching cycles.  
For the "OFF" setting:  
All cycle temperatures are suppressed during switching time  
programming  
Nominal room and DHW temperatures arise exclusively  
depending on daytime room temperature or daytime water  
heater temperature specification  
All connected wall devices react identically to parameter  
changes in the central device  
6.4 Enabling "Separate Control Mode"  
To make operation as easy as possible for most of the  
applications, a global control mode is set for all heating circuits  
when supplied. For those rare cases in which a separate control  
mode is necessary (e.g. for renters and landlords), it must be  
enabled in the "System Parameters" menu, Control Mode  
parameter.  
Function This parameter determines the operating mode and affects the  
control mode selected with the "Control Mode" key  
daytime temperature selected with the "Daytime Room  
Temperature" key  
night-time temperature selected with the "Night-Time Room  
Temperature" key  
Enabling 5.2.3.3 Operating mode, Pg. 74  
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Control Functions  
6.5 Switching from SDC to DHC  
Language selection occurs after the controller is started. You can  
then select the controller type:  
SDC (heating controller)  
or  
DHC (district heating controller)  
"SDC - DHC" appears on the top line. The selection option "SDC"  
or "DHC" appears at the bottom right. The controller type depends  
on the relay equipment or the set type/max code.  
Switching is only possible with relay equipment for which DHC  
types exist. This is not the case with any others.  
Switching the setting is also possible via a special system  
parameter.  
The type code setting is identical for both versions, i.e. the type  
code numbers of SDC equipment correspond to those of DHC  
equipment.  
Reducing a controller to a heating circuit expansion via type code  
(21 or 22) functions only with a presetting to controller type SDC.  
6.6 Selection of hydraulic parameter presettings  
Each controller type covers a specific hydraulic diagram in its "as  
supplied" condition. Depending on the configuration variants there  
is also the possibility of adapting the system by means of further  
parameter settings to hydraulic diagrams differing from the  
standard hydraulic system.  
With parameter 01 in the "Hydraulics" menu a preselection can be  
made from the hydraulic schemes collection. The corresponding  
inputs and outputs are assigned automatically according to the  
hydraulic diagram and can be altered if necessary. The  
associated system schematics are available in the hydraulic  
schemes collection.  
See also 5.4 Parameter settings, Pg. 81  
6.7 The variable inputs and outputs of device series SDC/DHC 43  
Variable inputs The selected functions can be assigned only once and are then  
no longer callable in other variable inputs. If an input function is  
absolutely necessary for a corresponding output function with  
regard to the variable outputs, no selection is possible.  
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Control Functions  
SDC / DHC  
6.8 General functions and their operation  
6.8.1 Outside temperature sensing  
6.8.1.1 Building type  
Function This parameter takes into account the relevant building type by  
means of various calculation methods for the determination of the  
outside temperature mean value according to the setting.  
Light construction The mean value is obtained over a period of 2 hours.  
Application:  
Wooden houses, lightweight brick buildings  
Medium construction The mean value is obtained over a period of 8 hours.  
Application:  
Medium-weight masonry in hollow blocks or bricks  
Heavy construction The mean value is obtained over a period of 24 hours.  
Application:  
Heavy masonry in tuff or natural stone  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92 and  
5.2.5 "Direct Heating Circuit" / "Mixed Heating Circuit 1" / "Mixed  
Heating Circuit 2" menu, Pg. 78  
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Control Functions  
6.8.2 Heating circuit outside temperature assignment  
NOTE Function active only when using a second outside sensor!  
Function If in the central device a second outdoor sensor (AF2) was  
connected to a variable input and registered, the heating circuit  
can be assigned either to the outside sensor 1, 2 or to the mean  
value of both sensors.  
For each outside sensor the following applies:  
In case of a defect affecting a sensor, switching to the remaining  
outside sensor with simultaneous fault indication occurs  
automatically. In case of a defect affecting both sensor circuits the  
heating circuit is regulated on the basis of a set heating  
characteristic curve and heating program corresponding to a  
fictitious outside temperature of 0°C with regard to the set  
minimum temperature.  
See also 5.2.5 "Direct Heating Circuit" / "Mixed Heating Circuit 1" / "Mixed  
Heating Circuit 2" menu, Pg. 78  
6.8.3 Outside temperature emergency operation value  
Function If a connected outside sensor fails during weather condition-  
controlled operation (sensor short-circuit or interruption),  
emergency operation takes effect.  
Weather condition-based control then adjusts the temperature  
based on an assumed fixed outside temperature specified via a  
parameter value.  
Designation  
Key/Menu  
Parameter  
Characteristic curve for  
emergency operation without  
outside sensor  
SYSTEM  
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6.8.4 Outside temperature disable  
Function The purpose of outside temperature disable is to prevent the heat  
generator from starting up above a defined outside temperature.  
If several heat generators are controlled though one device  
(automatic stoker, 2-stage), all stages of the device will be  
disabled with outside temperature disable.  
In the case of cascaded systems with multiple devices, the entry  
of an outside temperature disable is possible for each central  
device so that individual levels can be blocked by the outside  
temperature disable.  
6.8.5 Climate zone  
Function The climate zone is the coldest outside temperature value to be  
expected.  
For the heat demand coverage, this value is taken as the basis for  
the design of the heating system.  
This parameter defines the corresponding slope value of the  
heating curve of the heating circuit with regard to the climate  
zone.  
See also 5.2.3 "System Parameters" menu, Pg. 72  
6.8.6 Design temperature  
Until now, configuration of the heating curve calculation occurred  
via the values  
Climate zone (TANorm  
Slope (S)  
)
Heating system (m value)  
Supplemental to the slope, the setting of the design temperature  
TVLNorm is also possible directly at the controller.  
Setting range DESIGN TEMP: Setting range HCmin to HCmax (°C)  
There is a direct relation between the HEATING CURVE and  
DESIGN TEMP parameters in the following connection:  
TVLNorm = (20°C TANorm ) * S + 20°C  
This means that the value of the respective other parameter  
changes accordingly.  
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Control Functions  
The display for the heating curve adjustment occurs in  
combination, i.e. the design temperature (bottom right) and the  
slope (bottom left) are displayed and set in one display. Both flash  
during adjustment.  
The parameter (display above) is still HEATING CURVE.  
The jump occurs via the "Direct Heating Circuit" or "Mixed Heating  
Circuit 1"/"Mixed Heating Circuit 2" menu and the heating curve  
parameter.  
6.8.7 Summer switch-off  
NOTE This function is only effective in control mode AUTOMATIC.  
Function For higher outside temperatures, normally above 20°C, it does not  
make sense to keep the heating on in the building. You can thus  
choose to switch-off heating depending on the outside  
temperature according to the following criteria:  
Outside temperature rise  
A switch-off is initiated when the mean outside temperature  
exceeds the set value.  
d
a
c
b
a Current outside temperature  
b Mean outside temperature  
c
Summer switch-off on  
Set value  
d
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Cancelling switch-off  
The switch-off is cancelled when the current outside temperature  
drops below the set value by more than 1 K  
The summer switch-off function is cancelled:  
in case of an outside sensor defect  
in case frost protection is active  
NOTE The HEATING LIMIT parameter can be used to assist the  
summer switch-off function. This function allows setting non-  
heating periods on warm days for each individual heating circuit.  
In connection with a second outside sensor, the current averaged  
outside temperature is accepted for summer deactivation if the  
average value of both sensors is specified during outside sensor  
assignment.  
Active summer deactivation is represented by a beach umbrella  
symbol in the basic display. In case of separate operation of the  
heating circuits ("System Parameters" menu, Control Mode  
parameter) the symbol is not displayed. If two outside sensors are  
connected and they were assigned to different heating circuits,  
the symbol is furthermore only displayed if both sensors fulfil the  
condition for summer de-activation.  
See also 5.2.3 "System Parameters" menu, Pg. 72  
6.8.8 System frost protection  
Function To avoid the freezing of the heating system in switch-off mode,  
the controller is equipped with electronic frost protection.  
Operation without room temperature sensing  
If the outside temperature (current value) drops below the set  
limit, heating is turned on again. Heating is interrupted if the  
outside temperature exceeds the set limit by 1 K.  
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Control Functions  
Operation with room temperature sensing  
As long as the room temperature is above the set room setpoint,  
the heating circuit pumps are running if outside temperatures are  
below the set freezing limit.  
If the room temperature drops below the set room setpoint,  
heating is resumed.  
Switch-off occurs again when the room temperature exceeds the  
set room setpoint by 1 K. If at this moment the outside  
temperature is still below the set freezing limit, only the heating  
circuit pumps remain active.  
NOTE If not every heating circuit is operated with room temperature  
sensing, different frost protection functions can be assigned to the  
individual heating circuits. If, for example, a mixed heating circuit  
is operated with room temperature sensing and the direct heating  
circuit is not, the latter's heating curve and room temperature  
setpoint are to be set as low as possible.  
In connection with a second outside sensor, the frost protection  
function is activated as soon as one of the two outside  
temperatures drops below the frost protection limit. In case of a  
faulty outside sensor, frost protection is activated continuously.  
ATTENTION  
In connection with a room sensor, the thermostat function is  
not active with active frost protection.  
See also 5.2.3 "System Parameters" menu, Pg. 72  
Cycle operation  
The frost protection function is activated as soon as the  
temperature drops below the set frost protection limit ("System  
Parameters" menu, parameter 05). The frost protection function  
becomes effective when frost protection is active and there is no  
demand by the heating circuit.  
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With the frost protection setting "cycle operation", there is no  
continuous demand for the heat generator, in contrast to  
continuous operation.  
With system frost protection active, the heating circuit pumps  
are switched on and the mixed heating circuit valves are  
closed.  
As long as the measured flow temperature of the mixed  
heating circuits or the heat generator temperature in the direct  
heating circuit, respectively, does not drop below the current  
setpoint room temperature (RTFrost or RTNight), no demand  
value is forwarded to the heat generator.  
When the flow temperature drops below the current setpoint  
room temperature, heating is activated.  
Once the setpoint flow temperature has reached the setpoint  
room temperature and the set time ("System Parameters"  
menu, parameter 19) has passed, the demand value to the  
heat generator is retracted and the mixed heating circuit valve  
closes while the pumps continue running.  
If no data are detected from the outside sensor (e.g. because  
the sensor is defective), only the pumps are switched on while  
heating is disabled.  
The set minimum and maximum limits are taken into account  
while heating.  
When the heat generator is activated, the set start-up  
protection conditions of the heat generator are applied. This  
can mean that the heating circuit pumps are switched off  
temporarily.  
Frost protection function in case of heat generator fault  
If system malfunction message 30-3 or 31-3 occurs (e.g. switch-  
on failure of the burner(s) due to fuel shortage or burner  
malfunction), priority pump switch-off functions such as boiler  
start-up protection, DHW priority etc. are disabled if frost  
protection is active.  
The heating water circulated in the heating circuits adopts the  
overall mean room temperature and reduces or delays any  
freezing.  
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Control Functions  
6.8.9 Pump forced operation  
Function With this function activated, all the pumps are switched on every  
day for approx. 20 seconds to protect against blocking owing to  
corrosion in case of long switch-off periods (> 24 h) and the mixed  
heating circuit is opened temporarily during this period.  
See also 5.2.3 "System Parameters" menu, Pg. 72  
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7 Hydraulic Components  
7.1 Heat generator: Boiler  
7.1.1 Heat generator start-up protection  
The start-up protection function prevents condensate building up  
when heating up while cold.  
Function There are three different modes of start-up protection that can be  
set:  
Unlimited start-up protection  
When the temperature in the heat generator drops to 2 K below  
the set minimal limit, all heating circuits are separated, at the  
water side, from the heat generator (pumps = off, mixed heating  
circuit = closed) to pass through the dew point as quickly as  
possible. The heating circuits are enabled as soon as the  
temperature in the heat generator has reached the minimum limit  
plus half of the burner switching differential 1.  
Start-up protection controlled by weather conditions  
The heating-up characteristic is the same as for unlimited start-up  
protection, meaning the heat generator remains in operation until  
the set minimum temperature plus half of burner switching  
differential 1 is exceeded. Below the minimum temperature, the  
pumps remain switched off and the mixed heating circuit closed.  
Once the heat generator has been switched off, the start-up  
protection becomes active again only when the heat generator  
temperature drops below the weather-responsive demand value  
(acc. to heating curve setting and nominal room setting). The  
subsequent heating-up follows the same scheme as for unlimited  
start-up protection. The result is a mean value based on the  
difference between the weather condition-controlled demand  
value and the minimum limit setting. This mean value will be  
significantly lower than the value set for a heat generator  
operated with a permanent minimum temperature limit.  
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Separate start-up protection for heat generator and heating  
circuits  
This function allows separation of the temperatures for switching  
on the burner and switching off the heating circuit when the boiler  
temperature falls below the boiler minimum temperature limit.  
See also 5.2.4 "DHW" menu, pg. 77  
7.1.2 Heat generator minimum temperature limit  
To protect the heat generator from condensation formation, the  
minimum temperature limit specified by the heat generator  
manufacturer is to be set.  
Function  
The heat generator switches on when the temperature falls below  
the set value, while it switches off when the set value plus the  
burner switching differential is exceeded. During heating, the set  
limit value is not undershot.  
The setting of this parameter is used solely for the response of  
the heat generator (burner) to the set minimum temperature  
( KTminWEZ ). The function for the heat generator remains  
unchanged.  
The mode of operation of the set limit is defined via the "Heat  
Generator" menu, heat generator start-up protection parameter.  
There are three different modes of operation for the minimum  
temperature limit:  
Minimum limit based on demand  
As long as there is no demand from heating or hot water, the  
boiler remains switched off. The minimum limit is disabled. The  
burner is switched on and the heat generator is heated up to the  
set minimum temperature limit as soon as the temperature in the  
heat generator drops below the fixed heat generator frost  
protection temperature of +5°C.  
Conditional minimum limit  
The boiler minimum temperature acts as the lower limit, which will  
be maintained even if there is no demand. The boiler is switched  
off only if summer switch-off is active.  
Unlimited minimum limit  
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The boiler temperature is maintained according to the set  
minimum temperature, independent of demands or deactivating  
control modes.  
See also 5.2.4 "DHW" menu, pg. 77  
7.1.3 Maximum temperature limit heat generator  
In order to protect the heat generator against overheating, the  
controller is equipped with an electronic maximum temperature  
limit. It shuts off the burner if the temperature in the heat  
generator exceeds the limit value.  
Function  
The burner is switched on again if the temperature in the heat  
generator falls below the limit value by half of the burner switching  
differential plus 2 K.  
See also 5.2.4 "DHW" menu, pg. 77  
7.1.4 Heating circuits minimum temperature limit  
If the boiler temperature BTactual is less than or equal to the  
parameter setting 27 (BTmin - HC), the heating circuit pumps  
switch off (DHCP, SFP, MCP). The mixed heating circuit  
valves close.  
If BTactual is greater than BTmin - HC + SCmin - HC, the heating  
circuit pumps and mixed heating circuit valves are enabled  
again.  
7.1.5 Heat generator sensor control mode  
Function There are various ways in which the heat generator can react to a  
malfunction of the heat generator sensor:  
Burner switch-off in case of a faulty heat generator sensor  
A fault message appears in case of a short-circuit or interruption  
of the sensor; the burner will be switched off.  
External burner switch-off  
In case of the interruption of the sensor the burner is switched off  
without a fault message. It is used, for example, for external  
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burner switch-off or enabling in case of the interruption of the heat  
generator sensor.  
ATTENTION  
Only Ag (hard silver), Au (gold) or Ni (nickel) are to be used  
for the contacts.  
In case of a sensor short-circuit a relevant fault message appears  
and the burner is blocked.  
Burner enabling in case of a faulty heat generator sensor  
In case of a sensor short-circuit or interruption, a fault message  
appears upon simultaneous unlimited enabling of the burner.  
The control of the heat generator is carried out only manually by  
means of the mechanical boiler temperature controller (boiler  
thermostat) on the boiler panel according to the set value.  
ATTENTION  
Activation of this setting is only permissible if an  
electromagnetic boiler temperature controller is connected in  
series with the burner phase and the boiler temperature is  
thus limited by this boiler temperature controller. Otherwise,  
there is the danger of boiler overheating.  
See also 5.4.6 "Heat generator" menu (HEAT GENER., pg. 99  
7.1.6 Minimum burner runtime  
This function extends the burner runtimes and reduces the  
standby losses. After starting the burner, a minimum of the set  
time must elapse before the burner is deactivated again  
(regardless of the temperature increase).  
Function  
NOTE  
If the temperature in the heat generator exceeds the set heat  
generator maximum temperature limit, the minimum burner run  
time is stopped and the burner is switched off in advance.  
See also 5.4.6 "Heat generator" menu (HEAT GENER., pg. 99  
7.1.7 Switching: Multi-stage heat generator/Switching differential  
The control unit offers independently adjustable switching  
differentials with reference to the same setpoint.  
Function  
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Switching differential I Switching differential I controls the heat generator capacity  
required according to load and demand by switching on and off  
the stage required for the actual heat demand within the set  
range. Switching on and off is initiated symmetrically to the  
setpoint within half of the absolute value of the switching  
differential.  
Switching differential II Switching differential II (only two-stage heat generator and heat  
generator 2 x single stage) determines how many stages are  
required to meet the actual heat demand (partial load - stage I, full  
load - stage II). This switching differential is overlaid symmetrically  
on switching differential I and must always be set to higher  
values.  
In cascade mode, this setting would be superseded by the  
cascade setting and is therefore not available.  
NOTE  
Mode of operation with switching differential II  
When the heat generator temperature is below switching  
differential II, stage I is switched on without delay. Stage II is  
enabled after stage II delay has passed (see "Heat Generator"  
menu).  
Stage II is switched off as soon as the heat generator reaches  
the setpoint temperature plus half of switching differential I.  
Stage II is switched on again as soon as the heat generator  
undershoots the setpoint temperature minus half of switching  
differential I.  
Stage I is switched off when the heat generator temperature  
exceeds the set nominal value plus half of switching  
differential II.  
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Combined operation for 2-stage heat generators  
As long as just one stage can meet the heat demand (stage II  
inactive), stage I is switched according to switching  
differential I.  
As soon as stage 2 is needed to meet the heat demand,  
switching differential I takes over the switching on and off of  
stage II and switching differential II takes over the switching of  
stage I.  
e
b
a
e
a
b
a
b
x
s
3)  
1)  
i
2)  
i
c
d
c
d
d
c
i
f
h
g
i
y
a
b
c
Switch-off level stage I  
Switch-off level stage II  
Switch-on level stage II  
g Area 1 high use (start-up),  
coverage of heating demand at  
full load (burner stages I and II)  
h Area 2 low use, coverage of  
heat demand with partial load  
(burner stage I only)  
i
Area 3 increased use,  
coverage of heating demand at  
full load (both burner stages)  
d
e
Switch-on level stage I  
Swap of switching  
differential  
x Boiler temperature  
y Time  
f
Theoretical progression  
with stage I alone  
1) Temperature drop becomes slower after every switch-off of  
stage II, as stage I provides support.  
2) Switch-on level stage II is no longer reached, temperature is  
reached from stage I.  
3) Temperature drops due to increased heat demand under  
switch-on level stage II.  
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Time delay stage II Enabling of stage II (full load stage) is controlled not only by the  
switching differentials but also by a time delay. In this way, stage  
II remains disabled for the set delay so that stage I will be active  
longer. This function is only effective during the start-up phase  
(when there is demand for both stages). When stage I is in base-  
load operation and stage II in adjustment operation (covering  
excess heat demand), the latter is switched on immediately when  
the demand arises.  
In cascade mode, this setting would be superseded by the  
cascade setting and is therefore not available.  
NOTE  
Enabling mode stage II The parameter "Enabling mode full-load stage" allows changing  
the effect of a time delay stage II setting during the start-up  
phase below the heat generator minimum temperature limit.  
Unlimited enable during start-up relief  
Both stages are in unlimited operating during start-up.  
Time-out during start-up relief  
Stage II is switched on after the set time delay acc. to time delay  
stage II:  
In cascade mode, this setting would be superseded by the  
cascade setting and is therefore not available.  
NOTE  
Hot-water The function "hot-water loading mode stage 1-2" allows defining  
loading mode  
of the loading mode for the hot-water heater with 2-stage or 2 x  
single-stage heat generators. The following options are available:  
stage II  
2-stage hot-water circuit loading with delayed enabling of  
stage II acc. to time delay stage II  
Unlimited 2-stage hot-water circuit loading  
Hot-water loading with stage I only; stage II disabled  
In cascade mode, this setting would be superseded by the  
cascade setting and is therefore not available.  
NOTE  
See also 5.4.6 "Heat generator" menu (HEAT GENER., pg. 99  
When the actual outside temperature exceeds the set limit, all  
demand on the heat generator is disabled within a device. The  
heating circuits continue operating, but the heat generator will not  
be switched on. The preset minimum burner running times are  
Outside temperature  
disable  
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fulfilled. Only when the outside temperature drops to the outside  
temperature disable level minus 2 K is the heat generator enabled  
again. If several heat generators are controlled though one device  
(condensing burners, 2-stage burners), all stages of the device  
will be disabled.  
If a fault occurs at a heat generator, all outside temperature  
disables in the system are cancelled.  
NOTE  
Base load offset This setting becomes effective only if several heat generators are  
operated in cascade mode.  
Burner stages operating as base load are given a higher setpoint  
temperature than the modulating stage, which is switched on last.  
