Raypak Water Heater 503 2003 User Guide

CATALOG NO. 3400.53A  
Effective:  
Replaces:  
8-1-06  
6-15-06  
INSTALLATION  
AND OPERATING  
INSTRUCTIONS  
Models 503-2003  
Types H & WH  
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.  
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. Installation and  
service must be performed by a qualified installer, service agency or the gas supplier.  
* This unit contains materials that have been identified as carcinogenic, or possibly carcinogenic, to humans.  
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.  
This manual should be maintained in legible condition and kept adjacent to the heater or in a safe place for future  
reference.  
P/N 241288 Rev 2  
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Table of Contents  
WARNINGS................................................................2  
SECTION D Start-up..............................................41  
SECTION A Before Installation ..............................3  
Pre Start-up............................................................41  
Product Receipt .......................................................3  
Start-Up .................................................................42  
Model Identification ................................................3  
Ratings and Certifications........................................3  
Installations at Elevation .........................................4  
Component Locations..............................................4  
General Information ................................................4  
SECTION E Operation...........................................47  
Lighting Instructions .............................................47  
To Turn Off Gas To Appliance .............................47  
SECTION F Troubleshooting .................................49  
UDB Fault History ................................................50  
SECTION G Maintenance......................................51  
SECTION B Hot Water Supply General Safety.....5  
Suggested Minimum Maintenance Schedule.........51  
Time/Temperature Relationships in Scalds .............6  
Preventive Maintenance Schedule.........................52  
SECTION C Installation...........................................7  
Installation Codes ....................................................7  
SECTION H Appendix ...........................................53  
Inside Air Contamination ......................................53  
Equipment Base.......................................................7  
Clearances................................................................7  
Combustion and Ventilation Air..............................9  
Water Piping..........................................................11  
Gas Supply.............................................................17  
Electrical Power Connections................................19  
Venting ..................................................................21  
Controls .................................................................28  
Wiring Diagrams ...................................................38  
1
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WARNINGS  
PAY ATTENTION TO THESE TERMS:  
DANGER:  
WARNING:  
CAUTION:  
NOTICE:  
Indicates the presence of immediate hazards which will cause severe 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 impor-  
tant 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 PROPOSI-  
TION 65: This product contains chemicals  
known to the State of California to cause can-  
cer, 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  
105°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.  
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.  
WARNING: To minimize the possibility of  
improper operation, serious personal injury,  
fire, or damage to the heater:  
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 require-  
ments. 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.  
2
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SECTION A  
Before Installation  
Raypak strongly recommends that this manual be re-  
viewed thoroughly before installing your MVB heater.  
Please review the General Safety information in Sec-  
tion B before installing the heater. Factory warranty  
does not apply to heaters that have been improperly  
installed or operated. (Refer to the warranty at the back  
of this manual.) Installation and service must be per-  
formed 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 the manufacturer or your local Raypak repre-  
sentative.  
When ordering parts, you must specify the model and  
serial numbers of the heater. When ordering under war-  
ranty conditions, you must also specify the date of  
installation.  
Purchased parts are subject to replacement only under  
the manufacturer’s warranty. Debits for defective re-  
placement parts will not be accepted and will be  
replaced in kind only per Raypak’s standard warranties.  
Model Identification  
The model identification number and heater serial  
number are found on the heater rating plate located on  
the upper rear jacket panel of the heater. The model  
number will have the form H7-2003 or similar  
depending 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 identi-  
fies the firing mode (7 = electronic modulation). The  
second group of characters identifies the size of the  
heater (three or four numbers representing the ap-  
proximate MBTUH input), and, where applicable, a  
letter, indicating the manufacturing series.  
Thank you for purchasing a Raypak product. We hope  
you will be satisfied with the high quality and durabil-  
ity of our equipment.  
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. Remove  
the heater from the shipping packaging. Report any  
damage to the carrier immediately.  
On occasion, items are shipped loose. Be sure that you  
receive the correct number of packages as indicated on  
the Bill of Lading.  
Ratings and Certifications  
Standards:  
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  
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.  
3
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SECTION A: Before Installation  
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.  
The heater also complies with the latest edition of  
ASHRAE 90.1 Standard.  
WARNING: Altering any Raypak pressure vessel by  
installing replacement heat exchangers, tube bundle head-  
ers, 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. Al-  
tering the ASME or CSA ratings of the vessel also  
violates national, state, and local approval codes.  
