INSTALLATION & OPERATING
INSTRUCTIONS
Models 503–2003
Types H & WH
L
W
WARNING: Improper installation, adjustment, alteration, service or maintenance can
cause property damage, personal injury, exposure to hazardous materials* or loss of
life. Review the information in this manual carefully. *This unit contains materials that
have been identified as carcinogenic, or possibly carcinogenic, to humans.
FOR YOUR SAFETY: Do not store or use gasoline or other flammable vapors and
liquids or other combustible materials in the vicinity of this or any other appliance. To
do so may result in an explosion or fire.
WHAT TO DO IF YOU SMELL GAS:
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor's phone. Follow the gas
supplier's instructions.
• If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency or
the gas supplier.
This manual should be maintained in legible condition and kept adjacent to the heater or in a safe place for future
reference.
CATALOG NO. 3400.53G
Effective: 04-16-10
Replaces: 09-12-08
P/N 241288 Rev. 8
WARNINGS
Pay Attention to These Terms
Indicates the presence of immediate hazards which will cause severe
DANGER:
WARNING:
CAUTION:
NOTE:
personal injury, death or substantial property damage if ignored.
Indicates the presence of hazards or unsafe practices which could cause
severe personal injury, death or substantial property damage if ignored.
Indicates the presence of hazards or unsafe practices which could cause
minor personal injury or product or property damage if ignored.
Indicates special instructions on installation, operation, or maintenance which
are important but not related to personal injury hazards.
DANGER: Make sure the gas on which the heater
will operate is the same type as that specified on the
heater rating plate.
WARNING - CALIFORNIA PROPOSITION
65: This product contains chemicals known to the
State of California to cause cancer, birth defects or
other reproductive harm.
WARNING: Should overheating occur or the gas
supply valve fail to shut, do not turn off or disconnect
the electrical supply to the heater. Instead, shut off
the gas supply at a location external to the heater.
CAUTION: Operation of this heater in low
temperature systems requires special piping.
Harmful internal condensation will occur if the inlet
water temperature does not exceed 120°F. Warranty
claims will be denied when condensation occurs.
WARNING: Do not use this heater if any part has
been under water. Immediately call a qualified
service technician to inspect the heater and to
replace any part of the control system and any gas
control which has been under water.
CAUTION: If this heater is to be installed above
radiation level, it must be provided with a low water
cut-off device at the time of heater installation.
WARNING: To minimize the possibility of improper
operation, serious personal injury, fire, or damage to
the heater:
CAUTION: This heater requires forced water
circulation when the burner is operating. See
minimum and maximum flow rates. Severe damage
will occur if the heater is operated without proper
water flow circulation.
•
Always keep the area around the heater free of
combustible materials, gasoline, and other
flammable liquids and vapors.
CAUTION: If this heater is to be installed in a
negative or positive pressure equipment room, there
are special installation requirements. Consult factory
for details.
•
Heater should never be covered or have any
blockage to the flow of fresh air to the heater.
WARNING: Risk of electrical shock. More than one
disconnect switch may be required to de-energize
the equipment before servicing.
NOTE: Minimum 18 AWG, 105°C, stranded wire
must be used for all low voltage (less than 30 volts)
external connections to the unit. Solid conductors
should not be used because they can cause
excessive tension on contact points. Install conduit
as appropriate. All high voltage wires must be the
same size (105°C, stranded wire) as the ones on the
unit or larger.
4
the upper rear jacket panel of the heater. The model
number will have the form H7-2003 or similar depend-
ing on the heater size and configuration. The letter(s)
in the first group of characters identifies the application
(H = Hydronic Heating, WH = Domestic Hot Water
(DHW)). The number which follows identifies the firing
mode (7 = electronic modulation). The second group
of characters identifies the size of the heater (three or
four numbers representing the approximate MBTUH
input), and, where applicable, a letter, indicating the
manufacturing series.
BEFORE INSTALLATION
Raypak strongly recommends that this manual be re-
viewed thoroughly before installing your MVB heater.
Please review the General Safety information before
installing the heater. Factory warranty does not apply
to heaters that have been improperly installed or oper-
ated. (Refer to the warranty at the back of this
manual.) Installation and service must be performed
by a qualified installer, service agency or gas supplier.
If, after reviewing this manual, you still have questions
which this manual does not answer, please contact
your local Raypak representative or visit our website at
Ratings and Certifications
Standards:
Thank you for purchasing a Raypak product. We hope
you will be satisfied with the high quality and durability
of our equipment.
•
•
•
ANSI Z21.13 · CSA 4.9 - latest edition, Gas-Fired
Hot Water Boilers
CAN 3.1
-
latest edition, Industrial and
Commercial Gas-Fired Package Boilers
ANSI Z21.10.3 · CSA 4.3 - latest edition, Gas Wa-
ter Heaters
SCAQMD Rule 1146.2
Low-lead content (<.25%) CSA-verified
Product Receipt
On receipt of your heater it is suggested that you visu-
ally check for external damage to the shipping crate. If
the crate is damaged, make a note to that effect on the
Bill of Lading when signing for the shipment. Next,
remove the heater from the shipping packaging.
Report any damage to the carrier immediately.
•
•
All Raypak heaters are National Board Approved, and
design-certified and tested by the Canadian Standards
Association (CSA) for the U.S. and Canada. Each
heater is constructed in accordance with Section IV of
the American Society of Mechanical Engineers
(ASME) Heater Pressure Vessel Code and bears the
ASME stamp. This heater also complies with the latest
edition of the ASHRAE 90.1 Standard.
On occasion, items are shipped loose. Be sure that
you receive the correct number of packages as indi-
cated on the Bill of Lading.
Claims for shortages and damages must be filed with
the carrier by consignee. Permission to return goods
must be received from the factory prior to shipping.
Goods returned to the factory without an authorized
Returned Goods Receipt number will not be accepted.
All returned goods are subject to a restocking charge.
WARNING: Altering any Raypak pressure vessel
by installing replacement heat exchangers, tube
bundle headers, or any ASME parts not
manufactured and/or approved by Raypak will
instantly void the ASME and CSA ratings of the
vessel and any Raypak warranty on the vessel.
Altering the ASME or CSA ratings of the vessel also
violates national, state, and local approval codes.
When ordering parts, you must specify the model and
serial number of the heater. When ordering under war-
ranty conditions, you must also specify the date of
installation.
Installations at Elevation
Purchased parts are subject to replacement only
under the manufacturer’s warranty. Debits for defec-
tive replacement parts will not be accepted. Parts will
be replaced in kind only per Raypak’s standard war-
ranties.
Rated inputs are suitable for up to 4,500 ft elevation
without de-rating. Consult your local representative or
the factory for installations at altitudes over 4,500 ft
above sea level. No hardware changes are required to
the heaters for installations up to 10,000 ft (adjust-
ments may be required).
Model Identification
The model identification number and heater serial
number are found on the heater rating plate located on
5
Component Locations
HIGH VOLTAGE
ELECTRICAL CONNECTIONS
Fig. 3: Component Locations – Rear
Panels omitted for clarity
Fig. 1: Component Locations – Side
Top panel, blower and gas train omitted for clarity
Fig. 4: Component Locations – Top
General Information
Gas
Conn.
(NPT)
MBTUH
Input
Vent Size
(in.)
Water
Conn.
(NPT)
Model
No.
Max. Min.
500 125
750 188
N
P
1
1
1
1
1
1
1
Flue Intake
503
753
2
2
1
1
6
6
6
8
8
8
8
6
6
6
8
8
8
8
1003
999 250 2-1/2 1-1/4
1253 1250 312 2-1/2 1-1/4
1503 1500 375 2-1/2 1-1/4
1753 1750 438 2-1/2
2003 1999 500 2-1/2
2
2
Panels omitted for clarity
Fig. 2: Component Locations – Front
Table A: Basic Data
6
GENERAL SAFETY
To meet commercial hot water use needs, the high
limit safety control on this water heater will shut off the
main gas valve before the outlet temperature reaches
210°F. However, water temperatures over 125°F can
cause instant severe burns or death from scalds.
When supplying general purpose hot water, the rec-
ommended initial setting for the temperature control is
125°F.
This section applies to Hot Water Supply Boilers and
Hot Water Heaters ONLY. For sanitary rinse applica-
tions where outlet temperatures of 180°F to 195°F are
required, a boiler is recommended since the 210°F
limit on water heaters will NOT allow the heater to
maintain these desired sanitary rinse temperatures.
Water temperature over 125°F can
causeinstantsevereburnsordeath
from scalds.
Children, disabled, and elderly are
at highest risk of being scalded.
Safety and energy conservation are factors to be con-
sidered when setting the water temperature on the
thermostat. The most energy-efficient operation will
result when the temperature setting is the lowest that
satisfies the needs of the application.
See instruction manual before set-
ting temperature at water heater.
Feel water before bathing or show-
ering.
Water temperature over 125°F can cause instant
severe burns or death from scalds. Children, disabled
and elderly are at highest risk of being scalded.
Temperature limiting valves are
available, see manual.
•
•
Feel water before bathing or showering.
Temperature limiting valves are available.
Time/Temperature
Relationships in Scalds
NOTE: When this water heater is supplying general
purpose hot water for use by individuals, a
thermostatically controlled mixing valve for reducing
point of use water temperature is recommended to
reduce the risk of scald injury. Contact a licensed
plumber or the local plumbing authority for further
information.
The following chart details the relationship of water
temperature and time with regard to scald injury and
may be used as a guide in determining the safest
water temperature for your applications.
Water
Temp.
Time to Produce Serious
Burn
Maximum water temperatures occur just after the
heater’s burner has shut off. To determine the water
temperature being delivered, turn on a hot water
faucet and place a thermometer in the hot water
stream and read the thermometer.
120°F
125°F
130°F
135°F
140°F
145°F
150°F
155°F
More than 5 minutes
1-1/2 to 2 minutes
About 30 seconds
About 10 seconds
Less than 5 seconds
Less than 3 seconds
About 1-1/2 seconds
About 1 second
Table courtesy of The Shriners Burn Institute
Table B: Time to Produce Serious Burn
7
The temperature of the water in the heater can be reg-
ulated by using the Raypak Modulating Temperature
Control. To comply with safety regulations, the control
is set at 120°F when shipped from the factory (Mode 3
default setting for Tank Target).
Equipment Base
The heater should be mounted on a level, structurally
sound surface. The heater is approved for installation
on a combustible surface but must NEVER be
installed on carpeting. Gas-fueled equipment installed
in enclosed parking garages must be located at least
18 in. above the floor.
To adjust the water temperature, follow the instruction
for the operation of the control starting on page 30 of
this manual. The control is shown below for identifica-
tion purposes only. (See Fig. 5.)
CAUTION: This heater should be located in an
area where water leakage will not result in damage
to the area adjacent to the appliances or to the
structure. When such locations cannot be avoided, it
is recommended that
a
suitable catch pan,
adequately drained, be installed under the
appliance. The pan must not restrict air flow.
In addition, the heater shall be installed such that the
gas ignition system components are protected from
water (dripping, spraying, rain, etc.) during appliance
operation or service (circulator replacement, control
replacement, etc.).
If the heater needs to be secured to the ground, use
the brackets that were used to bolt the heater to the
shipping pallet.
Fig. 5: Modulating Temperature Control
CAUTION: Hotter water increases the risk of
scalding! There is a hot water scald potential if the
thermostat is set too high.
Clearances
Indoor Installations
Minimum Clearance
from Combustible
Surfaces
Minimum
Service
Clearance
INSTALLATION
Heater
Side
Floor*
Rear
0”
12”
1”
0”
24”
1”
Installation Codes
Installations must follow these codes:
Right
Side
Left Side
Top
1”
1”
•
•
•
•
Local, state, provincial, and national codes, laws,
regulations and ordinances
0”
10”
24”
1”
Front
Vent
Open
1”
National Fuel Gas Code, ANSI Z223.1/NFPA 54 –
latest edition (NFGC)
National Electrical Code, ANSI/NFPA 70 - latest
edition (NEC)
Standard for Controls and Safety Devices for
Automatically Fired Boilers, ANSI/ASME CSD-1,
(CSD-1) when required
For Canada only: CAN/CSA B149 Natural Gas
and Propane Installation Code and CSA C22.1
C.E.C. Part 1 (C22.1)
*DO NOT install on carpeting.
Table C: Clearances – Indoor Installations
When installed according to the listed minimum clear-
ances from combustible construction, these heaters
can still be serviced without removing permanent
structural construction around the heater. However, for
ease of servicing, a clearance of at least 24 in. in front,
at least 24 in. on the rear and 10 in. above the top of
the heater is required. This will allow the heater to be
•
8
lation codes and the requirements of the gas supplier.
Three sides must be open in the area under the over-
hang. Roof water drainage must be diverted away
from heaters installed under overhangs.
The combustion air intake terminal MUST be used for
outdoor installations. The elbow is shipped loose to be
installed on the rear of the heater at the job site.
Min. Clearance
from Combustible
Surfaces
Minimum
Service
Clearance
Heater
Side
Rear
Front
12”
24”
24”
1”
Open
Right Side
Left Side
Top
1”
1”
1”
Unobstructed
10”
Vent
Termination
12”
12”
Table D: Clearances – Outdoor Installations
Combustion and Ventilation Air
NOTE: Use of this heater in construction areas
where fine particulate matter, such as concrete or
dry-wall dust, is present may result in damage to the
heater that is not covered by the warranty. If
operated in a construction environment, a clean
source of combustion air must be provided directly to
the heater.
Indoor Units
Venting not shown for clarity. Heater must be vented
per instructions in this manual
This heater must be supplied with sufficient quantities
of non-contaminated air to support proper combustion
and equipment ventilation. Combustion air can be sup-
plied via conventional means where combustion air is
drawn from the area immediately surrounding the
heater, or via direct vent, where combustion air is
drawn directly from outside. All installations must com-
ply with the requirements of the NFGC (U.S.) and
B149 (Canada), and all local codes.
Fig. 6: Minimum Clearances from Combustible
Surfaces – Indoor and Outdoor Installations
serviced in its installed location without movement or
removal of the heater.
Service clearances less than the minimum may
require removal of the heater to service either the heat
exchanger or the burner components. In either case,
the heater must be installed in a manner that will
enable the heater to be serviced without removing any
structure around the heater.
CAUTION: Combustion air must not be
contaminated by corrosive chemical fumes which
can damage the heater and void the warranty. (See
the Appendix.)
Outdoor Installations
These heaters are design-certified for outdoor installa-
tion. Heaters must not be installed under an overhang
unless clearances are in accordance with local instal-
NOTE: It is recommended that the intake vent be
insulated to minimize sweating.