This higher value is composed of the current setpoint temperature  
plus the set base load offset. If several heat generators are  
switched though one control device, the setting applies to every  
heat generator.  
Heat generator reset With 2-stage heat generators, the counters for operating hours  
and burner starts (see Parameter settings 5.4, pg. 81) can be  
reset separately for stage 1 (ST-1) and stage 2 (ST-2).  
Resetting  
With the reset indicator flashing (RESET), the reset-ready  
indicator (SET) will flash when the input button is pressed briefly.  
A reset will be performed when the input button is pressed for  
approx. 5 seconds.  
After the parameter values are reset, a return to the first  
parameter in the "Heat Generator" menu occurs.  
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7.1.8 Operation for modulating burners  
Modulating burners are controlled in a way similar to mixed  
heating circuit control, through a PI control algorithm, since in this  
case an actuator integrated in the burner regulates the air/fuel  
ratio according to the heating power. However, in contrast to the  
control of conventional burners, operation of modulating burners  
is subject to the following criteria:  
In contrast to conventional ON/OFF burner control systems with  
their switching differentials symmetrical around the respective  
setpoint temperature, the switching differential for modulating  
burners is an asymmetric interval with the switch-on level always  
1 K below the setpoint temperature. This offers the advantage  
that, in case of another possible overshoot through the P part, the  
burner is not switched off, because the switch-off point lies above  
the setpoint by a wider margin than the switch-on point is below  
the setpoint (overshoot reserve). Also, when the heat demand is  
low (especially in the low-load area) the temperature will drop only  
slightly since the burner is switched on again as soon as there is  
a deviation of more than 1 K.  
Switching differential  
Example:  
Set nominal temperature = 50 K  
Switching differential = 6 K  
Switch-on at (50°C - 1 K) = 49°C  
Switch-off at (49°C + 6 K) = 55°C  
x
a
y
b
a
b
Switch-off level  
Switch-on level  
x
y
Deviation (K)  
Setpoint value  
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Activation of The modulating burner stage is activated when the heat generator  
modulation  
temperature has dropped below the set nominal temperature by  
more than 1 K. The burner is enabled through the burner relay. As  
soon as the heat generator temperature crosses the switch-off  
level the burner is deactivated, in contrast to the mixed heating  
circuit parameters.  
Adjustment to the setpoint temperature is realised through the  
conventional 2-point output (activating the burner) and an  
additional 3-point output for modulating the actuator in the burner.  
The temperature is registered by the heat generator sensor. In  
contrast to mixed heating circuit control, no end position function  
is assigned to this actuator. The control algorithm is running  
continuously.  
Adjustment  
The burner remains in operation for the duration of the set  
minimum burner runtime irregardless of temperature-based  
switch-off conditions.  
Minimum burner run  
time  
If the heat generator maximum temperature is exceeded or the  
heat generator minimum temperature is undershot, the same  
functions apply as with conventional heat generators.  
Minimum and  
maximum  
temperature limit  
7.1.9 Modulation of P part (Xp)  
The proportional part Xp defines how a step change of the  
setpoint effects a change of the corresponding actuator according  
to the new setpoint.  
Function  
Example:  
With a max. heat generator temperature of 70°C, the actuator in  
the modulating burner must cover a temperature differential of 50  
K (starting from a room temperature of 20°C). This corresponds to  
a control deviation of 100%. The set value is calculated as  
follows:  
Xp (%)/K x 50 K = 100% or Xp = 2%/K  
7.1.10 Modulation of sample time Ta  
The sample time is a controller-internal quantity which defines the  
time interval between two subsequent actuator pulses in the  
presence of a control deviation. Shorter sample times allow finer  
adjustments.  
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7.1.11 Modulation of integral action time Tn  
The integral part (= adjustment time) determines the dynamic  
behaviour of the controller and thus the time required by the  
controller to adjust for the actual control deviation. The adjustment  
time is independent of the amount of deviation.  
7.1.12 Modulation of runtime  
This function allows adjusting the actuator, with regard to its finite  
running time, to the control characteristics, meaning that actuators  
with different runtimes react to the same deviation by readjusting  
by the same amount through adapting the action times. The  
integral action time Tn remains unchanged in this. However, care  
must be taken that the latter must always exceed the runtime of  
the respective actuator.  
7.1.13 Modulation of start time  
The start time parameter determines the length of the start-up  
phase in modulation mode so that a stable start-up is ensured. As  
soon as the set start time has expired, the modulation switches to  
its normal control characteristics defined by the modulation  
parameters.  
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7.1.14 Modulation of start power  
The start power parameter determines a percentage setting for  
part of the modulation runtime during the start-up phase. With a  
setting of 0% the actuator valve remains always closed. As soon  
as the set start time has expired, the modulation switches to its  
normal control characteristics defined by the modulation  
parameters.  
x
a
100%  
70%  
b
d
c
g
42 s  
60s  
90s  
t (s)  
t (s)  
f
e
a Modulation  
e
Base load  
On  
b Upward/downward modulation  
depending on the control deviation  
f
c Adjustment operation  
d Start-up phase  
g
x
Start  
Starting load (%)  
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7.1.15 OpenTherm  
• OpenTherm is the plug & play bus system!  
OpenTherm has developed into a standard in heating  
technology. Many gas condensing boilers today feature an  
OpenTherm connection or manufacturers offer an optional  
OpenTherm interface.  
The OpenTherm bus uses simple bi-directional 2-wire  
communication between the heat generator and the room  
controller.  
The simple OpenTherm 2-wire bus allows bi-directional  
communication between the room controller and heat generator,  
i.e. data exchange occurs in both directions.  
In use, the simplicity of the OpenTherm system is key.  
The boiler setpoint is transmitted from the SDC controller to the  
automatic stokers via OpenTherm, and feedback of the boiler  
actual value occurs from the automatic stokers (in addition to the  
hot-water actual and outside temperature and fault messages, if  
appropriate).  
Setting in the "Heat Generator" menu, parameter 1, setting 5  
(automatically detected when a heat exchanger bus  
(OpenTherm) is connected (AUTOSET), however).  
If the OpenTherm function is active, the boiler minimum limit is  
automatically set to 5°C.  
To use the OpenTherm function, the boiler must have an  
OpenTherm logo.  
Electrical connection Terminals 37/38 on SDC  
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7.1.16 Use of boiler sensor 2  
Function Two single-stage heat generators  
For sensing of the temperature in the second heat generator with  
double boilers or two single-stage heat generators (see "Heat  
Generator" menu, parameter 1 boiler type = 3)  
Two measuring points in the combustion chamber  
In order to reduce standby losses by increasing the burner  
runtimes. With automatic sensor switching between boiler sensor  
1 and 2 after the burner switching cycle, the On signal for the  
burner will be determined by the upper sensor (BS1) and the Off  
signal by the lower sensor (BS2) based on the specified demand  
value and switching differential(s).  
7.1.17 External heat generator cut-off  
Function If the assigned variable input is short circuited, there will be a  
permanent deactivation of the heat generator. It is cancelled  
again once the short-circuit is remedied.  
ATTENTION  
This function is meant exclusively for external override  
signals and not for safety switch off!  
7.1.18 Heat generator forced discharge  
Function When the temperature in the heat generator exceeds the set  
maximum temperature limit, any excess energy is dissipated into  
circuits downstream. This function applies to all controllers on the  
bus system.  
Set values OFF  
No heat dissipation  
Dissipation into hot-water tank  
With provision tanks only  
ATTENTION  
Thermal mixing valve at water heater outlet obligatory  
because of scalding hazard.  
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Discharge to heating circuits  
Any excess heat is dissipated into the heating circuits. The set  
maximum temperature is not exceeded here. The intended room  
temperature may be exceeded for short periods. If the respective  
circuits are equipped with room stations, the thermostat function  
should be activated.  
ATTENTION  
For floor heating a contact thermostat must be installed to  
control forced switch-off of the pumps.  
Dissipation into buffer tank  
Any excess heat is dissipated into the buffer tank, without  
exceeding the set maximum temperature.  
7.1.19 Exhaust gas temperature monitoring  
NOTE Only if parameter 8 variable input 1 = 16 - Flue gas sensor set in the  
"Hydraulics" menu.  
A flue gas sensor can only be connected to the variable sensor  
input VI 1. Due to the high temperatures involved, a PT 1000  
sensor is used for this purpose. The control device automatically  
evaluates the sensor data, which are different from the data  
supplied by the standard sensors.  
When a sensor fault is detected with the flue gas sensor active,  
and if flue gas monitoring was set for temporary disable or  
permanent inhibit (safety functions), there will be a heat generator  
switch-off in addition to the malfunction message.  
Function This function controls the necessary measures in case the flue  
gas temperature exceeds the allowable limit.  
Display of flue gas temperature only  
No follow-up function; the actual flue gas temperature is displayed  
in the Information display.  
Heat generator lock if limit value is exceeded for set time  
When the temperature limit is exceeded the heat generator is  
disabled for the set time and a fault message is sent.  
Heat generator lock if limit value is exceeded  
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When the temperature limit is exceeded the heat generator is  
disabled and inhibited permanently. It can only be unlocked by a  
reset in the "Fault Messages" menu.  
Flue gas temperature With the parameter set accordingly, the allowable temperature  
limit limit for the flue gas, according to specifications of the heat  
generator manufacturer, has to be entered as the reference value  
for the follow-up functions described above.  
Recommended setting:  
Nominal flue gas temp. acc. to manufacturer data, plus 10 - 20 K  
See also 5.4.6 "Heat generator" menu (HEAT GENER., Pg. 99  
7.1.20 Burner counter mode  
The system features two operating hour and burner start-up  
counters (one each for the 1st and 2nd stages). The display is  
output on the information level of the counter.  
The function of the operating hour counter can be set via a  
parameter.  
OFF The operating hour counter is deactivated.  
AUTO If an operating hour counter is connected to the corresponding  
inputs of the controller (operating hour counter inputs), this value  
is called upon for counting.  
Otherwise, theoretical values are determined and included  
(switching times and switching frequency of the outputs).  
If a signal was detected once at the operating hour counter input  
and the operating hour counter signal does not follow the boiler  
demand, a fault message occurs.  
Feedback only Functions such as AUTO, however a theoretical value is not  
determined. Only signals from burners are processed.  
Free counter The operating hour counter input can be used as a free counting  
input. A fault message does not arise if a signal is missing.  
NOTE Since the counter values are only stored in the permanent data  
memory once per day, counter values of the current day could be  
lost in case of a power failure.  
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Returning The operating ours and start-ups can be reset separately for  
stage 1 and stage 2 via two parameters in the "Heat Generator"  
menu.  
7.2 Heat generation, heat exchanger, district heating  
Function The heat exchanger control assures that the right flow  
temperature is provided for all heating demands. The setpoint for  
the heat exchanger's secondary flow temperature is the maximum  
selection of all the required flow setpoints. An increase is to be  
entered under parameter 01.  
Para-  
meter  
Designation Range  
Presetti Step  
ng  
Unit  
01  
Increase  
–10 ... 50 0  
0,5  
K
The setpoint for the secondary flow temperature has a maximum  
limit through code 02.  
There is a fixed minimum limit of 10°C < 10°C, corresponding to  
the functionality of the return interval flushing.  
The parallel shift is valid only if there is a demand higher than  
15°C.  
Para-  
meter  
Designation Range  
Presetti Step  
ng  
Unit  
02  
Max. flow  
10 ... 130 90  
0.5  
°C  
temp. setpoint  
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7.2.1 On/Off operation of the district heating valve  
To always ensure a minimum flow so that the heat meter can  
work precisely, pure on/off switching is provided in low load mode.  
Code 03 is suitable for this function as shown in the following  
diagram.  
x
a
y
a
x
Minimum travel  
Valve travel  
y
Controller output  
Para-  
meter  
Designation Range Presetti Step  
ng  
Unit  
03  
Minimum  
travel  
0 ... 50 10  
1
%
Should the secondary flow temperature controller output fall  
below the settable minimum travel in % (code 03), two-step  
operation begins and the valve is closed. The valve remains  
closed until the internal controller output reaches 10% again. If a  
10% controller output is reached, the valve opens again to the  
minimum travel. If the controller output drops below 10% again,  
the valve closes again and the cycle starts from the beginning.  
This means that whenever there are demands of up to 10% on  
the heat generator the valve is operated in On/Off mode and the  
secondary flow temperature is controlled this way.  
7.2.2 Continuous heat exchanger valve control  
If the output of the secondary flow temperature controller rises  
above 10%, the PI controller controls the secondary flow  
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temperature according to the required setpoint within its limits.  
The "Proportional Range", "Adjustment Time" and "Motor  
Runtime" control parameters can be set in parameters 04 and 05.  
Para- Designation Range  
meter  
Presetti Step  
ng  
Unit  
04  
05  
S gain  
0,1 ... 30  
0 ... 60  
5
3
0.1  
1
%/K  
min  
Adjustment  
time  
0 = pure  
P controller  
06  
Runtime of  
district  
10 ... 1800 120  
1
s
heating valve  
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7.2.3 District heating return temperature limit  
Many district heating companies require min. volume flows in their  
networks. This can be achieved through a high temperature  
differential between the flow and return.  
a
b
Example 1 (factory setting) e Example 4  
Return temperature limit  
f
Starting points of the  
flexible return temperature  
limit in examples 3 and 4  
c
Example 2  
Example 3  
x
y
Return setpoint  
d
Outside temperature  
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By means of district heating return temperature limitation the  
required temperature difference is assured. The maximum limit  
can either be a fixed value limitation or a flexible limitation  
according to the outside temperature. A fixed value limit of e.g.  
50°C means that the district heating return temperature will not  
exceed this value over the entire outside temperature range.  
In case of higher outside temperatures it is desirable that the  
maximum limit can be reduced, i.e. flexible district heating return  
temperature limitation is to be adopted. Through the assignment  
to the respective outside temperature, the lowest possible district  
heating return temperature and thus good heat exploitation are  
obtained.  
The values for the maximum limitation of the district heating return  
temperature (code 08) and the starting point of the flexible district  
heating return temperature limitation (code 09) can be set for the  
operation with heating circuits. The flexible return temperature  
limitation can be switched off by selecting 10°C as the starting  
point.  
+40°C is set as the bottom return setpoint for the flexible return  
temperature limit.  
If the maximum limit is exceeded, a second Pl controller  
intervenes with the same parameters as in the secondary control  
(heating temperature control).  
Return temperature limit Starting point of the flexible  
return temperature limitation  
Example 1: 90°C  
Example 2: 50°C  
Example 3: 80°C  
Example 4: 50°C  
10°C Factory setting  
10°C Fixed value limit  
5°C  
–10°C  
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Besides return temperature limitation either volume flow limit or  
thermal output limit can also be set for this controller. The  
selection of these functions is described below in parameter 11.  
Para- Designation  
meter  
Range  
Pre-  
Step  
Unit  
setting  
08  
Max. return  
setpoint  
0 ... 100 90  
0.5  
°C  
09  
Starting point  
of the flexible  
district heating  
return  
Off  
Off  
0.5  
°C  
–40...+10  
temperature  
11  
Return limit  
0 / 1 / 2  
0
-
-
0 =  
Temperature  
1 = Volume  
flow and  
temperature  
2 = Heat output  
and  
temperature  
7.2.4 Return temperature limit for hot-water loading  
In the case of hot-water loading a special constant return setpoint  
applies. It is valid only if the hot-water loading pump is operating.  
The return setpoint is to be set with parameter 10.  
Para- Designation  
meter  
Range  
Presetti Step  
ng  
Unit  
10  
Hot-water  
40 ... 100 90  
0.5  
°C  
circuit loading:  
Target return  
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7.2.5 Hot-water pre-regulator with district heating systems  
The hot-water pre-control function is necessary for the controlled  
filling of hot water storage tanks with layered loading from the  
district heating network. Generally, such loading is carried out  
through a separate heat exchanger.  
The function is activated via a new setting in the "Hydraulics"  
menu, parameters 03 and 04.  
Function number: 30  
In the parameter tree for the heating circuits, parameters 14, 15,  
18, 19, 20, 21 and 22 are available. With the return flow limit  
activated, parameter 17 is displayed, too.  
Display With the FLOW display, the symbol WW for hot-water pre-mixing  
is displayed to the lower left.  
When the pump status is displayed, the string DEMAND is  
displayed instead of the control mode.  
When the hot-water pre-control is active, the respective mixed  
heating circuit cannot be used as a heating circuit anymore.  
When the hot-water pre-control is active, the request for hot-water  
loading is not sent directly to the energy management unit (and  
further to the district heating valve), but instead to the hot-water  
pre-control.  
The hot-water pre-control forwards the setpoint, taking into  
account the parameter-defined offset, to energy management and  
adjusts to the nominal value, which was received from hot-water  
loading, at the mixed heating circuit actuator.  
Any parameter-defined return flow limiter sensor (setting 7/8 at  
the variable input) acts according to its set function on the  
actuator of the hot-water pre-control.  
The switching behaviour of the tank loading pump is described in  
a separate demand.  
The hot-water pre-control must be activated in the same control  
device as the associated hot-water loading.  
The mixed heating circuit minimum and maximum limits are not  
adjustable and have no effect.  
The run-down time of the mixed heating circuit pump runs parallel  
with the tank loading pump extended running time.  
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The boiler parallel shift of the tank loading pump (parameter) acts  
on the mixed heating circuit demand.  
The boiler parallel shift of mixed heating circuits acts on the heat  
generator, provided the tank loading pump control mode has not  
been set to "external storage tank".  
The optional return flow limit acts on the flow mixture according to  
the setting.  
The hot-water pre-control acts only on hot-water loading  
configured in the same device.  
7.2.6 Mode of operation: Hot-water pre-control  
When operating in combination with hot-water pre-control,  
parameter 08 (tank drainage protection) does not act directly on  
the heat generator, but on the hot-water pre-control.  
Parameter 08 is always adjustable for function with pre-mixer.  
Here, the "OFF" and "ON" settings have different effects, which  
are described in the following.  
Function With the setting "OFF", there will be no start-up protection through  
the hot-water pre-control. The tank loading pump is switched on  
without any delay.  
With the setting "ON", the tank loading pump is switched on only  
when the flow sensor detects that the hot-water setpoint  
temperature + ½ switching difference hot water (without offset) is  
reached:  
HWPCsetpoint =WHsetpoint + P09(HW)  
1
SLP = ON if HWPCactual HWsetpoin t + SDHW  
2
SLP = OFF if HWPCactual HWsetpoint  
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Legend:  
HWPCsetpoint = Actual temperature at flow sensor "hot-water pre-  
control"  
HWsetpoint = Hot-water setpoint temperature  
P09(HW ) = Value of parameter 09 (hot-water loading temperature  
offset)  
SDHW = Switching difference hot water  
Both pumps (tank loading pump and hot-water pre-control) switch  
off after completion of a hot-water circuit loading, taking into  
account their extended running times. If they are to switch off  
simultaneously, identical extended running times must be  
selected for them.  
7.2.7 Quick hot-water control  
For monetary reasons, hot-water tanks are not used in many  
district heating systems, especially in Eastern Europe. The hot-  
water setpoint temperature is held in a closed loop pipeline here  
(see hydraulic example).  
SF  
a
b
SLP  
MK  
VF  
a Flow from closed loop  
pipeline  
b
Draw-off points  
New parameters Minimum spread between the tank sensor and the return  
sensor from which an offset at the valve is given (see "Mixed  
Heating Circuit 1"/"Mixed Heating Circuit 2" menu, parameter  
39)  
Additional value for offset in %/K deviation (valve staring point  
for controller) (see "Mixed Heating Circuit 1"/"Mixed Heating  
Circuit 2" menu, parameter 40)  
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Activation Set "quick hot-water control" in the "Hydraulics" menu,  
parameters 03 and 04 (MC-1/MC-2), set value 39.  
The tank loading pump is operated via the tank loading pump  
output on the controller. The mixed heating circuit pump output  
switches together with the tank loading pump.  
The OPEN and CLOSED outputs of the assigned mixed heating  
circuit are provided fixed to actuator operation.  
The mixed heating circuit 1 flow sensor is automatically assigned  
as a return sensor.  
The mixed heating circuit pump runs continuously except in the  
STANDBY and HOLIDAY control modes.  
With quick hot-water control, parallel operation is generally  
dominant.  
The control valve is operated via two relay outputs. The valve  
continually adjusts the hot-water setpoint temperature at the  
strap-on flow sensor (no hysteresis).  
The cycle time of the control unit must be less than or equal to 3  
sec. Normally, a mixed valve with a runtime of 30 to 60 sec. is  
used.  
Opening offset Attach a return sensor so that the mixing valve responds to the  
varying draw-off behaviour. A conclusion is made based on the  
quantity drawn off via the temperature differential, and the valve is  
charged proportionally accordingly.  
If the temperature spread between the tank sensor and the return  
sensor is greater than the set minimum spread, you can assume  
that water is being drawn off. In this case, give the valve an offset  
that anticipates down times and thus prevents heavy cycling of  
the mixing valve.  
The value to be added is dynamic and is yielded from the  
temperature differential and the set parameter value (% based on  
K deviation).  
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Set value Offset 0 - 100%  
Default value 0%: Represents the valve start-up value (degree  
of opening) in %. It functions as an offset to the current valve  
position (0% means no accessing of the valve)  
DTmin: 2 … 20 K, factory value: 5 K  
In case of a defect, the tank sensor or flow sensor switches off to  
prevent scalding.  
If hot-water loading is not activated, there is no setpoint for the  
mixed heating circuit. The setpoint for the mixed heating circuit is  
mandatory.  
