Bradford White Corp Water Heater IGI 1804 10NX User Manual
Tankless Gas Water Heater  
SERVICE  
MANUAL  
Troubleshooting Guide  
and Instruction for Service  
(To be performed ONLY by qualified service providers)  
®
For the Bradford White EverHot  
Interior Tankless  
Gas Water Heater Models:  
IGI-180R-10(N,X)  
IGI-180C-5(N,X)  
Save this manual for future reference  
Manual 45095A  
Download from Www.Somanuals.com. All Manuals Search And Download.  
TABLE OF CONTENTS  
Section  
Description  
Page  
- - -  
Glossary of Terms and Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . .4  
I. . . . . . . . . . . .General Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5  
a. How to Use This Manual. . . . . . . . . . . . . . . . . . . . . . . . . .6  
b. Cut Away illustration. . . . . . . . . . . . . . . . . . . . . . . . . . . . .7  
c. Schematic illustration. . . . . . . . . . . . . . . . . . . . . . . . . . . .8  
II. . . . . . . . . . . Specifications (General). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9  
a. Combustion Specifications. . . . . . . . . . . . . . . . . . . . . . . .11  
b. Default Dip Switch Settings. . . . . . . . . . . . . . . . . . . . . . .12  
c. Venting Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14  
III. . . . . . . . . . .Main Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15  
IV. . . . . . . . . . .Safety Device Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17  
V. . . . . . . . . . . Sequence of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19  
a. Operation Sequence Flow Chart. . . . . . . . . . . . . . . . . . . .21  
b. Sequence Timing Chart. . . . . . . . . . . . . . . . . . . . . . . . . .23  
VI. . . . . . . . . . .Troubleshooting (error messages). . . . . . . . . . . . . . . . . . . . . . . . . .25  
a. Quick Reference Diagnostic Points. . . . . . . . . . . . . . . . . .27  
b. Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29  
c. Troubleshooting Flow Chart. . . . . . . . . . . . . . . . . . . . . . .31  
d. Trouble Shooting Procedure. . . . . . . . . . . . . . . . . . . . . . .36  
VII. . . . . . . . . . Gas Pressure Setting Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . .46  
VIII. . . . . . . . . .Service Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48  
IX. . . . . . . . . . .Flushing Procedure for Lime Scale Removal . . . . . . . . . . . . . . . . . .54  
X. . . . . . . . . . . Parts Breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55  
Refer to installation and operation manual for the following reference information:  
• General Dimensions  
• Piping Recommendations  
• Remote Control Features  
• Water Flow Rates vs Temperature  
3
Download from Www.Somanuals.com. All Manuals Search And Download.  
GLOSSARY OF TERMS AND SYMBOLS  
This glossary of terms and symbols is provided to assist you in understanding some of the  
language used throughout this manual.  
dB(A)  
DC  
AC  
WFCD  
FB  
Hz  
-
-
-
-
-
-
sound pressure level in decibels, “A” range  
direct current  
alternating current  
water flow control device  
feedback information  
hertz  
IC  
BTU/H  
-
-
integrated circuit  
British thermal units per hour  
PSI  
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Pounds per square inch  
light emitting diode  
gallons per minute  
milliamps  
inches of water column  
millimeters  
oxides of nitrogen NO & NO2  
overheat switch  
printed circuit board  
central processing unit  
potentiometer  
revolutions per minute  
solenoid valve  
LED  
GPM  
mA  
W.C.  
mm  
NOx  
OHS  
PCB  
CPU  
POT  
rpm  
SV  
Ø
diameter  
∆°F  
POV  
TE  
TH  
TIN  
delta T or temperature rise above ambient  
modulating valve  
thermal efficiency  
thermistor  
temperature of incoming water  
Tout  
temperature of outgoing water  
4
Download from Www.Somanuals.com. All Manuals Search And Download.  
I - GENERAL INFORMATION  
This tankless water heater is a high output, high efficiency appliance, which heats the water  
continuously as hot water is being drawn for use. Unlike tank type storage water heaters, this water  
heater does not store hot water. The burner operates whenever there is a demand for hot water and  
is off when the hot water flow stops. Hot water is continuously supplied for any length of time  
required as long as the specified flow rates are not exceeded. There is no need to set the  
temperature higher than required for sufficient capacity. This water heater has sufficient capacity to  
supply several hot water faucets simultaneously. The hot water flow capability will be dependent  
upon the temperature of the outlet water selected. Operational feature of this water heater include:  
• The burners ignite by direct spark ignition within 3 seconds of detecting minimum  
operational water flow. There is no standing pilot.  
• A variable speed combustion air blower forces the combustion air supply into the burner  
compartment.  
• Direct vent design uses only outside air for combustion. The venting system is a coaxial  
design requiring a single 5 1/4" (13.3 cm) hole through the outside wall or roof. Vent pipe  
fittings have internal gaskets for a tight seal to prevent leakage of flue products and  
combustion air.  
• The burner flame is continuously monitored and modulated to match the heating  
requirements of the water flow. Temperature and flow sensors continually monitor the  
water flow and outlet water temperature and adjust the burner and combustion air blower  
to maintain temperature.  
• The Indoor Direct Vent model series have a digital temperature control integrally mounted  
to the front panel of the water heater. The outlet water temperature is adjustable from  
96-160°F for residential models or 96-180˚F for commercial models. The front panel  
temperature control also displays fault codes if the water heater malfunctions to assist with  
servicing the water heater. No installation is required for the main temperature control.  
• In addition to the main temperature controller, up to two optional bathroom temperature  
controls are available on the residential models for setting the water temperature in the  
bathroom fixtures up to 120°F.  
• The heat exchanger coil is provided with anti-freeze heaters for protection in cold climate  
conditions to ambient temperatures as low as -30°F (-34°C). Drain solenoids should be  
installed to drain the water heater in the event of a power failure.  
(See installation instructions)  
Tools Required for Troubleshooting  
Multifunction Digital Testmeter with needle point test leads.  
Long reach (12") Magnetic Phillips screw driver (#2 Tip)  
3/16 Allen wrench  
Small (pocket size) blade screw driver  
Monometer or Magnehelic inches water column gage  
5
Download from Www.Somanuals.com. All Manuals Search And Download.  
I - GENERAL INFORMATION (cont.)  
HOW TO USE THIS MANUAL  
It is intended for this manual to be used by qualified service personnel for the primary purpose of  
troubleshooting analysis and repair of this tankless gas fired water heater. Understanding the basic  
operation of the "Main Components" and the "Sequence of Operation" sections of this manual will  
contribute greatly to your success in the troubleshooting analysis of this product.  
Sections of this manual reference general information and specifications. The primary focus is trouble  
shooting analysis and repair. The trouble shooting section consists of the following:  
• Error Message Table.  
Table showing Error Message as displayed on remote control indicating likely fault and  
remedy.  
• Quick Reference Diagnostics Points Table.  
This guide will identify the specific diagnostic point for each component as well as the  
correct electrical value for each component.  
• Troubleshooting Flow Chart.  
The "Trouble Shooting Flow Chart" identifies fault potentials and directs service to  
the appropriate diagnostic check points. The check points are identified in the  
troubleshooting procedure and are shown on the wiring diagram by means of an  
encircled letter with a subscript number.  
Example:  
This chart will also refer to a page number to reference a pictorial version of the  
component analysis as outlined in the "Trouble Shooting Procedure" section of this  
manual.  
• Trouble Shooting Procedure.  
Pictorial procedure including diagnostic points, electrical values and referral to  
"Service Procedure" for replacement of faulty components.  
• Service Procedure.  
Pictorial procedure for removal and replacement of components.  
6
Download from Www.Somanuals.com. All Manuals Search And Download.  
I - GENERAL INFORMATION (cont.)  
CUT-AWAY ILLUSTRATION  
7
Download from Www.Somanuals.com. All Manuals Search And Download.  
I - GENERAL INFORMATION (cont.)  
SCHEMATIC ILLUSTRATION  
8
Download from Www.Somanuals.com. All Manuals Search And Download.  
II - SPECIFICATIONS - GENERAL  
Model type  
RESIDENTIAL  
COMMERCIAL  
Type of appliance  
Temperature controlled continuous  
flow gas hot water system  
Operation  
With / without remote controls, mounted  
in kitchen, bathroom, etc.  
Exhaust system  
Direct Vent - Forced combustion  
Maximum/Minimum gas rate  
(Input BTU's)  
180,000 BTU's - 15,000 BTU's Natural Gas  
180,000 BTU's - 15,000 BTU's Propane Gas  
Hot water capacity,  
(50°F rise)  
0.5 to 6.5 GPM  
Setpoint Temperature  
(without remote)  
Factory setting - 120°F  
Factory setting - 140°F  
Temperature range  
(with remote)  
MC controller : 96 - 160°F  
BC controller : 96 - 120°F  
BSC controller : 96 - 120°F  
MCC controller : 96-180°F  
Approved gas type  
Natural or Propane - Ensure unit matches  
gas supply type.  
Installation  
Dimensions  
Indoor Only  
Height 23 5/8"  
Width 13 25/32"  
Depth 8 13/16"  
Weight  
49 Lbs.  
Thermal Efficiency rating  
Noise level  
0.87 (Propane) 0.82 (Natural)  
49 dB (A)  
Connections  
Gas supply 3/4" NPT (Male)  
Cold water inlet 3/4" NPT (Male)  
Hot water outlet 3/4" NPT (Male)  
Ignition system  
Direct electronic ignition  
Electrical consumption  
Operating - 75 watts  
Standby - 5.5 watts  
Anti-frost protection 100 watts  
Water temperature control  
Water flow control  
Simulation feedforward and feedback.  
Water flow sensor, electronic water control  
device, and electronic by-pass control device  
Recommended Minimum water  
supply pressure  
20 PSI (recommend 50-80 PSI for maximum performance)  
150 PSI  
Maximum water supply pressure  
9
Download from Www.Somanuals.com. All Manuals Search And Download.  
II - SPECIFICATIONS - GENERAL  
Safety devices  
Appliance - AC 120 Volts - 60Hz. 15A - Dedicated  
Remote control DC 12 Volts (Digital)  
Flame failure - Flame rod  
Boiling protection - 203°F  
Remaining flame (OHS) 194°F bi-metal switch  
Thermal fuse 264°F  
Automatic frost protection - Bimetal sensor & anti-frost heaters  
Combustion fan rpm check - Integrated circuit  
Over current - Glass fuse (3 amp)  
If remote fails or becomes disconnected unit defaults to  
100°F with water flowing, this is an anti-scald feature.  