9
Fig. 7: Minimum Clearances from Vent/Air Inlet Terminations – Indoor and Outdoor Installations
U.S. Installations1
Canadian Installations2
Clearance above grade, veranda, porch,
deck, or balcony
A
1 ft (30 cm)
1 ft (30 cm)
4 ft (1.2m) below or to side
of opening; 1 foot (30 cm)
above opening
Clearance to window or door that may be
opened
B
C
3 ft (91 cm)
Clearance to permanently closed window
*
*
Vertical clearance to ventilated soffit located
above the terminal within a horizontal dis-
tance of 2 ft (61cm) from the centerline of the
terminal
D
5 ft (1.5m)
*
E
F
Clearance to unventilated soffit
Clearance to outside corner
Clearance to inside corner
*
*
*
*
*
G
6 ft (1.83m)
3 ft (91 cm) within a height
15 ft above the me-
ter/regulator assembly
Clearance to each side of center line ex-
tended above meter/regulator assembly
H
I
*
*
Clearance to service regulator vent outlet
6 ft (1.83m)
Clearance to non-mechanical air supply inlet 4 ft (1.2m) below or to side
to building or the combustion air inlet to any
of opening; 1 ft (30 cm)
J
3 ft (91 cm)
other appliance
above opening
3 ft (91 cm) above if within
10 ft (3m) horizontally
K
L
Clearance to mechanical air supply inlet
6 ft (1.83m)
7 ft (2.13m) t
Clearance above paved sidewalk or paved
driveway located on public property
7 ft (2.13m)
Clearance under veranda, porch, deck or
balcony
M
*
12 in. (30 cm) TT
1
2
In accordance with the current ANSI Z223.1/NFPA 54 National Fuel Gas Code
In accordance with the current CAN/CGA-B149 Installation Codes
t
Vent terminal shall not terminate directly above sidewalk or paved driveway located between 2 single family dwellings that serves
both dwellings
TT Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor and top of terminal and
underside of veranda, porch, deck or balcony is greater than 1 ft (30cm)
*
Clearances in accordance with local installation codes and the requirements of the gas supplier
Table E: Vent/Air Inlet Termination Clearances
10
or sealed single-wall galvanized ducting. The duct will
attach directly to the air collar located on the rear of the
heater, using three or four sheet metal screws (not
supplied) equally positioned around the circumference
of the duct. The screen assembly should be removed
before attaching any air duct to the heater. The screws
and duct connection point must be sealed with RTV
(not supplied). TruSeal is generally used when dam-
aging contaminants are present in the mechanical
room.
Air Filter
An air filter is supplied standard with the heater. This
filter is shipped loose for field installation. Refer to the
Air Filter Kit Installation Instructions (Part No. 241338)
for details.
All ducting should be self-supported.
CAUTION: Use TruSeal combustion air if
damaging airborne contaminants are or may be
present in the heater area. See the Appendix of this
manual regarding air contamination.
Conventional Combustion Air
Supply
Fig. 8: Air Filter Box
U.S. Installations
Direct Vent
All Air from Inside the Building
If outside air is drawn through the intake pipe directly
to the unit for combustion:
The confined space shall be provided with TWO per-
manent openings communicating directly with an
additional room(s) of sufficient volume so that the com-
bined volume of all spaces meets the criteria for a
room large in comparison (NFGC). The total input of all
gas utilization equipment installed in the combined
space shall be considered in making this determina-
tion. Each opening shall have a minimum free area of
1 in.2 per 1,000 BTUH (2,225 mm2 per kW) of the total
input rating of all gas utilization equipment in the con-
fined space, but not less than 100 in.2 (645 cm2). One
opening shall commence within 12 in. (305 mm) of the
top, and one opening shall commence within 12 in.
(305 mm) of the bottom of the enclosure. The mini-
mum dimension of air openings shall be not less than
3 in. (76 mm) in any direction.
1. Install combustion air direct vent in accordance
with Fig. 27 (horizontal) or Fig. 28 (vertical) of this
manual (pages 27 and 28, respectively).
2. Provide adequate ventilation of the space occu-
pied by the heater(s) by an opening(s) for
ventilation air at the highest practical point com-
municating with the outdoors. The total
cross-sectional area shall be at least 1 in.2 of free
area per 20,000 BTUH (111 mm2 per kW) of total
input rating of all equipment in the room when the
opening is communicating directly with the out-
doors or through vertical duct(s). The total
cross-sectional area shall be at least 1 in.2 of free
area per 10,000 BTUH (222 mm2 per kW) of total
input rating of all equipment in the room when the
opening is communicating with the outdoors
through horizontal duct(s).
All Air from Outdoors
The confined space shall communicate with the out-
doors in accordance with one of the methods below.
The minimum dimension of air openings shall not be
less than 3 in. (76 mm) in any direction. Where ducts
are used, they shall be of the same cross-sectional
area as the net free area of the openings to which they
connect.
3. In cold climates, and to mitigate potential freeze-
up, Raypak highly recommends the installation of
a motorized sealed damper to prevent the circula-
tion of cold air through the heater during the
non-operating hours.
TruSeal™ Combustion Air
1. Two permanent openings, one commencing
within 12 in. (305 mm) of the top, and one com-
mencing within 12 in. (305 mm) of the bottom of
the enclosure, shall be provided. The openings
In addition to the 3 previous steps, combustion air may
be ducted directly to the heater by using PVC, CPVC
11
shall communicate directly, or by ducts, with the
outdoors or spaces (crawl or attic) that freely com-
municate with the outdoors.
(65 cm2).
2. For heaters using a barometric damper in the vent
system there shall be a permanent air supply
opening(s) having a cross section area of not less
than 1 in.2 per 7,000 BTUH (320 mm2 per kW) up
to and including 1 million BTUH, plus 1 in.2 per
14,000 BTUH (160 mm2 per kW) in excess of 1
million BTUH. This opening(s) shall be either
located at or ducted to a point not more than 18 in.
(450 mm) nor less than 6 in. (152 mm) above the
floor level. The duct can also “goose neck” through
the roof. The duct is preferred to be straight down
and terminated 18 in. (450 mm) from the floor, but
not near piping. This air supply opening require-
ment shall be in addition to the air opening for
ventilation air required in 1. (above).
a. Where directly communicating with the out-
doors or where communicating to the
outdoors through vertical ducts, each open-
ing shall have a minimum free area of 1 in.2
per 4,000 BTUH (550 mm2 per kW) of total
input rating of all equipment in the enclosure.
b. Where communicating with the outdoors
through horizontal ducts, each opening shall
have a minimum free area of 1 in.2 per 2,000
BTUH (1,100 mm2 per kW) of total input rat-
ing of all equipment in the enclosure.
2. One permanent opening, commencing within 12
in. (305 mm) of the top of the enclosure, shall be
permitted where the equipment has clearances of
at least 1 in. (25 mm) from the sides and back and
6 in. (152 mm) from the front of the appliance. The
WARNING: Care must be taken to ensure that the
equipment room is not under negative pressure
conditions.
opening shall directly communicate with the out- 3. For heaters not using a barometric damper in the
doors or shall communicate through a vertical or
horizontal duct to the outdoors or spaces that
freely communicate with the outdoors, and shall
have a minimum free area of:
vent system, and when air supply is provided by
natural air flow from outdoors for a power burner
and there is no draft regulator, drafthood or similar
flue gas dilution device installed in the same
space, in addition to the opening for ventilation air
required in 1., there shall be a permanent air sup-
ply opening(s) having a total cross-sectional area
of not less than 1 in.2 for each 30,000 BTUH (74
mm2 per kW) of total rated input of the burner(s),
and the location of the opening(s) shall not inter-
fere with the intended purpose of the opening(s)
for ventilation air referred to in 1. This opening(s)
can be ducted to a point not more than 18 in. (450
mm) nor less than 6 in. (152 mm) above the floor
level. The duct can also “goose neck” through the
roof. The duct is preferred to be straight down 18
in. (450 mm) from the floor, but not near piping.
a. 1 in.2 per 3,000 BTUH (740 mm2 per kW) of
the total input rating of all equipment located in
the enclosure, and
b. Not less than the sum of the areas of all vent
connectors in the confined space.
WARNING: Do not use the “one permanent
opening” method if the equipment room is under
negative pressure conditions.
Canadian Installations
4. Refer to the B149 Installation Code for additional
information
CAUTION: All combustion air must be drawn from
the air outside of the building; the mechanical equip-
ment room must communicate directly with the
outdoors.
Water Piping
General
1. Ventilation of the space occupied by the heater
shall be provided by an opening(s) for ventilation The heater should be located so that any water leaks
air at the highest practical point communicating will not cause damage to the adjacent area or struc-
with the outdoors. The total cross-sectional area of
such an opening(s) shall be at least 10% of the
area required in 2. and 3. (below), but in no case
shall the cross-sectional area be less than 10 in.2
tures.
12
feed valve. Test at standard operating pressure for
at least 24 hours.
CAUTION: This heater requires forced water
circulation when the burner is operating. See Table F
and Table G for minimum and maximum flow rates
and water pump selection. The pump must be
interlocked with the heater to prevent heater
operation without water circulation.
2. Make sure constant gauge pressure has been
maintained throughout test.
3. Check for leaks. Repair if found.
NOTE: Minimum pipe size for in/out connections is
Cold Water Operation
1
2 in. NPT for 503 and 753 models and 2- ⁄
2
in NPT for
1003–2003 models. Verify proper flow rates and ∆T
as instructed in this manual.
CAUTION: Damage due to internal condensation
may occur if the heater inlet water temperature does
not exceed 120°F (49°C) within 7 minutes of start-
up.
Relief Valve Piping
WARNING: Pressure relief valve discharge piping
must be piped near the floor and close to a drain to
eliminate the potential of severe burns. Do not pipe
to any area where freezing could occur. Refer to
local codes.
This heater is equipped with a proprietary condensate
evaporation system which will evaporate any conden-
sate that may begin to accumulate inside the primary
heat exchanger with water temperatures as low as
120°F (49°C).
Heaters operated with an inlet temperature of less
than 120°F (49°C) MUST have a manual bypass (see
Fig. 16) or an approved low-temperature operation
system (Figs. 9 and 10) to prevent problems with con-
Temperature & Pressure Gauge
The temperature and pressure gauge is shipped loose
for field installation and must be installed within 12
inches of the boiler outlet (if possible) in an easily
readable location. Installation must comply with ASME
Section IV as well as all applicable national, state and
local codes.
densation.
This
piping
is
similar
to
a
primary/secondary boiler installation with a bypass
acting as the secondary boiler piping. Raypak strong-
ly recommends that thermometer(s) be placed into the
heater piping next to the in/out header to facilitate tem-
perature adjustment. Inlet water temperatures below
120°F (49°C) can excessively cool the products of
combustion, resulting in collection of condensate in the
heat exchanger area beyond the capacity of the con-
densate evaporation system.
Hydrostatic Test
Unlike many types of heaters, this heater does not re-
quire hydrostatic testing prior to being placed in
operation. The heat exchanger has already been fac-
tory-tested and is rated for 160 psi operating pressure.
However, Raypak does recommend hydrostatic test-
ing of the piping connections to the heater and the rest
of the system prior to operation. This is particularly
true for hydronic systems using expensive glycol-
based anti-freeze. Raypak recommends conducting
the hydrostatic test before connecting gas piping or
electrical supply.
Failure to reach or exceed 120°F (49°C) within 7 min-
utes may damage or cause failure of the heat
exchanger, combustion chamber, or other parts within
the combustion chamber. It can cause operational
problems, bad combustion, sooting, flue gas leakage
and reduced service life of the appliance and the vent
system. A bypass allows part of the heater discharge
water to be mixed with the cooler water returning to the
heater inlet to increase the heater inlet temperature
above 120°F (49°C). This precautionary measure
should prevent the products of combustion from con-
densing beyond the ability of the condensate
management system employed in this heater in most
installations. Warranty claims will be denied for
damage or failures caused by condensation.
Leaks must be repaired at once to prevent damage to
the heater. NEVER use petroleum-based stop-leak
compounds.
To perform hydrostatic test:
1. Connect fill water supply. With bleed valve open,
fill heater with water. When water flows from bleed
valve, shut off water. Close bleed valve. Carefully
fill the rest of the system, making sure to eliminate
any entrapped air by using high-point vents. Close
Cold water operation issues are applicable to both
cold water start and cold water run applications. Cold
water operation for 7 minutes or less on initial daily
start-up is acceptable. Where cold water starts will last
13
longer than 7 minutes or where cold water operation is water is kept in a narrow temperature range of no
continuous, provisions must be made to mix higher more than 10°F (5°C), a permanent manual bypass
temperature outlet water with the colder inlet water can be employed and manually adjusted to achieve an
and thereby raise the inlet temperature to at least inlet temperature of 120°F (49°C) or higher as adjust-
120°F (49°C) within the 7-minute time limit.
ed at the minimum temperature in this narrow
temperature range (i.e. Range 75°F to 85°F, adjust
bypass with temperature at 75°F (24°C)) so that when
temperature is 85°F (29°C), minimum inlet tempera-
ture would be 130°F (54°C). An injector pump
arrangement may also be utilized to keep the heater
loop at or above 120°F (49°C). An injector pump
approach has the added value of being able to adjust
to changes in the system water coming back to the
heater take-off.
Cold Water Starts
Cold water starts, where the inlet water temperature
remains below 120°F (49°C) for more than 7 minutes,
must have cold water start protection. Known pro-
tection methods consist of mixing heated outlet water
with the inlet water using a bypass to raise the inlet to
120°F (49°C) or higher. Once the system is heated up
and has return water temperatures of 120°F (49°C) or
higher, the mixing of outlet water with inlet water is no
longer needed and the bypass can be shut off. If the
bypass is not shut off as the system heats up, the out-
let temperature may continue to climb and trip the high
limit, thereby shutting down the heater. Thus an auto-
matic valve system, such as a three-way proportional
valve to control the bypass, should be used.
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 10: Cold Water Run
Hydronic Heating
Pump Selection
In order to ensure proper performance of your heater
system, you must install a correctly-sized pump. Ray-
pak requires designing for a ∆T within the range of
10°F to 40°F (5°C to 20°C). See Table F for accept-
able flow rates for each model (∆T is the temperature
difference between the inlet and outlet water when the
heater is firing at full rate).
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 9: Cold Water Start
Feedwater Regulator
Cold Water Run
Cold water run differs from cold water start in that the Raypak recommends that a feedwater regulator be in-
system water entering the heater remains below stalled and set at 12 psi minimum pressure at the
120°F (49°C) continuously. Typically, this is the case in highest point of the system. Install a check valve or
swimming pool heating and water source heat pump back flow device upstream of the regulator, with a
applications as well as some others. If the system manual shut-off valve as required by local codes.
14
Min. Flow
P (ft)
1.1
Max. Flow
20°F T
30°F T
40°F T
Model
No.
gpm
gpm
gpm
gpm
gpm
P (ft)
2.8
P (ft)
1.4
P (ft)
N/A
1.9
T
P (ft)
11.3
13.8
18.6
22.2
25.5
27.2
32.0
T
503
753
44
65
29
44
N/A
33
43
54
65
76
87
25
33
43
54
65
76
87
35 100
40 100
40 113
40 113
40 113
40 113
40 116
9
6.4
3.1
1.9
13
15
19
23
27
30
1003
1253
1503
1753
2003
87
12.0
20.9
N/A
N/A
N/A
58
6.0
3.7
3.7
109
N/A
N/A
N/A
73
10.2
16.0
22.5
32.0
6.2
6.2
87
9.5
9.5
102
116
13.4
18.9
13.4
18.9
Notes: Basis for minimum flow is ∆T . Basis for maximum flow is gpm.
Table F: Heater Rates of Flow and Pressure Drops
Piping
All high points should be vented. A heater installed
above radiation level must be provided with a low wa-
ter cut-off device (sales order option F-10). This
heater, when used in connection with a refrigeration
system, must be installed so that the chilled medium is
piped in parallel with the heater with appropriate
valves to pre-vent the chilled medium from entering
the heater.