Top panel, blower and gas train omitted for clarity  
Fig. 2: Component Locations - Top  
Installations at Elevation  
Rated inputs are suitable for up to 4,500 ft elevation with-  
out de-rating. Consult 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 (adjustments may be required).  
Component Locations  
Fig. 3: Component Locations – Rear  
General Information  
Gas  
MBTUH  
Input  
Vent Size  
(in.)  
Water  
Conn.  
(NPT)  
Conn.  
(NPT)  
Model  
No.  
Max. Min.  
N
P
1
1
1
1
1
1
1
Flue Intake  
503 500 125  
753 750 188  
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  
Panels omitted for clarity  
1753 1750 438 2-1/2  
2003 1999 500 2-1/2  
2
2
Fig. 1: Component Locations - Side  
Table A: Basic Data  
4
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SECTION B  
Hot Water Supply  
General Safety  
To meet commercial hot water use needs, the high limit  
safety control on this water heater is adjustable up to  
210°F. However, water temperatures over 125°F can  
cause instant severe burns or death from scalds. When  
supplying general purpose hot water, the recommended  
initial setting for the control is 125°F.  
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.  
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.  
Water temperature over 125°F can cause instant severe  
burns or death from scalds. Children, disabled and eld-  
erly are at highest risk of being scalded.  
Feel water before bathing or showering.  
Temperature limiting valves are available.  
NOTE: When this water heater is supplying general  
purpose hot water for use by individuals, a thermostati-  
cally 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.  
Water temperature over 125°F can  
causeinstantsevereburnsordeath  
from scalds.  
Children, disabled, and elderly are  
at highest risk of being scalded.  
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,  
place a thermometer in the hot water stream and read  
the thermometer.  
See instruction manual before set-  
ting temperature at water heater.  
Feel water before bathing or show-  
ering.  
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  
Temperature limiting valves are  
available, see manual.  
5
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SECTION B: General Safety  
CAUTION: Hotter water increases the risk of scald-  
ing! There is a hot water scald potential if the  
thermostat is set too high.  
Time/Temperature Relationships  
in Scalds  
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  
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  
The temperature of the water in the heater can be regu-  
lated 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).  
To adjust the water temperature, follow the instruction  
for the operation of the control starting on page 28 of  
this manual. The control is shown below for identifica-  
tion purposes only. (See Fig. 4.)  
Fig. 4: Modulating Temperature Control  
6
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SECTION C  
Installation  
Installation Codes  
Clearances  
Installations must follow these codes:  
Indoor Installations  
Local, state, provincial, and national codes, laws,  
regulations and ordinances  
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 Auto-  
matically Fired Boilers, ANSI/ASME CSD-1,  
(CSD-1) when required  
Minimum Clearance Recommended  
from Combustible  
Surfaces  
Heater  
Side  
Service  
Clearance  
Floor*  
Rear  
0”  
12”  
1”  
0”  
24”  
1”  
Right Side  
Left Side  
Top  
1”  
1”  
For Canada only: CAN/CSA B149.1 Natural Gas  
and Propane Installation Code and CSA C22.1  
C.E.C. Part 1 (C22.1)  
0”  
10”  
24”  
1”  
Front  
Open  
1”  
Vent  
Equipment Base  
* DO NOT install on carpeting.  
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 en-  
closed parking garages must be located at least 18 in.  
above the floor.  
Table C: Clearances – Indoor Installations  
When such locations cannot be avoided, it is recom-  
mended that a suitable catch pan, adequately drained,  
be installed under the appliance. The pan must not re-  
strict 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.).  
7
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SECTION C: Installation  
Fig. 5: 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  
B
C
D
Clearance to window or door that may be opened  
3 ft (91 cm)  
Clearance to permanently closed window  
*
*
*
Vertical clearance to ventilated soffit located  
above the terminal within a horizontal distance of  
2 ft (61cm) from the centerline of the terminal  
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-  
Clearance to each side of center line extended  
above meter/regulator assembly  
H
I
*
ter/regulator assembly  
Clearance to service regulator vent outlet  
*
6 ft (1.83m)  
Clearance to non-mechanical air supply inlet to  
building or the combustion air inlet to any other  
appliance  
4 ft (1.2m) below or to side  
of opening; 1 ft (30 cm)  
above opening  
J
3 ft (91 cm)  
3 ft (91 cm) above if within  
10 ft (3m) horizontally  
K
Clearance to mechanical air supply inlet  
6 ft (1.83m)  
Clearance above paved sidewalk or paved  
driveway located on public property  
L
7 ft (2.13m)  
7 ft (2.13m) t  
M
Clearance under veranda, porch, deck or balcony  
*
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 D: Vent/Air Inlet Termination Clearances  
8
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SECTION C: Installation  
the heater to be serviced without removing any struc-  
ture around the heater.  