Remote control cable  
Non-polarized two core cable or low voltage thermostat wire  
Clearances from combustibles  
Top of heater 6"  
Front of heater 6"  
Sides of heater 2"  
Back of heater 0"  
Floor 12"  
(12" min. recomended for service)  
(24" min. recomended for service)  
Vent/Air Intake 0"  
10  
Download from Www.Somanuals.com. All Manuals Search And Download.  
II - SPECIFICATIONS - COMBUSTION  
Item  
Gas consumption  
Gas type  
Minimum Btu’s  
Maximum Btu’s  
Upper  
Natural  
15,000  
180,000  
Ø.037 (.95mm)  
Ø.062 (1.6mm)  
Propane  
15,000  
180,000  
Ø.029 (.75mm)  
Ø.045 (1.15mm)  
Injector Diameter  
Inches (mm)  
Lower  
Main Burner  
B3A7-1(Lean and Rich Bunsen Burner)  
Main Damper  
Gas Pressure  
Supply/Manifold  
H73-115, Upper: Ø6, Lower: (Not used)  
Minimum supply  
Maximum supply  
Low Fire manifold  
High Fire manifold  
6" W.C.  
10" W.C.  
10.5" W.C.  
0.77” W.C  
3.7” W.C  
13.5" W.C.  
0.93” W.C  
4.2” W.C  
11  
Download from Www.Somanuals.com. All Manuals Search And Download.  
II - SPECIFICATIONS (cont.)  
DIP SWITCH SETTINGS  
DANGER  
Do not attempt to adjust dip switch settings from there factory default settings.  
Doing so will result in damage to unit, property damage, personal injury or death.  
Contact Technical Support for information pertaining to dip switch function.  
FACTORY DEFAULT SETTING, RESIDENTIAL UNITS  
Natural Gas  
Dip Switch Settings:  
(SW1)  
Propane Gas  
Dip Switch Settings:  
(SW1)  
(SW2)  
(SW2)  
#1 = Off  
#2 = On  
#3 = Off  
#4 = Off  
#5 = Off  
#6 = Off  
#7 = Off  
#8 = Off  
#1 = On  
#2 = Off  
#3 = Off  
#4 = Off  
#1 = Off  
#2 = On  
#3 = Off  
#4 = Off  
#5 = Off  
#6 = Off  
#7 = Off  
#8 = Off  
#1 = Off  
#2 = Off  
#3 = Off  
#4 = Off  
FACTORY DEFAULT SETTING, COMMERCIAL UNITS  
Natural Gas  
Dip Switch Settings:  
Propane Gas  
Dip Switch Settings:  
(SW1)  
(SW2)  
(SW1)  
(SW2)  
#1 = Off  
#2 = On  
#3 = Off  
#4 = Off  
#5 = Off  
#6 = Off  
#7 = Off  
#8 = Off  
#1 = On  
#2 = Off  
#3 = Off  
#4 = On  
#1 = Off  
#2 = On  
#3 = Off  
#4 = Off  
#5 = Off  
#6 = Off  
#7 = Off  
#8 = Off  
#1 = Off  
#2 = Off  
#3 = Off  
#4 = On  
See page 13 for special dip switch settings base on vent length.  
12  
Download from Www.Somanuals.com. All Manuals Search And Download.  
II - SPECIFICATIONS (cont.)  
DIP SWITCH SETTINGS  
Combustion Blower Dip Switch Settings for Vent Length Compensation Under 22 Feet (6.7 m):  
To assure optimum efficiency and reduced noise levels, the combustion blower switch has two dip switch  
settings. Dip switch number 1 (top dip switch) is shipped from the factory set to the OFF position to  
compensate for the maximum vent/air intake length.  
Depending upon the vent/air intake length of the installation, Dip Switch Number 1 may need to be adjusted  
to compensate for the venting system distance.  
When the Total Equivalent Length of vent pipe is more than 22 feet (6.7 m), leave the Dip Switch Number 1 in  
the OFF position. This is the factory Dip Switch setting.  
When the Total Equivalent Length of vent pipe is 22 feet (6.7 m) or less, Dip Switch Number 1  
must be moved to the ON position.  
Dip Switch #1 is located in the top row of dip switches, 1 through 8 on the PC board. See the following  
diagram to identify the correct switch. If you do not understand the information concerning the Dip Switch  
settings or the location of the Dip Switch, contact Bradford White Sales (800-523-2931) or Technical Service  
(800-334-3393 x3634) for assistance. Use the following examples and the previous discussion on calculating  
the equivalent vent length to determine the correct setting for Dip Switch #1.  
Example #1:  
Dip Switch Settings (Fig. 8)  
You have 6 feet (1.82 m) of vent pipe and two 90˚ elbows.  
D = 6 + (2 x 6) + (0 x 1.5)  
D = 18 feet (5.49 m) of equivalent vent pipe  
Dip Switch #1 should be moved to ON position.  
Example #2:  
You have 15 feet (4.57 m) of vent pipe, one 90˚ elbow, and two 45˚ elbows.  
D = 15 + (1 x 6) + (2 x 1.5)  
D = 24 feet (7.3 m) of equivalent vent pipe  
Leave Dip Switch #1 in the OFF position (factory setting).  
WARNING  
Do not alter Dip Switch #1 before using the formula and venting charts to determine the equivalent vent  
length. All other dip switches with the exception of Dip Switch #1 shown in the illustration MUST NOT be  
altered. Unauthorized adjustments can cause property damage, personal injury, scalding, or death.  
13  
Download from Www.Somanuals.com. All Manuals Search And Download.  
II - SPECIFICATIONS (cont.)  
VENTING TABLE  
Venting Table – Examples of Maximum Venting Distances with Various Elbow Combinations  
Maximum Straight  
Pipe Distance  
Number of  
90 degree elbows  
Number of  
45 degree elbows  
Maximum Total  
Equivalent Feet  
(meters) of Vent Pipe  
35 Ft. (10.7 m)  
29 Ft. (8.8 m)  
23 Ft. (7.0 m)  
17 Ft. (5.2 m)  
33.5 Ft. (10.2 m)  
32 Ft. (9.8 m)  
27.5 Ft. (8.4 m)  
1
2
3
4
1
1
2
41 (12.5 m)  
41 (12.5 m)  
41 (12.5 m)  
41 (12.5 m)  
41 (12.5 m)  
41 (12.5 m)  
41 (12.5 m)  
1
2
1
NOTICE  
Each 90 degree elbow is equivalent to 6 feet in straight vent pipe length. Each 45 degree elbow is  
equivalent to 1.5 feet (0.46 m) in straight pipe length. The total maximum equivalent vent pipe  
distance cannot exceed 41 feet (12.5 m) for horizontal venting distance. The maximum vertical height  
for through the roof venting cannot exceed 21 feet (6.4 m). A condensate collector must be used if  
the venting system height is more than 5 feet (1.52 m) above the water heater.  
14  
Download from Www.Somanuals.com. All Manuals Search And Download.  
III - MAIN COMPONENTS  
1. Mechanical Water Regulator  
The unique water regulator mechanism ensures the hot water is maintained with no noticeable  
change to the desired temperature during use, even if water pressure drops due to another tap being  
turned on and increasing the demand.  
2. Preset Bypass  
A preset volume of cold water is mixed with water heated in the heat exchanger.  
3. Burner  
The burner assembly is made up of 16 identical stainless steel  
Bunsen burners, secured by an aluminized steel framework.  
An aluminum manifold with 32 integral injectors supplies gas  
to the burners, and is attached to the front lower cover of the  
burner box and gas control assembly.  
4. Gas Control Valve  
The gas control valve uses four solenoids to fully modulate within four different input ranges to  
respond quickly and accurately to changes in water flow rate. The four ranges are as follows: up to  
18% of total btu’s (using three burners), up to 33% (using five burners), up to 50% (using eight  
burners, and up to 100% (using sixteen burners) This increases the flexibility of the regulator/  
modulating valve by supplying gas equally to each burners.  
15  
Download from Www.Somanuals.com. All Manuals Search And Download.  
III - MAIN COMPONENTS (cont.)  
5. Combustion Fan  
Air for the combustion is supplied by a centrifugal fan  
driven by a DC motor. After a pre-purge period of 0.2  
seconds, the fan speed is controlled by the PCB to  
provide the correct volume of air for combustion. The  
calculation for the fan speed is based upon incoming  
water temperature, water flow and the temperature  
selected on the remote controls.  
The actual speed of the motor is continuously monitored  
by a magnetic pulse sensor.  
This sensor emits (4) pulses per rotation of the fan. This is  
the fan feedback or confirmation data processed by the PCB.  
The fan speed is constantly correcting to provide optimum combustion conditions. In addition, the  
fan speed will determine the opening degree of the modulating gas valve. This enables the gas rate to  
always match the volume of air for combustion, as well as the input required to heat the water.  
6. Water Flow Sensor and Water Flow Control device  
Water flow is detected by a turbine/magnetic pulse generating device. Water flows through the  
turbine/magnetic sensor providing information to the PCB by generating a pre-determined number of  
pulses in proportion to the water flow. These pulses are counted by the PCB – no pulse indicates no  
water flow. The frequency of the magnetic pulses increases as the water flow increases, this enables  
the PCB to calculate the exact water flow, and determine the water flow in gallons per minute. As  
soon as the required water flow is detected, the PCB activates the combustion fan. The combustion  
fan speed is monitored by a magnetic pulse sensor. The output from this sensor is processed by the  
PCB which opens the gas modulating valve to a degree proportional to the fan speed. See above for  
further details on the combustion fan.  
The water flow control consists of a plug and barrel valve which is rotated by a motor to increase or  
decrease the volume of water passing through the heat exchanger.  
Automatic water flow control device.  
16  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IV - SAFETY DEVICE FUNCTION  
Flame Failure  
Situated to the right of the burner in the front of the combustion chamber, the flame rod monitors the  
combustion process. This sensor monitors the flame intensity, while the PCB compares this signal to  
the feed back signal from the combustion fan motor, water flow control, and gas flow through the POV  
valve. If any one of the feedback signals are incorrect, the unit will shut off, preventing discharge of  
gas to the burner.  
Over Heat Protection Device  
Also referred to as an Over Heat Switch. This device is fitted to a bend section at the inlet to the heat  
exchanger. If the flame remains on to the burner after the tap is closed and the water temperature  
inside the heat exchanger reaches 194 ° F, a 12 volt DC bi-metal cut-off switch will shut off the gas  
supply to the solenoids.  
No Water  
Should the incoming water flow become restricted or stop, the water flow sensor will cease to send a  
magnetic pulse signal to the PCB, in turn preventing gas to flow into the combustion chamber. If you  
have restricted flow, first check to ensure the inline water filter is not clogged.  