THERMOSTAT OR
SYSTEM SENSOR
The piping system of a hot water heater connected to
heating coils located in air handling units where they
may be exposed to circulating refrigerated air, must be
equipped with flow control valves or other automatic
means to prevent gravity circulation of the heater
water during the cooling cycle. It is highly recommend-
ed that the piping be insulated.
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Air-Separation/Expansion Tank
Fig. 12: Single Heater - Low-Temperature (Heat Pump)
Application with Primary/Secondary Piping
All heaters should be equipped with a properly sized
expansion tank and air separator fitting as shown in
Fig. 11.
THERMOSTAT OR
SYSTEM SENSOR
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 11: Air-Separation/Expansion Tank
Fig. 13: Dual Heaters (Reverse/Return)
with Primary/Secondary Piping
15
Three-Way Valves
NOTE: If local codes require a vacuum relief valve,
acquire one locally and install per valve
manufacturer’s instructions.
Three-way valves intended to regulate system water
temperatures by reducing flow in the boiler should not
be used. Raypak heaters are high-recovery, low-mass
heaters which are not subject to thermal shock. See
Fig. 16 and instructions on page 17 for adjusting the
manual bypass.
Potable Water and Space Heating
CAUTION: When this heater is used for both
potable water and space heating, observe the
following to ensure proper operation.
Domestic Hot Water
1. All piping materials and components connected to
the water heater for the space heating application
shall be suitable for use with potable water.
When designing the water piping system for domestic
hot water applications, water hardness should be con-
sidered. Table G indicates the suggested flow rates for
soft, medium and hard water. Water hardness is ex-
pressed in grains per gallon.
2. Toxic chemicals, such as used for boiler treatment,
shall not be introduced into the potable water used
for space heating.
SYSTEM
SUPPLY
3. If the heater will be used to supply potable water,
it shall not be connected to any heating system or
components previously used with a non-potable
water heating appliance.
4. When the system requires water for space heating
at temperatures higher than 140°F (60°C), a
means such as a mixing valve shall be installed to
temper the water in order to reduce scald hazard
potential.
Pool Heating
SYSTEM
RETURN
When a boiler or water heater is used in a pool heat-
ing application, ensure that all the following installation
requirements are met.
Fig. 14: Single Domestic Hot Water Heater and Storage
Tank
Soft (0-4 grains per gallon)
gpm MTS SHL
Medium (5-15 grains per gallon)
Hard* (16-25 grains per gallon)
Model
No.
gpm
50
MTS
2
SHL
gpm
MTS
2
SHL
18.1
22.2
T
P
T
P
3.6
6.4
T
P
503 17 50 3.6
753 26 50 4.0
2
2
5.9 17
6.3 20
5.9
9
95
10.4
65
2
10.2 13 100 13.8
2
1003 30 58 6.0 2-1/2 7.2 20
1253 30 73 10.4 2-1/2 12.1 20
1503 30 87 16.0 2-1/2 18.5 23
1753 30 102 22.7 2-1/2 26.0 27
2003 30 116 32.0 2-1/2 36.1 30
87
12.0 2-1/2 14.4 15 113 18.7 2-1/2 22.6
109 21.0 2-1/2 24.6 19 113 22.3 2-1/2 26.3
113 25.7 2-1/2 29.6 23 113 25.7 2-1/2 29.6
113 27.4 2-1/2 31.3 27 113 27.4 2-1/2 31.3
116 32.0 2-1/2 36.1 30 116 32.0 2-1/2 36.1
∆T = Temperature rise, °F
∆P = Pressure drop through heat exchanger, ft
SHL = System head loss, ft (based on heater and tank placed no more than 5 ft apart and equivalent length of 50 eq. ft. of tubing)
gpm = Gallons per minute, flow rate
MTS = Minimum tubing size
*Must utilize optional cupro-nickel tubes. If over 25 grains per gallon, a water softener/treatment system must be utilized.
Caution: For scale free operation with "Hard Water" (16-25 grains per gallon of total hardness), the operating control must NOT be set
higher than 130 F. For higher than 130 F operation, a water softener/treatment system must be utilized.
Table G: Domestic Water Heater Flow Rate Requirements
16
1. Turn on pump.
The MVB must be equipped with a field-supplied ex-
ternal pump and bypass arrangement. This 2. Turn on heater and wait until heater goes to full
arrangement blends outlet water with the inlet water to
increase the inlet water temperature to a minimum of
fire.
120°F (49°C), thereby reducing the likelihood of con- 3. With the heater operating at 100% firing rate, set
1
densation forming on the heat exchanger. The pump
also serves to circulate water through the heater from
the main system piping.
Valve A (the bypass) to ⁄
B to fully open position. See Fig. 16.
2
open position, and Valve
4. Adjust Valve A until the inlet water temperature is
120°F (49°C).
CAUTION: Power to the heater should be
interlocked with the main system pump to make sure
the heater does not fire without the main system
pump in operation. Improper flow control can
damage the heater. Uncontrolled flow (too high) or
restricted flow (too low) can seriously damage the
heater. Follow these instructions to make sure your
heater is properly installed.
NOTE: Opening the valve will increase the
temperature and closing the valve will decrease the
temperature.
5. If this process does not raise the inlet water tem-
perature to 120°F (49°C) and Valve A is fully open,
then slowly throttle Valve B closed to increase the
inlet water temperature to 120°F (49°C).
To complete the installation of the pool heater, the pool
thermostat must be installed in the main return water
line, upstream of the heater. This will ensure that the
heater will be energized at the right time.
POOL
THERMOSTAT
FROM
FILTER
*
TO POOL
CHEMICAL
FEED
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 15: Single Pool Heater Application
Adjustment of the manual bypass valve is critical to
proper operation of the heater. The manual bypass
valve should be adjusted to achieve a minimum inlet
water temperature of 120°F (49°C) and a system sup-
ply water temperature below 140°F (60°C). When
starting with a cold pool, make initial adjustments.
Make final adjustments when pool water approaches
desired temperature.
Fig. 16: “H” Bypass Setting
The use of a bypass is required for proper operation in
a pool heating application. Use the following instruc-
tions to set the manual bypass:
17
Pool/Spa Water Chemistry
NOTE: For automatic temperature adjustment, a
Cold Water Run (CWR) system can be used instead
of a manual bypass. See Fig. 10.
CAUTION: Corrosive water voids all warranties.
CAUTION: Combustion air must not be
contaminated by corrosive chemical fumes which
can damage the heater and void the warranty.
NOTE: Chemical imbalance can cause severe
damage to your heater and associated equipment.
Winterizing Your Heater
Chemical imbalance can cause severe damage to the
pool heater and associated equipment. Maintain the
water chemistry according to the chart below. If the
mineral content and dissolved solids in the water
become too high, scale forms inside the heat exchang-
er tubes, reducing heater efficiency and damaging the
heater. If the pH drops below 7.2, this will cause cor-
rosion of the heat exchanger and severely damage the
heater. Heat exchanger damage resulting from chem-
ical imbalance is not covered by the warranty.
Heaters installed outdoors as pool heaters in freezing
climate areas should be shut down for the winter. To
shut the down heater, turn off manual main gas valve
and main gas shut-off. Close isolation valves. Drain
the heater using the hose bibs located on the bottom
of the heat exchanger.
NOTE: There are 2 separate drains on the MVB
that must BOTH be drained to protect the heat
exchanger. These are both accessible by removing
the lower front door from the heater. Drain any
piping of all water that may experience below-
freezing temperatures.
For your health and the protection of your pool equip-
ment, it is essential that your water be chemically
balanced. The following levels must be used as a
guide for balanced water.
Occasional chemical shock dosing of the pool or spa
should not damage the heater providing the water is
balanced.
Automatic chemical dosing devices and salt chlorina-
tors are usually more efficient in heater water, unless
controlled, they can lead to excessive chlorine level
which can damage your heater.
Other Pool and Spa
Recommended Level(s)
Water Temperature
pH
Fiberglass Pools
68-88°F (20-31°C)
7.3-7.4
Fiberglass Spas
Types
89-104°F (31-40°C)
7.3-7.4
68-104°F (20-40°C)
7.6-7.8
Total Alkalinity (ppm)
Calcium Hardness (ppm)
Salt (ppm)
120-150
120-150
80-120
200-300
150-200
200-400
6000 Maximum
2-3
6000 Maximum
2-3
6000 Maximum
2-3
Free Chlorine (ppm)*
Total Dissolved Solids
(ppm)
3000 Maximum
3000 Maximum
3000 Maximum
*Free Chlorine MUST NOT EXCEED 5 ppm!
Table H: Water Chemistry
18
Further advice should be obtained from your pool or
spa builder, accredited pool shop, or chemical suppli-
er for the correct levels for your water.
The heater must be isolated from the gas supply pip-
ing system by closing the upstream manual shut-off
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less than
1/2 psi (3.45 kPa). Relieve test pressure in the gas
supply line prior to re-connecting the heater and its
manual shut-off valve to the gas supply line. FAILURE
TO FOLLOW THIS PROCEDURE MAY DAMAGE
THE GAS VALVE. Over-pressurized gas valves are
not covered by warranty. The heater and its gas con-
nections shall be leak-tested before placing the
appliance in operation. Use soapy water for leak test.
DO NOT use an open flame.
Automatic Chlorinators and
Chemical Feeders
All chemicals must be introduced and completely dilut-
ed into the pool or spa water before being circulated
through the heater. Do not place sanitizing chemicals
in the skimmer. High chemical concentrations will
result when the pump is not running (e.g. overnight).
Chlorinators must feed downstream of the heater and
have an anti-siphoning device to prevent chemical
back-up into the heater when the pump is shut off.
NOTE: High chemical concentrates from feeders
and chlorinators that are out of adjustment will cause
rapid corrosion to the heat exchanger. Such damage
is not covered under the warranty.
NOTE: Failure of a heat exchanger due to lime
scale build-up on the heating surface, low pH or
other chemical imbalance is non-warrantable.
Fig. 17: Gas Supply Connection
CAUTION: Do not use Teflon tape on gas line pipe
thread. A pipe compound rated for use with natural
and propane gases is recommended. Apply
sparingly only on male pipe ends, leaving the two
end threads bare.
Gas Supply
DANGER: Make sure the gas on which the heater
will operate is the same type as specified on the
heater’s rating plate.
CAUTION: Support gas supply piping with
hangers, not by the heater or its accessories. Make
sure the gas piping is protected from physical
damage and freezing, where required.
Gas piping must have a sediment trap ahead of the
heater gas controls, and a manual shut-off valve lo-
cated outside the heater jacket. It is recommended
that a union be installed in the gas supply piping adja-
cent to the heater for servicing. The gas supply
pressure to the heater must not exceed 10.5 in. WC for
natural gas or 13.0 in. WC for propane gas. A pounds-
to-inches regulator must be installed to reduce the gas
supply pressure if it is higher than noted above. This
regulator should be placed a minimum distance of 10
times the pipe diameter upstream of the heater gas
controls. Refer to Table I for maximum pipe lengths.
Gas Supply Pressure
A minimum of 4.0 in. WC and a maximum of 10.5 in.
WC upstream gas pressure is required under load and
no-load conditions for natural gas. A minimum of 4.0
in. WC and a maximum of 13.0 in. WC is required for
propane gas. The gas pressure regulator(s) supplied
on the heater is for low-pressure service. If upstream
pressure exceeds these values, an intermediate gas
pressure regulator, of the lockup type, must be
installed.
Gas Supply Connection
CAUTION: The heater must be disconnected from
the gas supply during any pressure testing of the gas
supply system at test pressures in excess of 1/2 psi
(3.45 kPa).
When connecting additional gas utilization equipment
to the gas piping system, the existing piping must be
checked to determine if it has adequate capacity for
the combined load.
19
1 in. NPT
1-1/4 in. NPT
1-1/2 in. NPT
2 in. NPT
2-1/2 in. NPT
Model
No.
N
P
N
P
N
P
N
P
N
P
503
753
15
5
35
65
150
130
360
15
65
35
15
10
100
55
75
35
25
15
180
90
250
125
85
1103
1253
1503
1753
2003
300
225
150
110
90
300
200
150
115
85
25
60
300
275
230
210
15
25
60
45
35
3
Natural Gas – 1,000 BTU/ft , 0.60 specific gravity at 0.5 in. WC pressure drop
3
Propane Gas – 2,500 BTU/ft , 1.53 specific gravity at 0.6 in. WC pressure drop
Table I: Maximum Equivalent Pipe Length
The gas valve pressure regulator on the heater is
nominally preset as noted in Table J.
•
•
Safety wiring must be NEC Class 1.
Heater must be electrically grounded as required
by the NEC.
During normal operation, carbon dioxide should be 8.5
to 9.0% at full fire for natural gas and between 9.5 and
•
In Canada, CSA C22. 1 C.E.C. Part 1.
10.0% for propane gas. Carbon monoxide should be The MVB 503-1503 heaters are wired for 120 VAC, 12
‹100ppm.
amps while the MVB 1753 & 2003 heaters are wired
for 120 VAC, 18 amps. Consult the wiring diagram
shipped with the heater. Before starting the heater,
check to ensure proper voltage to the heater and
pump.
Manifold Gas Pressure
(High Fire Values)
Model
No.
Natural Gas
Propane Gas
503
753
-0.1
-0.4
-0.8
-1.6
-2.4
-0.4
-1.0
-0.1
-0.1
-0.2
-0.2
-0.6
-0.1
-0.5
3
Boiler mounted pumps (up to ⁄
4
hp) get their power
supply directly from the boiler power supply (connec-
tions in rear wiring box). Install a circuit breaker sized
1003
1253
1503
1753
2003
sufficiently for both the heater and the pump. Pumps
3
larger than ⁄
4
hp must use a separate power supply
and run the power through the optional pump contac-
tor which is located in the rear wiring box. Use
appropriately-sized wire as defined by NEC, CSA
and/or local codes. All primary wiring should be 125%
of minimum rating.
NOTE: Manifold pressures should be 0.2 in. WC.
Table J: Manifold Gas Pressure Settings
If any of the original wire as supplied with the heater
must be replaced, it must be replaced with 105°C wire
or its equivalent.
CAUTION: For proper operation, no more than a
30% drop in gas supply pressure from no-load to full-
load conditions is acceptable. Under no
circumstances should the pressure be outside the
listed operational range.
All high voltage wiring connections to the MVB heater
are made inside the rear wiring box as shown in Fig.
18. Pump power should be taken from terminals 2
3
(Com), 3 (GND) and 6 (Hot) – ⁄
4
hp and smaller ONLY.
Power to the MVB heater should be connected to ter-
minals 1, 2, and 3 as noted in Fig. 18. All low voltage
wiring, including sensors, interlocks, enable/disable,
and various options are wired into terminals 1–20 on
the front wiring panel as noted in Fig. 18.
Electrical Power Connections
Installations must follow these codes:
•
National Electrical Code and any other national,
state, provincial or local codes or regulations hav-
ing jurisdiction.
20
WARNING: Using
a
multi-meter, check the
following voltages at the circuit breaker panel prior to
connecting any equipment. Make sure proper
polarity is followed and house ground is proven.
(See Fig. 19.)
Check the power source:
AC = 108 VAC Minimum, 132 VAC MAX
AB = 108 VAC Minimum, 132 VAC MAX
BC = <1 VAC Maximum
FRONT WIRING PANEL LOW VOLTAGE ELECTRICAL CONNECTIONS
Fig. 18: Wiring Electrical Connections
Field-Connected Controllers
Fig. 20: Multi-meter
It is strongly recommended that all individually-pow-
ered control modules and the heater should be
supplied from the same power source.