7.2.8 Mode of operation of hot-water control mode "external  
operation"  
If the energy supply for hot-water loading is not provided through  
the district heating valve, no hot-water demand may be sent to the  
heat generator. The following setting needs to be selected for this  
case:  
"Hot Water Circuit" menu, parameter 07 ("Hot-Water Circuit"  
control mode) = 7 (external operation)  
Function The hot-water pre-control is part of the hot-water loading.  
Consequently, the request from storage control is forwarded to  
the hot-water pre-control, which acts according to its function.  
In the "Hot-Water Circuit" "External Operation" control mode, the  
setpoint value from the hot-water pre-control is not forwarded to  
the energy management unit (or the district heating valve).  
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7.2.9 Conditional parallel operation for mixed heating circuits  
This function is only realised for district heating controllers.  
Additional setting in the "Hot Water" menu, parameter 07 ("Hot  
Water Circuit" control mode) = 8 (priority with enabling of mixed  
heating circuit control operation)  
Function Function as for hot-water priority operation (setting 2), with the  
difference that mixed heating circuits (mixed heating circuit  
control, constant control, fixed-value control) can still adjust to  
their setpoint. During an active hot-water loading, the heating  
circuits do post a setpoint value to energy management. Mixed  
heating circuits must operate at the temperature required by the  
hot-water demand. Direct heating circuits remain switched off.  
Hot-water loading with priority operation in the system has priority.  
The mixed heating circuits must shut in this case.  
7.2.10 Circulation pump control mode  
During service water loading, it should be possible to switch off  
the circulation pump.  
Setting New parameter: "Hot Water Circuit" menu, parameter 16 =  
circulation pump.  
Access level HS (heating specialist)  
1
2
Function as before  
Function  
While hot-water loading is active, the circulation pump is  
switched off  
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7.2.11 Switch-off of district heating control  
Operation "District Heating" menu, parameter 01: Setting range is extended  
to OFF,  
–10 ... +50.  
Function Setting OFF means district heating is deactivated.  
District heating valve permanently in STOP position when  
deactivated.  
The switch-over of the heat generator is controlled from the  
"District Heating" menu, parameter 01.  
7.2.12 Return interval flushing  
If the return max. limit is active and the district heating valve is  
opened less than 5%, the district heating valve is opened to 10%  
every 10 minutes for heat demand, so as to obtain an adequately  
precise return temperature measurement. This assures that the  
limit sensor is adequately supplied in the return.  
7.2.13 Heat meter for additional limitation according to the volume  
flow or thermal output  
The requirement for this function is the heat meter, whose  
information (pulse per volume or pulse per thermal output) is  
called upon for this limit. Calibration of the thermal output and the  
volume flow with parameters 12 and 13 allows calculating the  
entities thermal output and volume flow. These values are  
displayed with the ¤key. Setpoint limits for thermal output and  
volume flow are entered under parameters 14 and 15.  
This limitation function operates as PI controller above the  
setpoint value, using the same parameters as the temperature  
control function.  
The values are independent of the outside temperature. The heat  
flow is derived from a volume signal in the following way:  
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The pulses for the amount of heat flowing through are counted,  
e.g. 5 pulses within a minute. Through calibration via parameter  
12, the actual thermal output in kW is calculated.  
7.2.14 Charging pump (CHP)  
NOTE This function is only active if the charging pump function was  
assigned to one of the outputs "direct heating circuit pump",  
"variable output 1"or "variable output 2" in the "Hydraulics" menu.  
Function A charging pump to supply remote parts of the heating system is  
active at every heating or hot-water demand to the heat  
generator. It can be connected, through variable settings, at one  
of the variable outputs or at the direct circuit pump output.  
Bus system A charging pump connected to the central device under address  
10 will run as soon as any demand is present on the data bus  
(including all heating and hot-water circuits within the control  
network).  
A charging pump connected to an extension controller (address  
20, 30 ... 50) runs only on demand from the heating circuit  
associated with the respective control device.  
Charging pump To avoid a high-temperature safety switch-off of the heat  
extended running time generator, a charging pump is switched off according to the set  
time delay when a request to the heat generator is withdrawn.  
See also 5.4.1 "Hydraulics" menu (HYDRAULIC), Pg. 81  
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7.2.15 Primary pump  
NOTE Function only active if the PRIMARY PUMP function was  
assigned to one of the outputs variable output 1 or variable output  
2 in the "Hydraulics" menu.  
Function The primary pump is the functional equivalent of a loading pump.  
It is only active when heating demand to the heat generator is  
present. Hot-water requests are not considered.  
Bus system A primary pump connected to the central device under address 10  
will start up as soon as any request is present on the data bus  
(including all heating and hot-water circuits within the control  
network).  
A primary pump connected to an extension controller (address 20,  
30 ... 50) runs only upon a demand from the heating circuits  
associated with the respective control device.  
Primary pump To avoid a high-temperature safety switch-off of the heat  
extended running time generator, the primary pump is switched off according to the set  
time delay when a request to the heat generator is withdrawn.  
7.2.16 Boiler circuit pump  
NOTE This function is only active if the BOILER CIRCUIT PUMP 1  
function was assigned to one of the outputs, i.e. direct heating  
circuit pump, variable output 1 or variable output 2, in the  
"Hydraulics" menu.  
Function This function is mainly used with multi-boiler systems with  
thermohydraulic distributors and is used for water-side cut-off of a  
heat generator not in use. The variable output controls a boiler  
circuit pump with a non-return valve with a faulty spring or a  
motorised shut-off device. The function becomes active  
immediately upon demand for the heat exchanger. The heat  
exchanger is not enabled until the set pre-running time expires.  
Once the heat generator switches off, the variable output remains  
active for the duration of the set extended running time.  
Boiler circuit pump 2 For systems with two individual boilers or a double boiler, two  
boiler circuit pumps can be connected. The second output then  
controls the boiler circuit pump of the downstream boiler.  
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Boiler circuit pump pre- The pre-running time determines the switch-on delay of the  
running time burner and thus the pre-running time of the respective shut-off  
device used (motor valve, motor throttle) to ensure trouble-free  
circulation within the heat generator when switching on the  
burner.  
The setting of a pre-running time is only relevant if a shut-off  
device (e.g. motor throttle) is used instead of a boiler circuit pump  
at a variable output. Actuators with reversible motors must be  
operated via an auxiliary relay with a switch-over contact  
(separate control phases Lopen/Lclosed).  
Boiler circuit pump When the burner switches off, a boiler circuit pump is switched off  
extended running time after a delay based on the set time to prevent a safety switch-off  
of the heat generator at high temperatures.  
The extended running time depends on the type of heat  
exchanger used and is to be adapted accordingly.  
NOTE An external heat generator disable affects the output of the boiler  
circuit pump.  
7.2.17 Return increase  
Function To prevent the return flow temperature from dropping below the  
minimum return temperature required by some heat generators,  
the control system features various options for raising the return  
temperature. Once one of these return control options is active, a  
menu is activated where the appropriate settings can be entered.  
The parameter minimum return limit determines the lowest  
allowable return flow temperature for systems with direct or  
indirect return control. When the heat generator return  
temperature drops below the set limit, the respective return  
control device is activated and raises the return temperature until  
the set temperature is reached or exceeded.  
See also 5.4.8 "Return increase" menu (RETURN CONTR), Pg. 105  
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7.2.17.1 Bypass pump (RBP)  
Function The simplest way of controlling the return flow temperature is by  
means of a bypass pump. When the return temperature in the  
heat generator drops below the set boiler return minimum  
temperature limit, flow mixing is initiated by switching on a bypass  
pump parallel to the heat generator. As soon as the return  
temperature rises above the return minimum temperature plus the  
return switching differential, the bypass pump will be deactivated  
after the set delay time (extended pump running time "bypass  
pump"). As the mixing itself is not controlled, the bypass cross  
sections must be taken into account for the system layout.  
When the switch-off condition is reached, the bypass pump is  
switched off with a time delay in accordance with the set value.  
NOTE To avoid intermittent operation of the bypass pump, the return  
sensor must always be positioned downstream of the mixing point  
for this mode of return temperature control.  
7.2.17.2 Return maintenance through controlled feed water addition  
Function If the control unit is equipped with a mixed heating circuit output,  
this output can be programmed for controlled flow mixing.  
In this mode of return control the programmed mixed heating  
circuit adjusts the return temperature to the return temperature  
setpoint. The adjustment is independent of the status of any start-  
up protection of the heat generator. The return sensor for this  
function is connected at the sensor input of the respective mixed  
heating circuit (e.g. flow sensor 1 for mixed heating circuit 1).  
The mixed heating circuit pump operates like a boiler circuit pump  
without boiler start-up protection for this purpose.  
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7.2.17.3 Indirect return increase  
Function Indirect return increase is realised by means of the mixed heating  
circuit valves in the heating circuits. It only works for systems  
without a bypass pump and without controlled flow mixing.  
When this function is active, two values are calculated  
independently for regulating each mixed heating circuit. The first  
value is the control variable for the flow setpoint of the heating  
circuit; the second is the control variable for the return setpoint.  
The control variable used for mixed heating circuit control (mixed  
heating circuit control variable) results from the superimposition of  
both values. In this the adjustment of the return temperature is  
treated with priority.  
Indirect return control is only active with mixed heating circuits  
that are in heating operation as well. It does not affect a heating  
circuit in reduced operation.  
To avoid excessive pulsing, we recommend enabling the  
connected consumers (heating and hot-water circuits) with  
staggered switch-on times.  
This function does not affect direct heating circuits.  
NOTE Indirect return control is only feasible for systems without bypass  
pumps and without controlled flow mixing.  
7.3 Heating circuit  
7.3.1 General heating circuit functions  
7.3.1.1 Heating curve  
The prerequisite for a constant room temperature is the exact  
setting of the heating curve of the relevant heating circuit as well  
as a correct design of the heating system on the part of the  
heating technician according to the heat demand calculation.  
If adjustments are necessary, they should be made in small steps  
at a distance of a few hours to assure that a steady condition is  
obtained.  
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Differences that can be balanced by installing a wall device (see  
available accessories) may occur between the measured room  
temperature in the inhabited area and the desired room  
temperature.  
7.3.1.2 Heating curve setting (heating curve)  
Press and hold the input button for 3 seconds to access the  
î
"Heating Curve" menu.  
x
y
a
The slope of the heating curve describes the relation between the  
change in the flow temperature and the change in the outside  
temperature. With a larger heating surface, such as with floor  
heaters, the heating curve has a less extreme slope than with a  
smaller heating surface (e.g. radiators).  
The set value refers to the lowest outside temperature used for  
heat demand calculation.  
This parameter is to be set by the technician and should not be  
altered anymore.  
The setting of the heating curve should be carried out only in  
small steps and at adequately long intervals so that a stable  
condition can be set. We recommended making any corrections in  
0.1 – 0.2 steps after 1 – 2 days.  
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ATTENTION  
To measure the room temperature, the heating circuit of the  
most occupied room is to be used. Radiator thermostat  
valves are used together with correctly designed radiators to  
control the external heat gain and should hence be almost  
completely open. During the adjustment phase additional  
external heat sources like fireplaces, majolica stoves, etc.  
should not be used. Furthermore, during the measurement  
period excessive ventilation is to be avoided to prevent  
external cold from interfering with the adjustment process.  
The measurement period covers basically the heating phases.  
If the heating curve is correctly set, the room temperature remains  
constant according to the set daytime setpoint regardless of the  
changes in the outside temperature.  
If an automatic correction of the heating curve (heating curve  
adaptation) is made at the service level, this parameter can no  
longer be manually set. Instead of the slope display the message  
HEATING CURVE starts to flash during the adjustment and is  
corrected continuously.  
Recommended settings:  
Floor heating:  
0.3 ... 1.0  
Radiator heating: 1.2 ... 2.0  
Convector heating: 1.5 ... 2.0  
NOTE The heating curves are limited by the minimum and maximum  
temperature limits in their valid range. The relevant flow  
temperature is controlled within the limit range exclusively  
according to the specified limit values.  
With the central device, the jump always occurs with the direct  
heating circuit (HC). In case of wall devices, the assigned heating  
circuit will be the first. If other heating circuits exist, their slope  
values can be selected with the relevant access authorisation and  
modified if necessary.  
Setting 5.1.2.10 Heating curve, pg. 47  
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7.3.1.3 Reduced operation  
See 5.2.5.1 Reduced operation, Pg. 79  
7.3.1.4 Heating system  
See 5.2.5.2 Heating system, Pg. 80  
7.3.1.5 Heating circuit temperature limit  
NOTE This function is not active if the heating circuit control is used as  
constant control (CC).  
Function This function limits the flow temperature of a heating circuit. The  
minimum and maximum temperatures set in the relevant  
parameters of a heating circuit do not exceed or fall below the  
setpoints.  
Minimum temperature limitation is not active:  
in case of switch-off in standby mode above the frost  
protection limit  
in case of switch-off in reduced automatic mode with the  
activated ECO function above the frost protection limit  
in case of switch-off in continuously reduced mode with  
activated ECO function  
in case of automatic summer switch-off  
Application • Floor minimum limit  
Ventilation pre-adjustment (warm air curtain)  
Convector heating  
ATTENTION  
To protect the floor heating systems against accidental  
overheating (malfunction - manual mode) a controller-  
independent maximum temperature limit must be provided.  
For this purpose, we recommend a strap-on thermostat, the  
switching contact of which is looped through the control  
phase of the respective heating circuit pump. The thermostat  
is to be set to the maximum permissible system temperature.  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92  
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7.3.1.6 Heating circuit temperature offset  
Function For special applications this function offers the possibility to admit  
the heating curve of the direct heating circuit with a constant  
offset value. The demand value plus the offset value is  
transmitted to the heat generator.  
The displacement of the heating curve is carried out in parallel  
with the flow temperature.  
Application To ensure the desired setpoint temperature for remote heating  
circuits as well.  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92  
7.3.1.7 Heating circuit pump extended running time  
Function The heating circuit pump ceases operation if there is no heat  
demand from the heating circuit. Safety switch-off of the heat  
generator is prevented.  
While the pump extended running of a mixed heating circuit pump  
(MC-1 and MC-2 only) is active, the mixed heating circuit  
continues to adjust its setpoint without forwarding a demand value  
to the heat generator.  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92  
7.3.1.8 Screed function  
NOTE This function is not active if the heating circuit control is used as  
constant control (CC).  
If the screed function is active for a direct heating circuit, only  
requests of this heating circuit are forwarded to the heat  
generator. Requests of other heating circuits are suppressed.  
Activation of the screed function for a non-mixed heating circuit  
only functions at the direct heating circuit of the central device  
with address 10 (CD1 - DHC) and only if no other central devices  
are present on the bus network.  
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If another controller (addr. 20 ... 50) is connected to the direct  
heating circuit pump while the screed function is active, the  
screed function is cancelled automatically for the direct heating  
circuit pump.  
All other heating circuits except for the direct heating circuit at  
addr. 10 are disabled. Frost protection monitoring, for example,  
does not occur for these heating circuits during this time.  
Function The screed function is used exclusively for the required drying of  
newly applied screed on floor heating systems. The process is  
based on recommendations of the German Bundesverbandes  
Flächenheizungen (Federal Association for Surface Heating)  
concerning the heating of fresh floor covers (heating according to  
a mandatory temperature profile).  
This is a special function that is not interrupted by any other  
control mode (including manual operation or emission  
measurement.  
The screed function can be activated for mixed heating circuits  
and, in special cases (e.g. in conjunction with a condensing  
boiler) also for a direct heating circuit.  
When the screed function is active, all weather-dependent control  
functions of the heating circuit concerned are switched off. The  
respective heating circuit operates independent of the control  
mode (switching times) as a constant temperature controller.  
An active screed function can be deactivated at any time  
(parameter screed function = OFF).  
On completion of the screed function, the heating circuit returns to  
operation according the current control mode setting.  
The screed function consists of two steps:  
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Step 1 Function heating acc. to DIN 4725 Part 4 (setting 1)  
Constant heating at 25°C on the start day and for the following  
three days.  
Subsequently for another four days with the set maximum flow  
temperature with a maximum limit of 55°C.  
Maximum temperature setting = 40°C.  
Progression of screed function over time with functional heating  
Step 2 Heating function for floor covering (setting 2)  
The heating of the floor covering follows a preset temperature  
profile.  
Starting with 25°C on the first day, the requested temperature  
rises by 5°C per day over the following days until the maximum  
temperature of the heating circuit is reached. After that the  
setpoint temperature is reduced with the same stepping until the  
base point of 25°C is reached again.  
Example Maximum temperature setting for the heating circuit = 40°C  
1. day:  
2. day:  
3. day:  
4. day:  
constant heating at 25°C  
constant heating at 30°C  
constant heating at 35°C  
constant heating at 40°C  
5.-15. day: constant heating with max. flow temperature  
16. day:  
17. day:  
18. day:  
reduced heating at 35°C  
reduced heating at 30°C  
reduced heating at 25°C  
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On the start day, heating to 25°C is carried out until midnight. The  
first day of floor covering heating starts at midnight of the  
following day.  
Maximum temperature setting = 40°C.  
Progression of screed function over time with floor covering  
heating.  
7.3.2 Heating circuit constant temperature control  
NOTE This function must be activated in the "Hydraulics" menu for the  
corresponding heating circuit (direct heating circuit, mixed heating  
circuit 1, mixed heating circuit 2).  
Function The control circuit is operated with a constant temperature  
specification. The demand value is transmitted to the heat  
generator. The switching program of the respective heating circuit  
and the control modes can be activated.  
The specification of the constant temperature occurs via  
parameter "constant temperature setpoint".  
Upon activation of the function on a mixed heating circuit output, a  
flow sensor is to be set for adjustment of the flow temperature.  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92  
7.3.3 Fixed-value control  
Function As with constant control. The demand value is not transferred to  
the heat generator, and the switching time program and control  
modes can be activated.  
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7.3.4 Consideration of the room temperature/room influence  
7.3.4.1 Heating circuit room connection  
Function This function determines the enabling of the room sensor in  
conjunction with a wall device/room sensor with the direct heating  
circuit and all parameters affected by the room temperature  
sensing depending on the application.  
No room sensor with the following conditions:  
No room sensor connection with installation of the room  
sensor outside the inhabited area (e.g. in unheated rooms like  
basements etc.).  
No room sensor connection with multi-family dwellings that  
work with different room temperatures based on different  
assignments and do not offer a reference room.  
With room connection switched off, the current room  
temperature is not displayed in the system information.  
The flow temperature is corrected purely by weather  
conditions.  
Room sensor active for room influence and connected outside sensor:  
With the room sensor switched on, the heating circuit is  
controlled based on the weather taking into account the  
current room temperature. The room temperature deviation is  
taken into account based on the room factor parameter  
setting.  
If SDW 30 wall devices are connected, the actual room  
temperature is indicated in the basic display instead of the  
heat generator temperature.  
When the actual room temperature drops below the current  
setpoint room temperature + 1 K, any active summer switch-  
off is disabled, provided automatic operation was not selected.  
Room sensor active, This setting enables the room temperature-related functions,  
operation disabled while operation via the wall device is disabled.  
Application Public buildings (government, schools, public facilities, etc.)  
where only the registration of the room temperature is required.  
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Room sensor off, At this setting the room sensor is only used as a display device  
operation active without influencing the room temperature-related functions. The  
operation of the wall device is possible without restrictions.  
Application All system layouts that exclude room influence while the display of  
the actual room temperature is still required (in contrast to setting  
OFF).  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92  
7.3.4.2 Heating circuit room factor  
Function This function determines to what extent a deviation of the room  
temperature from the setpoint affects the control of boiler flow  
temperature.  
If there is no difference between the desired (TARGET) and the  
current (ACTUAL) room temperature, the direct heating circuit's  
flow temperature is controlled according to the set heating curve.  
If there is a difference between the room temperature and the  
setpoint, the heating curve is shifted parallel to the room  
temperature axis so that the deviation is compensated. The  
amount of the displacement depends on the setting of the room  
factor.  
The following relation applies:  
Deviation x Room factor  
Corrected room setpoin t = Set room setpoin t −  
Example:  
100  
set room setpoint = 21°C  
actual room temperature = 20°C  
Deviation = -1 K  
For a room influence of 100%:  
1 K x 100  
Corrected room setpoin t = 21°C −  
= 22 °C  
100  
The boiler temperature is controlled according to a heating curve  
which corresponds to a room temperature setpoint of 22°C.  
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High settings lead to a quicker adjustment of the control deviation,  
while they reduce the stability of the control circuit and can lead  
with excessively high setpoints to the oscillating of the control  
variable (room temperature).  
7.3.4.3 Heating circuit room controller  
With this setting the heating circuit concerned can be controlled  
through a room controller. This requires a wall device SDW 30  
with room control function. The room controller directly determines  
the required flow setpoint and transmits this information to the  
central device.  
With this setting the control of the respective heating circuit is  
completely room-guided. Weather condition control is inactive.  
However, the parameters for weather response ("heating curve"  
setting) can still be entered.  
7.3.4.4 Switch-on/switch-off optimisation  
Function The switch-on optimisation leads to the set day setpoint being  
reached at the beginning of the set time period of the heating  
cycle, e.g. 6 a.m. to 10 p.m., at 6 a.m. Without switch-on  
optimisation, the heat generator would not be started until 6 a.m.  
The desired day setpoint is not reached until some time later.  
Switch-on time optimisation can occur either with or without a  
room sensor.  