Thermal Fuse (Non-Resettable)  
Wrapped around the entire surface of the heat exchanger you will find a thermal fuse. This device  
activates in the event of excessive heat echanger temperatures, or the temperature outside the heat  
exchanger reaches 264 °F. If the thermal fuse melts, it breaks an electronic circuit which in turn shuts  
off the power supply to the gas solenoids, deactivating the unit.  
Combustion Fan Revolution Check  
The combustion fan rpm’s are continually monitored by a magnetic pulse generator connected to the  
PCB. If the fan revolutions deviate from the speed required for complete combustion, a signal is sent  
to the PCB and the revolutions adjust accordingly. (If not the unit deactivates)  
Automatic Frost Protection  
When the temperature inside the appliance drops below 37°F , the frost sensing device inside the  
appliance activates the anti-frost heaters to prevent the water inside the unit from freezing. The anti-  
frost heaters remain ON until the temperature inside the appliance rises to 57°F. There are four (16)  
watt anti-frost heaters located at various points throughout the main water flow area of the appliance.  
The unit also incorporates the ability to fire for (3) seconds in the event the anti-frost heaters can not  
keep the water temperature from dropping below 37°F. This unique feature will heat the water in the  
lines inside the appliance back up to 57°F. Both of the above features function as long as the unit  
has power and gas. There is an optional freeze protection system that can be added to the unit’s  
piping. Refer to the auto drain down diagram in the product installation instructions for instructions  
on how to install the optional freeze protection in the event of a power failure.  
17  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IV - SAFETY DEVICE FUNCTION (cont.)  
Over temperature Cut-Off  
The temperature of the outgoing hot water is constantly monitored by the water temperature  
thermistor located near the outlet of the appliance. If the outgoing water temperature reaches 5 °F  
above the preset temperature, the burner will automatically deactivate. The burner will ignite again  
when the outgoing hot water temperature falls below the preset temperature.  
18  
Download from Www.Somanuals.com. All Manuals Search And Download.  
V - SEQUENCE OF OPERATION  
The preset temperature is selected at one of the remotes controls (where fitted). Where no remote  
control is fitted , the default temperature can be set at 108, 120, 130, 140, 150, 160, 170, or 180°F.  
To select one of the above temperatures as your default setting, you MUST obtain written permission  
and training (Contact your technical service group).  
When the unit is first plugged into 120 volts, the PCB assumes an incoming water temperature of  
77°F. This prevents the appliance from starting in “High fire” and producing very hot water the first  
time it is used.  
The data used to determine the outgoing water temperature, initially, is incoming water flow and the  
remote control pre-set temperature.  
From the incoming water flow and remote control pre-set temperature data, the CPU is able to  
determine a suitable gas rate to initiate appliance operation once a hot water tap opens.  
The calculation of temperature rise and water flow is called simulation feed-forward.  
The water heater calculates incoming water temperature by subtracting the theoretical temperature  
rise from the outgoing hot water temperature to establish the correct gas flow.  
When a hot water tap is opened, water begins to flow through the water heater. The turbine in the  
water flow sensor begins to revolve. The revolution speed is proportional to the water flow. A sensor  
located inside the device relays information in the form of magnetic pulses to the main PCB to  
determine whether or not water is flowing, and also, the volume of water flowing. When a  
predetermined water flow is sensed, the ignition sequence begins.  
The combustion fan pre-purges the combustion chamber. A rev counter on the combustion fan  
indicates the fan rpm to the main PCB. When the pre-purge cycle is completed, the PCB controls the  
fan rpm by varying the DC voltage to the fan motor. This maintains the correct air/gas ratio  
throughout the time the water heater is in use and ensures proper combustion.  
The gas is ignited by direct spark and the flame is sensed by the flame rod. The opening degree of  
the modulating valve is determined by the combustion fan speed.  
The changeover valve directs gas to one side or both sides of the burner. At the point where the  
changeover valve opens or closes the modulating valve is instantly re-adjusted by the PCB to  
compensate for the change in the number of burners in use. From the information provided by the  
water flow sensor and the water temperature thermistor, the PCB determines how much gas is  
required to heat the water to the temperature selected on the remote control.  
The PCB is programmed to provide the maximum volume of water possible at a given temperature  
rise. As the water flow from the tap is increased, the PCB increases the gas and air flow to the burner.  
19  
Download from Www.Somanuals.com. All Manuals Search And Download.  
V - SEQUENCE OF OPERATION (cont.)  
When the hot water tap is turned off, the water flow sensor stops revolving, and the magnetic pulse  
ceases, indicating to the PCB that there is no water flowing, in turn the PCB closes the gas valves. The  
combustion fan continues to operate for 65 seconds. This will provide quicker ignition when the tap is  
turned on and off in rapid succession, and removes the need for a pre-purge cycle allowing the burner  
to re-light immediately when a hot water tap is opened again.  
20  
Download from Www.Somanuals.com. All Manuals Search And Download.  
V - SEQUENCE OF OPERATION (cont.)  
Operation Sequence Flow Chart  
21  
Download from Www.Somanuals.com. All Manuals Search And Download.  
V - SEQUENCE OF OPERATION (cont.)  
Operation Sequence Flow Chart  
22  
Download from Www.Somanuals.com. All Manuals Search And Download.  
V - SEQUENCE OF OPERATION (cont.)  
Sequence Timing Chart  
23  
Download from Www.Somanuals.com. All Manuals Search And Download.  
V - SEQUENCE OF OPERATION (cont.)  
Sequence Timing Chart  
24  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING  
Error Messages  
Error  
10  
Faulty  
Remedy  
Air Supply  
or Exhaust  
Blockage  
Check all vent components for proper connections.  
Check that nothing is blocking the flue inlet or exhaust.  
Ensure proper venting materials were used.  
Ensure condensation collar was installed correctly.  
Verify dip switches are set properly.  
11  
No Ignition  
Ensure you have gas to the appliance.  
Ensure gas type and pressure is correct.  
Bleed all air from gas lines.  
Verify dip switches are set properly.  
Disconnect all MSA controls.  
Ensure gas line, meter, and/or regulator is sized properly.  
Ensure appliance is properly grounded.  
Check gas solenoid valves for open or short circuits.  
Ensure igniter is operational.  
Check igniter wiring harness for damage.  
Remove burner cover and ensure all burners are properly seated.  
Remove burner plate and inspect burner surface for condensation or debris.  
12  
Flame Failure  
Ensure you have gas to the appliance.  
Ensure gas type and pressure is correct.  
Bleed all air from gas lines.  
Verify dip switches are set properly.  
Ensure flame rod wire is connected.  
Check flame rod for carbon build-up.  
Ensure gas line, meter, and/or regulator is sized properly.  
Ensure appliance is properly grounded.  
Check gas solenoid valves for open or short circuits.  
Check power supply for loose connections.  
Check power supply for proper voltage and voltage drops.  
Disconnect all MSA controls.  
Disconnect keypad.  
Disconnect and re-connect all wiring harnesses on unit and PC board.  
Ensure proper venting material was installed.  
Ensure condensation collar was installed properly.  
Ensure maximum vertical vent length does not exceed 21 ft. and three 90˚ elbows.  
Ensure maximum horizontal vent length does not exceed 41equivalent feet and three  
90˚ elbows.  
Immediate code 12 is usually a defective gas valve, power supply problem, or defective  
fan motor wiring harness.  
Remove burner plate and inspect burner surface for condensation or debris.  
14  
Thermo Fuse  
Ensure dip switches are set to the proper position.  
Ensure high fire and low fire manifold pressure is correct.  
Check gas type of unit and ensure it matches gas type being used.  
Check heat exchanger for cracks and/or separations.  
Check resistance on safety circuit.  
Check for improper conversion of product.  
Check for restrictions in air flow around unit and vent terminal.  
Check for a low flow circulating system that is causing the unit to short cycle.  
Check for foreign materials in combustion chamber and/or exhaust piping.  
16  
Over  
Check for clogged heat exchanger.  
Temperature  
Warning  
Check for restrictions in air flow around unit and vent terminal.  
Check for a low flow circulating system that is causing the unit to short cycle.  
Check for foreign materials in combustion chamber and/or exhaust piping.  
25  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING (cont.)  
Error Messages  
Error  
Faulty  
Remedy  
32  
Outgoing Water Check sensor wiring for damage.  
Temperature  
Sensor Faulty  
Check resistance onsensor.  
Check and clean dirt from sensor.  
Replace sensor.  
33  
34  
Heat Exchanger Check sensor wiring for damage.  
Outgoing  
Temperature  
Sensor Faulty  
Check resistance on sensor.  
Check and clean dirt from sensor.  
Replace sensor.  
Combustion Air  
Temperature  
Sensor Faulty  
Check sensor wiring for damage.  
Check resistance on sensor.  
Check and clean dirt from sensor.  
Clean blower blades, if dirty.  
Ensure fan blade is tight on motor shaft and it is in good condition.  
Check for restrictions in air flow around unit and vent terminal.  
Replace sensor.  
52  
Modulating  
Solenoid  
Check modulating gas solenoid valve wiring harness for loose or damage terminals.  
Check resistance on solenoid valve.  
Valve Signal  
Abnormal  
61  
71  
Combustion  
Fan Failure  
Ensure fan motor will turn freely. Motor will operate with a small amount of resistance.  
Check wiring harness to motor for damaged and/or loose connections.  
Check resistance on motor winding.  
SV0, SV1,  
Check wiring harness to all solenoids for damage and/or loose connections.  
Check resistance on each solenoid.  
SV2, and SV3  
Solenoid Valve  
Circuit Faulty  
72  
Flame Sensing  
Device Faulty  
Check micro amps produced by flame rod.  
Remove flame rod and check for carbon build-up, clean with sand paper.  
Ensure flame rod is touching flame when unit fires.  
Check inside burner chamber for any foreign material blocking flame at flame rod.  
Check all wiring to flame rod for damage.  
Replace flame rod.  
LC  
Scale Build-up  
in Heat  
Exchanger  
Turn off power supply, then reapply power;  
if code reappear separate control wires from the unit’s power supply.  
Flush heat exchanger.  
Replace heat exchanger.  
No code  
Nothing happens Clean inlet water supply filter.  
when water flow Ensure you have at least the minimum flow rate required to fire unit.  
is activated.  
Check for pipe dope inside water flow control turbine.  
On new installations ensure hot and cold water lines are not crossed.  
Check for bleed over. Isolate unit from building by turning off hot water line to building,  
then open your pressure relief valve. If unit fires, there’s a bleed over in your plumbing.  