Making the Electrical Connections
Refer to Fig. 18-21.
NOTE: Field-supplied isolation relays should be
installed when field-connected controllers are
mounted more than 50 equivalent feet (18 AWG)
from heater. See wiring diagrams.
1. Verify that circuit breaker is properly sized by
referring to heater rating plate. A dedicated circuit
breaker should be provided.
2. NOTE: Current draw noted on rating plate does
not include pump current.
NOTE: Minimum 18 AWG, 105°C, stranded wire
must be used for all low voltage (less than 30 volts)
external connections to the unit. Solid conductors
should not be used because they can cause
excessive tension on contact points. Install conduit
as appropriate. All high voltage wires must be the
same size (105°C, stranded wire) as the ones on the
unit or larger.
3. Turn off all power to the heater. Verify that power
has been turned off by testing with a multi-meter
prior to working with any electrical connections or
components.
4. Observe proper wire colors while making electri-
cal connections. Many electronic controls are
polarity sensitive. Components damaged by im-
proper electrical installation are not covered by
warranty.
Check the Power Source
BLACK
CIRCUIT
BREAKER
5. Provide overload protection and a disconnect
means for equipment serviceability as required by
local and state code.
WHITE
GREEN
GROUND
6. Install heater controls, thermostats, or building
management systems in accordance with the
applicable manufacturers’ instructions.
A
B
C
7. Conduit should not be used as the earth ground.
Fig. 19: Wiring Connections
21
Venting
NOTE: A grounding electrode conductor shall be
used to connect the equipment grounding
conductors, the equipment enclosures, and the
grounded service conductor to the grounding
electrode.
CAUTION: Proper installation of flue venting is
critical for the safe and efficient operation of the
heater.
General
Field Wiring Connection
Appliance Categories
CAUTION: Label all wires prior to disconnection
when servicing controls. Wiring errors can cause im-
proper and dangerous operation. Verify proper
operation after servicing.
Heaters are divided into four categories based on the
pressure produced in the exhaust and the likelihood of
condensate production in the vent.
Category I – A heater which operates with a non-pos-
itive vent static pressure and with a vent gas
temperature that avoids excessive condensate pro-
duction in the vent.
DANGER: SHOCK HAZARD
Make sure electrical power to the heater is discon-
nected to avoid potential serious injury or damage to
components.
Category II – A heater which operates with a non-pos-
itive vent static pressure and with a vent gas
temperature that may cause excessive condensate
production in the vent.
Category III – A heater which operates with a positive
vent pressure and with a vent gas temperature that
avoids excessive condensate production in the vent.
Category IV – A heater which operates with a positive
vent pressure and with a vent gas temperature that
may cause excessive condensate production in the
vent.
HIGH VOLTAGE
WIRING
See Table K for appliance category requirements.
NOTE: For additional information on appliance
categorization, see appropriate ANSI Z21 Standard
and the NFGC (U.S.), or B149 (Canada), or
applicable provisions of local building codes.
Fig. 21: Wiring Location
CAUTION: Condensate drains for the vent piping
are required for installations of the MVB. Follow vent
manufacturer instructions for installation and location
of condensate drains in the vent. Condensate drain
must be primed with water to prevent gas flue leak
and must be routed to an appropriate container for
neutralization before disposal, as required by local
codes.
LOCATOR DIMPLES
FOR OPTIONAL
COMPONENTS
WARNING: Contact the manufacturer of the vent
material if there is any question about the appliance
categorization and suitability of a vent material for
application on a Category III or IV vent system.
Using improper venting materials can result in
personal injury, death or property damage.
Fig. 22: Locator Dimples for Optional Components
22
Combustion
Air Supply
Exhaust
Configuration
Heater Venting
Category
Certified
Materials
Combustion Air
Inlet Material
Vertical
Venting
From Inside Building
(Non-Direct Venting)
Horizontal Through-
the-Wall Venting
Stainless Steel
AL29-4C
IV
Vertical
Venting
Galvanized Steel
PVC
From Outside Building
(Direct Venting)
ABS
CPVC
Horizontal Through-
the-Wall Venting
Table K: Venting Category Requirements
Use only the special gas vent pipes listed for use with
Category IV gas burning heaters, such as the AL29-4C
stainless steel vents offered by Heat Fab Inc. (800-
772-0739), Protech System, Inc. (800-766-3473),
Z-Flex (800-654-5600) or American Metal Products
(800-423-4270). Pipe joints must be positively sealed.
Follow the vent manufacturer’s installation instructions
carefully.
5. The bottom of the vent terminal and the air intake
shall be located at least 12 in. above grade, includ-
ing normal snow line.
6. Un-insulated single-wall Category IV metal vent
pipe shall not be used outdoors in cold climates for
venting gas-fired equipment without insulation.
7. Through-the-wall vents for Category IV appli-
ances shall not terminate over public walkways or
over an area where condensate or vapor could
create a nuisance or hazard or could be detrimen-
tal to the operation of regulators, relief valves, or
other equipment.
Support of Vent Stack
The weight of the vent stack or chimney must not rest
on the heater vent connection. Support must be pro-
vided in compliance with applicable codes. The vent
should also be installed to maintain proper clearances
from combustible materials. Use insulated vent pipe
spacers where the vent passes through combustible
roofs and walls.
8. Locate and guard vent termination to prevent acci-
dental contact by people or pets.
9. DO NOT terminate vent in window well, stairwell,
alcove, courtyard or other recessed area.
Vent Terminal Location
10. DO NOT terminate above any door, window, or
gravity air intake. Condensate can freeze, causing
ice formations.
NOTE: During winter months check the vent cap
and make sure no blockage occurs from build-up of
snow or ice.
11. Locate or guard vent to prevent condensate from
damaging exterior finishes. Use a rust-resistant
sheet metal backing plate against brick or mason-
ry surfaces.
1. Condensate can freeze on the vent cap. Frozen
condensate on the vent cap can result in a blocked
flue condition.
2. Give special attention to the location of the vent
termination to avoid possibility of property dam-
age or personal injury.
12. DO NOT extend exposed vent pipe outside of
building beyond the minimum distance required
for the vent termination. Condensate could freeze
and block vent pipe.
3. Gases may form a white vapor plume in winter.
The plume could obstruct a window view if the ter-
mination is installed near windows.
U.S. Installations
Refer to the latest edition of the National Fuel Gas
Code.
4. Prevailing winds, in combination with below-freez-
ing temperatures, can cause freezing of
condensate and water/ice build-up on buildings,
plants or roofs.
Vent termination requirements are as follows:
23
1. Vent must terminate at least 4 ft below, 4 ft hori-
zontally from or 1 ft above any door, window or
gravity air inlet to the building.
5. Within 6 ft (1.8 m) of any gas service regulator
vent outlet.
6. Less than 1 ft (305 mm) above grade level.
2. The vent must not be less than 7 ft above grade
when located adjacent to public walkways.
7. Within 3 ft (915 mm) of a window or door which
can be opened in any building, any non-mechani-
cal air supply inlet to any building or the
combustion air inlet of any other appliance.
3. Terminate vent at least 3 ft above any forced air
inlet located within 10 ft.
4. Vent must terminate at least 4 ft horizontally, and
in no case above or below unless 4 ft horizontal
distance is maintained, from electric meters, gas
meters, regulators, and relief equipment.
8. Underneath a verandah, porch or deck, unless the
verandah, porch or deck is fully open on a mini-
mum of two sides beneath the floor, and the
distance between the top of the vent termination
and the underside of the verandah, porch or deck
is greater than 1 ft (305 mm).
5. Terminate vent at least 6 ft away from adjacent
walls.
Venting Installation Tips
6. DO NOT terminate vent closer than 5 ft below roof
overhang.
Support piping:
7. The vent terminal requires a 12 in. vent terminal
clearance from the wall.
•
•
•
horizontal runs—at least every 5 ft (1.5m)
vertical runs—use braces
under or near elbows
8. Terminate vent at least 1 ft above grade, including
normal snow line.
WARNING: Examine the venting system at least
once a year. Check all joints and vent pipe
connections for tightness, corrosion or deterioration.
9. Multiple direct vent installations require a 4 ft
clearance between the ends of vent caps located
on the same horizontal plane.
Venting Configurations
WARNING: The Commonwealth of Massachusetts
requires that sidewall vented heaters, installed in
every dwelling, building or structure used in whole or
in part for residential purposes, be installed using
special provisions as outlined on page 55 of this
manual.
For heaters connected to gas vents or chimneys, vent
installations shall be in accordance with the NFGC
(U.S.), or B149 (Canada), or applicable provisions of
local building codes.
Vertical Venting (Category IV)
Canadian Installations
CAUTION: This venting system requires the
installation of a condensate drain in the vent piping
per the vent manufacturer’s instructions. Failure to
install a condensate drain in the venting system will
void all warranties on this heater.
Refer to latest edition of the B149 Installation Code.
A vent shall not terminate:
1. Directly above a paved sidewalk or driveway
which is located between two single-family dwell-
ings and serves both dwellings.
Installation
2. Less than 7 ft (2.13 m) above a paved sidewalk or
paved driveway located on public property.
The maximum and minimum venting length for this
Category IV appliance shall be determined per the
NFGC (U.S.) or B149 (Canada).
3. Within 6 ft (1.8 m) of a mechanical air supply inlet
to any building.
The diameter of vent flue pipe should be sized accord-
ing to the NFGC (U.S.) and Appendix B of B149
(Canada). The minimum flue pipe diameter for con-
ventional venting using Category IV, stainless steel
4. Above a meter/regulator assembly within 3 ft (915
mm) horizontally of the vertical centre-line of the
regulator.
24
Vertical Vent
Height1(Ft)
Air Inlet
Max. Length** (Ft)
Certified
Vent
Material
Combustion Air
Intake Pipe
Material
Vent Size
(in.)
Model
Min.
Max.
6” Ø 8” Ø 10” Ø
503
753
1
5
*
t
6
45
100
45
N/A
85
75
75
40
75
75
75
Galvanized Steel,
PVC,
1003
1253
1503
1753
2003
Category IV
(AL29-4C)
0
ABS,
CPVC
t
N/A
8
* Vent length may be extended up to 40 ft. using a barometric damper installed at 15 equivalent feet from
the heater where the category of the vent changes from Cat IV to Cat II. NOTE: Special vent materials
are still required.
1
Vent lengths are based on a lateral length of 2 ft. Refer to the latest edition of the NFGC for further
details.
** Subtract 10 ft per elbow. Max. 4 elbows.
t
Adapters supplied by others.
Table L: Category IV Vertical Venting
AL29-4C vent is: 6 in. (152mm) for Models 503-1003;
and 8 in. (203mm) for Models 1253-2003.
The connection from the appliance vent to the stack
must be as direct as possible and shall be the same di-
ameter as the vent outlet. The horizontal breaching of
a vent must have an upward slope of not less than 1/4
inch per linear foot from the heater to the vent termi-
nal. The horizontal portions of the vent shall also be
supported for the design and weight of the material
employed to maintain clearances and to prevent physi-
cal damage or separation of joints.
NOTE: A vent adapter (field-supplied) may be re-
quired to connect the Category IV vent to the heater.
Termination
The vent terminal should be vertical and should termi-
nate outside the building at least 2 ft above the highest
point of the roof that is within 10 ft. The vent cap
should have a minimum clearance of 4 ft horizontally
from and in no case above or below (unless a 4 ft hori-
zontal distance is maintained) electric meters, gas
meters, regulators and relief equipment.
The distance of the vent terminal from adjacent public
walkways, adjacent buildings, open windows and
building openings must be consistent with the NFGC
(U.S.) or B149 (Canada). Gas vents supported only by
flashing and extended above the roof more than 5 ft
should be se-curely guyed or braced to withstand
snow and wind loads.
Fig. 23: Vertical Venting
CAUTION: A listed vent cap terminal suitable for
connection to the Cat IV vent materials, adequately
sized, must be used to evacuate the flue products
from the building.
25
Common Venting
NOTE: For extractor sizing, typical CO2 levels are
8.5% for natural gas and 9.5% for propane gas and
The NFGC does not address sizing guidelines for the
common venting of multiple Category IV heaters. This
is covered in the NFGC under “Engineered Vent Sys-
tems”. Table M provides boiler discharge vent
pressures at vent pressure switch and volumes of flue
products at full fire for the calculation of appropriate
vent and extractor sizing for common venting.
flue temperature of 300° F.
Vent
Pressure
(in. WC)
Volume of
Flue Products
(CFM)
Vent
Size (in.)
Model
503
753
0.1
0.2
0.3
0.2
0.3
0.4
0.5
160
240
320
400
480
560
640
6
8
WARNING: Vent connectors serving any other
appliances shall not be connected into any portion of
mechanical draft systems operating under a positive
pressure. If an MVB heater is installed to replace an
existing heater, the vent system MUST be verified to
be of the correct size and of Category IV AL29-4C
vent material construction. If it is NOT, it MUST be
replaced.
1003
1253
1503
1753
2003
* NOTE: Data for 100% firing rate.
Table M: Typical Vent Pressure and Volume
of Flue Products
Fig. 24: Typical Common Venting
26
Horizontal Through-the-Wall Direct
Venting (Category IV)
Fig. 25: Horizontal Through-the-Wall Venting
Fig. 27: Horizontal Through-the-Wall Direct Venting
CAUTION: This venting system requires the
installation of a condensate drain in the vent piping
per the vent manufacturer’s instructions. Failure to
install a condensate drain in the venting system will
void all warranties on this heater.
Installation
These installations utilize the heater-mounted blower
to vent the combustion products to the outdoors.
Combustion air is taken from inside the room and the
vent is installed horizontally through the wall to the out-
doors. Adequate combustion and ventilation air must
be supplied to the equipment room in accordance with
the NFGC (U.S.) or B149 (Canada).
The total length of the horizontal through-the-wall flue
system should not exceed 75 equivalent ft in length. If
horizontal run exceeds 75 equivalent ft, an appropri-
ately sized variable-speed extractor must be used.
Each elbow used is equal to 10 ft of straight pipe. This
will allow installation in one of the four following
arrangements:
Fig. 26: Alt. Horizontal Through-the-Wall Venting
NOTE: While a drain connection is required in the
vent of all MVB installations, the drain can be ac-
complished in several different ways. The figures in
this manual show the drain in a vent tee, however,
this can also be accomplished using an inline collec-
tor for condensing stacks or an inline vertical or
horizontal collector available from several of the
listed vent manufacturers.
•
•
•
•
75’ of straight flue pipe
65’ of straight flue pipe and one elbow
55’ of straight flue pipe and two elbows
45’ of straight pipe and three elbows
The vent cap is not considered in the overall length of
the venting system.
27
Air Inlet
Maximum
Horizontal
Vent Length
(ft)
Certified
Vent
Material
Vent
Size
(in.)
Combustion Air
Intake Pipe
Material
Max. Length** (ft)
Model
No.
6” Ø
8” Ø
10” Ø
503
753
t
6
8
45
100
Galvanized Steel,
PVC,
1003
1253
1503
1753
2003
Category IV
(AL29-4C)
75
ABS,
CPVC
t
45
85
** Subtract 10 ft per elbow. Max. 4 elbows.
t
Adapters supplied by others.