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Parameter settings for the switch-on optimisation in the HC,  
MC-1 and MC-2 menu  
Para  
meter  
Designation  
Setting range/Setting values  
Factory  
setting  
3
Room connection (in  
conjunction with room  
sensor)  
OFF  
Display of heat generator  
temperature, room sensor off,  
operation active  
OFF  
1
Display of room temperature, room  
sensor active, operation active  
2
Display of room temperature, room  
sensor active, operation disabled  
3
Display of room temperature, room  
sensor off, operation active  
4
Room factor  
OFF  
OFF  
10 ...  
Influence active  
500%  
RC  
Room controller active  
26  
41  
Room setpoint ramp  
OFF, 0.5 ... 60 K/h  
OFF  
OFF  
OFF  
Switch-on  
optimisation  
1
2
3
Adaptation off  
Adaptation on  
Adaptation restart  
42  
43  
44  
Min. pre-heat time  
Max. pre-heat time  
0 ... set value of parameter 43  
Set value of parameter 42 to 30 h  
0 ... 30°C  
0,5  
5
Min. jump back  
temperature  
5
45  
46  
47  
Without room sensor  
Pre-heat time at 0°C  
Lowering ramp  
0 ... 10°C  
0 ... 30 h  
1
1
0 ... 500 %  
100  
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Activation of switch- Set Parameter 26 room setpoint ramp to OFF.  
on optimisation  
Set parameter 41 switch-on optimisation to 1 = adaptation off  
or with connected room sensor to 2 = adaptation on.  
NOTE If parameter 41 switch-on optimisation is set to 1, parameters 42  
min. pre-heating time and 43 max. pre-heating time are not  
required.  
If parameter 41 switch-on optimisation is set to 2, parameters 45  
no room sensor and 46 pre-heating time at 0°C are not required.  
Parameter Parameter 41 switch-on optimisation, 03 adaptation restart  
information  
If a controller is exchanged or structural changes are made, e.g.  
improvement in insulation, replacement of windows etc., adaptation  
must be restarted.  
Parameter 42 min. pre-heating time  
A pre-heating time takes place before the set heating cycle, e.g. 6  
a.m. This is only possible with a room sensor. Without a room  
sensor, parameter 45 is active without a room sensor.  
Parameter 43 max. pre-heating time  
This parameter setting limits the duration of pre-heating, which is  
set to 5 hours at the factory. This is only possible with a room  
sensor. Without a room sensor, parameter 45 is active without a  
room sensor.  
Parameter 44 min. jump back temperature  
This parameter setting specifies the outside temperature up to  
which the adaptation works. If this parameter is set to 5°C, for  
example, adaptation is active up to 5°C and deactivated starting  
with an outside temperature of 6°C.  
Parameter 45 without room sensor  
The set room temperature is increased by a specific amount, e.g.  
1°C, during switch-on optimisation so that the heat generator gets  
a higher temperature setpoint and thus the heating circuit can  
heat up faster.  
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Parameter 46 pre-heating time at 0°C  
By setting the quick heat-up time at an outside temperature of  
0°C, the heat-up speed affected. This value is included in the  
calculation of the pre-heating time.  
Pre-heating time = pre-heating time 0°C/20°C x (room setpoint –  
outside temperature)  
Parameter 47 lowering ramp  
This parameter setting specifies how fast the temperature is  
reduced before the end point of the heating cycle is reached, e.g.  
10 p.m.  
Switch-on optimisation with room sensor (adaptation)  
a
20 C  
16 C  
4:30  
6 h 7 h  
16 h  
17 h  
b
c
a
c
Calculation via the  
controller  
b
min. pre-heat time  
max. pre-heat time  
Switch-on optimisation without room sensor  
a
b
20 C  
16 C  
6 h 7 h  
16 h  
17 h  
c
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a
c
Calculation by the  
controller based on the  
outside temperature  
b
21°C parameter 45 without  
room sensor  
Pre-heat time at 0°C  
7.3.4.5 Room setpoint ramp  
Setting range OFF, 0.5 ... 60 K/h  
Function This function is only active in conjunction with an "RC" (room  
controller) function. The set value acts as a filter between the  
setpoint jump (change of the room setpoint temperature setting)  
and the room setpoint at the controller output. The ramp functions  
as an artificial down time on the control path and slows  
heating/cooling. Configuration of the actual control path is  
dependent on this.  
Application In historic buildings (churches, galleries), it is important that  
heating up and cooling down are damped via a room setpoint  
value ramp so that masonry and artwork are not damaged.  
The function starts with the switching times switch-on/switch-off  
point and the control mode change.  
NOTE This function helps prevent jumps in temperature. For this reason:  
The ramp is recalculated starting from the actual room  
temperature after a power failure. A setpoint jump does not  
occur.  
If a new setpoint jump (setpoint increased, lowering initiated)  
occurs before the room setpoint temperature is reached, the  
new ramp is recalculated starting with the current actual room  
temperature.  
An activated ramp takes affect in all control modes.  
7.3.4.6 Heating limit function  
This parameter supplements the summer switch-off function. It  
deactivates the respective heating circuit as soon as the  
computed flow temperature setpoint approaches the current room  
temperature setpoint.  
The heating limit parameter can be activated separately for each  
heating circuit.  
Function Switch-off: Flow setpoint < (current room setpoint + heating limit  
setting)  
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Switch-on: Flow setpoint < (current room setpoint + heating limit  
setting + 2 K)  
Example:  
Room setpoint = 22°C, heating limit setting = 2 K  
Switch-off at flow setpoint 24°C (22°C + 2 K)  
Switch-on at flow setpoint 26°C (22°C + 2 K + 2 K)  
Boundary conditions The SUMMER SWITCH-OFF function ("System Parameters"  
menu, parameter 04) has priority over the HEATING LIMIT  
function.  
The FROST PROTECTION function ("System Parameters" menu,  
parameter 05) has priority over the HEATING LIMIT function.  
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7.3.4.7 Heating circuit room frost protection limit  
Function This function determines the room temperature of the  
corresponding heating circuit during switch-off mode with frost  
protection active  
during holiday mode  
in automatic mode between the heating cycles with active  
ECO function (see parameter 1 - Reduced mode).  
in constant reduced mode with active ECO function (see  
parameter 1 - Reduced mode)  
In conjunction with a wall device, the heating circuit is adjusted to  
the frost protection room temperature.  
Without a wall device, the set value serves as a specification for  
the lowered room temperature and is adjusted to it.  
NOTE With continuous frost protection mode and sensitive objects in the  
house like antiques, plants, etc. the set value is to be adjusted  
accordingly.  
7.3.4.8 Mixed heating circuits cooling switch-over  
Function If the cooling function was activated at a variable output  
("Hydraulics" menu, parameters 6 and 7, setting 25), the  
additional parameters appear in the "System Parameters" menu,  
parameter 25 and in the "Mixed Heating Circuit 1"/"Mixed Heating  
Circuit 2", parameter 28.  
The cooling function must also be activated via parameter 28  
"heating circuit cooling setpoint temperature" in the "Mixed  
Heating Circuit 1"/"Mixed Heating Circuit 2" menu for each  
heating circuit.  
The cooling function for the corresponding heating circuit is  
active; if a setpoint temperature was configured (<> OFF), the  
cooling function is active for the corresponding heating circuit.  
The output for the cooling function works without pump forced  
operation.  
Wall device functionality limitation:  
If a wall device is connected to a heating circuit, all factors that  
influence a room remain ignored during active cooling (correction  
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of room setpoint, thermostat function, room controller setpoint  
etc.).  
Switch-over from heating mode to cooling mode:  
If the outside temperature is greater than summer switch-off (see  
"System Parameters", summer parameter) and the switch-on  
temperature for cooling, the cooling function is active.  
If the outside temperature is lower than the summer switch-off and  
the cooling switch-on temperature of cooling –1 K, the cooling  
function is not active. A switching differential is required.  
With the cooling function active, the "cooling switch-over" output  
in the "Hydraulics" menu, parameter 06/07, setting 25 = ON. This  
is switched on inversely via an input on the heat pump. If cooling  
mode is interrupted due to the switching conditions of the timer  
(ECO lowering phase), the output switches OFF, even if the  
switching conditions are present otherwise.  
Heating circuit correction:  
For cooling operation, the mixed heating circuit corrects to the  
setpoint temperature at the flow sensor (see the "Heating Circuit"  
menu, heating circuit cooling setpoint temperature parameter) and  
functions as a heating controller.  
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Humidistatic switch-off:  
To prevent excessive humidity build-up in the room, a humidistat  
can be connected to a variable input.  
Cooling without humidistatic switch-off:  
MC1  
para. 28  
cooling  
temp.  
Cooling  
on /  
off  
Output  
DCP or  
System  
para. 25  
switch-on  
temp.  
O1 or  
V
VO2  
MC2  
Cooling  
on /  
off  
para. 28  
cooling  
temp.  
=25  
Cooling with humidistatic switch-off:  
MC1  
para. 28  
cooling  
temp.  
Output  
Input  
System  
para. 25  
switch-on  
temp.  
DCP or  
VO1 or  
VO2  
VI1 od.  
VI2 od.  
VI3  
Cooling  
on /  
off  
MC2  
=25  
para. 28  
cooling  
temp.  
=29  
NOTE If the set humidity is exceeded, a short-circuit results. A triggered  
humidistat interrupts cooling mode.  
Active cooling does not affect the heat generator. Demand from  
other heating circuits for the heating generator or hot-water  
loading is served in parallel.  
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Ensure that the cooling circuits to be cooled are decoupled  
hydraulically from the actual heating system during active  
cooling.  
Configured cooling is only active in automatic mode  
When setting ECO mode, cooling does not take place during a  
lowering phase  
With the lowering mode setting, cooling is carried out at the  
same cooling temperature (continuous cooling)  
Cooling mode is not active in any other control modes  
(HEATING, RED. HEATING, STANDBY, PARTY TIL,  
ABSENT TIL, HOLIDAY TIL)  
7.3.4.9 Heating circuit name  
Access code No access restriction  
Factory setting empty  
00000 … ZZZZZ  
Setting range  
Function The max. three heating circuits available in a controller are  
provided with the short names DC (direct heating circuit), MC1  
(mixed heating circuit 1) and MC2 (mixed heating circuit 2). The  
heating circuits are given unique names here.  
To enable easy assignment of the heating circuits to the living  
area by the end customer, a unique 5-digit short name can be  
assigned to each of the three heating circuits.  
With the "empty" setting, a unique name is not assigned. The  
default short name appears.  
Set the flashing position with the input button.  
Confirm by pressing the input button î.  
The remaining positions are set in the same way.  
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The display of the unique heating circuit name appears  
in the menu selection  
in the parameter tree  
on the information level  
7.3.4.10 Room thermostat function (maximum room temperature limit)  
Function This function determines a room temperature-related limit with  
adjustable switching differential. If the room temperature of the  
relevant heating circuit exceeds the current daytime or reduced  
room setpoint by the set switching differential, heating is  
temporarily stopped (heating circuit pump switched off).  
Heating is resumed as soon as the room temperature of the  
respective heating circuit drops 0.5 K below the switch-off  
temperature.  
Example:  
Daytime room setpoint = 22°C  
Thermostat function set value = 4 K  
Interruption of heating:  
T
Room > (22°C + 4 K) > 26.0°C  
Resumption of heating:  
Room > (26°C – 0.5 K) < 25.5°C  
T
Set value OFF disables the thermostat function.  
NOTE The thermostat function is effective while heating and in reduced  
mode.  
The thermostat function is disabled when outside temperature  
frost protection is active.  
See also 5.4.4 "Direct heating circuit" menu (UNMIXED CIRC), Pg. 92  
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Special mixing circuit functions (district heating control  
devices only)  
Return limit By setting an additional return sensor in the mixed heating circuit,  
the return temperature can be limited using this function. This is a  
maximum temperature limit.  
With some applications, an excessively high return temperature  
causes problems (e.g. district heating or condensing  
applications). They can occur if heat is not being extracted in the  
occupied room (e.g. thermostat valve closed).  
If the return temperature exceeds the set maximum value, the  
mixed heating circuit valve is adjusted to this maximum  
temperature. The flow temperature then remains ignored.  
7.3.4.10.1 Mixed heating circuit control  
7.3.4.10.1.1 Proportional part Xp  
The proportional band Xp defines how a step change of the  
setpoint effects a change of the corresponding actuator according  
to the selected setting.  
Example:  
Consider an actuator moving though an angle of 90°C in an action  
time of two minutes. When a sudden flow temperature control  
deviation of 10 K occurs (e.g. when the system switches from  
reduced to daytime operation) and the P-part setting is 5%/K, the  
actuator has to open by 50% (5%/K x 10 K). Consequently, the  
duration of the actuation pulse is one minute (= 50% of the  
actuator runtime).  
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7.3.4.10.1.2 Integral action time Tn  
The integral part (adjustment time) determines the dynamic  
behaviour of the controller and thus the time required by the  
controller to adjust for the actual control deviation. The adjustment  
time is independent of the amount of deviation.  
Example:  
With a sudden flow temperature control deviation of 10 K (e.g.  
when the system switches from reduced to daytime operation)  
and an I-part setting of 7 minutes, the controller will adjust for the  
new (10 K higher) flow temperature after the set time.  
NOTE The adjustment time can be determined through the Ziegler-  
Nichols method. The mixed heating circuit is closed, initially, and  
the heat generator is taken to the maximum temperature for the  
heating circuit concerned. As soon as half of all consumers at the  
circuit to be measured have been opened, the mixer is fully  
opened from cold condition (room temperature) by means of the  
relay test function. The heat-up curve, i.e. the temperature  
progression over time following this action, shows an inflection  
point. The crossing of the tangent through that point and the time  
axis is the delay time. This value multiplied by the factor 3.3 is the  
optimum integral action time for this heating circuit.  
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Application  
Adjustment  
time  
Floor heating and other static heating surfaces  
Radiator heating  
10 - 30 min.  
6 -10 min.  
3 - 6 min.  
Convector heating  
7.3.4.10.1.3 Sample time Ta  
The sample time is a controller-internal value which defines the  
time interval between two subsequent actuator pulses in the  
presence of a control deviation. Shorter sample times allow finer  
adjustments.  
7.3.4.10.1.4 Actuator runtime  
This function allows adjustment of the actuator, with regard to its  
finite runtime, to the control characteristics, meaning that  
actuators with different runtimes (e.g. 1 min., 2 min., 4 min.) react  
to the same deviation by readjusting by the same amount through  
adapting the action times. The integral action time Tn remains  
unchanged here. However, care must be taken that the latter  
must always exceed the runtime of the respective actuator. If  
necessary, actuators must be used with other runtimes.  
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Example  
Coaction of P-part, I-part, adjustment time and sample time  
x
a
b
c
y
d
e
f
g
h
i
a OPEN position  
g Actuator pulse with control  
deviation XW = 25%  
b Actuator behaviour with  
control deviation 50%  
h P-part  
adjustment time Tn = 7 min.  
c Actuator behaviour with  
control deviation 25 %  
i
I-part  
adjustment time Tn = 7 min.  
d Adjustment time Tn  
(XW = 25%)  
x Mixed heating circuit  
opening (%)  
e Adjustment time Tn  
(XW = 50%)  
y Action time (min.)  
f
Actuator pulse with control  
deviation XW = 50%  
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Jump response to various control deviations  
(open control circuit, actuator removed)  
Adjustment time Tn = 7 min.  
Sample time Tn = 20 sec.  
Mixed heating circuit runtime = 2 min.  
The P-pulse that brings the mixed heating circuit to the new  
position and is proportional to the control deviation is followed by  
additional actuation pulses if the control deviation is not yet  
remedied (I-part). The adjustment time remains constant despite  
varying control deviations.  
7.3.4.10.1.5 Actuator end position function  
This function determines the type of control signal in the end  
positions OPEN or CLOSED of each actuator.  
1 = Continuous voltage at connection OPEN or CLOSED at the  
respective end position  
2 = De-energised at end position OPEN or CLOSED respectively  
Recommendation for the basic setting of the adjustment time with  
different heating systems:  
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7.3.5 Hot-water production  
7.3.5.1 Hot-water tank loading (SLP)  
The output controls a hot-water circuit loading pump during the  
respective operational-readiness times upon demand.  
Function  
The hot-water daytime temperature provides for the desired hot  
water temperature during hot-water circuit operational-readiness  
times in automatic mode and in the PARTY and HEATING control  
modes.  
Hot-water circuit -  
daytime  
This set value is the initial value for the temperature specifications  
that can be set for each heating cycle in the switching-time  
programs. The temperature settings in the switching time  
programs are automatically adjusted when the hot-water daytime  
temperature is changed.  
Example: Before  
Daytime hot-water temperature value: 50°C  
Temperatures in switching-time program:  
05:00 hours – 08:00 hours  
08:00 hours – 16:00 hours  
16:00 hours – 22:00 hours  
60°C  
50°C  
60°C  
Example: After  
Daytime hot-water temperature value: 52 °C  
Temperatures in switching-time program:  
05:00 hours – 08:00 hours  
08:00 hours – 16:00 hours  
16:00 hours – 22:00 hours  
62°C  
52°C  
62°C  
Changed settings are stored when key §or îis briefly pressed  
again or after automatic return at a preset time. Once the settings  
are stored, the unit automatically switches to the basic display.  
5.1.2.4 "Daytime hot-water temperature" button, pg. 25  
See also  
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Hot-water circuit - night- Hot-water economy temperature is the setpoint for the hot-water  
time  
tank between the active operating mode times in automatic mode.  
If a hot-water thermostat is used to determine the water heater  
temperature, the parameter for the setting of the economy  
temperature is skipped.  
Legionella protection In order to kill Legionella germs in the tank, a Legionella  
protection function can be activated. Activation is carried out in  
the "Hot Water" menu, parameter 2.  
To ensure full destruction of germs, the set value of the Legionella  
protection temperature must be at least 65°C.  
The setting is carried out with two parameters. The weekday for  
Legionella protection can be selected by the user with a freely  
accessible parameter. With parameters 03 and 04, the time and  
temperature can be set by the heating technician.  
Type of temperature measurement  
Temperature  
measurement  
This function determines the type of temperature measurement in  
the hot-water tank.  
In general, an electronic temperature sensor (immersion sensor in  
hot-water tank) is used. The temperature is measured via the  
change in resistance of this sensor here.  
Alternatively, hot water provision can also be controlled by a  
mechanical temperature controller (thermostat switching contact).  
A hot-water thermostat is connected to tank sensor input and set  
to the required setpoint hot-water temperature. When the  
thermostat requires energy via the tank sensor input (contact  
closed), the tank is loaded with hot water at the set hot water  
maximum temperature until the contact opens again.  
With hot water control through a thermostat, the current hot water  
temperature cannot be measured and registered and will  
therefore not be displayed as part of the system information. Also,  
the hot water nominal temperatures cannot be set.  
NOTE  
This function limits the temperature in the water heater upward  
based on the set value. The desired water heater daytime  
temperature to be set on the user level is limited by this set value.  
Maximum hot water  
temperature  
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ATTENTION  
Hot water maximum temperature limit is a function protecting  
the tank and terminates hot water loading. If overshooting  
occurs, the tank loading pump switches off immediately. In  
this case it cannot be ensured that the set extended running  
time is adhered to.  
If a hot-water circuit thermostat is used instead of an electronic  
sensor, the hot water maximum temperature setting (plus the  
specified temperature shift during loading) is forwarded to the  
heat generator.  
NOTE  
Control mode With this function it is set how the rest of the heating system  
reacts to heat demand from the hot-water tank. There are 5  
different setting options.  
Parallel operation  
During hot-water circuit loading, the heating circuits remain  
operative.  
Priority mode  
During hot-water loading, the heating circuits are put out of  
operation. They are restarted as soon as the hot-water circuit  
loading pump extended running time is over.  
If the hot-water setpoint temperature is not reached after 4 hours,  
a fault message is indicated on the display.  
Conditional priority  
If the temperature of the heat generator has exceeded the loading  
temperature for the hot-water tank, mixed heating circuits are  
enabled. Non-mixed heating circuits (DHCP) remain disabled  
during hot-water circuit loading. The heating circuits are enabled  
according to the following criteria:  
Enabling the heating circuits:  
Heat generator actual temperature > hot-water setpoint  
temperature + hot-water switching differential/2 + 10 K  
Disabling the heating circuits:  
Heat generator actual temperature < hot-water setpoint  
temperature + hot-water switching differential/2 + 5 K  
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In this control mode, the loading temperature offset for the tank is  
to be selected so that the heat generator does not switch off  
before the heating circuits are enabled. A parallel shift of at least  
10 K should be set so that this function can operate correctly.  
NOTE  
Parallel operation based on weather conditions  
Above the set outside frost protection limit, hot water provision is  
carried out in priority mode; in case of active frost protection there  
is a switch-over to parallel mode.  
Priority mode with intermediate heating  
With this setting hot-water circuit loading is limited to a maximum  
of 20 minutes in order to provide for a 10-minute long  
intermediate heating. The loading procedure is continued at the  
end of the intermediate heating. Hot-water loading and  
intermediate heating are carried out in an alternating order until  
hot-water tank loading is finished.  
Priority isolating circuit  
Hot-water loading is carried by means of a three-way switch-over  
valve; the heating circuit pump is also the hot-water circuit loading  
pump. At the end of the hot-water loading and at the expiration of  
the extended time the three-way switch-over valve is changed  
back to heating mode.  
The heating circuit pump is connected at output direct heating  
circuit pump and the three-way valve to output tank loading pump  
in this case.  
If there is no hot-water demand (standby), the valve is switched to  
the hot-water tank (relay output closed).  