If a circulating system is in use, it must be isolated also.  
Remote control does not light up but you have 12 VDC at the terminals for controls.  
Disconnect water flow control motor, then turn on hot water, if unit fires replace water  
flow control assembly.  
Check resistance on the water flow control sensor.  
26  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING (cont.)  
Quick Reference Diagnostic Points  
IMPORTANT SAFETY NOTES:  
There are a number of (live) tests that are required when fault finding this product. Extreme care  
should be used at all times to avoid contact with energized components inside the water heater.  
Only trained and qualified service agencies should attempt to repair this product.  
Remember, before checking for resistance readings, you should disconnect the power source  
(unplug it) to the unit and isolate the item to be checked from the circuit.  
(TR) Transformer:  
Wire color  
Voltage  
Resistance  
Connector #  
Pin #’s  
Black White  
Blue Brown  
~
100 120 VAC  
110 120 VAC  
~
51 63 ohms  
51 63 ohms  
~
F9  
F7  
1
1
2
3
~
~
~
~
~
(SV0, SV1, SV2, SV3 and POV) Gas valve and Modulating solenoids: (Set meter above 2K)  
(SV0) Pink Black  
80 100 VDC  
1,8K 2K ohms  
E1  
E2  
E3  
E4  
C2  
1
2
2
2
3
2
3
4
5
4
~
~
~
~
~
~
~
~
(SV1) Black Yellow  
~
80 100 VDC  
~
1,8K 2K ohms  
~
(SV2) Black Blue  
~
80 100 VDC  
~
1,8K 2K ohms  
~
(SV3) Black Brown  
~
80 100 VDC  
~
1,8K 2K ohms  
~
(POV) Pink Pink  
~
2
15 VDC  
67 81 ohms  
~
~
(M) Water Flow Control Device Servo or Geared Motor:  
Red Blue  
11 13 VDC  
22 26 ohms  
~
B2  
B2  
B2  
B2  
9
10  
7
8
~
~
~
Grey Brown  
~
4
6 VDC  
N/A  
N/A  
N/A  
5
5
5
~
~
~
~
Grey Yellow  
~
N/A  
11 14 VDC  
Grey Orange  
~
6
~
NOTE: The grey wire listed above turns to black at B connector on the PCB, the orange wire turns to red.  
(QS) Water Flow Sensor:  
Black Red  
Yellow Black  
~
11 13 VDC  
5.5K 6.2K  
~
B4  
B4  
5
1
6
5
~
~
~
~
4
7 VDC  
1 meg 1.4 meg  
~
~
By-pass Flow Control:  
Brown White  
2
6 VDC  
Unit in operating  
mode  
G4 G5  
~
4
2
1
3
5
5
5
5
~
~
~
~
~
~
Orange White  
~
G2 G5  
~
Yellow White  
~
15 35K  
G1 G5  
~
~
Red White Gnd  
~
G3 G5  
~
(IG) Ignition System:  
Grey Grey  
90 100 VAC  
N/A  
N/A  
F8  
2
3
~
~
~
(FM) Combustion Fan Motor:  
Red Black  
6
6
45 VDC  
45 VDC  
A1  
A1  
A1  
1
2
2
2
4
3
~
~
~
~
~
~
White Black  
~
9.2K 9.4K  
~
Yellow Black  
~
11 13 VDC 3  
.5K 3.9K  
~
~
Set your meter to the Hertz scale. Reading across the red and yellow wires at terminals 2 and 3 you should  
read between 60 and 350 Hertz.  
27  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING (cont.)  
Thermal Fuse:  
Wire color  
Voltage  
Resistance  
Connector #  
Pin #’s  
Red ~ Red  
100 VAC  
Below 1 ohm  
B ~ C  
B6 ~ C1  
Overheat Switch:  
Red ~ Red  
100 VAC  
Below 1 ohm  
B ~ C  
B6 ~ C1  
Flame Rod:  
Place one lead of your meter to the flame rod and the other to earth or ground. With the unit running  
you should read between 5 ~ 150 VAC. Set your meter to the µ amp scale, series your meter in line  
with the flame rod. You should read1µ or greater for proper flame circuit. In the event of low flame  
circuit remove the flame rod and check for carbon and/or damage.  
Heat Exchanger, Air Temperature, and Outgoing Water Temperature Thermistors:  
Check all thermistors by inserting meter leads into each end of the thermistor plug. Set your meter to  
the 20K scale and read resistance. You should be able to apply heat to the thermistor bulb and see  
the resistance decrease. Then apply some ice to the thermistor and the resistance should increase.  
See below for examples of temperatures and resistance reading at those temperatures.  
Example:  
59ºF = 11.4 ~ 14K  
86ºF = 6.4 ~ 7.8K  
113ºF = 3.6 ~ 4.5K  
140ºF = 2.2 ~ 2.7K  
221ºF = 0.6 ~ 0.8K  
Outgoing Water Thermistor:  
White ~ White  
N/A  
See example above  
See example above  
B4  
B5  
B3 ~ B4  
B3 ~ B12  
example  
Heat Exchanger Temperature Thermistor:  
White ~ Pink  
N/A  
Air Temperature Thermistor:  
White  
~
Orange  
N/Asee  
ab  
Surge Protector:  
Black ~ White  
Blue ~ Brown  
108 ~ 132 VAC  
108 ~ 132 VAC  
N/A  
N/A  
Surge Protector D 1  
Surge Protector D 2  
1 ~ 3  
1 ~ 2  
Remote Controls:  
Terminals D1  
10 ~ 13 VDC digital 1.5K ~ 1.9K ohms  
H
1 ~ 3  
Frost Protection:  
This unit has four frost protection heaters mounted at different points inside the unit to protect the  
water heater from freeze ups. There are two heaters located on the outlet hot water line next to the  
thermistor. Using a voltage meter set on the 200 ohm scale, you should have a resistance reading of  
26 ~ 30 ohms through each of these heaters. The heater located on the heat exchanger piping  
should have a resistance reading of 81 ~ 86 ohms and the one located in the water flow sensor valve  
has a resistance reading of 16 19 ohms. Voltage throughout this circuit should be 120 VAC.  
~
28  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Fuses:  
This unit has two inline (3) amp glass fuses. Remove the fuse and check continuity through it. If you  
have Continuity through the fuse, it is good. If you can not read continuity, the fuse is blown and must  
be replaced.  
Wiring Diagram  
29  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Wiring Schematic  
30  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
Troubleshooting Flow Chart  
BEFORE CARRYING OUT CHECKS MARKED WITH  
A # SIGN, DISCONNECT THE POWER SUPPLY.  
Examination  
Service  
Nature of Fault  
Point  
Diagnostic Point  
Values  
Y/N  
Yes  
Action  
Procedure  
A. The LED on  
the remote  
control does not  
light up, when  
the system is  
powered up  
1. Do you have  
voltage to the unit?  
Power source  
Do you have 120  
VAC at the power  
supply?  
Go to A – (2)  
No  
Plug in cord  
Go to A – (3)  
2. Is supply voltage  
correct?  
Measure voltage at  
power point.  
120 VAC  
Yes  
No  
Check power  
supply circuit.  
Check fuses.  
3. Check surge  
protector.  
Inspect visually  
Do you have 120  
volts AC across the  
blue and brown  
wires at the surge  
protector?  
Yes  
No  
Go to A – (4)  
Go to A – (5)  
4. Check both 3  
amp electrical fuses. measure resistance to  
confirm if fuse is blown.  
# Disconnect and  
Is fuse blown?  
Yes  
No  
Yes  
Go to A – (5)  
replace fuse  
Go to A – (6)  
Normal < than 1 MΩ  
5. Check for short  
circuits.  
1. Measure resistance of Are valves within  
Go to  
A – (6) - 2  
each solenoid valve. #  
Remove connector E  
from the PCB before  
measuring.  
those specified at  
left? # Measure  
after checking that  
there are no broken  
wires or shorts.  
Pink Black (SV0)  
No  
Replace gas  
valve.  
IGI – 9  
~
1.7 2.1KΩ  
~
Yellow Black (SV1)  
~
1.7 2.1KΩ  
~
Brown Black (SV2)  
~
1.7 2.1KΩ  
~
(See page 40)  
Is resistance >1MΩ ?  
1. Measure the  
resistance.  
Go to  
Yes  
No  
A (5 – 3)  
# Disconnect sparker  
connector F8 and  
measure the resistance  
between both terminals.  
(See page 39)  
IGI – 4  
Replace  
sparker.  
3. Check wiring.  
Rectify  
/Replace  
Yes  
No  
Are there any  
shorts?  
Replace PCB  
IGI – 2  
6. Check to ensure  
you have 120 VAC  
across both  
1. Measure voltage at  
the blue and brown  
wires.  
100 120 VAC  
~
Yes  
No  
Go to A (6 – 2)  
Check for  
terminals feeding  
the surge protector.  
proper voltage  
to unit.  
31  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
Troubleshooting Flow Chart  
BEFORE CARRYING OUT CHECKS MARKED WITH  
A # SIGN, DISCONNECT THE POWER SUPPLY.  
Examination  
Service  
Nature of Fault  
Point  
Diagnostic Point  
Values  
Y/N  
Yes  
Action  
Procedure  
2. Measure the voltage  
at connector F with  
appliance power supply  
on.  
Are values within  
those specified at  
left.  
Go to A – (7)  
No  
Replace  
transformer  
IGI – 7  
F – Black White  
~
100 120 VAC  
~
F7 – Blue Brown  
~
100 120 VAC  
~
7. Check remotes (s) Measure voltage  
(where connected.)  
11 13 VDC Digital  
~
Yes  
No  
Check cable  
for shorts or  
broken wires.  
Replace  
remote  
control.  
between remote control  
terminals at D.  
Replace PCB.  
IGI – 2  
IGI – 2  
B. Digital monitor 1. Check water flow  
1. Measure voltage  
11 13 VDC  
~
Yes  
No  
Go to B–1-2  
Replace PCB.  
between red black of  
lights up, but  
sensor.  
~
connector B4.  
combustion does  
not commence.  
(when remotes  
are connected).  
(See page 37)  
2. Measure voltage  
Yes  
No  
Go to B - 2  
4
7 VDC  
~
between yellow black  
Replace water IGI – 3  
flow sensor.  
~
at connector B4.  
(See page 37)  
Error code "72"  
displayed on the  
digital monitor.  
2. Check flame rod  
# Measure resistance  
between flame rod  
terminal C1 and earth.  
(See page 38)  
Resistance > 1MΩ?  