Table N: Category IV Horizontal Vent & Horizontal Direct Vent
Direct Vent—Vertical
The vent must be installed to prevent flue gas leakage.
Care must be taken during assembly to ensure that all
joints are sealed properly and are airtight. The vent
must be installed to prevent the potential accumulation
of condensate in the vent pipes. It is required that:
1. The vent must be installed with a condensate
drain located in proximity to the heater as directed
by the vent manufacturer.
2. The vent must be installed with a slight upward
slope of not less than 1/4 inch per foot of horizon-
tal run to the vent terminal.
3. The vent must be insulated through the length of
the horizontal run.
Termination
The flue direct vent cap MUST be mounted on the ex-
terior of the building. The direct vent cap cannot be
installed in a well or below grade. The direct vent cap
must be installed at least 1 ft above ground level and
above normal snow levels. The Raypak-approved
stainless steel flue direct vent cap must be used (sales
order option D-15). The vent terminal must be located
NO CLOSER than 12” off the wall.
Fig. 28: Direct Vent - Vertical
CAUTION: This venting system requires the
installation of a condensate drain in the vent piping
per the vent manufacturer’s instructions. Failure to
install a condensate drain in the venting system will
void all warranties on this heater.
Installation
WARNING: No substitutions of flue pipe or vent
cap material are allowed. Such substitutions would
jeopardize the safety and health of inhabitants.
These installations utilize the heater-mounted blower
to draw combustion air from outdoors and vent com-
bustion products to the outdoors.
28
The total length of air supply pipe cannot exceed the The stainless steel flue direct vent cap must be fur-
distances listed in Tables L and N. Each elbow used is nished by the heater manufacturer in accordance with
equal to 10 ft of straight pipe. This will allow installation its listing (sales order option D-15).
in any arrangement that does not exceed the lengths
shown in Tables L and N.
Outdoor Installation
The vent cap is not considered in the overall length of
Outdoor models must be vented with listed vent mate-
the venting system.
rial per the following instructions and installed with the
optional factory-supplied outdoor vent kit. A special
Care must be taken during assembly that all joints are
vent cap and air intake hood are provided in accor-
sealed properly and are airtight.
dance with CSA requirements. These must be
installed directly on the vent pipe as illustrated in Fig.
The vent must be installed to prevent the potential ac-
29.
cumulation of condensate in the vent pipes. It is
required that:
Care must be taken when locating the heater out-
doors, because the flue gases discharged from the
1. The vent must be installed with a condensate
vent cap can condense as they leave the cap.
drain located in proximity to the heater as directed
Improper location can result in damage to adjacent
by the vent manufacturer.
structures or building finish. For maximum efficiency
and safety, the following precautions must be
2. The vent must be installed with a slight upward
observed:
slope of not more than 1/4 inch per foot of hori-
zontal run to the vent terminal.
1. Outdoor models must be installed outdoors and
must use the outdoor vent cap and air intake hood
3. The vent must be insulated through the length of
available from the manufacturer (sales order
the horizontal run.
option D-11).
Termination
2. Periodically check venting system. The heater’s
venting areas must never be obstructed in any
The vent cap MUST be mounted on the exterior of the
way and minimum clearances must be observed
building. The vent cap cannot be installed in a well or
to prevent restriction of combustion and ventilation
below grade. The vent cap must be installed at least 1
air. Keep area clear and free of combustible and
ft above ground level and above normal snow levels.
flammable materials.
The vent cap MUST NOT be installed with any com-
3. Do not locate adjacent to any window, door, walk-
bustion air inlet directly above a vent cap. This vertical
way, or gravity air intake. The vent must be
spacing would allow the flue products from the vent
located a minimum of 4 ft horizontally from such
cap to be pulled into the combustion air intake installed
areas.
above.
4. Install above grade level and above normal snow
This type of installation can cause non-warrantable
levels.
problems with components and poor operation of the
heater due to the recirculation of flue products. Multi-
5. Vent terminal must be at least 3 ft above any
ple vent caps installed in the same horizontal plane
forced air inlet located within 10 ft.
must have a 4 ft clearance from the side of one vent
cap to the side of the adjacent vent cap(s).
6. Adjacent brick or masonry surfaces must be pro-
tected with a rust-resistant sheet metal plate.
Combustion air supplied from outdoors must be free of
particulate and chemical contaminants. To avoid a
blocked flue condition, keep the vent cap clear of
snow, ice, leaves, debris, etc.
NOTE: The vent cap and air intake hood must be
furnished by the heater manufacturer in accordance
with its listing (sales order option D-11).
WARNING: No substitutions of flue pipe or vent
cap material are allowed. Such substitutions would
jeopardize the safety and health of inhabitants.
29
NOTE: Condensate can freeze on the vent cap.
Frozen condensate on the vent cap can result in a
blocked flue condition.
CAUTION: Risk of electric shock: More than one
disconnect switch may be required to de-energize
the equipment before servicing.
The Raypak modulating temperature control is pro-
vided to maintain the desired system water
temperature. The control has various modes of opera-
tion which are listed on the following pages.
Setpoint: The intended system supply temperature.
Deadband: Deadband is a band of temperature sens-
ing where no action occurs. All temperature controllers
have a deadband and the purpose is to prevent short-
cycling of the heater. The on-board temperature
controller has a deadband of 2ºF around the differen-
tial.
Differential: A heat source must be operated with a
temperature differential in order to prevent short-
cycling. The temperature differential is divided around
the “target” temperature or set-point. The Call For Heat
(CFH) contact will close in the controller when the
water temperature is below the target temperature by
1/2 of the differential setting, and will open when the
water temperature is above the target temperature by
1/2 of the differential setting. See Fig. 30.
Fig. 29: Outdoor Venting
Freeze Protection
The Raypak electronic temperature control includes a
freeze protection feature. In the event the temperature
drops below 40°F at any of the boiler temperature sen-
sors, the pump is turned on and will remain on until the
temperature at all boiler sensors rises to 45°F.
Controls
Fig. 30: Differential Graph
WARNING: Installation, adjustment and service of
heater controls, including timing of various operating
functions, must be performed by a qualified installer,
service agency or the gas supplier. Failure to do so
may result in control damage, heater malfunction,
property damage, personal injury, or death.
Operating Modes
Mode 1 (Not supported) – Setpoint operation using
primary piping. The heater outlet water temperature is
controlled to the boiler target setpoint.
WARNING: Turn off the power to the heater before
installation, adjustment or service of any heater
controls. Failure to do so may result in board
damage, heater malfunction, property damage,
personal injury, or death.
Mode 2 – Setpoint operation using primary/secondary
piping. The control operates the heater to satisfy a
remote system sensor. The heater is turned off based
on boiler max and boiler differential (factory default).
See Fig. 31.
CAUTION: This appliance has provisions to be
connected to more than one supply source. To
reduce the risk of electric shock, disconnect all such
connections before servicing.
30
Mode 5 – Outdoor reset using primary/secondary pip-
ing. The heater is operated as in Mode 2. However, the
target temperature is based on outdoor reset. See Fig.
33.
MODULATING
MODULATING
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 31: Mode 2 Primary/Secondary Piping
Mode 3 – Dedicated DHW operation using UniTemp
80 piping. A call for heat is determined by the DHW
sensor and the DHW boiler target. The heater outlet
water is also controlled to the boiler target tempera-
ture. See Fig. 32.
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 33: Mode 5 Primary/Secondary Piping with
Outdoor Reset
Mode 6 (Not supported) – Designed for an external
input signal with primary piping. The external input sig-
nal can be provided from a BMS, an EMS or a
sequencing control. The external input signal changes
the boiler target according to a linear scale. The con-
trol operates the boiler burner to maintain the boiler
target at the boiler outlet sensor.
MODULATING
Mode 7 – Designed for an external input signal with
primary/secondary piping. The external input signal
can be provided from a BMS, an EMS or an external
control. The external input signal changes the boiler
target according to a linear scale, as shown in Tables
O and P. The control operates the boiler burner to
maintain the boiler target at the system sensor. See
Fig. 34
Fig. 32: Mode 3 Dedicated DHW
Mode 4 (Not supported) – Outdoor reset using pri-
mary piping. The heater is operated as in Mode 1.
However, the target temperature is based on outdoor
reset.
31
RAYPAK
MODULATING
TEMP CONTROL
MODULATING
OUTDOOR AIR
SENSOR
*
*
*Maximum 4 times the pipe diameter or 12”, whichever is less.
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 34: Mode 7 Primary/Secondary Piping with
External Target Temp
Fig. 35: Mode 8 Primary/Secondary Piping with
External Direct Drive
Mode 8 – This mode is for remote firing control of the
heater via an external sequencer such as the Raypak
TempTracker MOD+. The Boil Max setting is the
heater shutdown temperature (max temperature). The
heater is enabled via dry contact at the Enable/Disable
connection at the low voltage terminal strip, and the fir-
ing rate is controlled by a 0-10 VDC signal from the
external sequencer. A control signal of ≥0.5 VDC
equates to minimum fire, and a signal of 10 VDC
equates to 100% firing rate. See Fig. 35.
NOTE: For Modes 7 and 8, connect to pins 13 and
14 on the low-voltage panel. See page 21. Use these
modes for systems using an external signal.
32
0-10 VDC
0-20 mA*
Boiler Target
--- (OFF)
50°F
2-10 VDC
4-20 mA*
Boiler Target
--- (OFF)
--- (OFF)
50°F
0
0
2
0
1
2
3
4
5
6
7
8
9
0
2
1
2
4
68.9°F
4
3
6
87.8°F
6
71.3°F
4
8
106.7°F
125.6°F
144.1°F
163.3°F
182.2°F
201.1°F
220°F
8
92.5°F
5
10
12
14
16
18
20
10
12
14
16
18
20
113.8°F
135°F
6
7
156.3°F
177.5°F
198.8°F
220°F
8
9
10
10
*Requires a 500Ω resistor.
*Requires a 500Ω resistor.
Table P: 2-10 VDC or 4-20 mA External Input Signal
Table O: 0-10 VDC or 0-20 mA External Input Signal
Item
Modes
Default Setting
Range
OFF, 70 to 220°F
OFF, 70 to 190°F
OFF, 70 to 220°F
OFF, 120 to 225°F
OFF, 120 to 190°F
OFF, 80 to 180°F
0:00 to 3:00 min
1 (Low), 2 (Med), 3 (High)
Auto, 2 to 42°F
OFF, 70 to 190°F
2 to 10°F
1, 2
160°F
160°F
180°F
200°F
180°F
150°F
0:00 min
1 (Low)
Auto
Boil Target
3
4, 5, 6, 7
1, 2, 4, 5, 6, 7, 8
Boil Max
3
Boil Min
‘Burner’ Delay
Boil Mass
Diff
1, 2, 3, 4, 5, 6, 7
All
All
1, 2, 3, 4, 5, 6, 7
DHW Target
DHW Diff
‘Pump’ Dly
Outdr Start
Outdr Design
Boil Start
3
120°F
5°F
3
All
3:00 min
70°F
OFF, 0:20 to 9:55 min, ON
35 to 85°F
4, 5
4, 5
4, 5
4, 5
4, 5
All
-10°F
135°F
180°F
70°F
-60 to 32°F
35 to 150°F
Boil Dsgn
WWSD
120 to 220°F
35 to 100°F
Units
°F
°F or °C
Mode
N/A
6, 7
6, 7
2
1, 2, 3, 4, 5, 6, 7, 8
2 to 10 VDC or 0 to 10 VDC
-10°F to 10°F
External Input Signal
Offset
2 to 10 VDC
0°F
Table Q: Temperature Control Default Setpoints
33
0-10VDC or 0-20 mA external input signal – When
the 0-10VDC signal is selected, an input voltage of 1
VDC corresponds to a boiler target temperature of
50°F (10°C). An input voltage of 10 VDC corresponds
to a boiler target temperature of 220°F (104°C). As the
voltage varies between 1 VDC and 10 VDC, the boiler
target temperature varies linearly between 50°F
(10°C) and 220°F (104°C). If a voltage below 0.5 VDC
is received, the boiler target temperature is displayed
as “– – –” indicating that there is no longer an internal
call for heat. A 0-20 mA signal can be converted to a 0-
10 VDC signal by installing a 500 Ω resistor on the
external input signal device’s terminals.
Definitions
NOTE: The defined terms are not active in all
modes of control operation.
% OUT - Current percent modulation rate of heater.
BOIL DSGN - Design boiler water temperature used in
heat loss calculations.
BOIL MASS - This setting allows adjustment in the
field for high or low thermal masses; High thermal
mass (setting=3) provides slower reaction, lower ther-
mal mass (setting=1) provides faster reaction.
2-10VDC or 4-20 mA external input signal – When
the 2-10VDC signal is selected, an input voltage of 2
VDC corresponds to a boiler target temperature of
50°F (10°C). An input voltage of 10 VDC corresponds
to a boiler target temperature of 220°F (104°C). As the
voltage varies between 2 VDC and 10 VDC, the boiler
target temperature varies linearly between 50°F
(10°C) and 220°F (104°C). If a voltage below 1.5 VDC
is received, the boiler target temperature is displayed
as “– – –” indicating that there is no longer an internal
call for heat. A 4-20 mA signal can be converted to a 2-
10 VDC signal by installing a 500 Ω resistor on the
external input signal device’s terminals.
BOIL MAX - Highest outlet water temperature that the
control is allowed to use as a target temperature.
BOIL MIN - Lowest outlet water temperature that the
control is allowed to use as a target temperature.
BOIL ON - Accumulated runtime of heater (up to 999
hours, then resets to 0).
BOIL OUT - Actual heater outlet water temperature.
BOIL START - Starting boiler water temperature.
BOIL SUP - Actual system supply water temperature.
FP - Flame proof warning.
MODE - Operating mode of the heater.
BOIL TARGET - Target temperature that the heater is
OFFSET - The Offset setting allows the boiler target
temperature to be fine tuned to the external input sig-
nal. The control reads the external input signal and
converts this to a boiler target temperature. The Offset
setting is then added to the boiler target temperature.
trying to maintain.
‘BURNER’ DELAY - Holds control output at ignition
setting from the start of the ignition sequence to the
specified burner delay time (0 to 3:00 min.).
OUTDR - Outdoor air temperature.
DEM 1 - Indicates 24 VDC signal has been supplied to
the H+D terminal.
OUTDR DESIGN - Design outdoor air temperature
used in the heat loss calculation.
DEM 2 - Indicates 24 VDC Flame Proof signal is pres-
ent.
OUTDR START - Starting outdoor air temperature.
DIFF - The operating differential of the heater; The
PUMP DLY - Sets the operating time of the pump once
the CFH is satisfied.
heater outlet water temperature is allowed to rise
1
above the BOIL TARGET temperature by ⁄
2
of this dif-
ferential before the heater shuts off. For example, if
the heater target temperature is set to 160°F (71°C)
and the differential is set to 10°F (5°C), on temperature
rise, the heater will shut off at 165°F (74°C). Once the
heater shuts off, it will not come on again until the tem-
perature falls to 155°F (68°C).
TANK - Current DHW tank temperature (Mode 3).
TANK DIFF - Storage tank differential (Mode 3).
TANK TARGET - Target temperature in the DHW
storage tank (Mode 3).