NOTE  
External mode (request does not act on heating generator  
and heating circuit)  
In external mode, hot-water loading is switched only according to  
the set switching differentials. There is no heat demand for the  
heat generator. There is no tank priority mode for the heating  
circuits. The parameters boiler parallel shift, tank discharge  
protection, pump extended running time and boiler start-up  
protection no longer act on the hot-water loading pump.  
Tank discharge protection  
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With discharge protection activated and a hot-water demand  
present, the hot-water loading pump enabled only when the  
temperature in the heat generator rises by more than 5 K above  
the current temperature in the hot-water tank.  
This measure prevents any rear tank discharge through the heat  
generator. The hot-water loading pump is disabled again as soon  
as the temperature differential between the heat generator and  
the hot-water tank has dropped to less than 2 K.  
The heat generator minimum temperature limit operates  
continuously to protect the heat generator and blocks the hot-  
water loading pump in case of temperatures below the set value.  
NOTE  
ATTENTION  
In case of hot-water temperature specifications above 60°C,  
this function should not be activated to avoid safety switch-  
off (in particular for heat generators with a low water  
capacity).  
Tank discharge protection must be set accordingly for hot-  
water loading from buffer tanks.  
Boiler temperature This function determines the default setting of the tank loading  
offset temperature compared to the set hot-water circuit setpoint. In  
case of setpoint modifications the heating energy needed for the  
hot-water supply is adjusted.  
In case of several devices in the bus system and several hot-  
water circuits the tank loading temperature depends on the  
highest setpoint if several tanks are loaded simultaneously.  
Switching differential This function determines the size of the hot-water circuit switching  
differential. The switching differential affects the relevant hot-  
water setpoint symmetrically.  
Loading enabling The current hot-water temperature is lower than the hot-water  
setpoint by half the amount of the hot-water switching differential  
The current hot-water temperature overshoots the hot-water  
circuit setpoint by half the amount of the hot-water switching  
differential. After switching-off the heat generator, the tank loading  
pump is stopped only after a time delay to prevent a safety  
switch-off in case of high temperatures. The set value can be  
adjusted to the holding capacity of the hot-water tank used.  
Pump extended running  
loading cancellation  
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Excessively long extended running times unnecessarily interrupt  
heating and increase the temperature in the hot-water tank.  
NOTE  
Depending on the parameter setting, a setpoint present in the  
system may or may not be forwarded to the heat generator during  
the extended running time  
The boiler is operated according to the following rules during a  
tank pump extended running time:  
Parallel hot-  
Hot-water  
Conditional hot-  
water peration priority mode water priority mode  
DC  
MC  
HC setpoint  
AUTO Active  
OFF OFF  
HC setpoint  
OFF  
setpoint  
setpoint  
OFF  
OFF  
Active  
OFF  
OFF  
Tank sensor 2 For complete loading of a hot-water tank by means of automatic  
measuring point switch-over between tank sensors 1 and 2 (layer  
loading). The measured value of the hotter sensor (SF1 or SF2) is  
evaluated for the activation of the loading pump. Termination of  
loading is carried out on the basis of the measured value of the  
colder sensor. The set values for the hot-water setpoint  
temperature and the specified hot-water switching differential  
continue to apply.  
See also 5.2.4 "DHW" menu, pg. 77  
Quick hot-water connection in cascaded systems  
With cascaded systems, it is often the case that all heat  
generators are often not needed for hot-water production. In  
addition, the required heat generators must be connected faster  
than when heating.  
If there is a demand for hot water, a fixed value of 10 seconds is  
used for connection of the subsequent stages up to the set  
maximum stage number for quick hot-water connection instead of  
the general connection delay ("Cascading" menu, parameter 02).  
Function  
For further stages, connection occurs based on the connection  
delay that can be set.  
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For hot-water loading without heating (tank priority), the number  
of heat generators is limited by the setting in the quick hot-water  
connection parameter.  
With parallel operation (heating circuit and hot-water demand  
simultaneously), there is no stage number limitation.  
With active hot-water loading, reversion of stages occurs under  
consideration of the configured switch-off delay.  
If heating circuit operation is active with more stages than were  
enabled for hot-water circuit operation and hot-water loading then  
occurs in priority mode, the stages above and beyond the number  
of stages enabled for hot-water loading are switched off directly.  
Reversion of the activated stages does not occur in parallel  
operation.  
The "stage sequence switch-over power" must be taken into  
account for connection of the following stage.  
Example:  
Cascaded system with five stages  
Parameter 02 = 1 min.  
Parameter 03 = 2 min.  
Parameter 09 = 3 min.  
Heating  
1min  
2min  
1min  
2min  
1min  
2min  
1min  
2min  
WEZ1  
WEZ2  
WEZ3  
WEZ4  
WEZ5  
Connection and disconnection with the configured delay of  
parameters 02 and 03.  
Tank priority (no heating demand):  
10s  
10s  
WEZ1  
WEZ2  
WEZ3  
WEZ4  
WEZ5  
2min  
2min  
Connection immediately with minimum delay  
Reversion with configured delay P3  
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Tank parallel operation (combined operation: hot-water  
loading/heating)  
10s  
10s  
1min  
2min  
1min  
2min  
WEZ1  
WEZ2  
WEZ3  
WEZ4  
WEZ5  
2min  
2min  
Connection up to the stage of parameter 09 with minimum  
delay for hot-water loading  
In case of further need via heating, further connection with  
configured delay of parameter 02  
Reversion with configured delay parameter 03  
7.3.5.2 Circulation pump (CIR.)  
NOTE This function is only available, if a variable output is assigned to a  
circulation pump  
Function The output controls a hot-water circulation pump.  
Economy interval The use of the economy interval minimises the usual circulation  
(pulse) losses owing to adjustable switch-on intervals during operation  
and determines the standstill time of the hot-water circulation  
pump within an adjustable period (economy interval).  
Economy interval This parameter determines the length of the period and hence the  
(period duration) duration of the pause in a circulation pump pulse operating mode.  
Economy interval Pause = Economy interval Period duration - Economy  
interval Pulse  
The switching-on degree is calculated from the ratio:  
n = Pulse time/Period duration x 100 (%)  
Example:  
With an standstill time of 15 min. and a period of 20 min., the  
circulation pump will run for 5 min. before the subsequent pause  
of 15 min.  
The following is used to calculate the switching-on degree:  
n = 5/20 = 25%  
Switching times In this function a hot-water circulation pump can be coupled to an  
existing automatic program of a control circuit with regard to the  
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switch-on and switch-off times. The hot-water circulation pump is  
in operation during the heating or hot-water cycles of the selected  
circuit and program.  
NOTE If operation of the time programs P2 and P3 were not enabled  
(see "System Parameters" menu, time program parameter) and  
the circulation pump is assigned to one of these programs, the  
pump will operate according to the stored default times. The same  
applies if a switching-time program was selected that does not  
exist for the controller type in use (e.g. an MC2 for SDC 9-21).  
Circulation pump with Hot-water parameter 16 allows switching off of the circulation  
district heating pump during hot-water loading.  
7.3.5.2.1 Electrical heating element (ELH)  
Function The function indirectly controls (via circuit breaker) an electrical  
insert in the water heater if the automatic summer switch-off is  
active.  
Switch-off of the electrical heating element occurs via an  
additional hot-water circuit thermostat to be created with the  
corresponding safety equipment.  
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7.3.6 Solar/Solid fuel/Buffer  
7.3.6.1 Solar function  
Function The solar function makes it possible to combine solar power  
systems with heating and hot-water production systems in order  
to support the economy of the system. The solar loading pump  
can be controlled according to various switching conditions.  
NOTE This function can only be called up, if a configurable switching  
output was occupied with a solar loading pump.  
Two separate sensor inputs are available for the connection of the  
sensors:  
KVLF for the solar collector sensor  
KSPF for the collector tank sensor  
For heat metering, an optional collector return sensor (KRLF) can  
be connected via a variable input (VI1 - VI3).  
NOTE The solar loading pump is disabled if the collector flow sensor is  
defective.  
(switching differential ON)  
With sufficient solar heat energy, the temperature differential  
Solar switch-on  
differential  
between collector flow and tank will become bigger than the set  
value and the solar loading pump is switched on to load the buffer  
tank. The minimum set value is 3 K above the switch-off  
differential.  
Solar switch-off (switching differential OFF)  
differential  
If the temperature differential between the collector flow and tank  
falls below or equal to the set value, the solar loading pump is  
switched off and loading terminated. The maximum set value is  
always 3 K below the selected switch-on differential.  
Minimum runtime of The activated solar loading pump remains in operation for this set  
solar loading pump time. The minimum runtime has priority over the switch-off  
(SOP) differential (switching differential OFF).  
Collector maximum This limit is used for thermal protection of the collector and causes  
temperature limit forced switch-on of the solar loading pump if the set value is  
exceeded. If the temperature drops below the set value –5 K, all  
solar functions become active again based on their settings.  
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Solar tank maximum If the temperature in the solar tank (hot-water tank or buffer tank)  
temperature limit exceeds the set value, an active forced switch-on of the solar  
loading pump (see description for collector maximum temperature  
limit) is interrupted. This forced switch-on is enabled again as  
soon as the solar tank temperature falls more than 10 K below its  
set limit.  
Solar control mode This function defines the solar loading mode.  
Solar priority mode (disabling of heat generator)  
During solar loading, all demand for the heat generator is  
suppressed.  
Solar parallel operation  
During solar loading, demand for the heat generator is permitted.  
Solar priority mode - hot water (setpoint control)  
During solar loading, demand for the hot-water control at the heat  
generator is suppressed.  
Solar priority mode - buffer (setpoint control):  
During solar loading, demand for the buffer control at the heat  
generator is suppressed.  
Heat generator cycle Heat generator cycle disable (only with solar control mode =  
disable priority mode)  
The cycle disable serves to prevent frequent switching between  
solar loading and loading by the heat generator. After a solar  
loading pump switch-off, the set time has to pass before the solar  
buffer tank can be loaded again by the heat generator (boiler).  
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Parallel switch-over Solar priority/parallel switch-over (only with solar control  
mode = priority mode)  
Operation in hot-water priority mode  
If the actual hot-water temperature undershoots the hot-water  
setpoint by the set amount, solar priority mode is cancelled until  
the hot-water setpoint has been reached.  
Example:  
Hot-water setpoint is 50°C, set value switch-over: 10 K.  
There is no demand for the heat generator until the hot-water  
temperature drops below 40°C.  
Operation in buffer priority mode  
If the actual buffer temperature undershoots the buffer setpoint by  
the set amount, solar priority mode is cancelled until the buffer  
setpoint has been reached.  
Example:  
Setpoints at buffer of heating circuits: 45°C  
Buffer offset: 10 K  
Switch-over set value: 20 K  
There is no demand for the heat generator until the buffer  
temperature drops below 35°C.  
Heat balancing Heat balancing is activated through a parameter setting. The user  
can select between flow calculation via the pump runtime and  
determination of the flow volume via the pulse signal input of the  
device, if such an input is available. Any commercial flow meter  
can be connected to the pulse input.  
Reset heat balancing (only if heat balancing is activated)  
With this function, the heat balancing counter can be reset when  
heat balancing is activated.  
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Volume flow (only if heat balancing is activated)  
This set value allows choosing between volume flow computed in  
litres/minute for calculating the flow volume or  
litres/pulse when using the pulse input corresponding to the  
respective pumping capacity of the solar loading pump.  
NOTE With set value 0 L/min., no calculation of heat balancing is  
possible.  
Density of medium (only if heat balancing is activated)  
This set value defines the fluid density of the heat carrier medium  
used according to the manufacturer data.  
Heat capacity Specific heat capacity medium (only if heat balancing is activated)  
This set value defines the specific heat capacity of the heat carrier  
medium used according to the manufacturer data.  
NOTE The physical values of volume flow, density and specific heat  
capacity form the basis for determining the solar heat balancing  
and the solar power and are calculated according to the  
mathematical relation  
W = (V/t) · ρ · cW · Δδ · tSOP  
The results can be seen on the information level.  
W = Heat balancing  
V / t = Volume flow of the heat carrier medium  
ρ = Density of the heat carrier medium  
cW = Specific heat capacity of the heat carrier medium  
Δδ = Temperature differential (collector flow/return)  
Anti-blocking function This is an automatic function of the controller. If the solar loading  
pump was switched off longer than 24 hours, it is operated for  
approx. 20 seconds to prevent blocking via corrosion.  
7.3.6.2 Buffer tank function  
NOTE This function is only active if a buffer loading pump is assigned to  
a programmable switching output or if a buffer sensor has been  
connected to a variable input.  
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For stratified discharge, an optional second buffer tank sensor  
(PF2) can be connected to a variable input (VI1 to VI3).  
The heat generator temperature is supplied by the temperature  
measuring device of the heat generator.  
Function Buffer or energy tanks are used for storing energy that is available  
without control (e.g. from solar power system or wood boilers).  
This energy buffer covers the energy demand from heating  
circuits and hot-water systems.  
Additional energy demand can be covered by controlled heat  
generators (boilers).  
The buffer loading pump function ensures that a controlled heat  
generator supplies the additional energy to the buffer tank or the  
heating and hot-water circuits, respectively.  
If no controlled heat generator is used (e.g. heating by wood  
boilers only), buffer functions such as forced dissipation into the  
heating circuits can be used by connecting and activating buffer  
sensor 1 to a variable input.  
Control modes To support the full range of available combination options in  
multivalent heating systems with buffer support, the control  
system offers the possibility to set various control modes for buffer  
operation. The different settings cause different processing  
sequences of heat demand for heating circuit and hot water. In  
the following, the different control modes are illustrated using  
exemplary hydraulics layouts.  
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Control mode 1 – Loading control for heating circuit and hot-water  
demand  
System hydraulics  
b
c
a
a Heat generator  
b Buffer tank  
c
Hot-water tank  
Heating circuit and hot-water controls send their demand values  
to buffer control. Buffer control demand additional energy from the  
heat generator via the buffer loading pump.  
See the table below for detailed correlations.  
Control mode 2 – Loading control for heating circuit demand  
System hydraulics  
a
b
c
a Heat generator  
b Buffer tank  
c
Hot-water tank  
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Heating circuit controls send their demand value to buffer control.  
Hot-water and buffer controls demand energy from the heat  
generator when required.  
With hot-water priority activated, this function acts on the buffer  
loading pump and not on the heating circuits.  
See the table below for detailed correlations.  
Control mode 3 – Discharge control for heating circuit and hot-  
water demand  
System hydraulics  
b
a
c
a Buffer tank  
c
Hot-water tank  
b Heat generator  
Heating circuit and hot-water controls send their demand value to  
buffer control. The buffer loading pump output switches ON when  
the energy demand can be met by the buffer. If the energy in the  
buffer is insufficient, buffer control demands additional energy  
from the heat generator and the buffer loading pump switches  
OFF.  
If there is no demand for the heating circuits and hot-water  
loading, the buffer loading pump switches off.  
See the table below for detailed correlations.  
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Control mode 4 – Discharge control for heating circuit demand  
System hydraulics  
b
a
c
a Buffer tank  
c
Hot-water tank  
b Heat generator  
As control mode 3, except that the demand from hot-water control  
are sent directly to the heat generator.  
An active hot-water priority only acts on the heating circuits when  
there is no buffer discharge in progress.  
See the table below for detailed correlations.  
Control mode 5 – Loading control with hot-water switch-over valve  
System hydraulics  
a
b
a Heat generator  
b
Buffer tank  
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Heating circuit controls send their demand value to buffer control.  
Hot-water and buffer controls demand energy from the heat  
generator when required. The buffer loading pump output is ON  
during buffer discharge and hot-water loading.  
Any active hot-water priority is not effective here.  
Control mode 6 – Discharge control to heat generator  
System hydraulics  
b
a
c
a Buffer tank  
c
Hot-water tank  
b Heat generator  
This hydraulic layout is used when an alternative-energy buffer  
tank is added to an existing system. In such systems it is often the  
case that there are existing unit boilers with integrated hot-water  
circuit loading tank and hot-water loading in the boiler.  
All heat demand is forwarded to the heat generator.  
When the buffer tank can cover the energy demand, the heat  
generator nominal temperature is maintained by the buffer via  
buffer loading pump instead of the burner.  
In this way the heat generator always operates at its setpoint  
temperature and cannot be exposed to excessive buffer  
temperatures.  
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See the table below for detailed correlations:  
Buffer control mode  
1
2
3
4
5
6
Buffer demand from  
HC/HW  
HC  
HC/HW  
HC  
HC  
Heat generator  
demand from  
BUFFER BUFFER/ BUFFER BUFFER/ BUFFER/ HC/HW  
HW  
HW  
HW  
Buffer control mode  
Load  
Load  
Dis-  
Dis-  
Load  
Dis-  
charge 1 charge 1  
charge 2  
Buffer start-up  
protection acts on  
HC/HW  
HC  
X
HC/HW  
HC  
HC  
X
Buffer discharge  
protection  
X
Buffer frost protection  
monitoring  
X
X
X
Buffer minimum  
X
X
X
temperature monitoring  
Buffer maximum  
X
X
X
X
X
X
temperature monitoring  
Buffer forced  
HC/HW  
HC  
HC/HW  
HC  
HC  
HC/HW  
dissipation into:  
Buffer siphon function  
X
X*  
X*  
Loading temperature  
offset acts from:  
HC/HW  
HC  
HC  
Heat generator start-up X  
protection on buffer  
loading pump  
X
X
Buffer loading pump  
with no demand  
OFF  
OFF  
ON  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
ON  
OFF  
OFF  
OFF  
Buffer loading pump for ON  
manual operation  
Buffer loading pump  
function for sensor  
defect  
ON  
ON  
ON  
Buffer loading pump  
function for heat  
ON  
ON  
generator disable  
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Buffer control mode  
1
2
3
4
5
6
Buffer loading pump  
function if heat  
generator is not  
available and buffer  
start-up protection is  
active  
OFF  
OFF  
Buffer loading pump  
function if heat  
ON  
ON  
generator is not  
available and buffer  
start-up protection is  
not active  
Action of heating  
generator start-up  
protection on heating  
circuits (HDCP, MC1,  
MC2):  
No  
No  
Yes  
Yes  
No  
Yes  
Yes  
No  
No  
Yes  
Yes  
No  
Action of heat  
No  
Yes  
Yes  
No  
generator start-up  
protection on hot-water  
circuit (tank loading  
pump)  
Action of heat  
Yes  
Yes  
generator start-up  
protection on buffer  
loading pump  
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Loading control  
The supply of energy from a controlled heat generator to the  
heating circuits is realised through loading the buffer. The buffer  
control ensures that the buffer is supplied with sufficient energy  
from the heat generator, via the buffer loading pump.  
With buffer discharge controls, it must be ensured that the  
residual energy from the buffer can be transported to the heating  
circuits if a controlled heat generator is not available. With control  
mode 3 and 4, the buffer loading pump output must be switched  
for this purpose in this case. With control mode 6, only the burner  
demand is suppressed with a heat generator disable.  
If a heat generator is not available and the actual buffer  
temperature is below the minimum buffer temperature while buffer  
start-up protection is active, the buffer loading pump output  
remains switched off (priority).  
A heat generator is not available if:  
An external heat generator disable is active at a variable input  
Heat generator cycle disable is active via configuration in the  
"Solid Fuel" menu, parameter 05  
Heat generator cycle disable is active via configuration in the  
"Solar" menu, parameter 07  
A heat generator is not present in the system (e.g. purely solid  
fuel buffer combinations)  
Discharge control 1  
The heating circuits are supplied with energy either from the  
buffer through discharging the buffer tank via buffer loading pump,  
provided the buffer tank contains sufficient energy, or through  
direct supply from the heat generator.  
If a heat generator disable is active (e.g. through external burner  
disabling via contact, cycle disable (solid fuel/solar)), the energy  
contained in the buffer, independent of the current buffer level, is  
dissipated into the heating circuits by enabling the buffer  
discharge channel (e.g. switching on the buffer loading pump or  
switching over the buffer loading pump valve). The buffer  
minimum temperature is monitored. Hot-water loading is enabled  
under the conditions of buffer/tank discharge protection.  
NOTE  
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Discharge control 2  
The heating circuits are always supplied with energy from the  
heat generator. As long as the buffer contains sufficient energy,  
the heat generator will be heated via the buffer loading pump  
instead of the burner. If the energy in the buffer is not sufficient,  
the burner will be started.  
NOTE If a heat generator disable is active (e.g. through external burner  
disabling via contact or cycle disable (solid fuel/solar)), this will  
only result in the suppression of the demand for the burner.  
Buffer setpoint The buffer setpoint temperature is the temperature that the buffer  
temperature tank has to provide for supplying the connected heating circuits. It  
corresponds to the highest demand value of these heating  
circuits.  
Example:  
Demand value MC1 = 45°C  
Demand value MC2 = 55°C  
Demand value hot water = 65°C  
=> buffer setpoint temperature = 65°C  
A required offset value (e.g. hot-water load temperature offset)  
has already been taken into consideration in the demand value of  
the heating circuits.  
Buffer minimum When there is heat demand for the buffer tank from the heating  
temperature limit circuits or from hot water, this request will be maintained at least  
to the minimum temperature limit. When the temperature drops  
below this limit, the buffer tank is recharged by the heat generator  
under the conditions of the buffer start-up protection.  
Buffer tank maximum If the buffer tank temperature exceeds the set value of the buffer  
temperature limit tank maximum temperature limit, forced switch-off of the buffer  
loading pump occurs. The excess heat is dissipated into the  
selected circuits (see forced dissipation). Forced dissipation is  
disabled and buffer operation is resumed when the temperature in  
the buffer tank drops more than 2 K under the set maximum  
temperature limit.  