Outdoor Installations  
These heaters are design-certified for outdoor installa-  
tion. Heaters must not be installed under an overhang  
that is less than 3 ft from the top of the vent terminal.  
Three sides must be open in the area under the over-  
hang. Roof water drainage must be diverted away from  
heaters installed under overhangs.  
Min. Clearance  
from Combustible  
Surfaces  
Recommended  
Service  
Clearance  
Heater  
Side  
Rear  
Right Side  
Left Side  
Top  
12”  
24”  
1”  
1”  
1”  
1”  
Unobstructed  
12”  
Unobstructed  
12”  
Vent  
Termination  
Table E: Clearances – Outdoor Installations  
The combustion air intake terminal MUST be used for  
outdoor installations. The hood is shipped loose and  
installed on the rear of the heater at the jobsite.  
Combustion and Ventilation Air  
NOTICE: Use of the heater in construction areas  
where fine particulate matter, such as concrete or dry-  
wall dust, is present may result in damage to the burner  
that is not covered by the warranty. If operated in a  
construction environment, a clean source of combus-  
tion air must be provided directly to the heater.  
Venting not shown for clarity. Heater must be vented  
per instructions in this manual  
Fig. 6: Minimum Clearances from Combustible  
Surfaces – Indoor and Outdoor 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, we recommend 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. This will allow the heater to be ser-  
viced in its installed location without movement or  
removal of the heater.  
Indoor Units  
The 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  
comply with the requirements of the NFGC (U.S.) and  
B149.1 (Canada), and all local codes.  
Service clearances less than the minimum may require  
removal of the heater to service either the heat ex-  
changer or the burner components. In either case, the  
heater must be installed in a manner that will enable  
9
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SECTION C: Installation  
CAUTION: Combustion air must not be contaminated  
by corrosive chemical fumes which can damage the  
heater and void the warranty. (See Section H.)  
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 Section H of this manual regarding air  
contamination.  
NOTICE: It is recommended that the intake vent be  
insulated to minimize sweating.  
Optional Construction Air Filter  
Conventional Combustion Air Supply  
U.S. Installations  
An optional construction air filter is available for use.  
The filter should be removed after construction is fin-  
ished to allow for unrestricted air flow to the heater.  
All Air from Inside the Building  
The confined space shall be provided with TWO per-  
manent openings communicating directly with an  
additional room(s) of sufficient volume so that the  
combined 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 determination.  
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 confined  
space, but not less than 100 in.2 (645 cm2). One open-  
ing 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 minimum  
dimension of air openings shall be not less than 3 in.  
(76 mm) in any direction.  
Direct Vent  
If outside air is drawn through the intake pipe directly  
to the unit for combustion:  
1. Install combustion air direct vent in accordance  
with Fig. 24 (horizontal) or Fig. 25 (vertical) of  
this manual (pages 26 & 27 respectively).  
2. Provide adequate ventilation of the space occupied  
by the heater(s) by an opening(s) for ventilation air  
at the highest practical point communicating 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 outdoors 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 at least 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 non-  
operating hours.  
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  
shall communicate directly, or by ducts, with the  
outdoors or spaces (crawl or attic) that freely  
communicate with the outdoors.  
TruSeal™ Combustion Air  
In addition to the 3 previous steps, combustion air may  
be ducted directly to the heater by using PVC, CPVC  
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 sup-  
plied) equally positioned around the circumference of  
the duct. The screen assembly should be removed be-  
fore 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 damag-  
ing contaminants are present in the mechanical room.  
a. Where directly communicating with the out-  
doors or where communicating to the outdoors  
through vertical ducts, each opening 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.  
10  
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SECTION C: Installation  
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.  
minated 18 in. (450 mm) from the floor, but not  
near piping. This air supply opening requirement  
shall be in addition to the air opening for ventila-  
tion air required in 1. (above).  
WARNING: Care must be taken to ensure that the  
equipment room is not under negative pressure  
conditions.  