Yes  
No  
Replace PCB  
Replace flame  
rod  
IGI – 2  
Error code "32"  
displayed on the  
digital monitor.  
3. Check outgoing  
water temperature  
thermistor.  
# Disconnect connector  
B5 and measure  
resistance.  
Open circuit: > 1MΩ  
Short circuit: < 1Ω  
(See page 38)  
Are values as shown Yes  
at left?  
Replace water IGI – 6  
temperature  
thermistor.  
No  
Go to B - 4  
Error code "61"  
displayed on the  
digital monitor.  
4. Check  
combustion fan.  
1. Check motor.  
Measure voltage  
6
45 VDC (Fan on) Yes  
Go to B – 5-2  
Replace PCB  
~
0 VDC (Fan off)  
No  
IGI – 2  
IGI – 2  
IGI – 5  
between black red at  
~
connector A1.  
(See page 39)  
2. Check fan rotation  
sensor. Measure voltage  
11 13 VDC  
~
Yes  
No  
Go to B – 4-3  
Replace PCB  
between black yellow  
~
at connector A1.  
(See page 39)  
3. Measure voltage  
between black ~ white  
of connector A1.  
6
45 VDC  
Yes  
No  
Go to B – 5  
Replace fan  
~
(See page 39)  
32  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
Troubleshooting Flow Chart  
BEFORE CARRYING OUT CHECKS MARKED WITH  
A # SIGN, DISCONNECT THE POWER SUPPLY.  
Examination  
Service  
Nature of Fault  
Point  
Diagnostic Point  
Values  
Y/N  
Yes  
Action  
Procedure  
Error code "11"  
displayed on  
digital monitor.  
5. Check ignition  
module.  
1. Measure voltage  
90 110 VAC  
~
Go to B-5-2  
between grey grey of  
~
No  
Replace PCB  
IG2 – 2  
IGI – 4  
connector F8 (sparker).  
(See page 39)  
2. # Remove connector  
F8 and measure the  
resistance between  
sparker and terminals.  
(See page 39)  
Go to B-5-3  
Adjust/  
Replace  
ignition  
Is resistance >  
1MΩ?  
Yes  
No  
module  
3. Check if unit is  
sparking.  
Is the ignition  
module sparking?  
Yes  
No  
Go to B-6  
Adjust/  
Replace  
electrode  
6. Check main gas  
solenoid valve (SV0)  
Error code 71  
1. # Disconnect the main 1.7 2.1KΩ  
~
Yes  
No  
Go to B-6-2  
solenoid valve connector  
E from the PCB, and  
Replace gas  
valve  
IGI – 9  
IGI – 2  
measure the resistance  
between pink black  
~
(SV0)  
2. Measure voltage  
80 100 VDC  
~
Yes  
No  
Go to B-7  
Replace PCB  
between pink black of  
~
SV0 connector.  
(See page 40)  
7. Check solenoid  
valve (SV1)  
1. # Disconnect  
connector E from the  
PCB. Measure resistance  
between yellow black  
of (SV1).  
1.7 2.1KΩ  
~
Yes  
No  
Go to B-7-2  
Replace gas  
valve  
IGI – 9  
IGI – 2  
~
2. Measure voltage  
Yes  
No  
Go to B-8  
Replace PCB  
80 100 VDC  
~
between yellow black  
~
of SV1 connector.  
(See page 40)  
8. Check  
changeover solenoid  
valve (SV2)  
1. # Disconnect  
1.7 2.1KΩ  
~
Yes  
No  
Go to B-8-2  
connector E from the  
PCB. And measure  
resistance between blue  
Replace gas  
valve  
IGI – 9  
IGI – 2  
black (SV2)  
~
2. Measure the voltage  
between blue black or  
SV2 connector.  
80 100 VDC  
~
Yes  
No  
Go to B-9  
Replace PCB  
~
(See page 40)  
Error code "14"  
displayed on  
digital monitor  
9. Check thermal  
fuse  
1. # Disconnect  
connector B3 and C3  
measure resistance  
Is resistance < 1Ω?  
Is resistance < 1Ω?  
Yes  
No  
Go to B-10  
Replace  
thermal fuse  
IGI – 11  
IGI – 2  
between red red.  
~
2. # Disconnect OHS  
(remaining flame) bi-  
metal switch festoon  
terminal B3 and C3, and  
measure resistance  
between terminal on  
switch. (See page 42)  
10. Check overheat  
(remaining flame) bi-  
metal switch  
Replace PCB  
Yes  
No  
Replace  
remaining  
flame bi-metal  
switch  
33  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
Troubleshooting Flow Chart  
BEFORE CARRYING OUT CHECKS MARKED WITH  
A # SIGN, DISCONNECT THE POWER SUPPLY.  
Examination  
Service  
Nature of Fault  
Point  
Diagnostic Point  
Values  
Y/N  
Yes  
No  
Action  
Procedure  
C. Combustion  
occurs, but flame  
fails.  
1. Check flame rod.  
1. Measure the voltage  
between flame rod  
terminal C1 and  
5
150 VAC  
Go to C-1-2  
Replace PCB  
~
IGI – 2  
appliance ground.  
Go to C-2  
Replace/  
rectify  
Is it secure?  
Yes  
No  
2. Check to ensure flame  
rod bracket is not loose.  
Error code "12"  
displayed on  
digital monitor.  
2. Check ground  
wire.  
Are connections  
OK?  
Check for faulty ground  
wire connections at unit,  
receptacle, and ground  
rod to home, and for  
Check for  
other causes  
of flame  
failure.  
Replace or  
repair  
Yes  
No  
broken or shorted wires.  
grounding  
circuit to unit.  
D. Cannot adjust  
water  
temperature.  
1. Check hot water  
thermistor.  
(outgoing  
# Disconnect connector  
B5 and measure the  
resistance between  
Resistance values  
match table on page No  
#43  
Yes  
Go to D – 2  
Replace water IGI – 6  
temperature  
thermistor)  
thermistor.  
white white.  
~
(See page 43)  
2. Check  
1. # Disconnect  
1.7 2.1KΩ  
~
Yes  
No  
Go to D – 2-2  
changeover solenoid connector E from PCB  
valve (SV3).  
Replace  
manifold  
assembly  
IGI – 8  
IGI – 2  
and measure the  
resistance between  
brown black.  
~
Yes  
No  
Go to D – 3  
Replace PCB  
80 100 VDC  
~
2. Measure the voltage  
between brown black  
wire of the changeover  
solenoid valve (SV3) at  
connector E.  
~
(See page 41)  
3. Check  
modulating valve.  
1. # Disconnect  
67 81Ω  
~
Yes  
No  
Go to D – 3-2  
replace gas  
valve  
modulating valve at C2  
festoon terminal and  
measure resistance at  
IGI – 9  
IGI – 2  
solenoid terminals.  
(See page 44)  
Yes  
No  
Go to D – 3-3  
Replace PCB  
2
15 VDC  
2. Measure the voltage  
between two harness  
terminals at C2.  
~
(See page 44)  
3. Check whether the  
manifold pressure alters  
when remote control  
temperature is altered  
Yes  
No  
Go to D – 4  
Replace gas  
valve  
Does the manifold  
pressure change?  
IGI – 9  
IGI – 3  
between 96° 140°F.  
~
4. Check water flow- 1, # Measure resistance  
22 26Ω  
~
Yes  
No  
Go to D – 4-2  
Replace water  
flow servo  
between red blue  
servo.  
~
wires of the water flow  
servo connector B2.  
(See page 44)  
sensor.  
34  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
Troubleshooting Flow Chart  
BEFORE CARRYING OUT CHECKS MARKED WITH  
A # SIGN, DISCONNECT THE POWER SUPPLY.  
Examination  
Service  
Nature of Fault  
Point  
Diagnostic Point  
Values  
Y/N  
Yes  
No  
Action  
Procedure  
2. Measure voltage  
11 13 VDC  
~
Go to 4-3  
Replace PCB  
between orange (+) and  
grey (-) of the water flow  
servo connector B2.  
3. Measure voltage  
IGI – 2  
Yes  
No  
Go to D-4-4  
Replace water IGI – 3  
flow servo  
4
4
6 VDC  
6 VDC  
between brown grey  
~
~
~
of water flow servo  
connector B2 (Don not  
turn water on)  
sensor.  
(See page 44)  
4. Measure voltage  
Yes  
No  
Normal  
Replace water IGI – 3  
flow servo  
between yellow grey  
~
of the water flow servo  
connector B2 (Do not  
turn water on)  
sensor.  
(See page 44)  
E. Anti-frost  
heater does not  
work.  
1. check anti-frost  
heater.  
1. # Disconnect  
connector F4 and F5  
measure resistance  
across each of the  
heating elements. (white  
wires)  
348 375Ω  
~
Yes  
No  
Go to E-1-2  
Replace Anti-  
frost sensing  
switch.  
(See page 45)  
Yes  
No  
Go to E-2  
Replace Anti-  
frost heater  
that is  
2. # Read resistance of  
the heating element that  
is mounted on the front  
of the heat exchanger.  
(white wires)  
100 110 Ω  
~
defective.  
(See page 45)  
Yes  
No  
Go to E-2  
Replace Anti-  
frost heater  
that is  
3. Read resistance of  
heating elements on the  
heat exchanger outlet  
hot water line.  
33 39Ω  
~
(See page 45)  
defective.  
2. Check frost  
sensing switch  
# Disconnect connector  
F2 and measure across  
the bi-metal sensing  
switch located on the  
upper right hand of the  
heat exchanger. check  
this switch at  
Is resistance <1Ω  
Yes  
Check wiring  
Replace Anti-  
frost sensing  
switch.  
after applying ice to No  
this switch for five  
minutes?  
temperatures below 37  
°F. You can place an ice  
cube against the switch  
to activate it.  
(See page 45)  
35  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
Troubleshooting Procedure  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
Unit’s wiring diagram can be found on page 29.  
Appliance fails to operate (even remote control fails to operate).  
1) Is the fuse blown  
Check fuse.  
a.  
b.  
Disconnect unit from power supply.  
# Measure resistance to check the electric fuse  
(3 amp)  
Fuses are located in plastic  
holders in the main harness,  
on the lower right hand side  
of the appliance.  
Normal: less than 1Ω  
If normal, proceed to check item 2 below.  
Faulty: Replace 3 amp glass fuse. If the fuse  
blows again, investigate cause of short circuit.  
2) Is the main transformer normal?  
Check the transformer.  
a. Measure the voltage and/or resistance at  
connector F, black white wires.  