EXTERNAL INPUT SIGNAL – Selects external input
signal range (0-10VDC or 2-10VDC):
UNITS - Selects the temperature units to be displayed
(°F or °C).
34
Rank
Item Field
Number Field
Type
Fault Description
0
1
E01
FP
Err
Error
Warning
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
EEPROM error
Flame proof warning
Boiler outlet sensor short
Boiler outlet sensor open
Boiler inlet sensor short
Boiler inlet sensor open
System sensor short
System sensor open
Outdoor sensor short
Outdoor sensor open
DHW sensor short
Err
2
BOIL OUT
BOIL OUT
BOIL IN
BOIL IN
SUP
SHr
3
OPn
4
SHr
5
OPn
6
SHr
7
SUP
OPn
8
OUTDR
OUTDR
DHW
SHr
9
OPn
SHr
10
11
DHW
OPn
DHW sensor open
Table R: Error Codes
Menu Field
WWSD - Selects the outdoor temperature that shuts
the heater off, no matter what the demand. NOTE: The
WWSD segment will be displayed on the LCD.
Item Field
Displays the current menu
Displays an
abbreviated
name of the
selected item
Number Field
Displays the
current value of
the selected
item
Operation
The Raypak modulating temperature control uses a
Liquid Crystal Display (LCD) as a method of supply-
ing information. The LCD is used to setup and monitor
system operation by means of three push buttons
(Item, L and M) shown at the bottom of Fig. 36.
Status Field
Displays the
current status
of the control’s
inputs, outputs
and operation
DHW
External Input
Modulation Offset Signal
Modulating
Control
Buttons
Selects
Menus,
Items and
adjusts
Item
All items displayed by the control are organized into
two menus, the view menu and the adjust menu. The
active menu is displayed in the upper right hand side
of the display in the menu field. The default menu is
the view menu.
{
settings
Fig. 36: Modulating Temperature Control Display
To make an adjustment to a setting in the control,
begin by selecting the “ADJUST” menu. To change
from the view menu to the adjust menu, simultaneous-
ly press and hold all three buttons for 1 second. The
menu name, “ADJUST” will be displayed in the menu
field.
When the temperature control is powered up, the con-
trol turns on all segments in the display for 2 seconds,
then the software version is displayed for 2 seconds.
At the end of that 4 second period, the control enters
the normal operating mode and “VIEW” is displayed.
Pressing the scroll button “scrolls” through the dis-
played values in the “VIEW” menu.
The menu will automatically revert back to the view
menu after 20 seconds of keyboard inactivity. Then
scroll to the desired item using the scroll button. Fi-
nally, use the L or M button to make the adjustment.
In the absence of other information, the values pro-
vided in Table Q should be used as default settings.
35
Heater Sequence of Operation
If all limits are satisfied and there is a call for heat:
1. The heater pump is powered and begins circulat-
ing water through the heat exchanger.
2. The blower is powered and goes through a 15 sec-
ond prepurge beginning when air flow is proven by
closure of the blower suction air pressure switch.
3. The igniter is powered, and once proven, heats up
for 20 seconds.
Fig. 37: Ignition Module
4. The gas valve is then energized for a 4 second
trial for ignition period. Trial for ignition is fixed at
50% input. The heater is allowed to modulate once
flame is proven and the firing rate will adjust to
match the load based on the configuration and set-
tings of the temperature control or external input.
The optional single-try ignition module will lock out
after failing to light one time. To reset it, press and
release the small, recessed black push button located
inside of the cut-out on the lower right-hand corner of
the ignition module case. Turning off the power to
the heater WILL NOT reset the ignition module.
5. Once the heat demand is satisfied the gas valve
will close and the blower will run a 30 second post
purge. The heater pump will continue to circulate
water for 0 to 10 minutes depending on the pump
delay setting on the Raypak modulating tempera-
ture control.
Code
On
Condition
System OK; No faults present
Possible control fault; Check power
Low air
Off
1 Flash
Ignition Module
Flame in combustion chamber;
No call for heat
2 Flashes
When additional heat is needed, the combustion air
blower starts to purge air from the combustion cham-
ber for 15 seconds. On proof-of-air flow, the
air-proving switch closes and the igniter is energized.
To ensure safe operation, the gas valve cannot open
until the igniter is verified. The main burner is automat-
ically lit when the device is powered and pre-purged.
The heater performs its own safety check and opens
the main valve only after the igniter is proven to be
capable of ignition. The standard ignition module will
attempt to light three times before locking out. To reset
it, turn off power to the heater, wait 30 seconds and re-
apply power.
3 Flashes
4 Flashes
5 Flashes
6 Flashes
Ignition lockout
Low HSI current
Low 24 VAC
Internal fault; Replace control
Table S: Ignition Module Diagnostic LED Flash Codes
High Limit—Manual Reset
This heater is equipped with a fixed setting manual re-
set high limit temperature device as standard or it may
have an optional adjustable setting manual reset high
temperature device.
The fixed setting manual reset high limit is located on
the In/Out header of the heat exchanger on the right
side of the heater (accessible through the front door
for reset as necessary).
The optional adjustable manual reset high limit is lo-
cated inside the heater junction box. Push the reset
button and adjust the setting to approx. 40°F (20°C)
above desired outlet temperature.
36
Modulating Temperature Control
This heater is equipped with a Raypak modulating
temperature control. Refer to information starting on
page 30 for information on the setting and use of this
control.
Fig. 38: High Limit (Manual Reset)
High Limit—Auto Reset (Optional)
This heater may be equipped with an optional adjust-
able auto reset high limit temperature device.
Fig. 41: Modulating Temperature Control
The optional adjustable auto reset high limit is located
inside the heater junction box. Adjust the setting to
approx. 20°F (10°C) above desired outlet temperature.
Low Water Cut-Off (Optional)
The optional low water cut-off automatically shuts
down the burner whenever water level drops below the
level of the sensing probe. A 5-second time delay pre-
vents premature lockout due to temporary conditions
such as power fluctuations or air pockets.
Fig. 39: Adjustable High Limit (Auto Reset)
Flow Switch
This standard, dual-purpose control, mounted and
wired in series with the main gas valve, shuts off
heater in case of pump failure or low water flow.
Fig. 42: Low Water Cut-Off
High & Low Gas Pressure Switches
(Optional)
The optional low gas pressure switch connection
mounts upstream of the gas valve (on the inlet flange
to the gas valve) and is accessible through the remov-
able access panels on the rear of the heater to reset
the gas pressure switch, as necessary. It is used to
ensure that sufficient gas pressure is present for prop-
er valve/regulator performance. The low gas pressure
switch automatically shuts down the heater if gas sup-
ply drops below the factory setting of 3.0 in. WC for
natural gas or propane gas.
Fig. 40: Flow Switch
37
The optional high gas pressure switch connection
mounts down-stream of the gas valve. Special ports
are located on the backside of the gas valve and
accessible from the front of the heater (to reset the gas
pressure switch) or through the removable access
panels on the rear of the heater (to reset the gas pres-
sure switch), as necessary. If the gas pressure
regulator in the valve fails, the high gas pressure
switch automatically shuts down the burner.
Blocked Vent Switch
This heater is equipped with a blocked vent pressure
switch to prevent the operation of the heater when too
much of the vent is blocked. This switch is located on
the right side of the heater near the right rear corner.
Operation of either the High or Low Gas Pressure
Switch will turn on an LED inside the switch housing.
Push the top of the plastic switch housing as shown in
Fig. 43 to reset a tripped pressure switch. The LED
will go out when the switch is reset.
Fig. 45: Blocked Vent Switch
UDB Diagnostic Board
This heater is equipped with a diagnostic board which
will indicate faults as they occur. Refer to the Trouble-
shooting section for instructions on accessing,
reviewing and clearing these faults.
Fig. 43: High/Low Gas Pressure Switch
Air Pressure Switch
This heater is equipped with an air pressure switch to
prove the operation of the blower before allowing the
ignition control to begin a Call for Heat. It is located on
the right side of the lower flange of the blower mount-
ing assembly, directly behind the junction box.
Fig. 46: UDB Diagnostic Board
NOTE: The wiring diagrams in this manual show all
standard options. Refer to the large wiring diagram
provided with your heater for options installed on
your specific unit(s).
Fig. 44: Air Pressure Switch
38
WIRING DIAGRAMS - Models 503–1503
39
Models 1753–2003
40
BEFORE OPERATING, smell all around the appliance
area for gas. Be sure to smell near the floor because
some gas is heavier than air and will settle on the floor.
START-UP
NOTE: The following steps must be performed by a
factory-trained technician.
WHAT TO DO IF YOU SMELL GAS:
Pre Start-up
•
•
Do not try to light any appliance.
Do not touch any electrical switch; do not use any
telephone in your building.
Filling System (Heating Boilers)
•
Immediately call your gas supplier from a neigh-
bor’s telephone. Follow the gas supplier’s
instructions.
If you cannot reach your gas supplier, call the fire
department.
Use only your hand to push in or turn the gas con-
trol knob. Never use tools. If the knob will not turn
by hand, do not try to repair it, call a qualified serv-
ice technician. Forced or attempted repair may
result in a fire or explosion.
Do not use this appliance if any part has been
under water, immediately call a qualified service
technician to inspect the appliance and to replace
any part of the control system and any gas control
which has been under water.
Check around unit for debris and remove com-
bustible products, i.e. gasoline, etc.
Fill system with water. Purge all air from the system.
Lower system pressure. Open valves for normal sys-
tem operation, and fill system through feed pressure.
Manually open air vent on the compression tank until
water appears, then close vent.
•
•
Air Purge (Domestic Hot Water
Heaters)
•
Purge all air from system before heater operation. This
can be normally accomplished by opening a down-
stream valve.
Raypak offers an optional air vent valve for the MVB
heaters which can be installed directly into the inlet
side of the header to ensure that air is purged from the
system. This option also includes an adapter to allow
the air vent to be piped (in the field) to a suitable drain
as re-quired by the jurisdiction having authority.
•
Pre Start-up Check
1. Verify the heater is filled with water.
2. Check system piping for leaks. If found, repair
immediately.
3. Vent air from system. Air in system can interfere
with water circulation.
4. Purge air from gas line to heater.
CAUTION: An air vent valve should be installed at
the highest point in the system for proper operation.
If water piping is located higher than the header, the
air vent valve should be relocated to the highest
point in the installed system.
Initial Start-up
Venting System Inspection
Required tools
1. Check all vent pipe connections and flue pipe ma-
terial.
•
•
•
•
•
•
(1) 12-0-12 (24” scale) U-tube manometer
(2) 6-0-6 (12” scale) U-tube manometer
Screwdrivers (assorted sizes and shapes)
(1) Crescent wrench (8” or 10”)
(1) Multi-meter
2. Make sure vent terminations are installed per code
and are clear of all debris or blockage.
For Your Safety
(1) Amp probe
WARNING: If you do not follow these instructions
exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.
(Metric Allen wrenches will be required for servicing
the gas valve, but not during start-up)
This appliance has a hot surface igniter. It is equipped
with an ignition device which automatically lights the
burners. Do not try to light the burners by hand.
NOTE: Digital manometers are not recommended.
41
mum supply pressure for propane gas is 4.0 in.
WC, recommended supply is 11.0 in. WC (dynam-
ic readings, full fire input).
Preparation
WARNING: Do not turn on gas at this time.
3. If the gas pressure is greater than 14.0 in. WC,
turn off the main gas shut-off valve, upstream of
the heater.
Check Power Supply
With multi-meter at incoming power, check voltage
between:
Start-Up
Hot - Common (≈120 VAC)
Hot - Ground (≈120 VAC)
Common - Ground (< 1 VAC)
NOTE: The values in Tables T, U and V represent
the conditions when the heater is at full firing rate at
sea level.
NOTE: Pressure and combustion data are provided
with the heater.
WARNING: If Common - Ground is > 1 VAC,
STOP: Contact electrician to correct ground failure.
Failure to do this may burn out 120V-24V
transformer, or may cause other safety control
damage or failure.
1. Turn power on.
2. Turn on the heater, wait approximately 15 seconds
after the blower starts, the igniter should start to
glow (observable through the observation port
located at the front, bottom of the heater). Look
into the sight glass located at the bottom of the
front panel to check igniter operation. Gas valve
should open in 45-60 seconds.
Attach Manometers to Measure Pressures
1. Turn off main gas valve.
2. Attach (1) 12” scale manometer to an upstream
bleedle valve on the gas supply pipe to the heater
(Measure point “A” in Fig. 47).
3. The heater ignites at 50% of full rate (as indicated
on the LCD display of the temperature control
located in the upper right of the front panel).
3. Attach (1) 24” scale manometer to the manifold
pressure tap located on the elbow downstream of
the valve (Measure point “D” in Fig. 47).
4. If the burner fails to light on the first trial, it will try
for ignition up to three times before going into lock-
out with the standard ignition module. If the heater
is equipped with the optional single-try ignition
module, it will go into lockout.
4. Attach (1) 12” scale manometer near the fan-prov-
ing switch. Pull black cap from air pressure switch
tee and connect the manometer. NOTE: Retain
caps for reinstallation later.
5. Wait until the controller indicates 100% on the fir-
ing rate display screen (approximately 30
seconds).
Blower Check
TO BURNER
1. Check blower suction using the manometer
attached to the fan pressure switch tee, with the
heater firing at 100% input. The reading should be
as noted in Table T for both natural and propane
gas.
GAS
B
A
C
D
Fig. 47: Gas Pressure Measurement Locations
Check Gas Supply Pressure
NOTE: Most commercially available amp probes
are not accurate enough and/or are not shielded well
enough to read accurately in the heater
environment. Blower amp draw readings are for
reference only.
1. Slowly turn on main gas shut-off valve.
2. Read the gas supply pressure from the manome-
ter; minimum supply pressure for natural gas is 4.0
in. WC, recommended supply is 7.0 in. WC, mini-
42
2. FOR REFERENCE ONLY: Measure the blower
amp draw with the heater firing at 100% input and
compare the measured value to the values in
Table U. The amp draw is measured with a clamp-
on type amp probe clamped to the 14 AWG black
power wire going into the blower.
Manifold Gas Pressure Setting
High Fire Values (in. WC)
Model
Natural Gas
-0.1
Propane Gas
-0.1
503
753
-0.4
-0.1
3. When firing at 100%, the desired heater combus-
tion CO2 is between 8.5 and 9.0% for natural gas
and 9.5 and 10.0% for propane with CO less than
100 ppm. If this combustion cannot be achieved
with the blower suction within the tolerances spec-
ified in Table T, contact the factory. The reference
amp draw reading may help to indicate if there is
a problem with the system or if blower adjustment
is required.
1003
1253
1503
1753
2003
-0.8
-0.2
-1.6
-0.2
-2.4
-0.6
-0.4
-0.1
-1.0
-0.5
Table V: MVB Manifold Pressure Settings
Manifold Check
CAUTION: Special manifold and air settings may
be required.
1. Check manifold gas pressure at the gas valve out-
let pressure tap (connection “D” in Fig. 47). This
pressure should read per the values in Table V for
natural and propane gas.
Finishing
1. Record all data on the “Start-up Checklist” located
at the back of this manual.
2. If the pressure reading differs by more than 0.2
in. WC, STOP – Call the factory for directions
on what to do next!
2. Disconnect the manometers and reconnect the
cap on the fan pressure switch tee and reinsert the
sealing screws into the bleedle valves.