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Buffer temperature To ensure an adequate control reserve for all consumers  
offset of heat generator connected to the buffer tank, the demand value sent to the heat  
generator can be raised by an additional temperature offset.  
Buffer switching If the buffer tank temperature rises above the current demand  
differential value by the set amount, the buffer loading pump is switched off.  
The pump is switched on again as soon as the buffer tank  
temperature drops below the current demand value.  
Buffer forced If the set buffer maximum temperature limit is exceeded, the  
dissipation excess energy can be dissipated into the heating circuits and the  
hot-water tank. The heating circuits into which the forced  
dissipation is routed are determined by the respective parameter.  
Set value OFF  
No heat dissipation  
Tank loading pump (with provision tanks only)  
Dissipation of the excess heat occurs to an existing water heater.  
ATTENTION  
Use a thermal mixing valve in accordance with the  
regulations, as there is a risk of scalding.  
Heating circuit pump(s)  
Any excess heat is dissipated into the heating circuit(s). The set  
maximum temperature is not exceeded here. The intended room  
temperature may be exceeded for short periods.  
NOTE Activate the thermostat function in conjunction with room  
station(s).  
ATTENTION  
With floor heaters, use a system thermostat for pump forced  
switch-off.  
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Buffer siphon function Whenever the buffer tank is not being loaded by the heat  
generator (buffer setpoint reached) the differential between the  
heat generator temperature and the buffer tank temperature is  
measured continuously if configured to do so. The buffer loading  
pump is switched on as soon as the temperature differential rises  
above the set extended running switch-on differential. The buffer  
loading pump is switched off immediately when the temperature  
differential drops to the extended running switch-off differential.  
This siphon function ensures that excess energy in the heat  
generator (e.g. due to extended heating) will not be lost.  
Buffer start-up When operating a heating system without buffers, boiler start-up  
protection protection is generally implemented via temporary separation of  
the energy consumers from the heat generator (switch-off of  
pumps, close mixed heating circuits).  
With buffer operation, there is no start-up protection for the heat  
generator acting on the heating circuits. The start-up protection  
only acts on the buffer loading pump. If the buffer minimum  
temperature is undershot when the buffer start-up protection is  
switched on, all consumer circuits (heating circuits, hot water) are  
separated on the water side (pumps switch off). The buffer start-  
up protection is disabled (pumps are switched on again) when the  
buffer temperature exceeds the buffer minimum temperature plus  
half of the buffer switching differential. All consumer circuits  
remain in operation when buffer start-up protection is switched off.  
With operation in conjunction with buffer tanks, the hydraulic  
conditions for each buffer control mode deviate from this. Special  
considerations must be made regarding boiler start-up protection  
for this reason.  
Buffer start-up protection can be switched off.  
Buffer discharge Buffer discharge protection disables the buffer loading pump until  
protection the heat generator temperature has risen to more than 5 K above  
the buffer setpoint temperature.  
This function helps prevent rear buffer discharge though the heat  
generator. The buffer loading pump is disabled again as soon as  
the temperature differential between the heat generator and the  
buffer tank has dropped to less than 2 K.  
For operation without buffer tanks, tank discharge protection ("Hot  
Water" menu, parameter 08) acts on the heat generator. The heat  
generator sensor and the hot-water circuit sensor are compared.  
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Depending on the activated buffer control mode, activated tank  
discharge protection must act on the buffer instead of the heat  
generator. The required conditions can be seen in the following  
table.  
Buffer control mode  
1
2
3
4
5
6
Tank discharge  
protection/heat  
Buffer Heat Heat Heat Heat Buffer  
gene- gene- gene- gene-  
generator available  
rator rator  
rator rator  
Tank discharge  
Buffer Heat Buffer Heat Heat Buffer  
protection/heat  
generator not available  
gene-  
rator  
gene- gene-  
rator rator  
Buffer sensor 2 (BS2) Buffer sensor 2 (BS2)  
As an option, the buffer tank can be equipped with the second  
buffer sensor (BS2) via the variable inputs, for stratified loading.  
The buffer is loaded through the active heat generator as soon as  
the higher temperature (of the two sensors) undershoots the  
setpoint value. Loading though the heat generator is terminated  
when the lower temperature (of the two sensors) has reached the  
setpoint plus the set buffer switching differential (stratified loading)  
Buffer loading pump extended running time  
When buffer loading of a buffer loading system is complete, an  
extended running time for the buffer loading pump can be  
configured via a parameter setting.  
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7.3.6.3 Solid fuel function  
NOTE This function can only be called up, if a configurable switching  
output was occupied with a solid fuel loading pump.  
The following sensors can be used for control:  
SFS for the solid fuel boiler sensor  
The connection occurs automatically depending on the  
assignment of the output to VI1 or VI2.  
SFS for the solid fuel buffer sensor (optional)  
The connection occurs to variable input 1 – variable input 3  
depending on the assignment to an available variable input.  
If no solid fuel buffer sensor is connected, the collector  
tank/buffer sensor value (dedicated sensor input) is accepted  
as the buffer sensor. In this way, the collector tank/buffer  
sensor input can be used as a sensor input for several  
uncontrolled heat generators (e.g. solar or solid-fuel).  
ATTENTION  
Note the sensor position and stratification conditions.  
A forced switch-on will be initiated for the solid fuel loading pump  
if a solid-fuel boiler sensor is defective.  
Function The solid-fuel function allows the integration of solid-fuel boilers  
(usually in combination with a buffer tank) into the system to  
support heating. Under this function the solid fuel loading pump  
can be controlled through various switching conditions as  
described in the following.  
Solid-fuel boiler If the temperature in the solid-fuel boiler rises 10 K above the set  
minimum temperature value, the solid-fuel loading pump is enabled.  
limit  
If the temperature in the solid-fuel boiler undershoots the  
minimum boiler temperature, the solid-fuel loading pump is  
switched off and loading is interrupted.  
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Solid-fuel boiler If the temperature in the solid fuel boiler rises above the set  
maximum temperature maximum temperature limit, the solid-fuel loading pump is forced  
limit to switch on. The excess heat is then dissipated into the  
preselected circuits (see "Buffer Tank" menu). This forced  
dissipation will be cancelled and the temperature differential  
control enabled when the solid-fuel boiler temperature  
undershoots the maximum limit by more than 10 K.  
Solid-fuel boiler buffer If the temperature in the solid-fuel boiler rises above the current  
tank switch-on temperature in the buffer tank by at least the set amount, the  
differential (switching solid-fuel loading pump is switched on and the buffer tank is  
differential ON) loaded.  
Prerequisite:  
The temperature of the solid-fuel boiler is at least 10 K over the  
minimum temperature limit.  
The min. set value is 3 K above the switch-off differential.  
Solid-fuel boiler buffer If the differential between the solid-fuel boiler and buffer tank  
tank switch-off temperatures is less than the set amount, the solid-fuel loading  
differential (switching pump is switched off and loading is interrupted. The max. set  
differential OFF) value is constantly 3 K below the selected activation difference in  
order to prevent rear discharging of the buffer tank.  
Heat generator Heat generator solid-fuel cycle disable  
cycle disable  
The solid-fuel cycle disable serves to prevent frequent switching  
between loading through the solid-fuel boiler and loading through  
a conventional oil/gas heat generator.  
After the solid-fuel loading pump has been switched off, the set  
time must pass before loading of the buffer tank is continued  
through the conventional heat generator.  
Anti-blocking function This is an automatic function of the controller. If the solar loading  
pump was switched off longer than 24 hours, it is operated for  
approx. 20 seconds to prevent blocking via corrosion.  
7.3.7 Tank loading switch-over  
In systems that have both an external hot-water tank and a buffer  
tank, a diverter valve can be used to switch between loading the  
hot-water tank and loading the buffer tank from solar power  
system. This allows economical and effective use of solar power  
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to support heating during periods when less solar power is  
available.  
To ensure that the solar tank in priority operation (temperature  
sensing by the sensor of the solar loading switch-over, usually  
hot-water tank) can be loaded, checks are performed at regular  
intervals to determine whether sufficient solar power is available  
(meaning the solar panel temperature is sufficiently high for  
loading and the set switch-over temperature can be reached).  
Diverter valve This function allows switching of a diverter valve according to the  
load condition of two heat storage tanks (two-point output) so that  
solar energy can be used to support heating during periods of low  
solar intake.  
Test cycle If the switch-over condition is not fulfilled after a preset time  
interval of 30 minutes (meaning the temperature in the first-priority  
tank remains below the set switch-over temperature) and if the  
loading conditions for the second-priority tank (temperature  
sensing by the collector tank/buffer sensor, usually buffer tank for  
heating support) are fulfilled, the solar loading pump (SOP) is  
temporarily switched off after the time set in the "Solar" menu,  
parameter 15. During the switch-off time, the differential between  
the collector flow sensor (SPFS) and the sensor for solar loading  
switch-over (SLVF) is determined. If the switch-on condition is  
fulfilled, the first-priority tank is loaded. If the loading condition is  
not fulfilled after the set time, loading is continued into the lower  
priority tank as long as the loading conditions are not fulfilled.  
These cyclical checks are suspended if the temperature at the  
solar loading switch-over sensor plus the switch-on differential  
becomes greater or equal the set final switch-off temperature.  
Solar loading switch-over operation  
Only a setting option if a solar loading pump is set on the  
hydraulic level.  
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7.3.8 Hydraulic buffer relief (HBR)  
1
1 Buffer tank  
Function Using a 3-way switching valve (output active), hydraulic buffer  
relief (HBR) causes temporary intake into the upper region of the  
buffer tank, if that region has not reached its setpoint temperature  
yet, so that connected heating or hot water circuits receive priority  
supply of energy.  
When the buffer temperature exceeds the buffer setpoint by 2.5  
K, the 3-way switching valve is hydraulically coupled to the lower  
region of the buffer tank so that the entire buffer tank can be  
loaded. Another switch-over to the upper region of the buffer tank  
is initiated as soon as the buffer temperature undershoots the  
buffer setpoint temperature by 2.5 K.  
Application Partial buffer loading with priority supply for heating and hot water  
for all types of loading control modes (see buffer control modes 1,  
2 and 5)  
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Hydraulic function If the output is deactivated (de-energised), the buffer is loaded  
(valve position A–AB, discharge deactivated).  
If the output is activated (energised), only the top region of the  
buffer is loaded (valve position B–AB, discharge activated)  
Switching  
SDHPE: 5 K (fixed)  
differential:  
Switch-on:  
Switch-off:  
Buffer setpoint  
Buffer setpoint +5 K  
7.3.9 Easy enabling and disabling of a heating pump  
The stages of the heat generator (then heating pump) should be  
able to switch off below a settable outside temperature.  
Setting range OFF, -20 – +30  
Special handling of heat generator version, setting 3:  
With a setting of heat generator type 3 (2x single-stage), special  
handling with regard to the outside temperature disable occurs so  
that a heating pump can be combined with supplemental heat  
generators. Below a set outside temperature, the heat pump (first  
heat generator) is then disabled, but the supplementary heater  
(second heat generator) remains enabled.  
If no "inverse outside temperature disable" was configured  
("Heat Generator" menu, parameter 38 = OFF), a configured  
"outside temperature disable" ("Heat Generator" menu,  
parameter 25) occurs on both heat generators.  
If an "inverse outside temperature disable" was configured  
("Heat Generator" menu, parameter 25 not OFF), the "inverse  
outside temperature disable" acts on the first heat generator  
(stage 1) and the "outside temperature disable" acts on the  
second heat generator (stage 2).  
NOTE A separate boiler sensor (BS2) must be configured for the second  
heat generator.  
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7.3.10 Other system components  
7.3.10.1 Global fault message input  
Function Activating this function causes the corresponding input to act as a  
switching contact. With the contact closed (short-circuited), the  
fault message input is treated as an additional fault in the control  
system. Intruding fault messages can thus be forwarded via the  
data bus or taken into account via an additional fault message  
output.  
Up to three different fault messages can intrude via variable  
inputs.  
7.3.10.2 Global fault message output  
NOTE This function must be activated in the "Hydraulics" menu for a  
variable output (VO1 or VO2).  
Function The function becomes active on detection of fault messages of  
any kind. It serves as a global fault message output for  
connecting optical or acoustic alarm signal devices.  
7.3.10.3 Timer  
NOTE Only active if setting "14" (timer) was selected for parameter 05  
(direct heating circuit pump output) in the "Hydraulics" menu.  
Function This function controls a consumer according to the current  
switching time program of the direct heating circuit.  
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7.3.10.4 External switching modem  
Function Only activated if setting 11 (external switching modem) was  
selected for parameter 08, 09 or 10 (variable inputs) in the  
"Hydraulics" menu.  
This configuration allows switching between control modes via the  
telephone using a switching modem to be provided by the user  
(for holiday homes etc.).  
Assignment A switching modem can be assigned to each of the three variable  
inputs (VI1 ... VI3). If a variable input is assigned this function, the  
associated parameter appears in the "System" menu for  
assignment of the switching modem to the respective heating  
circuit. The same parameters and areas are involved here as with  
the demand contact, i.e. the modem acts either on the direct  
circuit (DC), mixed heating circuit 1 (MC1), mixed heating circuit 2  
(MC2), hot-water circuit (HW) or the entire system (ALL), i.e.  
globally on all central devices on the data bus system.  
The control mode depends on the wiring at the respective variable  
input in the following way:  
Connection terminal of variable input 1 (2, 3) open:  
Control based on the current control mode (AUTO, RED.  
HEATING, HEATING, STANDBY)  
Connection terminal of variable input 1 (2, 3) short-circuited:  
Control functions in standby mode; heating and hot water are  
switched off frost protected.  
Connection terminal of variable input 1 (2, 3) with terminating  
resistor with 10 kOhm  
Control based on continuous heating.  
Connection terminal of variable input 1 (2, 3) with terminating  
resistor with 2.2 kOhm  
Control based on continuously reduced operation (according to  
specification as reduced or switch-off mode).  
NOTE Only one modem can be connected to each control device.  
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In case of simultaneous access to a heating circuit, the following  
rules apply:  
If multiple variable inputs are configured to the same heating  
circuit, the priority is as follows: variable input 1, variable input  
2, variable input 3.  
If a variable input is assigned to ALL, it has a higher priority  
than a heating circuit assignment  
If multiple variable inputs are configured to ALL, the priority is  
again as follows: variable input 1, variable input 2, variable  
input 3.  
ATTENTION  
Short-circuit or terminating resistor may be connected to  
GND (ground) only.  
7.3.10.5 External information  
Function A temperature value sensed by a standard sensor is displayed as  
an information value in the information display. This function is  
controller-independent and is for information only  
7.3.10.6 Demand contact  
NOTE This function is active for a demand contact if "demand contact"  
was selected for a variable contact and a heating circuit function  
was assigned to the associated output. The heating circuit  
functions are: mixed heating circuit, direct heating circuit, constant  
controller and fixed-value controller.  
Function If a variable input (see note) was defined as a demand contact,  
the corresponding parameter for assigning the contact to the  
respective heating circuit (i.e. the heating circuit to be addressed  
by the demand contact) is displayed in the "System" menu.  
The setting range includes all control circuits within a controller  
(DC, MC1, MC2, HW or ALL) so that the demand contact can be  
assigned either to each individual heating and hot-water circuit or,  
if required, to all circuits.  
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ATTENTION  
No global controller function for data bus system with  
several central devices.  
Control modes and switching time settings are not effective when  
the demand contact is activated. The respective heating circuit  
only responds to requests from the demand contact.  
The control modes manual, emission measurement with safety  
temperature limiter check and screed function are of higher  
priority.  
System information  
An open demand contact is signaled by the string "disable" in the  
status display; a closed contact is identified by the string  
"demand".  
Contact function A variable input that has been defined as a demand contact acts  
on the heating circuit in the following way:  
Variable input open: No demand  
The heating circuit is switched of unconditionally (no frost  
protection, no standby function).  
Variable input short-circuited: Demand  
The heating circuit is in control mode HEATING (continuous  
heating) and works according to its parameter settings.  
ATTENTION  
Customers must take appropriate frost protection measures  
for the respective control circuit.  
This function can be activated up to three times (once for each  
available variable input).  
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7.3.11 Bus communication  
7.3.11.1 Bus address of central device  
Function Control devices SDC and DHC 43 can be connected via a data  
bus. This makes it possible  
to control additional heating circuits by adding up to four  
additional central devices.  
to connect wall devices to the central devices and assign  
heating circuits.  
to cascade multiple heat generators with one built-in central  
device each.  
The following figure shows the maximum possible expansion  
stage of the bus system.  
The individual devices in the SDC/DHC 43 bus system contain a  
unique address. It is set in the corresponding parameter in the  
"Data Bus" menu. Assignment is carried out using the table  
below.  
Address Device type  
Assignment  
10  
20  
30  
40  
50  
SDC/DHC 43  
SDC/DHC 43  
SDC/DHC 43  
SDC/DHC 43  
SDC/DHC 43  
Central device 1 as "base unit"  
Additional central device 2  
Additional central device 3  
Additional central device 4  
Additional central device 5  
NOTE There must always be a control device with the bus address 10 in  
the bus system.  
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Note that bus addresses can only be issued once. Duplicated  
addresses cause problems on the data bus.  
7.3.11.2 Control functions via the data bus  
7.3.11.2.1 Boiler start-up protection  
If the selected heat generator operates with boiler start-up  
protection, it signals the status of start-up protection to all the  
corresponding heating circuits. They block the energy tapping  
(pumps off, mixed heating circuit closed) for the period of the  
start-up protection.  
7.3.11.2.2 Indirect return increase  
The heat generator in the base unit (addr. 10) transmits its current  
boiler data, and each mixed heating circuit in the system can  
carry out indirect boiler return increase.  
7.3.11.2.3 Tank control mode (tank priority operation)  
Each central device can carry out hot-water circuit loading. For  
loading in priority operation, hot-water circuit loading that has  
been started disables all other heating circuits and hot-water  
circuit loading within the bus system. If tank loading occurs in  
parallel operation, all heating circuits in the system remain active  
and an additional hot-water circuit loading with set parallel  
operation can be activated.  
7.3.11.2.4 Heating circuit demand  
Each heating circuit demand within the data bus system is  
processed by the base unit (addr. 10). It takes on the greatest  
demand and passes it on to the heat generators as a setpoint  
value. A selected manual mode with manual temperature  
specification also counts as demand.  
7.3.11.2.5 Clock synchronisation  
The time of day is sent to the entire system by the base unit  
(addr. 10). There is a system time.  
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7.3.11.2.6 Room temperature transmission  
The wall devices send their current room temperature to the  
assigned heating circuit at regular intervals.  
7.3.11.2.7 Fault messages/Status indications  
Fault messages and status indications are sent from the central  
device to the associated wall units and displayed there.  
7.3.11.2.8 Examples with multiple control devices  
Heating system with a two-stage heat generator, industrial water  
production and four mixed heating circuits. The following diagram  
shows the hydraulics of this system.  
Example 1  
b
a
a Boiler  
b
Hot-water tank  
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The following components are connected to the first controller  
with bus address 10:  
Outside sensor  
Stages 1 and 2 of the burner  
Boiler sensor  
Tank sensor  
Tank loading pump  
Mixed heating circuit pump, mixed heating circuit open/closed  
and flow sensor of heating circuit 1  
Mixed heating circuit pump, mixed heating circuit open/closed  
and flow sensor of heating circuit 2  
The following components are connected to the second control  
device with bus address 20:  
Mixed heating circuit pump, mixed heating circuit open/closed  
and flow sensor of heating circuit 3  
Mixed heating circuit pump, mixed heating circuit open/closed  
and flow sensor of heating circuit 4  
Heating system with a two-stage heat generator, two mixed  
heating circuits and two industrial water loadings (used, for  
example, for a duplex with one heat generator). The following  
diagram shows the hydraulics of this system.  
Example 2  
b
b
a
a Boiler  
b
Hot-water tank  
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7.3.11.2.9 Correction of the heat generator after the total flow  
temperature  
Total flow sensor The sensor connected to variable input 1 (2, 3) measures the total  
flow temperature in thermohydraulic distributors or in the common  
flow.  
Correction of the boiler temperature no longer occurs based on  
the measured temperature of the boiler sensor, but rather based  
on the total flow sensor. The boiler sensor still checks the boiler  
minimum and maximum temperatures of the heat generator.  
Using a PI control algorithm, the behaviour of the heat generator  
can be influenced by a deviation between the total flow setpoint  
temperature and the total flow actual temperature.  
The PI controller can be influenced via three setting options:  
P-part:  
Proportional part of the controller  
Sample time: The sample time is a controller-internal value  
which defines the time interval between two  
subsequent actuator pulses in the presence of a  
control deviation.  
Adjustment  
time:  
The adjustment time determines the dynamic  
behaviour of the controller based on the set  
sample time.  
Important note for parameter setting:  
The factor for the I-part within the controller is related to the  
parameter setting values as follows:  
(Ki = factor for the I-part, Ta = sample time, Tn = adjustment time)  
Ta  
Ki = Kp  
Tn  
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Example  
Initial values:  
P-part = 0.5%/K  
Sample time = 20 sec.  
Adjustment time = 600 sec.  
Total flow setpoint (w) = 68°C  
Total flow actual value (x) = 53°C  
SVLF setpoint  
SVLF actual  
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7.3.11.3 Operation of wall devices  
7.3.11.3.1 Operation of digital wall device SDW 30  
Function A digital wall device SDW 30 can be connected to the control  
device.  