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  
opening shall directly communicate with the out-  
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:  
3. For heaters not using a barometric damper in the  
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 re-  
quired in 1., there shall be a permanent air supply  
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 may be under negative  
pressure conditions.  
Canadian Installations  
4. Refer to B149.1 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  
air at the highest practical point communicating  
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 (65  
cm2).  
The heater should be located so that any water leaks  
will not cause damage to the adjacent area or structures.  
CAUTION: This heater requires forced water circula-  
tion when the burner is operating. See Table F for  
minimum and maximum flow rates for water pump  
selection. The pump should be interlocked with the  
heater to prevent heater operation without water circu-  
lation.  
2. For heaters using a barometric damper in the vent  
system there shall be a permanent air supply open-  
ing(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 ter-  
NOTICE: Minimum pipe size for in/out connections is  
2 in. NPT for 503 and 753 models and 2-½ in NPT for  
1003 – 2003 models. Verify proper flow rates and T  
as instructed in this manual.  
11  
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SECTION C: Installation  
like a primary/secondary boiler installation with a by-  
pass acting as the secondary boiler piping. Raypak  
strongly recommends that thermometer(s) be placed  
into the heater piping next to the in/out header to facili-  
tate temperature adjustment. Inlet water temperatures  
below 120ºF (49ºC) can excessively cool the products  
of combustion, resulting in collection of condensate in  
the heat exchanger area beyond the capacity of the  
condensate evaporation system.  
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.  
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 testing  
of the piping connections to the heater and the rest of  
the system prior to operation. This is particularly true  
for hydronic systems using glycol-based antifreeze.  
Raypak recommends conducting the hydrostatic test  
before connecting gas piping or electrical supply.  
NOTE: Vent piping MUST contain a condensate  
drain which is installed according to the vent manufac-  
turer’s instructions and plumbed to an appropriate  
condensate management system (field supplied).  
Failure to reach or exceed 120ºF (49ºC) within 7 min-  
utes may damage or cause failure of the heat exchanger,  
combustion chamber, or other parts within the combus-  
tion chamber. It can cause operational problems, bad  
combustion, sooting, flue gas leakage and reduced ser-  
vice life of the vent system. A bypass allows part of the  
heater discharge water to be mixed with the cooler wa-  
ter returning to the heater inlet to increase the heater  
inlet temperature above 120ºF (49ºC). This precaution-  
ary measure should prevent the products of combustion  
from condensing 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 field-installed  
bleed valve open, fill heater with water. When wa-  
ter 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 us-  
ing high-point air vents. Close feed valve. Test at  
standard operating pressure for at least 24 hours.  
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 longer  
than 7 minutes or where cold water operation is con-  
tinuous, provisions must be made to mix higher  
temperature outlet water with the colder inlet water and  
thereby raise the inlet temperature to at least 120ºF  
(49ºC) within the 7-minute time limit.  
2. Make sure constant gauge pressure has been main-  
tained throughout test.  
3. Check for leaks. Repair if found.  
Cold Water Operation  
Cold Water Starts  
CAUTION: Damage due to internal condensation may  
occur if the heater inlet water temperature does not  
exceed 120˚F (49ºC) within 7 minutes of start-up.  
Cold water starts, wherein the inlet water temperature  
remains below 120ºF (49ºC) 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 with a bypass to raise the inlet to  
120ºF (49ºC) or higher. Once the system is heated up  
and has return water temperatures of 120ºF (49ºC) 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 outlet  
temperature may continue to climb and trip the high  
limit, thereby shutting down the heater. Thus an auto-  
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  
120ºF (49ºC).  
Heaters operated with an inlet temperature of less than  
120ºF (49ºC) MUST have a manual bypass (see Fig.  
14) or an approved low-temperature operation system  
to prevent problems with condensation. This piping is  
12  
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SECTION C: Installation  
matic valve system, such as a three-way proportional  
valve or a modulating two-way valve to control the  
bypass, should be utilized.  
temperature would be 130ºF. An injector pump ar-  
rangement may also be utilized to keep the heater loop  
at or above 120ºF (49ºC). 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.  