Air Pressure
Setting (in. WC)
Setting
Tolerance
Model
3. Start-up is complete and the heater should be
operating properly.
503
753
-2.3
-2.9
-3.0
-3.5
-4.0
-4.6
-4.1
0.2 in. WC
0.2 in. WC
0.2 in. WC
0.2 in. WC
0.2 in. WC
0.2 in. WC
0.2 in. WC
Safety Inspection
1003
1253
1503
1753
2003
1. Check all thermostats and high limit settings.
2. During the following safety checks leave manome-
ters hooked up, check and record.
Table T: MVB Air Pressure Settings
3. If other gas-fired appliances in the room are on the
same gas main, check all pressures on the MVB
with all other equipment running.
Setting
Model
Amp Draw
Tolerance
4. Check thermostats for ON-OFF operation.
5. Check high limits for ON-OFF operation.
6. While in operation, check flow switch operation.
503
753
1.9
2.9
+0.0/-0.2
+0.0/-0.2
+0.0/-0.2
+0.0/-0.2
+0.0/-0.2
+0.0/-0.5
+0.0/-0.5
1003
1253
1503
1753
2003
4.8
6.3
8.1
7. Check the low gas pressure switch (if provided).
(For proper adjustment, use the attached
manometers, if available, to set pressure. The
scales on the switch are approximate only.) Low
10.5
13.0
Table U: MVB Amp Draw—Reference Information
43
gas pressure switch (if provided) must be set at 4. Next, close the upstream manual gas valve (field
3.0 in. WC for natural gas and propane gas.
supplied) and remove the manometers from the
bleedle valves in test point A and test point B.
Connect a rubber tube from the test point A blee-
dle valve to the test point B bleedle valve and
open the upstream manual gas valve. Make sure
that test point A & B bleedle valves have been
opened so as to allow gas to flow. This will bring
gas pressure to the second valve seat.
8. Make sure that the high gas pressure switch (op-
tional) is set to 3.0 in. WC for both natural gas and
propane gas.
Follow-Up
Safety checks must be recorded as performed.
Turn heater on. After main burner ignition:
5. Open the bleedle valve at test point C and connect
a second rubber tube to it. Connect the other end
of the tube to a manometer and look for a build-up
of pressure. Increasing pressure indicates a leak-
ing gas valve which must be replaced.
1. Check manometer for proper readings.
2. Cycle heater several times and re-check readings.
6. Remove rubber tube and manometers. Close
each test point bleedle valve as the tubes are
removed.
3. Remove all manometers and replace caps and
screws.
4. Check for gas leaks one more time.
7. After no leakage has been verified at all valve
seats and test valves, open downstream leak test
valve and restore electrical power to the heater.
Leak Test Procedure: Dual-Seat Gas
Valve
Proper leak testing requires three pressure test points
in the gas train.
Remove the access panel on the rear of the heater to
access the gas valve for this test. Test point A is a blee-
dle valve located upstream of the combination gas
valve on the supply manifold.
Test point B is a bleedle valve located between the two
automatic gas valve seats.
Test point C is a bleedle valve located downstream of
both automatic gas valve seats and upstream of the
manual valve. Refer to Fig. 48.
These tests are to be conducted with the electrical
power to the heater turned OFF.
1. Manually close the downstream leak test valve.
2. Open the bleedle valve at test point A and connect
a manometer to it. Verify that there is gas pressure
and that it is within the proper range (NOTE: must
not exceed 14.0 in. WC).
TO BURNER
GAS
B
A
C
3. Open test point B and connect a rubber tube to it.
Connect the other end of the tube to a manometer
and look for a build-up of pressure. Increasing
pressure indicates a leaking gas valve which must
be replaced.
D
Fig. 48: Leak Test Procedure
44
11. Check to see that the high limit control is set
above the design temperature requirements of the
system. For multiple zones: Check to make sure
the flow is adjusted as required in each zone.
Post Start-Up Check
Check off steps as completed:
1. Verify that the heater and heat distribution units or
storage tank are filled with water.
12. Check that the heater is cycled with the thermo-
stat. Raise the setting on the thermostat to the
highest setting and verify that the heater goes
through the normal start-up cycle. Reduce to the
lowest setting and verify that the heater goes off.
2. Confirm that the automatic air vent (if used) was
opened two full turns during the venting proce-
dure.
13. Observe several operating cycles for proper oper-
ation.
3. Verify that air has been purged from the system.
4. Verify that air has been purged from the gas pip-
ing, and that the piping has been checked for
leaks.
14. Set the heater thermostat to desired temperature.
15. Review all instructions shipped with this heater
with owner or maintenance person, return to enve-
lope and give to owner or place the instructions
inside front panel on heater.
5. Confirm that the proper start-up procedures were
followed.
6. Inspect burner to verify flame.
OPERATION
7. Test safety controls: If heater is equipped with a
low water cut-off or additional safety controls, test
for operation as outlined by manufacturer. Burner
should be operating and should go off when con-
trols are tested. When safety devices are restored,
burners should re-ignite after pre-purge time
delay.
Lighting Instructions
1. Before operation, make sure you have read all of
the safety information in this manual.
2. Remove upper front panel.
8. Test limit control: While burner is operating, move
indicator on high limit control below actual water
temperature. Burner should go off while blower
and circulator continue to operate. Raise setting
on limit control above water temperature and
burner should re-ignite after pre-purge time delay.
NOTE: Ignition control may have to be reset
after this portion of the test.
3. Set the thermostat to the lowest setting.
4. Turn off all electrical power to the appliance.
5. This appliance is equipped with an ignition device
which automatically lights the burner. Do not try to
light the burner by hand.
9. Test ignition system safety device:
a. Open manual gas valve. Turn power on.
b. Set thermostat to call for heat.
6. Turn on main manual gas valve field installed near
gas inlet connection on back of heater.
7. Wait 5 minutes to clear out any gas. Then smell for
gas, especially near the floor. If you then smell
gas, STOP! Follow the steps in the safety informa-
tion on the front cover of this manual. If you do not
smell gas, go to next step.
c. When the heater is in operation, pull the hoses
off of the air switch. The burner should shut off
almost immediately.
8. Turn on all electrical power to the appliance.
d. Reattach hoses. Burner should re-ignite after
pre-purge time delay. NOTE: Ignition control
may have to be reset after this portion of
the test.
9. Set thermostat to desired setting. The appliance
will operate. The igniter will glow after the pre-
purge time delay (15 seconds). After igniter
reaches temperature (30 seconds) the main valve
should open. System will try for ignition up to three
10. To restart system, follow lighting instructions in the
Operation section.
45
times (one time on optional single-try ignition mod-
ule). If flame is not sensed, lockout will
commence.
To Turn Off Gas To Appliance
1. Shut off manual gas valve field installed near gas
inlet connection on back of heater.
10. If the appliance will not operate, follow the instruc-
tions “To Turn Off Gas To Appliance,” and call your
service technician or gas supplier.
2. Remove upper front panel.
3. Set the thermostat to lowest setting.
11. Replace upper front panel.
4. Turn off all electrical power to the appliance if serv-
ice is to be performed.
12. If heater fails to start, verify the following:
a. There are no loose connections or that the
service switch is off.
5. Replace access panel.
b. High temperature limit switch is set above wa-
ter temperature or manual reset high limit is
not tripped.
c. Thermostat is set above water temperature.
d. Gas is on at the meter and the heater.
e. Incoming dynamic gas pressure to the gas
valve is NOT less than 4.0 in. WC for natural
gas or propane gas.
46
TROUBLESHOOTING
Does the power switch provide
NO
Check the switch and/or
line voltage
power to the control panel?
Step 1
Is there a Call For
YES
NO
Unit is in standby mode.
Heat?
YES
NO
Is Disable connection intact?
Step 2
Reattach.
YES
Check and correct power
connections at main terminal
block, circuit breaker panel or
blower relay.
Is there 120VAC at the blower or
blower relay?
Does the combustion air
blower come on?
NO
NO
Step 3
YES
Is 4-20mA present at the quick
disconnects on the black and blue
wires of the temperature controller?
Is diagnostic board
indicating open
safeties?
Replace temperature
NO
NO
NO
controller.
YES
YES
Correct Safety
YES
Does F2 on ignition module
have AC power?
Is there continuity in the wire
between F2 and Pin J5-6?
Repair or
Replace wire.
NO
Correct the shutter
setting or blower
amp draw.
Is blower pressure setting
(vacuum) correct?
Is 24VAC at the NC side of
the air pressure switch?
NO
NO
Step 4
YES
YES
Replace air pressure switch.
Is 24VAC at PS on ignition module?
Is connecting plug secure?
Step 5
Step 6
Correct wiring.
NO
YES
Is Amp draw during heat-
up for HSI greater than
3.1 Amps?
Does igniter prove?
YES
NO
NO
Replace HSI
YES
NO
Is air switch bouncing?
NO
YES
Step 7
Is the flame sensor signal to the
ignition module greater than 1 uA DC?
Is gas pressure correct?
YES
NO
YES
Is static and dynamic inlet gas
pressure correct?
Correct the gas pressure.
NO
Is the unit running?
Step 8
Step 9
YES
YES
NO
The unit is okay
Call our Technical Service Department
1-805-278-5300
47
UDB Fault History
MAINTENANCE
To view the fault codes in the UDB history file:
Suggested Minimum
1. Press the UP or DOWN buttons on the membrane
Maintenance Schedule
switch for 2 seconds to access the fault history.
Regular service by a qualified service agency and
maintenance must be performed to ensure maximum
operating efficiency.
2. Press either button to scroll through the recorded
faults in history.
3. The most recent fault recorded will be the first fault
displayed (the last 16 faults are stored in the his-
tory, on a rolling basis). There is no time or date
stamp associated with these faults.
Maintenance as outlined below may be performed by
the owner.
Daily
4. When the history of faults has been exhausted,
pushing the UP or DOWN buttons again will roll
the fault history over and it will start again.
1. Check that the area where the heater is installed
is free from combustible materials, gasoline, and
other flammable vapors and liquids.
5. To exit the fault history, wait for 10 seconds and
the board will automatically exit the history mode.
2. Check for and remove any obstruction to the flow
of combustion or ventilation air to heater.
To clear the fault history, press and hold both the UP
and DOWN buttons for 5 seconds while the power is
on.
Monthly
1. Check for piping leaks around pumps, mixing
valves, relief valves, and other fittings. If found,
repair at once. DO NOT use petroleum-based
stop-leak compounds.
NOTE: Once the history has been cleared, it cannot
be recovered.
2. Visually inspect burner flame.
Diagnostic information is provided any time a fault is
recorded. This information is intended to assist in
locating the problem with the heater, but is not exhaus-
tive.
3. Visually inspect venting system for proper func-
tion, deterioration or leakage.
4. Visually inspect for proper operation of the con-
densate drain in the venting. If leaks are observed
repair at once.
If multiple fault conditions occur at the same time, only
the fault that caused the heater to shut down will be
recorded in the history.
5. Check air vents for leakage.
Yearly (Beginning Of Each Heating
Season)
Schedule annual service call by qualified service
agency.
1. Visually check top of vent for soot. Call service
person to clean. Some sediment at bottom of vent
is normal.
2. Visually inspect venting system for proper func-
tion, deterioration or leakage. Ensure that
condensate drain is inspected and ensure that
condensate is being directed to appropriate con-
48
densate management system or drain, as required
by local codes.
Weekly
For low-pressure heaters, test low-water cut-off
device. (With heater in pre-purge, depress the low
water cut-off test button. Appliance should shut-off
and ignition fault light should come on. Depress reset
button on front of heater control panel to reset).
3. Check that area is free from combustible materi-
als, gasoline, and other flammable vapors and
liquids.
4. Check air filter and replace as necessary.
Monthly
5. Follow pre-start-up check in the Start-up section.
1. Check flue, vent, stack, or outlet dampers.
6. Visually inspect burner flame. It should be light
blue at full input. Remove and visually inspect hot
surface igniter and sensor for damage, cracking or
debris build-up.
2. Test blower air pressure. (See “Blower Check” on
page 42.)
3. Test high and low gas pressure interlocks (if
equipped). (See “Safety Inspection” on page 43.)
7. Check operation of safety devices. Refer to manu-
facturers’ instructions.
Semi-Annually
8. Follow oil-lubricating instructions on pump (if re-
quired). Over-oiling will damage pump.
Water-lubricated circulators do not need oiling.
1. Recalibrate all indicating and recording gauges.
2. Check flame failure detection system components.
9. To avoid potential of severe burn, DO NOT REST
HANDS ON OR GRASP PIPES. Use a light touch;
return piping will heat up quickly.
3. Check firing rate control by checking the manifold
pressure. (See “Manifold Check” on page 43.)
10. Check blower and blower motor.
4. Check piping and wiring of all interlocks and shut-
off valves.
11. Check for piping leaks around pumps, relief valves
and other fittings. Repair, if found. DO NOT use
petroleum-based stop-leak.
5. Check air filter and replace as necessary.
Annually
Periodically
1. Test flame failure detection system and pilot turn-
down.
1. Check relief valve. Refer to manufacturer’s
instructions on valve.
2. Test high limit and operating temperature. (See
“Post Start-Up Check,” page 45.)
2. Test low water cut-off (if equipped). Refer to manu-
facturer’s instructions.
3. Check flame sensor.
Preventive Maintenance
Schedule
4. Conduct a combustion test at full fire. Carbon diox-
ide should be 8.5 to 9.0% at full fire for natural gas,
and between 9.5 to 10.0% for propane gas.
Carbon monoxide should be < 100 ppm.
The following procedures are recommended and are
good practice for all MVB installations.
5. Check valve coil for 60 cycle hum or buzz. Check
for leaks at all valve fittings using a soapy water
solution (while heater is operating). Test other
operating parts of all safety shut-off and control
valves and increase or decrease settings
(depending on the type of control) until the safety
circuit opens. Reset to original setting after each
device is tested.
Daily
1. Check gauges, monitors and indicators.
2. Check instrument and equipment settings. (See
“Post Start-Up Check” on page 45.)
3. Check burner flame. (Should see light blue flame
at full input rate).
49
6. Perform leakage test on gas valves. (See Fig. 48.)
Filter Replacement
7. Test air switch in accordance with manufacturer’s
instructions. (Turn panel switch to the “On” posi-
tion until blower is proven, then turn the switch to
“Off.”
1. Remove the filter box cover by loosening and
removing the two wing nuts holding it in place.
8. Inspect and clean burner using shop air.
As Required
1. Recondition or replace low water cut-off device (if
equipped).
2. Check drip leg and gas strainers.
3. Check flame failure detection system. (See “Post
Start-Up Check,” page 45.)
Fig. 49: Remove the Air Filter Box Cover
4. Check igniter. (Resistance reading should be 42-
70 ohms at ambient temperature).
2. Remove the filter by lifting it straight up and out of
the slot in the filter box.
5. Check flame signal strength. (Flame signal should
be greater than 1 microampere as measured at
the 2 pins on the upper left corner of the ignition
control).
6. Check firing rate control by checking the manifold
pressure. (See “Manifold Check” on page 43.)
7. Test safety/safety relief valves in accordance with
ASME Heater and Pressure Vessel Code Section
IV.
Filter Maintenance
NOTE: Use Raypak replacement filters, kit number
012552F (12”X12”) for models 503-1003 and kit
number 012553F (16”X16”) for models 1253-2003.