With a digital wall device, remote control for a central device (e.g.  
from a living room) is possible in addition to the room temperature  
detection. Settings can be carried out for all the existing heating  
circuits.  
The bus address of the wall device is used to specify the heating  
circuit on which the room sensor (room influence) is to act.  
When an SDW 30 is connected for the first time to the bus  
system, the address is selected for the heating circuit to which the  
SDW 30 is to be assigned (bus address).  
After the input has been confirmed, feedback of the heating circuit  
(DC, MC1, MC2) and the central unit (CU) to which the digital wall  
device has been assigned is output.  
Assignment is carried out on the basis of the following table:  
Address CD address Assignment  
11  
12  
13  
21  
22  
23  
31  
32  
33  
41  
42  
43  
51  
52  
53  
10  
10  
10  
20  
20  
20  
30  
30  
30  
40  
40  
40  
50  
50  
50  
CU 1 – Direct heating circuit  
CU 1 – Mixed heating circuit 1  
CU 1 – Mixed heating circuit 2  
CU 2 – Direct heating circuit  
CU 2 – Mixed heating circuit 1  
CU 2 – Mixed heating circuit 2  
CU 3 – Direct heating circuit  
CU 3 – Mixed heating circuit 1  
CU 3 – Mixed heating circuit 2  
CU 4 – Direct heating circuit  
CU 4 – Mixed heating circuit 1  
CU 4 – Mixed heating circuit 2  
CU 5 – Direct heating circuit  
CU 5 – Mixed heating circuit 1  
CU 5 – Mixed heating circuit 2  
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ATTENTION  
Double assignments of bus addresses are not permissible  
and inevitably lead to errors in data transmission and thus to  
faulty control behaviour of the heating system.  
Changing bus addresses  
A bus address can be changed at a later time using the following  
procedure:  
Disconnect wall devices from the data bus line (disconnect  
plug connection at the bottom of the device)  
Reconnect the wall device, holding the input button pressed  
down until the address setting screen is displayed.  
Set and confirm the new bus address.  
7.3.11.3.2 Operation with wall device SDW 10  
Function A wall device SDW 10 can be connected to the control device.  
With an SDW 10, it is possible to detect the room temperature,  
adjust the room setpoint temperature and change the control  
mode for a heating circuit remotely. The settings only apply for the  
assigned heating circuit.  
The bus address of the wall device is used to specify on which  
heating circuit the room sensor and the adjustment of the control  
mode are to act.  
The connection is carried out via the data bus.  
Setting the bus The address of the SDW 10 is set by means of the rotating  
address encoding switch on the inside of the wall device in accordance  
with the following table:  
Address CU address Assignment  
0
1
2
3
4
5
6
Undefined  
Undefined  
10  
10  
10  
20  
20  
20  
CU 1 – Direct heating circuit  
CU 1 – Mixed heating circuit 1  
CU 1 – Mixed heating circuit 2  
CU 2 – Direct heating circuit  
CU 2 – Mixed heating circuit 1  
CU 2 – Mixed heating circuit 2  
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Address CU address Assignment  
7
30  
30  
30  
40  
40  
40  
50  
50  
50  
CU 3 – Direct heating circuit  
8
CU 3 – Mixed heating circuit 1  
CU 3 – Mixed heating circuit 2  
CU 4 – Direct heating circuit  
CU 4 – Mixed heating circuit 1  
CU 4 – Mixed heating circuit 2  
CU 5 – Direct heating circuit  
CU 5 – Mixed heating circuit 1  
CU 5 – Mixed heating circuit 2  
9
A
B
C
D
E
F
Current room The integrated room sensor determines the current room  
temperature sensing temperature for all the room temperature-related functions and  
transfers them to the central device every 20 sec.  
Control mode  
selection  
The desired control mode is selected with the input button î  
(press and hold approx. 2 – 3 seconds) and indicated by the  
corresponding LED. When the button is pressed, the control  
mode is adjusted in the following sequence:  
AUTOMATIC MODE – HEATING – LOWERING – AUTOMATIC  
MODE - ...  
After control mode selection, the selected control mode is  
transferred to the central device. Only the control mode of the  
heating circuit to which the SDW 10 is assigned is transferred.  
Automatic mode The heating circuit is controlled constantly in accordance with the  
specification of the automatic program P1 – P3 set in the central  
device plus or minus the room setpoint correction at the input  
button.  
Heating The heating circuit is controlled constantly in accordance with the  
desired daytime room temperature plus or minus the room  
setpoint correction at the input button.  
Reduction The heating circuit is controlled constantly in accordance with the  
reduced room temperature plus or minus the room setpoint  
correction at the input button. The function depends on the setting  
in the parameter selection for the heating circuit (reduced  
parameter).  
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Room setpoint The input button can be used to modify the room temperature set  
correction at the central device by +/-6 K referenced to the central position.  
Turn clockwise: Temperature increase  
Turn anti-clockwise: Temperature decrease  
Display The indicator display is comprised of three LEDs. The possible  
states are listed in the table below:  
Control mode/Function Moon LED Clock LED Sun LED  
Automatic  
OFF  
OFF  
ON  
ON  
OFF  
ON  
Permanent heating  
Permanent reduction  
Start-up phase  
OFF  
OFF  
BRIEF  
OFF  
BRIEF  
BRIEF  
FLASHING FLASHING FLASHING  
FLASHING ON ON  
FLASHING ON  
Error at address setting  
Bus fault as well as  
indication when  
ON  
parameters are disabled  
Party (can be set via  
central device)  
OFF  
OFF  
FLASHING  
Absent (can be set via  
central device)  
FLASHING OFF  
OFF Flash  
OFF  
OFF  
Holiday (can be set via  
central device)  
Definition:  
Flashing:  
0.8 sec. on and 0.8 sec. off  
0.08 sec. on and 0.7 sec. off  
Brief  
flashing:  
Flash:  
0.08 sec. on and 1.4 sec. off  
The operation indication is updated immediately after adjustment  
when adjusted at the SDC 10 and at the latest after about 20 sec.  
after adjustment when adjusted at the central device.  
NOTE In all other control modes not defined in the table above, all three  
LEDs are activated.  
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7.3.11.3.3 Operation with NTC 20K room temperature sensor  
Instead of the RFF, an NTC 20 room sensor can be connected to  
a sensor input (VI1-VI3)  
Function Configuration is carried out in the "Hydraulics" menu, parameter  
08, 09 or 10.  
Assignment to the heating circuit to be acted upon by the room  
sensor is carried out via a fixed heating circuit assignment using  
parameter settings (e.g. 30 = DC, 31 = MC1, 32 = MC2)  
The combined operation of an NTC 20 room sensor and an SDW  
10/SDW 30 room sensor for a heating circuit is not possible. If an  
SDW 10/SDW 30 room sensor is connected, it always has first  
priority. In this case, the NTC 20 room sensor has no effect. With  
operation via a connected SDW 30 (room sensor with no effect),  
an NTC 20 room sensor can be combined with a variable input.  
With an NTC 20 room sensor connected, all room functions of the  
heating circuit are in effect ("Direct Heating Circuit", "Mixed  
Heating Circuit 1" or "Mixed Heating Circuit 2" menu, parameter 4  
= active). In conjunction with the NTC 20 room sensor, this means  
a shift of the controller (software) to the central device. The  
configuration of the room controller with NTC 20 room sensor  
operation occurs via additional parameters in the central device  
menu trees DC/MC1/MC2. The room controller in the SDW 30  
functions as before. Room control in conjunction with SDW 10 is  
not possible.  
7.3.11.3.4 Heating circuit bus authorisation  
Function This setting serves to determine the authorisation status of a  
room station connected to a heating circuit. One parameter per  
available heating circuit is available for this setting.  
Set value Simple access authorisation  
Only switching times and parameters of the specific heating  
circuit concerned can be read and modified. On call-up, only the  
information for the heating circuit concerned are displayed to the  
respective user (operator).  
Application Tenant status  
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Extended access authorisation  
This authorisation status allows access to all heating circuits and  
to the hot-water circuit and their parameters and switching times  
within the respective central device  
Application Landlord status  
NOTE Once a wall device is connected and registered via the data bus  
to the central device, the central device automatically switches to  
remote operating mode! This is necessary to ensure clear  
operation of the system with connected wall devices.  
7.3.12 Cascading of heat generators in the bus system  
7.3.12.1 General description of cascading of control devices  
Function In its standard version the control system features the possibility  
to couple and cascade several boilers. The cascade control is  
independent of the type of heat generators to be combined. For  
instance, condensing boilers can be easily combined with  
atmospheric gas boilers.  
The system automatically recognises a cascade by checking if  
several central devices have programmed a heat generator, or if  
more than one condensing boiler is connected to a central device.  
In cascade operation an additional cascade selection level is  
displayed for handling the parameters in the central device  
assigned to bus address 10.  
NOTE Cascade operation excludes 2-stage boiler control. All available  
stages are operated by the cascade management. Consequently,  
the respective parameters of the "Heat Generator" menu are not  
available. All control is now governed by cascade control.  
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7.3.12.2 Function of the cascade parameters  
Switching differential Each heat generator has its own switching differential. The  
cascade switching differential must be set in such a way that it is  
always larger than the switching differential of any individual heat  
generator.  
Connection delay The afterheating characteristics of the boilers used must be taken  
into account when rating the heating system. The cascade switch-  
on delay is used to adjust the system to the start-up delays of the  
individual boilers. When does the heat generator deliver its  
energy into the system after being switched on (start-up phase,  
pre-running time)? The appropriate setting is the maximum delay  
time of the boilers in the system.  
Deactivation delay To prevent all heat generators switching off simultaneously if the  
set cascade switching differential is exceeded, the run-down of  
heat generators is controlled by the switch-off delay. The setting  
has to be adjusted to the afterheating characteristics of the heat  
generators.  
Stage reversal To ensure the balanced utilisation of the heat generators within a  
cascade, a runtime-dependent leading stage swap can be  
activated.  
After the set operating time of the presently leading heat  
generator has passed, the system switches to the heat generator  
with the next higher bus address.  
Stage swap can only be executed between several central  
devices. It cannot be applied if several condensing boilers are  
switched by a single central device.  
Guidance stage The leading cascade stage can still be set manually to any  
existing stage even when automatic stage-sequence switching is  
disabled.  
NOTE Changing the heat generator type within the central device at  
address 10 leads to an automatic reset of the leading stage to the  
first heat generator.  
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7.3.12.3 Mode of operation of cascade control  
7.3.12.3.1 Switch-on characteristics  
The switch-on characteristics of the boiler stages are determined  
by the set switching differential and the dynamic switch-on delay.  
The stage number is incremented only when the following criteria  
are fulfilled:  
BTACTUAL < BTSETPOINT – SD/2  
t >= tSwitch-on delay * (100 – (dVT * 100 / VLSetpoint) ) / 100  
StagesNumber = StagesSelection  
The boiler temperature of the leading boiler or the total flow  
sensor must have exceeded the specified boiler setpoint minus  
half of the switching differential (switch-on delay time) for at least  
the calculated switch-on delay. Additionally, the requested stage  
number must have been sent to central device 10 as the active  
status response.  
7.3.12.3.2 Switch-off characteristics  
The stage number is decreased again as soon as the temperature  
of the leading boiler or of the total flow sensor exceeds the  
present setpoint boiler temperature plus half of the switching  
differential for at least the calculated switch-off delay time.  
BTACTUAL > BTSETPOINT – SD/2 or BTACTUAL >= BTMAX  
t >= tSwitch-on delay * (100 – (dVT * 100 / VLSetpoint) ) / 100  
StagesNumber = StagesSelection  
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7.3.12.3.3 Control characteristics  
The heat generator that was switched on last adjusts the  
system to the set nominal temperature.  
All other heat generators operate at the set maximum  
temperature (base load).  
The boiler stage number can be reduced as soon as the  
adjusting stage has withdrawn its demand to the heat  
generator and the boiler temperature has risen above the  
setpoint temperature plus the set switching differential.  
For each heat generator the displayed setpoint temperature  
always is the currently demanded temperature to be adjusted  
to.  
A heat generator that is not available in the system  
(malfunction, external disable or outside temperature disable)  
is ignored within the stage sequence. The next available heat  
generator will be switched on instead.  
7.3.12.3.4 Delay, enabling, full load in cascade operation  
The switch-over power set within the cascade selection level is  
only intended for the operation of automatic stokers. As long as  
the last burner stage is not started, all burner stages up to that  
point which are currently operating are reduced to the specified  
switch-over power (power limit). When switching on the last  
burner stage, all other automatic stokers are enabled to 100%  
power (full load) after another progression of the dynamically  
determined switch-on delay (at least 5 min.).  
If the system is operating with all available stages, no power limit  
is active for the automatic stokers. If a level is reduced, the set  
switch-over power for the automatic stokers is once again in  
effect.  
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Grouping for base and peak loads (ANF118-V2.2  
specifications)  
High quality, expensive condensing boilers are used for the base  
load, especially with gas systems. During cold months, low-  
temperature boilers are used for covering peak loads. It is  
necessary that an activated stage reversal only affect the base  
load boiler here. The peak-load boilers are excluded from the  
stage reversal.  
Function The configuration defines which peak load heat generator is the  
first one (all heat generators with addresses greater than or equal  
to the setting).  
The time-based stage reversal (see "Cascading" menu,  
parameter 05) only affects the connected base-load boiler  
(smaller address setting).  
The first peak-load boiler is not switched on until the base-load  
boilers are operating at 100%.  
If grouping was carried out via the configuration and the peak-  
load boiler was in demand, a change of the leading group can be  
activated via a parameter. If this parameter is set to ON, the group  
of peak-load boilers take over the base load upon demand and  
the base-load boilers take over adjustment of the flow  
temperature. Further switching of stages is still only active for the  
actual base-load boilers.  
7.3.12.3.5 Special function characteristics  
Manual mode The heating circuits of the control device in which manual  
operation was activated, operate according to the manual  
function. The set demand value is forwarded to the energy  
management module of cascade control and adjusted to by the  
available boiler stages.  
Emission measurement This function works as described under "Emission measurement",  
with the following extensions:  
The effect on heating circuits is extended to all heating circuits  
of the system.  
Enabling of the heat generators (burner) is initiated at the  
same devices where emission measurement was activated.  
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Safety temperature This function works as described under "Safety temperature  
limiter limiter check", with the following extension:  
As soon as a safety temperature limiter function is detected within  
the BUS system, all consumers (heating circuits) are disabled.  
Emergency mode Configuration of cascade control occurs in the central device with  
the bus address 10. If that controller becomes unavailable due to  
some defect, the remaining stages continue operating in an  
emergency mode. In this mode all heat generators adjust to the  
same boiler setpoint temperature (parallel operation). As soon as  
the cascade manager comes back into operation, cascade control  
is reactivated automatically.  
Data transmission To enable the cascade function to process fast switching events,  
the cascade data are transferred with a higher priority.  
Consequently, the data transmission from any device to the  
master device, and of the request values from the master to the  
slave devices, takes no longer than approx. 3 seconds.  
7.3.13 Commissioning, maintenance and troubleshooting help  
7.3.13.1 Automatic set function  
Function The central devices are equipped with a function which ignores  
unused sensors and control functions. Fault messages from non-  
connected sensors are not displayed.  
The AUTO SET function is only active at power up. There are two  
possibilities for calling up the AUTO SET function.  
Automatic call-up If the commissioning date has not yet been stored and the  
corresponding system parameters for activating this function are  
set to ON, connected or disconnected sensors are registered  
automatically whenever the control device is switched on. Fault  
messages from sensors (short-circuit interruption) are suppressed  
in this period. After the commissioning date has been saved, a  
change to the sensor configuration is only still possible after the  
manual SET function. The AUTO SET function can be enabled at  
any time again for a day (day change) using the system  
parameter.  
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Manual call-up Manual call-up of the AUTO SET function is always possible. The  
call-up is activated by pressing the input button during the version  
display until the AUTO SET function is shown in the display. The  
basic display is activated after the function has been carried out.  
A change in the function assignment by the AUTO SET function is  
only carried out depending on the following inputs and selected  
configuration:  
Input  
Only executed if:  
Outside sensor (AF)  
Flow sensor 1 (VF1) MC1:  
OFF/Mixed heating circuit  
valve  
Flow sensor 2 (VF2) MC2:  
OFF/Mixed heating circuit  
valve  
Tank sensor  
Boiler sensor  
(SF)  
(KF)  
SLP:  
BR:  
OFF/Tank loading pump  
OFF/Single-stage  
The current setting values are checked beforehand so that the  
configuration carried out is not changed by the AUTO SET  
function. A change is only carried out if one of the settings  
specified above is applicable. This ensures that the AUTO SET  
function cannot, for example, ever log off a return increase at the  
MC2 or re-function it into a mixed heating circuit.  
7.3.13.2 Emission measurement (not for DHC 43)  
By pressing this key, the heat generator is controlled for 20  
minutes according to the maximum temperature limit. The  
remaining time is displayed and counted down.  
With two-stage heat generators, both stages are in operation  
(measurement at nominal power).  
Function The heat generator is adjusted to the maximum heat generator  
temperature. All heating circuits and the hot-water production  
adjust their setpoint to the respective maximum temperature.  
ATTENTION  
There is danger of scalding because the hot-water  
temperatures may rise above the setpoint temperature.  
Application Emission measurement via chimney sweep  
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Cancellation Emission measurement can be terminated at any moment in  
advance with the key.  
Safety check Safety temperature limiter check may be performed only by the  
technician  
Function  
By keeping the input button îpressed during an emission  
measurement, the integrated heat generator maximum  
temperature limit is bypassed and the heat generator remains in  
operation continuously until the safety temperature limiter (STL) is  
triggered. During the safety temperature limiter check, all the  
consumers are separated from the heat generator, i.e. any  
available mixed heating valve is closed and all the heating and  
hot-water loading pumps are stopped. The emission  
measurement is continued from the moment of termination with  
the previously saved remaining time.  
Application Safety temperature limiter check by the heating technician  
Cancellation Release the input button. The emission measurement still active  
is stopped with the  
key.  
7.3.13.3 Relay/function test  
Function Depending on the controller version, various outputs can be  
tested. This is not only a relay test, but a function test by means  
of which the hydraulic components are tested. The partially  
compulsory sequence of the switching procedures is considered  
here.  
After selecting the test function, the relevant relays can be  
switched one after the other by pressing the input button îin the  
specified switching sequence.  
Heat generator Heat generator test  
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Single-stage heat generator  
("Heat Generator" menu, parameter 1 = 1)  
Switching sequence:  
OFF, ON, OFF ...  
2-stage heat generator  
("Heat Generator" menu, parameter 1 = 2)  
Switching sequence: OFF, STAGE 1, STAGE 1+2,  
STAGE 1, OFF ...  
2x single-stage heat generators  
("Heat Generator" menu, parameter 1 = 3)  
Switching sequence:  
OFF, HG 1, HG 1+2, HG 2, OFF ...  
Modulating mode  
("Heat Generator" menu, parameter 1 = 4)  
Switching sequence:  
OFF, ON, OPEN, STOP, CLOSED,  
OFF ...  
Pumps/VOs Pump test  
(Direct heating circuit pump, mixed heating circuit pump, tank  
loading pump, variable output 1, variable output 2)  
Switching sequence  
OFF, ON, OFF, ...  
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Mixer motor: Mixed heating circuit actuator test  
Switching sequence STOP, OPEN, STOP, CLOSED,  
STOP ...  
Function For easier diagnosis by the technician, a test run that detects  
implausibilities in the system has been implemented.  
The jump occurs via an additional item in the relay test. The test  
run is started by pressing the input button. The sensor test  
sequence is similar to the final device test.  
Value  
Range  
OT  
–50°C – 40°C  
10°C – 90°C  
5°C ... 90°C  
0°C ... 40°C  
5°C – 90°C  
5°C – 90°C  
5°C – 90°C  
VF  
SF  
RT (SDW 10/SDW 30)  
SVLF  
SBUS  
VF1 (evaluation as NTC 20,  
not PT 1000)  
VF2  
VF3  
5°C – 90°C  
5°C – 90°C  
Confirmation is required for each sensor value. All available  
inputs are checked. Unoccupied inputs are marked with "–".  
Meaning  
Display  
80°C  
Value OK  
Value outside the sensible  
range  
IRR  
Short-circuit/Interruption  
Error, –  
Error, –  
Function programmed,  
but no sensor at input  
No function programmed,  
but a sensor is at input  
Error  
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Bus test  
The system configuration is conveyed via the SMILE BUS.  
Display occurs using an overview representation for a central  
device.  
The following are displayed:  
Central devices in the system network  
Wall devices that are directly assigned to the corresponding  
central device  
Display  
Bottom right: Address of the operated central device  
Bottom left:  
Display of the control network (1 = ZG10,  
2 = ZG20, 3 = ZG30)  
Top:  
Display of the peripheral devices of operated  
central device 1, 2, 3 = wall devices DC, MC1,  
MC2 assigned to operated controller  
Example:  
The central device is operated at address 10. Two central devices  
are found in the bus system (addr. 10 and 20). A wall unit MC1 is  
connected (addr. 12) to central device 10. An additional mode is  
found in the bus system (9).  
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7.4 Error messages  
ATTENTION  
Inform the heating technician whenever any fault messages  
are output.  
The control device contains substantial error-notification logic.  