Fig. 7: Cold Water Start  
Fig. 8: Cold Water Run  
Cold Water Run  
Cold water run differs from cold water start in that the  
system water entering the heater remains below 120ºF  
(49ºC) continuously. Typically, this is the case in  
swimming pool heating and water source heat pump  
applications as well as some others. If the system water  
is kept in a narrow temperature range of no more than  
10ºF, a permanent manual bypass can be employed and  
manually adjusted to achieve an inlet temperature of  
120ºF (49ºC) or higher as adjusted at the minimum  
temperature in this narrow temperature range (i.e.  
Range 75ºF – 85ºF – adjust bypass with temperature at  
75ºF) so that when temperature is 85ºF, minimum inlet  
Temperature & Pressure Gauge  
The temperature and pressure gauge is shipped loose  
for field installation in the outlet piping.  
Min. Flow  
Max Flow  
20°FT  
30°FT  
40°FT  
Model  
No.  
gpm  
gpm  
gpm  
gpm  
25  
33  
43  
54  
65  
76  
87  
gpm  
100  
100  
113  
113  
113  
113  
116  
P (ft)  
2.8  
P (ft)  
1.4  
P (ft)  
N/A  
1.9  
P (ft) T  
P (ft) T  
503  
753  
44  
65  
29  
44  
N/A  
33  
1.1  
1.9  
35  
40  
40  
40  
40  
40  
40  
11.3  
13.8  
18.6  
22.2  
25.5  
27.2  
32.0  
9
6.4  
3.1  
13  
15  
19  
23  
27  
30  
1003  
1252  
1503  
1753  
2003  
87  
12.0  
20.9  
N/A  
N/A  
N/A  
58  
6.0  
43  
3.7  
3.7  
109  
N/A  
N/A  
N/A  
73  
10.2  
16.0  
22.5  
31.9  
54  
6.2  
6.2  
87  
65  
9.5  
9.5  
102  
116  
76  
13.4  
18.9  
13.4  
18.9  
87  
Notes: 1. Basis for minimum flow is T . Basis for maximum flow is gpm.  
Table F: Heater Rates of Flow and Pressure Drops  
13  
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SECTION C: Installation  
Hydronic Heating  
Three-Way Valves  
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.  
Pump Selection  
In order to ensure proper performance of your heater  
system, you must install a correctly-sized pump. Ray-  
pak recommends designing for a T within the range  
of 10°F to 40°F. See Table F for acceptable flow rates  
for each model (T is the temperature difference be-  
tween the inlet and outlet water when the heater is  
firing at full rate).  
Feedwater Regulator  
Raypak recommends that a feedwater regulator be in-  
stalled and set at 12 psi minimum pressure at the  
highest point of the system. Install a check valve or  
back flow device upstream of the regulator, with a  
manual shut-off valve as required by local codes.  
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). The 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.  
Fig. 10: Single Heater - Low-Temperature (Heat  
Pump) Application with Primary/Secondary Piping  
See Fig. 14 and instructions on page 16 for adjusting  
the manual bypass.  
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 recommended that  
the piping be insulated.  
Air-Separation/Expansion Tank  
All heaters should be equipped with a properly sized  
expansion tank and air separator fitting as shown in  
Fig. 9.  
Fig. 11: Dual Heaters (Reverse/Return)  
with Primary/Secondary Piping  
Domestic Hot 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.  
Fig. 9: Air-Separation/Expansion Tank  
14  
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SECTION C: Installation  
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, a means such  
as a mixing valve shall be installed to temper the  
water in order to reduce scald hazard potential.  
Pool Heating  
When a boiler or water heater is used in a pool heating  
application, ensure that all the following installation  
requirements are met.  
CAUTION: Power to the heater should be interlocked  
with the main system pump to ensure the heater does  
not fire without the main system pump in operation.  
Improper flow control can damage the heater. Uncon-  
trolled flow (too high) or restricted flow (too low) can  
seriously damage the heater. Follow these instructions  
to make sure your heater is properly installed.  
Fig. 12: Single Domestic Hot Water Heater and  
Storage Tank  
Potable Water and Space Heating  
CAUTION: When this heater is used for both potable  
water and space heating, observe the following to en-  
sure proper operation.  
The MVB must be equipped with a field-supplied ex-  
ternal pump and bypass arrangement. This arrangement  
blends outlet water with the inlet water to increase the  
inlet water temperature to a minimum of 120°F,  
thereby reducing the likelihood of condensation form-  
ing on the heat exchanger. The pump also serves to  
circulate water through the heater from the main sys-  
tem piping.  
1. All piping materials and components connected to  
the water heater for the space heating application  
shall be suitable for use with potable water.  