~
Normal: 100 120 VAC  
~
51 63 Ω resistance  
~
Faulty: Check for 120 125 VAC at the surge  
~
protector, blue brown wires, connector  
~
F7.  
Resistance reading 51 63 Ω  
~
If normal, check item 3 on next page.  
Faulty: Replace the transformer.  
(Service Procedure IGI-7, page 51)  
36  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
3) Is the remote control normal ?  
Check voltage between the two remote control cable  
connectors.  
a.  
Check the voltage between terminals on the  
remote control terminal mount D1.  
Normal: 11 13 VDC  
~
If normal, check for an open circuit or short before  
replacing the remote control.  
Faulty: Replace PCB.  
(Service Procedure IGI-2, page 49)  
No combustion (despite remote control indication)  
1) Is the water flow sensor normal ?  
Check the water flow sensor.  
a.  
Check the voltage at PCB connector B4 , red and  
black wires.  
Normal: 11 ~ 13 VDC or 5.8 ~ 6.4K Ω  
If normal, check (b) below.  
Faulty: Replace the PCB.  
(Service Procedure IGI-2, page 49)  
b.  
Check the voltage at PCB connector B4, yellow and  
black wires.  
Normal: 4 ~ 7 VDC or 1M ~ 1.2M Ω.  
If normal, proceed to check item 2 on next page.  
Faulty: Replace the water flow sensor.  
(Service Procedure IGI-2, page 49)  
37  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
2) Is the flame rod normal ? Error “72” is displayed  
Checking the flame rod.  
a.  
# Detach the flame rod terminal C1, and re-attempt  
operation.  
(“72 is displayed)  
Proceed to check item 3 below.  
(no “72” displayed)  
Inspect flame rod wiring for current leak and inspect  
flame rod for carbon build-up.  
Measure resistance between the flame rod  
Terminal C1 and the appliance earth.  
Normal: 1 M Ω or more.  
If normal, replace the PCB unit.  
Faulty: Replace the flame rod.  
(Service Procedure IGI-2, page 49)  
See page 42 for additional information and resistance values  
pertaining to the flame rod.  
3) Is the water temperature thermistor normal?  
If error “32” is displayed, check the water  
temperature thermistor.  
a.  
# Disconnect connector B5, and measure resistance of  
the white ~ white wires.  
Resistance > 1 M Ω = open circuit.  
Resistance < 1 Ω = short circuit.  
Normal: Proceed to check item 4 on the next page.  
Faulty: Replace the water temperature thermistor.  
(Service Procedure IGI-6, page 50)  
See page 43 for additional information and  
resistance readings pertaining to the  
temperature themistor.  
38  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
4) Is the combustion fan motor normal ?  
Motor check.  
If error “61” is displayed, check the combustion fan.  
a.  
Measure voltage at connector A1. Black and red wires.  
Normal: 6 ~ 45 VDC (Fan on)  
0 VDC (Fan off)  
If normal, check item b below.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
Fan revolution sensor check.  
b.  
Measure voltage at connector A1, black and yellow wires.  
Normal: 11 ~ 13 VDC or 3.1 ~ 3.7 K Ω  
If normal, check item c below.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
c.  
Measure voltage at connector A1, black and white wires.  
Normal: 6 ~ 45 VDC or 9 ~ 9.4 K Ω  
(33 ~ 400 Hz.)  
If normal, proceed to check item 5 below.  
Faulty: Replace the combustion fan motor.  
(Service Procedure IGI-5, page 50)  
5) Is the ignition module operating normally ?  
Check the sparker module.  
a.  
b.  
Measure voltage at connector F8, grey and grey wires.  
Normal: 90 ~ 110 VAC  
0 VDC (when fan is off)  
If normal, check b below.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
# Disconnect connector F8, and measure the  
resistance between the two sparker terminals.  
Normal: > 1 M Ω  
Faulty: Replace the igniter module.  
(Service Procedure IGI-5, page 50)  
Electrode gap should be 3/16” to 1/4" .  
39  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
6) Is the main gas solenoid valve (SV0) operating normally ?  
If error “11” or “71” is displayed, check the main gas solenoid  
valve.  
a.  
# Disconnect the main gas solenoid valve (SV0)  
connector and measure the resistance at the solenoid  
terminals.  
Normal: 1.7 ~ 2.1 K Ω  
If normal, check b below.  
Faulty: Replace gas valve.  
(Service Procedure IGI-9, page 52)  
Measure voltage at the main gas solenoid (SV0)  
Pink and black wires.  
b.  
Normal: 80 ~ 100 VDC  
If normal, proceed to check item 7 below.  
Faulty: Replace PCB unit.  
(Service Procedure IGI-2, page 49)  
7) Is the change over solenoid (SV1) operating normally ?  
If error “11” or “71” is displayed, check the change over  
solenoid (SV1).  
a.  
# Disconnect the change over solenoid (SV1)  
connector, and measure resistance at the solenoid  
terminals.  
Normal: 1.7 ~ 2.1 K Ω  
If normal, check b below.  
Faulty: Replace the gas valve.  
(Service Procedure IGI-9, page 52)  
Measure voltage at the change over solenoid  
(SV1) yellow ~ black wires.  
b.  
Normal: 80 ~ 100 VDC  
If normal, check 8 below.  
Faulty: Replace PCB unit.  
(Service Procedure IGI-2, page 49)  
8) Is the change over solenoid (SV2) operating normally?  
If error “11” or “71” is displayed, check the change over  
solenoid (SV2).  
a.  
b.  
# Disconnect the changeover solenoid (SV2) connector,  
and measure the resistance at the solenoid terminals.  
Normal: 1.7 – 2.1 K Ω  
If normal, check b below.  
Faulty: Replace the gas valve.  
(Service Procedure IGI-9, page 52)  
Measure the voltage at the changeover solenoid (SV2),  
blue – black wires.  
Normal: 80 – 100 VDC  
If normal, check 9, on next page.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
40  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
9) Is the change over solenoid (SV3) operating normally?  
If error “11” or “71” is displayed, check the change over  
solenoid (SV3).  
a.  
# Disconnect the changeover solenoid (SV3)  
connector, and measure the resistance at the  
solenoid terminals.  
Normal: 1.7 – 2.1 K Ω  
If normal, check b below.  
Faulty: Replace the manifold assembly.  
(Service Procedure IGI-8, page 51)  
b.  
Measure the voltage at the changeover solenoid  
(SV3), brown – black wires.  
Normal: 80 – 100 VDC  
If normal, reconfirm gas pressures are correct.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
41  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
Error code “14” Check the thermal fuse.  
a.  
# Disconnect connector B3 and C3, measure the  
resistance between the red – red wires.  
Normal: Less than 1 Ω  
If normal, check b below.  
Faulty: Check manifold gas pressure. Check heat  
exchanger for cracks and/or separations. If there is  
nothing abnormal, replace the thermal fuse.  
(Service Procedure IGI-11, page 53)  
b.  
Check bi-metal switch, (remaining flame safety  
device). Measure resistance between the two  
terminals at B3 and C3.  
Normal: Less than 1 Ω  
If normal, process to item a below.  
Faulty: Replace the bi-metal switch.  
Combustion stops due to flame failure  
1) Is the flame rod functioning normally?  
a.  
Measure the voltage between the flame rod  
terminal C1 and the appliance earth.  
Normal: 5 – 150 VAC from yellow to ground.  
If normal, check b below.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
Check that the flame rod attachment is not loose.  
Normal: Replace the PCB unit.  
b.  
(Service Procedure IGI-2, page 49)  
Faulty: Secure the flame rod bracket.  
2) Is the earth lead wire connected?  
a.  
Check for defective earth terminal, or an open  
circuit or short. If normal, investigate other  
possible causes for the flame failure.  
(Eg. Is the gas valve open ? Is the filter mesh  
blocked ?) Was proper venting material used?  
Did you regulate your gas supply pressure to the  
proper gas pressure for gas type being used?  
Faulty: Ensure unit is properly grounded. Check  
ground circuit outside home at service pole.  
There should be an eight foot ground rod driven  
in the earth and a copper lead tied to the service  
meter. Ensure connection on ground rod is tight.  
42  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VI - TROUBLESHOOTING(cont.)  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
Unable to adjust hot water temperature  
1) Is the water temperature thermistor operating normally ?  
a.  
# Disconnect the connector B5, and measure the  
resistance between the white wires, see below  
for resistance readings.  
Thermistor resistance valves:  
59 ºF = 11.4 ~ 14 K Ω  
86 ºF = 6.4 ~ 7.8 K Ω  
113 ºF = 3.6 ~ 4.5 K Ω  
140 ºF = 2.2 ~ 2.7 K Ω  
221 ºF = 0.6 ~ 0.8 Ω  
Normal: Proceed to check item 2 below.  
Faulty: Replace the water temperature  
thermistor.  
(Service Procedure IGI-6, page 50)  
2) Is the change over solenoid (SV1) normal ?  
a.  
# Disconnect the changeover solenoid (SV1)  
connector, and measure resistance at the  
solenoid terminals.  
Normal: 1.7 2.1 K Ω  
~
If normal, proceed to b.  
Faulty: Replace the gas valve.  
(Service Procedure IGI-9, page 52)  
b.  
Measure the voltage at the changeover solenoid  
(SV1) yellow black wires.  
~
Normal: 80 100 VDC  
~
If normal, proceed to check item 3, on next  
page.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
43  
Download from Www.Somanuals.com. All Manuals Search And Download.  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
3) Is the modulating valve operating normally ? Error code 52  
a.  
# Disconnect the modulating valve festoon C2  
terminals and measure the resistance at the terminals.  
Normal: 67 81 Ω  
~
If normal, check b.  
Faulty: Replace gas valve.  
(Service Procedure IGI-9, page 52)  
Re-connect terminal C2 and measure voltage  
b.  
across the pink pink wires when the unit is  
~
firing.  
Normal: 2 15 VDC  
~
If normal, check c below.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
Investigate the change in the manifold gas  
pressure, when the remote control pre-set  
c.  
temperature is altered from 96 140 ºF.  
~
Normal: If the manifold pressure changes,  
proceed to check item 4 below. DO NOT  
adjust manifold pressures.  
Faulty: Replace gas valve.  
(Service Procedure IGI-9, page 52)  
4) Is the water flow servo normal ?  
a.  
b.  
# Disconnect connector B2 and measure the  
resistance of the water flow servo, red blue wires.  
~
Normal: 22 26 Ω  
~
If normal, proceed to b.  
Faulty: Replace the water flow servo and sensor.  
(Service Procedure IGI-2, page 49)  
Disconnect connector B2 , and measure the voltage on  
the PCB unit side, were the orange (+), and/or grey or  
black (-) wires connect to the board.  