Fig. 50: Remove the Air Filter
•
•
Inspect quarterly
3. Reverse steps 1 and 2 to install the new filter. Use
Raypak replacement filters, kit number 012552F
(12”X12”) for models 503-1103 and kit number
012553F (16”X16”) for models 1253-2003.
Replace when tracking pressure exceeds -0.5 in.
WC at 100% fan speed, except for models 1003,
1753 and 2003, which need to be replaced when
tracking pressure exceeds -0.7 in. WC at 100% fan
speed.
50
APPENDIX
Areas where contaminated combustion air commonly
exists:
Inside Air Contamination
•
•
•
•
•
•
•
•
•
•
•
dry cleaning/laundry areas
metal fabrication plants
beauty shops
refrigeration repair shops
photo processing plants
auto body shops
All heaters experience some condensation during
start-up. The condensate from flue gas is acidic.
Combustion air can be contaminated by certain vapors
in the air which raise the acidity of the condensate.
Higher acidity levels attack many materials including
stainless steel, which is commonly used in high effi-
ciency systems. The heater can be supplied with
corrosion-resistant, non-metallic intake air vent materi-
al. You may, however, choose to use outside
combustion air for one or more of these reasons:
plastic manufacturing plants
furniture refinishing areas and establishments
new building construction
remodeling areas
open pit skimmers
Check for areas and products listed above before in-
stalling heater. If found:
1. Installation is in an area containing contaminants
listed below which will induce acidic condensation.
•
•
remove products permanently, OR
install TruSeal direct vent.
2. You want to reduce infiltration into your building
through openings around windows and doors.
3. You are using AL29-4C stainless steel vent pipe,
which is more corrosion-resistant than standard
metallic vent pipe. In extremely contaminated ar-
eas, this may also experience deterioration.
Products causing contaminated combustion air:
•
•
•
•
•
•
•
•
•
•
•
•
spray cans containing chloro/fluorocarbons
permanent wave solutions
chlorinated waxes/cleaners
chlorine-based swimming pool chemicals
calcium chloride used for thawing
sodium chloride used for water softening
refrigerant leaks
paint or varnish removers
hydrochloric acid/muriatic acid
cements and glues
antistatic fabric softeners used in clothes dryers
chloride-type bleaches, detergents, and cleaning
solvents found in household laundry rooms
adhesives used to fasten building products
similar products
•
•
51
Important Instructions for the Commonwealth of Massachusetts
The Commonwealth of Massachusetts requires compliance
with regulation 248 CMR 4.00 and 5.00 for installation of
through – the – wall vented gas appliances as follows:
(b) EXEMPTIONS: The following equipment is exempt from
248 CMR 5.08(2)(a)1 through 4:
1. The equipment listed in Chapter 10 entitled "Equipment
Not Required To Be Vented" in the most current edition of
NFPA 54 as adopted by the Board; and
(a) For all side wall horizontally vented gas fueled equipment
installed in every dwelling, building or structure used in
whole or in part for residential purposes, including those
owned or operated by the Commonwealth and where the
side wall exhaust vent termination is less than seven (7) feet
above finished grade in the area of the venting, including but
not limited to decks and porches, the following requirements
shall be satisfied:
2. Product Approved side wall horizontally vented gas fueled
equipment installed in a room or structure separate from the
dwelling, building or structure used in whole or in part for res-
idential purposes.
(c) MANUFACTURER REQUIREMENTS - GAS EQUIP-
MENT VENTING SYSTEM PROVIDED. When the
manufacturer of Product Approved side wall horizontally
vented gas equipment provides a venting system design or
venting system components with the equipment, the instruc-
tions provided by the manufacturer for installation of the
equipment and the venting system shall include:
1. INSTALLATION OF CARBON MONOXIDE DETECTORS.
At the time of installation of the side wall horizontal vented
gas fueled equipment, the installing plumber or gasfitter shall
observe that a hard wired carbon monoxide detector with an
alarm and battery back-up is installed on the floor level
where the gas equipment is to be installed. In addition, the
installing plumber or gasfitter shall observe that a battery
operated or hard wired carbon monoxide detector with an
alarm is installed on each additional level of the dwelling,
building or structure served by the side wall horizontal vent-
ed gas fueled equipment. It shall be the responsibility of the
property owner to secure the services of qualified licensed
professionals for the installation of hard wired carbon
monoxide detectors
1. Detailed instructions for the installation of the venting sys-
tem design or the venting system components; and
2. A complete parts list for the venting system design or vent-
ing system.
(d) MANUFACTURER REQUIREMENTS - GAS EQUIP-
MENT VENTING SYSTEM NOT PROVIDED. When the
manufacturer of a Product Approved side wall horizontally
vented gas fueled equipment does not provide the parts for
venting the flue gases, but identifies "special venting sys-
tems", the following requirements shall be satisfied by the
manufacturer:
a. In the event that the side wall horizontally vented gas
fueled equipment is installed in a crawl space or an attic, the
hard wired carbon monoxide detector with alarm and battery
back-up may be installed on the next adjacent floor level.
b. In the event that the requirements of this subdivision can
not be met at the time of completion of installation, the owner
shall have a period of thirty (30) days to comply with the
above requirements; provided, however, that during said
thirty (30) day period, a battery operated carbon monoxide
detector with an alarm shall be installed.
1. The referenced "special venting system" instructions shall
be included with the appliance or equipment installation
instructions; and
2. The "special venting systems" shall be Product Approved
by the Board, and the instructions for that system shall
include a parts list and detailed installation instructions.
2. APPROVED CARBON MONOXIDE DETECTORS. Each
carbon monoxide detector as required in accordance with
the above provisions shall comply with NFPA 720 and be
ANSI/UL 2034 listed and IAS certified.
(e) A copy of all installation instructions for all Product
Approved side wall horizontally vented gas fueled equip-
ment, all venting instructions, all parts lists for venting
instructions, and/or all venting design instructions shall
remain with the appliance or equipment at the completion of
the installation.
3. SIGNAGE. A metal or plastic identification plate shall be
permanently mounted to the exterior of the building at a min-
imum height of eight (8) feet above grade directly in line with
the exhaust vent terminal for the horizontally vented gas
fueled heating appliance or equipment. The sign shall read,
in print size no less than one-half (1/2) inch in size, "GAS
VENT DIRECTLY BELOW. KEEP CLEAR OF ALL
OBSTRUCTIONS".
GAS PRESSURE SUPERVISION
The Commonwealth of Massachusetts requires listed high
and low gas pressure switches (manual reset) for any model
with a maximum firing input greater than 1,000,000 Btu/Hr in
accordance with 248 CMR 7.04(11)(d).
4. INSPECTION. The state or local gas inspector of the side
wall horizontally vented gas fueled equipment shall not
approve the installation unless, upon inspection, the inspec-
tor observes carbon monoxide detectors and signage
installed in accordance with the provisions of 248 CMR
5.08(2)(a)1 through 4.
A gas pressure regulator (field supplied) is required in the
gas train ahead of the heater, for heaters having input rates
greater than 1,000,000 Btu/Hr, in accordance with 248 CMR
7.04 Figure 3B requirements.
52
LIMITED PARTS WARRANTY
MVB – TYPES H AND WH
MODELS 503-2003
SCOPE
Raypak, Inc. (“Raypak”) warrants to the original owner that all parts of this heater which are actually manufactured by Raypak will be free
from failure under normal use and service for the specified warranty periods and subject to the conditions set forth in this Warranty. Labor
charges and other costs for parts removal or reinstallation, shipping and transportation are not covered by this Warranty but are the
owner’s responsibility.
HEAT EXCHANGER WARRANTY
Domestic Hot Water
Five (5) years from date of heater installation. Includes copper heat exchanger with bronze waterways.
Ten (10) years from date of heater installation. Includes only cupro-nickel heat exchanger with bronze waterways.
Space Heating (Closed Loop System)
Ten (10) years from date of heater installation. Includes both cupro-nickel and copper heat exchanger with bronze water-ways.
Thermal Shock Warranty
Twenty (20) years from date of heater installation against “Thermal Shock” (excluded, however, if caused by heater operation at large
changes exceeding 150°F between the water temperature at intake and heater temperature, or operating at heater temperatures exceed-
ing 230°F).
ANY OTHER PART MANUFACTURED BY RAYPAK
One (1) year warranty from date of heater installation, or eighteen (18) months from date of factory shipment based on Raypak’s records,
whichever comes first.
SATISFACTORY PROOF OF INSTALLATION DATE, SUCH AS INSTALLER INVOICE, IS REQUIRED. THIS WARRANTY WILL BE
VOID IF THE HEATER RATING PLATE IS ALTERED OR REMOVED.
ADDITIONAL WARRANTY EXCLUSIONS
This warranty does not cover failures or malfunctions resulting from:
1. Failure to properly install, operate or maintain the heater in accordance with our printed instructions provided;
2. Abuse, alteration, accident, fire, flood and the like;
3. Sediment or lime build-up, freezing, or other conditions causing inadequate water circulation;
4. High velocity flow exceeding heater design rates;
5. Failure of connected systems devices, such as pump or controller;
6. Use of non-factory authorized accessories or other components in conjunction with the heater system;
7. Failing to eliminate air from, or replenish water in, the connected water system;
8. Chemical contamination of combustion air or use of chemical additives to water.
PARTS REPLACEMENT
Under this Warranty, Raypak will furnish a replacement for any failed part. The failed part must first be returned to Raypak if requested,
with transportation charges prepaid, and all applicable warranty conditions found satisfied. The replacement part will be warranted for
only the unexpired portion of the original warranty. Raypak makes no warranty whatsoever on parts not manufactured by it, but Raypak
will apply any such warranty as may be provided to it by the parts manufacturer.
TO MAKE WARRANTY CLAIM
Promptly notify the original installer, supplying the model and serial numbers of the unit, date of installation and description of the prob-
lem. The installer must then notify his Raypak distributor for instructions regarding the claim. If either is not available, contact Service
Manager, Raypak, Inc., 2151 Eastman Avenue, Oxnard, CA 93030 or call (805) 278-5300. In all cases proper authorization must first be
received from Raypak before replacement of any part.
EXCLUSIVE WARRANTY - LIMITATION OF LIABILITY
This is the only warranty given by Raypak. No one is authorized to make any other warranties on Raypak’s behalf. THIS WARRANTY IN
LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MER-
CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. RAYPAK’S SOLE LIABILITY AND THE SOLE REMEDY AGAINST
RAYPAK WITH RESPECT TO DEFECTIVE PARTS SHALL BE AS PROVIDED IN THIS WARRANTY. IT IS AGREED THAT RAYPAK
SHALL HAVE NO LIABILITY, WHETHER UNDER THIS WARRANTY, OR IN CONTRACT, TORT, NEGLIGENCE OR OTHERWISE,
FOR ANY SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGE, INCLUDING DAMAGE FROM WATER LEAKAGE. Some states
do not allow limitations on how long an implied warranty lasts, or for the exclusion of incidental or consequential damages. So the above
limitation or exclusion may not apply to you.
This Limited Warranty gives you specific legal rights. You may also have other rights which may vary from state to state. We suggest that
you complete the information below and retain this certificate in the event warranty service is needed. Reasonable proof of the effective
date of the warranty (date of installation) must be presented, otherwise, the effective date will be based on the rate of manufacture plus
thirty (30) days.
Original Owner
Model Number
Mailing Address
Serial Number
Date of Installation
Installation Site
Contractor/Installer
City
State
Zip Code
Daytime Telephone Number
RAYPAK, INC 2151 Eastman Avenue Oxnard, CA 93030-9786 (805) 278-5300 Fax (800) 872-9725 www.raypak.com
53
START-UP CHECKLIST FOR FAN-ASSISTED
RAYPAK PRODUCTS
This start-up checklist is to be completely filled out by the service technician starting up the Raypak Boiler or Heater
for the first time. All information may be used for warranty purposes and to ensure that the installation is correct.
Additionally this form will be used to record all equipment operation functions and required settings.
GAS SUPPLY DATA
Regulator Model & Size
Gas Line Size (in room)
Length of Gas Line
Low Gas Pressure Setting
High Gas Pressure Setting
Gas Shut-Off Valve Type
( Ball, Lube cock)
CLEARANCES
Front Clearance
Right Side Clearance
Left Side Clearance
Rear Clearance
_________ / ______CFH
________________In. NPT
________________Eq Ft
________________In. WC
________________In. WC
________________
_______________In.
_______________In.
_______________In.
_______________In.
_______________In.
Overhead Clearance
ELECTRICAL
Sediment Trap
Port
________________Y/N
_______Std______Full
Voltage Supply (VAC)
Voltage -24 VAC
Voltage Com to Ground
Hot Surface Igniter
Auto High Limit Setting
Manual Reset High Limit Setting
Operating Control Setting
No Load______ Load_____
_______________VAC
_______________VAC
_______________Ohms
_______________deg F
_______________deg F
_______________deg F
VISUAL INSPECTION OF COMPONENTS
Verify inspection was done and condition of components are in
good working order with a “yes”
Wiring Harness
Burner/s (flame)
Refractory (visual)
Remote flame sense
Covers in place for outdoor
_________________ Y/N
_________________ Y/N
_________________ Y/N
_________________ Y/N
_________________ Y/N
Sketch plumbing on reverse side
WATER SUPPLY
Flow Rate in GPM or Delta T
Measure flow rate at full fire
Pump Economaster setting
Low Water Cutoff
_______________If Avail
_______________Minutes
_______________Test
Qty____ _______Gallons
_______________
Pump HP: ______
Pump Model___________
Screens________________
VENTING
Vent Size: _____________
Category: _________
Vent Material:
Vent Termination Type:
Combustion Air Openings:
Ventilation air
Stack Height:_______
sketch vent on reverse side *** Number of Tanks and Size
__________________
__________________
Low __________ in2
High __________ in2
Plumbing Size
Pump Size: _________(boiler)
Impeller trim____________
Louvers __________________
EMISSIONS SETTINGS AND TEST INFORMATION
(AT FULL FIRE)
Nominal Factory Recommended Settings
Blower Pressure Setting
Supply Gas Pressure
_________________In. WC
_________________In. WC
See manual or card tag
See manual or card tag
Verify stable pressure static & dynamic condition
Pilot Gas Pressure
Manifold Gas Pressure
_________________In. WC
_________________In. WC
See manual or card tag
See manual or card tag
The following measurements must be obtained with a Combustion Analyzer.
NOX
Free Oxygen
CO
_________________PPM
_________________%
_________________PPM
_________________%
Less than 20 PPM (If required by Certifying Agency)
See manual
Less than 150 PPM
See manual
CO2
Model Number: ______________________________
*** Note: draw venting with details, such as extractors,
barometric dampers, blast dampers or draft inducers
Serial Number: _______________________________
Site Altitude Above Sea Level __________________Ft.
Job Name _______________________________________________________________________________________
Address _________________________________________________________________________________________
Physical Location of Boiler: Indoors______; Outdoors______; Ground Level______; Roof______; Below Grade______
Mechanical Contractor / Installer _______________________________________________________________________
Date and Time of Start-up _____________Print Name and Signature of Start-up Technician_________________________
Information must be faxed to: (805) 278-5471 in order to ensure warranty consideration Attn: Service Manager
54
55
Raypak, Inc., 2151 Eastman Avenue, Oxnard, CA 93030 (805) 278-5300 Fax (805) 278-5468
Litho in U.S.A.
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