The error messages appear in continuous alteration with the basic  
display. Multiple errors that occur at the same time appear one  
after another in the order in which they occurred. The following  
types of error message exist:  
Sensor error Sensor measured values that do not lie in the measurement  
messages range are evaluated as an interruption or short-circuit. They  
appear depending on the type and allocation with fault code 10 to  
20 and index 0 for short-circuit or 1 for interruption.  
Heat generator error These error messages evaluate the respective switching status.  
messages They appear depending on the type and allocation with fault code  
30 to 40 and index 0, 1 or 2.  
Logical error These error messages evaluate the control result to be expected.  
messages They appear depending on the type and allocation with fault code  
50 to 60 and index 0, 1 or 2.  
Bus error messages These error messages refer to address faults such as double  
issuance or non-recognition of address settings on the data bus.  
They appear with fault code 70 and index 0 or 1, depending on  
the type and assignment.  
The display and further processing of logical fault messages can  
be suppressed through corresponding configuration.  
Detected faults are proceed via:  
Display in the basic display of the controller  
System fault via display on the information level with the  
corresponding information value  
Inclusion in the fault log (see below for description)  
If activated, via switching of a fault message output  
Forwarding via the data bus  
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Fault messages  
Fault status Designation  
Fault type  
Fault object  
code  
Remark  
System  
System  
System  
System  
System  
Outside sensor  
Outside sensor  
Boiler sensor  
Boiler sensor  
Flow sensor 1  
Interruption  
Short-circuit  
Interruption  
Short-circuit  
Interruption  
10-0  
10-1  
11-0  
11-1  
12-0  
MCP = off,  
MIMO = de-energised  
System  
Flow sensor 1  
Short-circuit  
12-1  
MCP = off,  
MIMO = de-energised  
System  
System  
System  
System  
System  
System  
System  
System  
System  
System  
System  
System  
Tank sensor  
Tank sensor  
VI-2  
Interruption  
Short-circuit  
Interruption  
Short-circuit  
13-0  
13-1  
14-0  
14-1  
VI-2  
VI-2  
Fault message 14-7  
VI-3  
Interruption  
Short-circuit  
15-0  
15-1  
VI-3  
VI-3  
Fault message 15-7  
VI-1  
Interruption  
Short-circuit  
16-0  
16-1  
VI-1  
VI-1  
Fault message 16-7  
Buffer sensor of  
collector  
Interruption  
Short-circuit  
Interruption  
Short-circuit  
Interruption  
Short-circuit  
Interruption  
17-0  
17-1  
18-0  
18-1  
19-0  
19-1  
20-0  
System  
System  
System  
System  
System  
Buffer sensor of  
collector  
Flow sensor 2  
MCP = off,  
MIMO = de-energised  
Flow sensor 2  
MCP = off,  
MIMO = de-energised  
Flow sensor of  
collector  
Flow sensor of  
collector  
System  
Room sensor  
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Fault messages  
Fault status Designation  
Fault type  
Fault object  
code  
Remark  
(RSC/RS)  
System  
Room sensor  
(RSC/RS)  
Short-circuit  
20-1  
System  
System  
System  
System  
System  
System  
Burner 1  
Burner 1  
Burner 2  
Burner 2  
Heat meter  
No switch-off 30-2  
No switch-on 30-3  
No switch-off 31-2  
No switch-on 31-3  
No pulse  
32-3  
33-5  
Flue gas  
Overshoot  
temperature  
System  
Flue gas  
STL triggered 33-8  
temperature  
logical  
logical  
logical  
Boiler temperature Not reached  
Tank temperature Not reached  
50-4  
51-4  
52-4  
MC1 flow  
Not reached  
temperature:  
logical  
logical  
logical  
logical  
System  
MC2 flow  
temperature  
Not reached  
53-4  
54-4  
55-4  
56-4  
70-0  
Room temperature Not reached  
HC  
MC1 room  
temperature  
Not reached  
MC2 room  
temperature  
Not reached  
Address  
Address  
collision  
System  
System  
System  
System  
Activity  
No T2B signal 70-1  
EEPROM  
71-0  
71-1  
EEPROM defect  
Pulse input fault  
No signal  
Lock  
90-0  
Fault message if no  
signal after 5 minutes  
System  
Fault  
EnXX  
Automatic stoker fault  
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Fault messages  
Fault status Designation  
Fault type  
Blocking  
Fault object  
code  
Remark  
Automatic stoker fault  
System  
Fault  
EnXX  
Fault message log The control device has a fault message log in which a maximum  
of five fault messages can be saved. The fault messages are  
displayed with the date, time and fault type (fault number); the  
query is carried out in the sequence of the entered fault  
messages in the "Fault Message" menu.  
The last (most recent) fault message is in first position (No. 01);  
the previous fault messages are shifted down by a position upon  
each new fault message. The fifth fault message is deleted when  
a new fault message appears.  
If a heat generator defect occurs (fault message 30-1 or 31-3) and  
system frost protection is active at the same time, boiler start-up  
protection is switched off and thus the heating circuit pumps are  
started to minimise the danger of system freezing.  
Fault message Five fault messages from automatic stokers (condensing  
log expansion versions) with OpenTherm  
These fault messages come from automatic stokers and are  
categorised as either locks, blockages or warnings.  
The display and further processing of logical fault messages from  
the SMILE system can be enabled or suppressed via a  
corresponding configuration (see "System Parameters" menu,  
parameter 13 (logical fault message)).  
The display and further processing of fault messages from a  
connected automatic stoker can be controlled as follows.  
Using parameter 27 in the "System Parameters" menu, you can  
specify which of the fault messages transmitted by an automatic  
stoker is forwarded to the SMILE system.  
Using parameter 28 in the "System Parameters" menu, you can  
specify whether or not fault messages of an automatic stoker are  
to be written to a separate fault memory. If the parameter is set to  
ON, another menu appears in the menu with the designation  
"Fault 2". Only faults of the automatic stokers are saved in this  
fault memory.  
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Additional fault processing:  
Faults appear in the basic display of the controller. System faults  
appear on the information level with the corresponding  
information value. Faults may be copied to the fault message log  
(see below for description). If configured accordingly, faults  
activate a fault message output to the connection of an optical or  
acoustic transducer and are forwarded to the corresponding  
gateways.  
With connection of an automatic stoker, further fault messages  
may arrive from it. They are displayed as follows:  
Fault type  
Fault  
code  
Field 1  
Field 2 Field 3  
HIGH  
Water  
pressure  
S0-1  
S0-5  
S0-2  
S1-0  
Water pressure  
Water pressure  
Water pressure  
Water  
pressure  
LOW  
Water  
pressure  
MIN  
Ventilation  
Ventilation  
Maintenance  
Switch-off  
Service  
Maintenance S2-0  
Switch-off  
Service  
OFF  
240-1  
Fault message log The control unit features two fault message logs (FAULT  
MESSAGE for system faults and FAULT 2 for faults from  
automatic stokers), in which max. 20 fault messages can be  
saved. The fault messages are displayed with their date, time and  
fault type (fault number). The query is carried out in the sequence  
of the entered fault messages in the "Fault Message" menu.  
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The last (most recent) fault message is in first position; the  
previous fault messages are shifted down by a position with each  
new fault message. The fifth fault message is deleted when a new  
fault message appears.  
Operating  
information  
Key/Menu  
Parameter  
13  
Display of logical  
fault messages  
SYSTEM  
Fault memory  
inquiry  
FAULT MESSAGE  
ERR-1 . ERR-5  
NOTE In the case of condensing systems with automatic stokers, the  
outside sensor input can be used to switch off the heating system.  
A sensor short-circuit at the outside sensor suppresses a fault  
message regarding this and switches off the system. The  
message "Heating system off" appears instead of the fault  
message in this case.  
If a heat generator defect occurs (fault message 30-1 or 31-3) and  
system frost protection is active at the same time, boiler start-up  
protection is switched off and thus the heating circuit pumps are  
started to minimise the danger of system freezing.  
7.4.1 Basic display/fault stack fault messages  
With connection of an automatic stoker, further fault messages  
may arrive from it. They are displayed as follows.  
Fault type  
Fault  
code  
Field 1  
Field 2 Field 3  
HIGH  
Water  
pressure  
S0-1  
S0-5  
S0-2  
S1-0  
Water pressure  
Water pressure  
Water pressure  
Water  
pressure  
LOW  
Water  
pressure  
MIN  
Ventilation  
Ventilation  
Maintenance  
Switch-off  
Service  
Maintenance S2-0  
Switch-off  
Service  
OFF  
240-1  
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7.4.1.1 Sensor calibration  
Function If the measured values of the connected sensors do not match  
the actual temperatures, a comparison of the sensor values is  
possible in the "Sensor Comparison" menu. In this menu, all  
sensors connected to the device can be corrected by ±5 K based  
on the factory calibration value.  
The current measured value, plus or minus the correction made  
and the correction itself, appears in the display. The increment of  
the compensation is 0.5 K.  
ATTENTION  
The sensor circuits are calibrated at the factory using precise  
measuring equipment. Compensation should only be carried  
out if you are sure that the amount of the deviation remains  
constant over the entire measurement range.  
With sensor compensation, the respective amount must be  
noted down, as otherwise the factory setting is no longer  
valid and the reference value is lost.  
The original factory setting cannot be restored via a reset!  
Application Compensation in the case of very longer sensor cables  
Constant external temperature influence on sensors  
7.4.1.2 Full controller reset  
To revert the controller to its state of delivery, a full reset can be  
performed. Here, all parameters, values and counters accessible  
via the enabled code are reset and the controller is restarted.  
Values that are not accessible via the set access code remain in  
tact.  
Activation  
Press the ¢, ¥, ¦and §keys simultaneously  
7.4.1.3 Controller time correction  
In some special cases it may be necessary to adjust the runtime  
of the clock integrated in the controller. Please contact the  
manufacturer if necessary.  
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8 Technical data  
8.1 General  
Mains connection  
voltage  
230 V +6 % / –10 %  
Rated frequency  
50 ... 60 Hz  
Power consumption  
Pre-fuse  
max. 5.8 VA  
max. 6.3 A slow-blowing  
2 (2) A  
Contact load of the  
output relays  
Bus interface  
For the connection of external devices (wall device, PC, modem  
or gateway)  
Max. bus length  
50 m  
Power supply via bus  
Ambient temperature  
Storage temperature  
Degree of protection  
12 V/150 mA  
0 ... +50°C  
–25 ... +60°C  
IP 30  
Protection class as per II  
EN 60730  
Protection class as per III  
EN 60529  
Radio protection  
EN 55014 (1993)  
Interference resistance EN 55104 (1995)  
EC conformity  
89/336/EEC  
Housing dimensions  
Housing material  
144 x 96 x 75 mm (W x H x D)  
ABS with static inhibitor  
Connection technology Plug-in screw terminal connections  
250  
EN2H-0221GE51 R0808  
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SDC / DHC  
Technical data  
8.1.1 Installation recommendations  
Mains voltage lines  
(mains connection, burners, pumps, servo motors):  
Diameter  
1.5 mm2  
Max. permissible length  
Safety low-voltage lines  
No limit for installation in buildings.  
(sensors, ext. switches upon demand via switching contact, modem connection lines, analog  
signal lines etc.)  
Diameter  
0.5 mm2  
Max. permissible length  
100 m (looped circuit); longer connection lines should be avoided  
to prevent the risk of interference  
Data bus lines  
Diameter  
0.6 mm2  
Max. permissible length  
50 m (looped circuit, longest distance between a central device  
and a device to be supplied); longer connection lines should be  
avoided to prevent the risk of interference.  
Recommended layouts  
J-Y(St)Y 2 x 0.6  
8.2 Sensor resistance values  
8.2.1 NTC 20  
For outside sensor (OT), heat generator sensor (BLRS/BS), tank  
sensor (DHWS), mixed heating circuit 1 flow sensor (VF1), mixed  
heating circuit 2 flow sensor (VF2), variable input 1 (VI-1) (setting  
not for exhaust gas sensor), variable input 2 (VI-2), variable input 3  
(VI-3), collector tank/buffer sensor (SBUS).  
°C  
k  
°C  
0
2
4
6
kΩ  
°C  
20  
25  
30  
35  
40  
45  
50  
55  
60  
65  
kΩ  
°C  
70  
75  
80  
85  
90  
95  
100  
kΩ  
–20  
–18  
–16  
–14  
–12  
–10  
–8  
–6  
–4  
–2  
220.6  
195.4  
173.5  
154.2  
137.3  
122.4  
109.2  
97.56  
87.30  
78.23  
70.20  
63.04  
56.69  
51.05  
46.03  
41.56  
37.55  
33.97  
30.77  
27.90  
25.34  
20.00  
15.88  
12.69  
10.21  
8.258  
6.718  
5.495  
4.518  
3.734  
3.100  
2.587  
2.168  
1.824  
1.542  
1.308  
1.114  
8
10  
12  
14  
16  
18  
EN2H-0221GE51 R0808  
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Technical data  
SDC / DHC  
8.2.2 PT 1000  
For variable input 1 (VI-1) (setting of exhaust gas sensor),  
collector flow sensor (SPFS)  
°C  
°C  
°C  
°C  
0
1000.00  
1039.02  
1077.93  
1093.46  
1116.72  
1155.39  
1193.95  
1232.39  
1270.72  
1289.84  
80  
1308.93  
1327.99  
1347.02  
1366.03  
1385.00  
1403.95  
1422.86  
1441.75  
1460.61  
1498.24  
140  
150  
160  
170  
180  
190  
200  
220  
240  
260  
1535.75  
1573.15  
1610.43  
1647.60  
1684.65  
1721.58  
1758.40  
1831.68  
1904.51  
1976.86  
280  
300  
320  
340  
360  
380  
400  
450  
500  
2048.76  
2120.19  
2191.15  
2261.66  
2331.69  
2401.27  
2470.38  
2641.12  
2811.00  
10  
20  
25  
30  
40  
50  
60  
70  
75  
85  
90  
95  
100  
105  
110  
115  
120  
130  
8.3 Sensor measurement ranges  
Designation  
Brief description  
Sensor type  
Measurement  
range  
Outside sensor  
Heat generator sensor  
Flow sensor 1  
AF  
NTC 20  
NTC 20  
NTC 20  
NTC 20  
NTC 20  
PT 1000  
NTC 20  
–50 °C to 90 °C  
–50 °C to 120 °C  
–50 °C to 120 °C  
–50 °C to 120 °C  
–50 °C to 120 °C  
–50 °C to 210 °C  
–50 °C to 120 °C  
KF  
VF1  
VF2  
SF  
Flow sensor 2  
Tank sensor  
Collector flow sensor  
KVLF  
KSPF  
Collector tank/buffer  
sensor  
Variable input VI-1*)  
VE1  
NTC 20  
PT 1000  
NTC 20  
NTC 20  
–50 °C to 120 °C  
–50 °C to 500 °C  
–50 °C to 120 °C  
–50 °C to 120 °C  
Variable input VI-2  
Variable input VI-3  
VE2  
VE3  
*) Depending on the selection of the assigned function.  
PT 1000 e.g. for exhaust gas sensor connection.  
252  
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SDC / DHC  
Technical data  
8.4 Digital inputs  
Brief description  
Designation  
Input type  
Measurement  
range  
Impulse metering unit  
Imp  
Extra-low voltage  
230 V  
10 Hz  
Burner stage 1 operating BZ1  
hour counter  
OFF, ON  
Burner stage 2 operating BZ2  
hour counter  
230 V  
OFF, ON  
EN2H-0221GE51 R0808  
253  
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Log  
SDC / DHC  
9 Log  
Weekly switching program  
Set by:  
Object:  
On:  
Mon  
(1)  
Cont. circuit  
Time  
Setpoint  
Opt.  
Tue  
(2)  
Cont. circuit  
Time  
Setpoint  
Opt.  
Wed  
(3)  
Cont. circuit  
Time  
Setpoint  
Opt.  
Thu  
(4)  
Cont. circuit  
Time  
Setpoint  
Opt.  
Fri (5) Cont. circuit  
Time  
Setpoint  
Opt.  
Sat (6) Cont. circuit  
Time  
Setpoint  
Opt.  
Sun  
(7)  
Cont. circuit  
Time  
Setpoint  
Opt.  
254  
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SDC / DHC  
Index  
Index  
Conditional priority 189  
Constant temperature control 168  
Cooling switch-over 177  
Cycle operation 125  
B
Boiler circuit pump 158  
Boiler circuit pump extended running time  
159  
D
Boiler circuit pump pre-running time 159  
Boiler sensor 2 141  
Delay, enabling, full load in cascade  
operation 235  
Boiler temperature offset 191  
Buffer  
Demand contact 219  
Discharge protection 211  
Design temperature 122  
District heating control 156  
District heating valve 145  
Forced dissipation 209  
Minimum temperature limit 208  
Sensor 2 211  
E
Economy interval 194  
Setpoint temperature 208  
Siphon function 210  
Electrical heating element 195  
Electromagnetic compatibility 15  
Emission measurement 238  
Enabling mode stage II 134  
Start-up protection 210  
Stratified loading 211  
Switching differential 209  
Exhaust gas temperature monitoring 142  
Extended running time CHP 157  
External switching modem 218  
Temperature offset of heat generator  
209  
F
Buffer tank  
Fixed-value control 168  
Flue gas temperature limit 143  
Forced discharge 141  
Function 199  
Maximum temperature limit 208  
Building type 120  
G
Burner counter mode 143  
Bus address 221  
Global fault message output 217  
Grouping for base and peak loads 236  
Bypass pump 160  
H
C
Heat exchanger valve 145  
Heat generator  
Cascading 232  
Charging pump 157  
Cycle disable 213  
Circulation pump 194  
Circulation pump 155  
Climate zone 122  
Heat generator  
Collector maximum temperature limit 196  
EN2H-0221GE51 R0808  
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Index  
SDC / DHC  
Fault 126  
L
Maximum temperature limit 130  
Minimum temperature limit 129  
Reset 135  
Legionella protection 188  
Loading enabling 191  
Loading pump extended running 191  
M
Sensor control mode 130  
Start-up protection 128  
Menu  
Direct Heating Circuit 172, 180  
Heating circuit bus authorisation 231  
Heating circuit name 180  
Heating circuit pump extended running  
time 165  
Mixed Heating Circuit 180  
Mixed Heating Circuits 172  
Minimum burner runtime 131  
Heating circuits minimum temperature limit  
130  
O
Heating curve 161, 162  
Heating limit 175  
OpenTherm 140  
Operating mode 118  
Heating system 164  
Operating states 40  
Hot water  
Operation with NTC 20K room  
temperature sensor 231  
Outside temperature 121, 122, 135  
Outside temperature emergency operation  
value 121  
Circuit switching differential 191  
Control mode 154, 189  
Maximum temperature 188  
Night-time temperature 188  
Pre-control 151  
Outside temperature sensing 120  
Overview of the technician parameters 81,  
119, 135  
Pre-regulator 150  
Quick connection in cascaded systems  
192  
P
Parallel operation 155, 189  
Parallel operation based on weather  
conditions 190  
Hot-water  
Control 152  
Primary pump 158  
Production 187  
Extended running time 158  
Hot-water loading mode stage II 134  
Hot-water tank  
Priority isolating circuit 190  
Priority mode 189  
Loading 187  
Pump forced operation 127  
Hydraulic buffer relief 215  
R
I
Reduced operation 164  
Relay/function test 239  
Reset 77, 249  
Indirect return increase 161, 222  
Return increase 159  
256  
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SDC / DHC  
Index  
Return interval 156  
Function 212  
Return temperature 147, 149  
Room connection 169  
Room factor 170  
Solid fuel  
Minimum temperature 212  
Solid fuel  
Room frost protection limit 177  
Room influence 169  
Maximum temperature 213  
Room sensor 169, 170  
Room setpoint ramp 175  
Room thermostat function 181  
Solid fuel  
Switch-on differential 213  
Solid fuel  
Switch-off differential 213  
S
Solid fuel  
Screed function 165  
Anti-blocking protection of solid-fuel  
pump 213  
Selection level 48, 54, 59, 61, 72  
Selection of parameter presettings 119  
Sensor calibration 249  
Solar  
Summer switch-off 123  
Switching differential I 132  
Switching differential II 132  
Switching times 73  
Anti-blocking protection 199  
Collector maximum temperature limit  
196  
Switch-off optimisation 171  
Switch-on optimisation 171, 173, 174  
System frost protection 124  
Function 196  
Heat balancing 198  
Heat capacity 199  
T
Tank discharge protection 190  
Tank loading switch-over 213  
Tank sensor 2 192  
Heat generator cycle disable 197  
Minimum runtime of loading pump SOP  
196  
Temperature displays 37  
Temperature limit 164  
Temperature measurement 188  
Temperature offset 165  
Time delay stage II 134  
Timer 217  
Priority mode 197  
Priority/parallel switch-over 198  
Resetting heat balancing 198, 199  
Switch-off differential 196  
Switch-on differential 196  
Tank maximum temperature limit 197  
Solid fuel  
Total flow sensor 225  
V
Variable inputs and outputs 114, 119  
EN2H-0221GE51 R0808  
257  
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Manufactured for and on behalf of the Environmental and Combustion Controls Division of Honeywell Technologies  
Sàrl, Ecublens, Route du Bois 37, Switzerland by its Authorized Representative:  
Automation and Control Solutions  
Honeywell House  
Arlington Business Park  
Bracknell, Berks, RG12 1EB  
Phone(44) 1344 656000  
Fax (44) 1344 656644  
http://honeywell.com/uk  
Printed in Germany  
All rights reserved. Subject to change without notice.  
EN2H-0221GE51 R0808  
./.  
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