Normal: 3.3 4.5 VDC  
~
If normal, proceed to c.  
Faulty: Replace the PCB unit.  
(Service Procedure IGI-2, page 49)  
c.  
With connector B2 , connected (do not turn water  
ON … wait for the water flow servo to return to  
fully open), measure the voltage at the brown  
~
grey wires.  
Normal: 4 6 VDC vent limiter OFF  
~
Faulty: Replace the water flow servo and  
sensor. (Service Procedure IGI-2, page 49)  
d.  
With connector B2 , connected (do not turn  
water ON… wait for the water flow servo to  
return to fully open), measure the voltage at the  
yellow grey wires.  
~
Normal: Less than 0.5 VDC when unit is set at  
120 °F and there is no water flowing through the unit.  
Faulty: Replace water flow servo and sensor.  
(Service Procedure IGI-2, page 49)  
44  
Download from Www.Somanuals.com. All Manuals Search And Download.  
BEFORE CARRYING OUT CHECKS MARKED WITH A # SIGN, DISCONNECT THE POWER SUPPLY.  
Anti-frost heaters do not operate  
1) Are the ceramic anti-frost heaters operating normally ?  
a.  
# Disconnect connector F4, and measure the  
resistance of the heater mounted in the water  
flow control valve, these are white wires.  
Disconnect connector F5, and measure the  
resistance of the heater in the outlet line  
connector See connectors in the first and second  
picture t o the left.  
Normal: 348 375 Ω  
~
If normal, proceed to b.  
Faulty: Replace defective element.  
b.  
# Take an ohm meter and read resistance across  
the heater on the face of the heat exchanger. The  
resistance across this element is listed below. See  
third picture to the left for location of this element.  
These are white wires.  
Normal: 100 110 Ω  
~
If normal, proceed to check item 2 below.  
Faulty: Replace defective anti frost heater  
assembly.  
c.  
Check resistance of the two heat exchanger  
outlet line heater elements, as shown in the  
third picture to the left. Check across each heater  
independently.  
Normal: 33 39 Ω  
~
Faulty: Replace defective anti frost heater  
assembly.  
2) Is the frost sensor switch operating normally ?  
a. # Disconnect connector F2, and measure the  
resistance through this switch, measure when  
atmospheric temperature is 37°F + or – 3°F. (See Note)  
See drawing to left for location of this bimetal  
switch. These are white wires to this switch.  
Normal: Less than 1 Ω  
If normal, check wiring harness for defects.  
(100 volts AC)  
Faulty: Replace the frost sensing bimetal switch.  
Note: If the atmospheric temperature is too high,  
cool the switch with ice.  
45  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VII - GAS PRESSURE SETTING PROCEDURE  
All settings/adjustments must be performed  
by a qualified Service Technician.  
Turn unit off at power source and turn off the gas to the water heater.  
Remove the front cover from the water heater.  
1.  
2.  
3.  
Remove the gas pressure test port plug. Connect manometer to this port. (See Figure #1 for  
location of the test port plug.) Turn on the gas and power to the water heater.  
4.  
5.  
Flow water through the water heater at the maximum flow rate obtainable.  
To adjust the “Low” fire pressure, use small (pocket) common screwdriver to set combustion  
control dip switch #1 to the “OFF” position, switch # 7 to the “ON” position, and switch #8 to  
the “OFF” position (see figure #2 for location of combustion control switches.) This will put the  
unit into forced low fire. Check the pressure reading on your manometer. If the pressure needs  
adjusting, remove the rubber plug from the bottom of the water heater casing (located beneath  
the regulator), to access the regulator adjustment screw. Adjust the pressure to the correct  
setting (See figure #1 for location of the regulator adjustment screw.) Below are the proper  
pressures for “Low” fire, per gas type being used.  
Propane  
Natural  
0.93” w.c. @ 11” w.c. supply  
0.77” w.c. @ 7” w.c. supply  
(Low fire rate of 15,000 BTU’s)  
(Low fire rate of 15,000 BTU’s)  
6.  
To adjust the “High” fire pressure, use small (pocket) common screwdriver to set combustion  
control dip switch #1 to the “ON” position, switch # 7 to the “ON” position, and switch #8 to  
the “ON” position (see figure #2 for location of the combustion control switches), this will put  
the unit into forced high fire. Check the pressure reading on your manometer. If the pressure  
needs adjusting, use small (pocket) common screwdriver to adjust the high pressure “Pot”.  
(See figure #2 for location of “high pressure setting pot”.)  
Below are the proper pressures for “High” fire, per gas type being used.  
Propane  
Natural  
4.2” w.c. @ 11” w.c. supply  
3.7” w.c. @ 7” w.c. supply  
(High fire rate of 180,000 BTU’s)  
(High fire rate of 180,000 BTU’s)  
7.  
Verify both low and high fire pressures by placing the water heater into “Forced Low Fire” and  
“Forced High Fire” as described in steps 5 and 6 above. This completes the gas pressure  
setting procedure.  
46  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VII - GAS PRESSURE SETTING PROCEDURE  
WARNING  
Dip switched #7 and #8 (combustion control switches) MUST  
be returned to the "OFF" position, after setting pressures.  
Dip switch #1 MUST be returned to the proper position  
based upon the length of vent pipe (see page 13).  
Refer to page 12 for factory default dip switch settings.  
8.  
Turn off the gas to the water heater. Remove the manometer connection. Reinstall the  
pressure port plug.  
Turn on the gas to the water heater and check for gas leaks around test port with a leak  
solution.  
9.  
Reinstall the front cover and place the unit back into operation.  
10.  
Verify the proper water temperature, as set on the controller at your outlets.  
If controllers are not being used the output temperature should be 120°F for residnetial  
models or 140˚ for commercial models.  
Figure #1  
Figure #2  
47  
Download from Www.Somanuals.com. All Manuals Search And Download.  
VIII - Service Procedure  
NOTE: Before proceeding with dismantling, be sure to follow the CAUTION instructions before  
each explanation. Always disconnect the electrical supply, turn off water and gas supply  
service valves, and drain all water from the unit before proceeding. Only trained and qualified  
service agencies should attempt to repair this product.  
Service Procedure  
IGI – 1. Removal of the Front Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49  
IGI – 2. Removal of the PC Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49  
IGI – 3. Removal of the Water Flow Control and Sensor . . . . . . . . . . . . . . . . . . . 49  
IGI – 4. Removal of the Ignition Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50  
IGI – 5. Removal of the Combustion Fan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50  
IGI – 6. Removal of the Water Temperature Thermistor . . . . . . . . . . . . . . . . . . . 50  
IGI – 7. Removal of the Transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51  
IGI – 8. Removal of the Burner and Burner Manifold . . . . . . . . . . . . . . . . . . . . . 51  
IGI – 9. Removal of the Gas Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52  
IGI – !0. Removal of the Heat Exchanger Assembly. . . . . . . . . . . . . . . . . . . . . . . 52  
IGI – 11. Removal of the Thermal Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53  
Re-assembly in all tasks listed above in the reverse order of dismantling (unless stated otherwise).  
48  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IGI – 2. Removal of PC board  
IMPORTANT  
CAUTION  
When dismantling the unit you should always isolate  
the following items:  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
• Gas supply  
• Electrical supply  
• Water supply  
• Drain all water from the appliance  
a.  
Remove the two (2) screws holding the PCB in  
place with a Phillips screw driver, then pull the  
PC board out of the appliance.  
The following diagram will be of assistance in  
locating the above.  
Disconnect all connectors.  
IGI – 3. Removal of the Water Flow Sensor and  
Water Flow Control Valve Assembly  
IGI – 1. Removal of the Front Panel  
CAUTION  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
a.  
Remove one (1) Phillips screw from the heat  
exchanger water supply line and (1) screw from  
the bypass valve assembly. Lift the water line  
retainer up and over the housing it attaches  
to, pull water line towards yourself to  
disconnect water lines from the assembly.  
Inspect o-rings for damage, replace if  
defective.  
a.  
Remove the four (4) screws holding the  
panel in place with a Phillips driver.  
49  
Download from Www.Somanuals.com. All Manuals Search And Download.  
b.  
Remove the four (4) Phillips screws that secure IGI – 5. Removal of the Combustion Fan:  
the water inlet filter housing to the unit. See  
picture below for location of screws. Once  
screws are removed reach into the unit and  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
pull up and out on the flow control assembly reconfirm power has been disconnected using a multi-  
to remove it from the appliance. Inspect o-ring meter.  
for damage.  
a.  
b.  
Disconnect wiring harness from fan motor.  
Remove the (2) Phillips screws that secure the  
combustion fan motor to the fan housing. Pull  
the fan motor assembly towards yourself to  
remove it.  
c.  
Disconnect wiring harness from assembly and  
remove the water flow control assembly from  
the unit.  
IGI – 4. Removal of Ignition Module:  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi- IGI – 6. Removal of the Water Temperature  
meter.  
Thermistor:  
a.  
Remove one (1) Phillips screw that secures the  
sparker module to the unit casing.  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
b.  
Disconnect high tension lead and connector.  
a.  
Remove the two (2) Phillips screws that secure  
the thermistor in place to remove the water  
outlet temperature thermistor.  
50  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IGI – 7. Removal of Transformer:  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
a.  
b.  
c.  
Remove the combustion fan motor assembly  
as described in IGI - 5 a,b.  
Remove the two (2) Phillips screws to release  
the transformer.  
Disconnect wiring harness connectors to  
transformer and pull out towards you.  
d.  
e.  
To remove the burner assembly remove  
(8) Phillip screws around the sight glass  
panel. Remove this panel.  
Locate the (2) Phillip screws inside the  
burner chamber that hold the burner  
assembly in place. Remove these two  
screws, grip the burner assembly and  
slide it out of the combustion housing.  
IGI – 8. Removal of Burner Manifold and the Burner:  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
a.  
To remove the burner manifold, remove (6)  
Phillip screws around the burner plate as  
shown in the upper right picture.  
Remove the (3) Phillip screws at the gas valve  
assembly.  
b.  
c.  
f.  
If you need to remove each burner from  
this housing remove the (2) Phillip screws  
on each side of the burner, as shown  
below.  
Grip the burner manifold and remove it from  
the unit.  
51  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IGI – 9. Removal of the Gas Valve Assembly:  
b.  
c.  
Remove the heat exchanger water connection  
lines, refer to IGI - 3 a.  
Remove the three (3) Phillip screws securing  
the gas manifold assembly to the gas control  
valve.  
Remove the six (6) Phillip screws that secure  
the heat exchanger assembly in place.  
Disconnect connectors B1, B5, B6, C1, C3,  
F1and F8. These are the igniter, flame rod,  
thermo-fuse, hot water inlet and outlet  
thermistor, and the anti-freeze heater  
connections.  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
d.  
e.  
a.  
b.  
Remove the burner manifold, refer to  
IGI - 8 a,b,c.  
Remove the four (4) Phillips screws that hold  
the gas connection and gas control valve in  
place at the bottom of the unit. Pull the gas  
connection down to disconnect it from the gas  
valve assembly. Inspect o-ring for damage  
and/or defects. Ensure o-ring is in place when  
re-assembling this connection.  
f.  
g.  
Pull the heat exchanger out of the heater.  
Transfer all components found on the old heat  
exchanger over to the new exchanger.  
c.  
Disconnect connectors from solenoids, note  
which connector goes to each solenoid, alone  
with the proper wire colors. Pull gas valve  
assembly out of unit.  
IGI – 10.  
Removal of Heat Exchanger:  
CAUTION  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
a.  
Remove PCB unit, refer to IGI - 2 a.  
52  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IGI – 11. Removal of Thermal Fuse:  
a.  
b.  
The unit has four thermal fuses, see picture  
below for location.  
CAUTION  
Disconnect and remove the thermal fuse.  
Re-install new thermo fuse using the existing  
thermo fuse clips. Reconfirm inlet and  
manifold gas pressures are set to the proper  
setting. Ensure unit matches gas type being  
supplied to the heater.  
120 volt potential exposure. Isolate the appliance and  
reconfirm power has been disconnected using a multi-  
meter.  
This process may involve removing the heat exchanger  
if the thermo-fuse on the rear of the heat exchanger is  
blown. (Service Procedure IGI - 10, see page 52)  
53  
Download from Www.Somanuals.com. All Manuals Search And Download.  
IX - FLUSHING PROCEDURE FOR LIME  
SCALE REMOVAL FROM HEAT EXCHANGER  
The amount of calcium carbonate (lime) released from water is in direct proportion to water temperature and  
usage. The higher the water temperature or water usage and the harder the water (more dissolved calcium  
carbonate), the more lime deposits are dropped out of the water. This is the lime scale that forms in pipes,  
water heaters and on cooking utensils.  
Lime accumulation reduces the efficiency and longevity of the heat exchanger coil and will cause the water  
heater to malfunction. The lime scale may need to be periodically removed from the heat exchanger (indicated  
by the "LC" code on the remote display). The usage of water softening equipment greatly reduces the  
hardness of the water. However, this equipment does not always remove all of the hardness (lime). The heat  
exchanger may occasionally need to be flushed to clear out the lime deposits. Use the following procedure  
and diagram to flush the heat exchanger and remove the lime scale.  
1. Disconnect power to the water heater.  
2. Close valves in the cold water inlet and outlet supply.  
3. Connect PVC hoses (may use garden hose to the drain valve outlet fittings). Connect a circulator pump to  
the hose connected to the cold water inlet. See figure 11 for hose and circulator connections.  
4. Pour 4 gallons of fresh vinegar into a 5 gallon bucket.  
5. Place the ends of the hose into the bucket.  
6. Open the drain valves to the hose fittings.  
7. Turn on power to the circulating pump and allow the vinegar to circulate through the heat exchanger coil for  
at least 45 minutes. Heavily limed heat exchangers may require several hours.  
8. Turn off power to the circulating pump.  
9. Run hose from hot water outlet to a drain.  
10. Close the drain valve on the cold water inlet. Leave hot  
water drain valve open. Open cold water inlet to flush with  
fresh water.  
11. Allow water to flow out of the hose for 5 minutes to flush  
vinegar from the water heater.  
12. Shut off cold water inlet valve. Remove filter screen and  
clean out any sediment. Reinstall.  
13. Close the hot water drain valve. Open the cold water inlet  
and hot water supply valves.  
14. Disconnect the hoses from the drain valve connections.  
15. Restore power to the water heater and check operation.  
54  
Download from Www.Somanuals.com. All Manuals Search And Download.  
X - PARTS BREAKDOWN  
Disassembled View - Cabinet  
55  
Download from Www.Somanuals.com. All Manuals Search And Download.  
X - PARTS BREAKDOWN  
Disassembled View - Internals  
56  
Download from Www.Somanuals.com. All Manuals Search And Download.  
X - PARTS BREAKDOWN  
Disassembled View - Internals  
57  
Download from Www.Somanuals.com. All Manuals Search And Download.  
X - PARTS BREAKDOWN  
Disassembled View - Electrical  
58  
Download from Www.Somanuals.com. All Manuals Search And Download.  
PARTS LIST  
Number  
Description  
Quantity  
001  
002  
003  
004  
005  
006  
007  
008  
100  
101  
102  
103  
104  
105  
106  
107  
108  
109  
110  
110  
111  
Casing Assembly  
Wall Fitting Bracket  
Rubber Bushing  
Connection Reinforcement Panel  
Heat Protection Plate  
Front Panel  
1
2
1
1
1
1
1
2
1
2
1
1
1
1
1
16  
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
2
Front Panel Gasket  
Front Panel Gasket – Side  
Gas Control Assembly  
Screw  
Gas Connection (3/4" NPT)  
Burner Unit Assembly  
Burner Case Front  
Burner Case Bottom Panel  
Burner Air Orifice Plate  
Bunsen Burners  
Burner Case Back Panel  
Damper Plate  
Manifold Assembly – Natural Gas  
Manifold Assembly – L.P. Gas  
Upper Burner Manifold Gasket  
Lower Burner Manifold Gasket  
Combustion Chamber Pressure Tap Screw  
Combustion Chamber Front Plate Assembly  
Combustion Chamber Front Plate  
Spark Ignition Electrode  
Flame Sense Rod  
112  
113  
114  
115  
116  
117  
118  
119  
120  
121  
122  
125  
126  
127  
128  
129  
130  
131  
132  
135  
136  
137  
138  
139  
140  
141  
142  
145  
400  
401  
402  
403  
404  
Electrode Gasket  
Electrode Holder  
Upper Combustion Chamber Gasket  
Combustion Chamber Pressure Tap  
Pressure Tube  
Combustion Blower Assembly  
Blower Housing Assembly  
Blower Mounting Bracket  
Blower Gasket  
Blower Motor  
Blower Venturi Inlet Plate  
Bellow Connecting Bracket/Intake Duct  
Combustion Chamber Bracket  
Side Air Inlet Box Assembly  
Bellows Connecting Bracket/Blower  
Bellows  
Bellows Clamping Ring  
Top Air Inlet Box Assembly  
Exhaust Bracket  
Exhaust Bracket Holder  
Air Inlet Box Cover  
Heat Exchanger – Complete Assembly  
Water Inlet – _" NPT  
Water Flow Servo and Sensor Assembly  
Rectifier  
By-pass Servo Assembly  
Sensor Bracket  
59  
Download from Www.Somanuals.com. All Manuals Search And Download.  
405  
406  
407  
408  
409  
410  
411  
700  
701  
702  
703  
704  
705  
706  
707  
708  
709  
710  
711  
712  
713  
714  
715  
716  
717  
718  
719  
720  
721  
722  
723  
724  
725  
726  
800  
801  
802  
803  
804  
805  
810  
811  
812  
813  
814  
815  
816  
817  
Bypass O-Ring  
Water Filter Assembly  
Filter Plug  
Hot Water Outlet – _" NPT  
Sensor Bracket  
Small Plug Gasket  
Drain Valve  
PCB Board Assembly  
Surge Protector  
PCP Cover - Side  
PCB Cover - Front  
Transformer  
PCB Bracket  
Igniter  
High Tension Lead  
Spark Electrode Boot  
Thermistor  
Thermistor Clip - Large  
Thermal Fuse Clip  
Frost Sensing Switch  
120v Anti-Frost Heater Assembly  
Heater Connecting Harness  
120v Valve Heater Assembly  
Anti-Frost Heater Clip  
Anti-Frost Heater Clip A  
Anti-Frost Heater Clip  
Inlet Air Thermistor  
Power Supply Harness  
Fuse Harness  
100v Harness  
Solenoid Valve Harness  
Sensor Harness  
Thermal Fuse Harness  
Mold-type Limit Switch  
Screw  
Screw  
Washer  
Screw  
Screw  
Screw  
O-Ring  
O-Ring  
O-Ring  
O-Ring  
O-Ring  
O-Ring  
O-Ring  
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
5
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
8
4
4
3
1
3
2
1
1
2
2
2
1
1
2
1
1
1
1
1
1
O-Ring  
Gasket  
818  
238-44958-00  
239-44509-00  
239-44510-00  
239-44507-00  
239-44508-00  
238-44957-00  
Installation and Operating Instructions  
Main Control - Residential  
Main Control - Commercial  
Bathroom Remote Temperature Control  
2nd Bathroom Remote Temperature Control  
Venting System Installation Instruction  
Note: When ordering service replacement parts, the full model and  
serial numbers from the water heater nameplate are required.  
60  
Download from Www.Somanuals.com. All Manuals Search And Download.  
OPTIONAL VENTING COMPONENTS  
Note: When ordering service replacement parts, the full model and serial numbers from the water  
heater nameplate are required.  
61  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Notes  
62  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Notes  
63  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Ambler, PA  
For U.S. and Canada field service,  
contact your professional installer or  
local Bradford White sales representative.  
Sales/800-523-2931  
Fax/215-641-1670  
Technical Support/800-334-3393  
Fax/269-795-1089  
Warranty/800-531-2111  
Fax/269-795-1089  
International:  
Telephone/215-641-9400  
Telefax/215-641-9750  
Fax on Demand:  
888-538-7833  
www.bradfordwhite.com  
Mississauga, ON  
Sales/866-690-0961  
905-238-0100  
Fax/905-238-0105  
Technical Support/800-334-3393  
Email  
[email protected]  
[email protected]  
www.bradfordwhite.com  
www.bradfordwhitecanada.com  
Download from Www.Somanuals.com. All Manuals Search And Download.  

Black Box Modem 3600 User Manual
Blue Microphones Microphone The Snowball User Manual
Boston Acoustics Car Speaker SX85 User Manual
Brother All in One Printer 3200c User Manual
Cabletron Systems Switch DLE22 MA User Manual
Cadillac Washer Dryer XLR V User Manual
Califone CD Player CD102 PLC User Manual
Cannon All in One Printer K10376 MX712 User Manual
Canon Photo Printer CP 10 User Manual
Chariot Carriers Car Seat 51100913 User Manual