2. Toxic chemicals, such as used for boiler treatment,  
shall not be introduced into the potable water used  
for space heating.  
Soft (0-4 grains per gallon)  
gpm MTS SHL  
Medium (5-15 grains per gallon)  
Hard* (16-20 grains per gallon)  
Model  
No.  
gpm  
50  
MTS SHL  
gpm  
MTS SHL  
T  
P  
T  
17  
20  
20  
P  
3.6  
6.4  
T  
9
P  
503 17 50 3.6  
753 26 50 4.0  
2
2
5.9  
6.3  
2
2
5.9  
95  
10.4  
2
2
18.1  
22.2  
65  
10.2  
14.4  
24.6  
29.6  
31.3  
36.1  
13  
15  
19  
23  
27  
30  
100 13.8  
1003 30 58 6.0 2-1/2 7.2  
87  
12.0 2-1/2  
113 18.7 2-1/2 22.6  
113 22.3 2-1/2 26.3  
113 25.7 2-1/2 29.6  
113 27.4 2-1/2 31.3  
116 32.0 2-1/2 36.1  
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  
109 21.0 2-1/2  
113 25.7 2-1/2  
113 27.4 2-1/2  
116 32.0 2-1/2  
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 25 ft of tubing)  
gpm = Gallons per minute, flow rate  
MTS = Minimum tubing size  
* Must use optional cupro-nickel tubes. If over 20 grains per gallon, a water softening system must also be used.  
Table G: Domestic Water Heater Flow Rate Requirements  
15  
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SECTION C: Installation  
To complete the installation of the pool heater, the pool  
thermostat needs to be installed in the main return wa-  
ter line, upstream of the heater. This will ensure that  
the heater will be energized at the right time.  
Fig. 14: “H” Bypass Setting  
Automatic Chlorinators and Chemical  
Feeders  
Fig. 13: 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 and a system supply water  
temperature below 140°F. When starting with a cold  
pool, make initial adjustments. Make final adjustments  
when pool water approaches desired temperature.  
CAUTION: Combustion air must not be contaminated  
by corrosive chemical fumes which can damage the  
heater and void the warranty.  
All chemicals must be introduced and completely di-  
luted into the pool or spa water before being circulated  
through the heater. Do not place chlorine tablets or  
bromine sticks in the skimmer. High chemical concen-  
trations will result when the pump is not running (e.g.  
overnight).  
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:  
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.  
1. Turn on pump.  
2. Turn on heater and wait until heater goes to full  
fire.  
NOTICE: High chemical concentrates from feeders  
and chlorinators that are out of adjustment will cause  
very rapid corrosion of the heat exchanger in the heater.  
Such damage is not covered under the warranty.  
3. With the heater operating at 100% firing rate, set  
Valve A (the bypass) to ½ open position, and  
Valve B to fully open position.  
Winterizing Your Heater  
4. Adjust Valve A until the inlet water temperature is  
120°F. NOTE: Opening the valve will increase  
the temperature and closing the valve will decrease  
the temperature.  
Heaters installed outdoors as pool heaters in freezing  
climate areas should be shut down for the winter. To  
shut 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.  
5. If this process does not raise the inlet water tem-  
perature to 120°F and Valve A is fully open, then  
slowly throttle Valve B closed to increase the inlet  
water temperature to 120°F.  
16  
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SECTION C: Installation  
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.  
Total Dissolved Solids  
Total dissolved solids (TDS) is the measure of all min-  
erals and solids that are dissolved in the water. The  
concentration of total dissolved solids is usually ex-  
pressed in parts per million (ppm) as measured in a  
water sample. Water with a high TDS concentration  
will greatly accelerate lime and scale formation in the  
hot water system. Most high TDS concentrations will  
precipitate out of the water when heated. This can gen-  
erate a scale accumulation on the heat transfer surface  
that will greatly reduce the service life of a water  
heater. This scale accumulation can also impede ade-  
quate flow of water and may totally block the water  
passages in the tubes of the heat exchanger. A heat  
exchanger that is damaged or blocked by lime/scale  
accumulation must be replaced. Failure of a water  
heater due to lime scale build up on the heating surface  
is non-warrantable. The manufacturer of the water  
heater has no control of the water quality, especially  
the TDS levels in your system. Total dissolved solids  
in excess of 2,500 ppm will accelerate lime and scale  
formation in the heat exchanger. Heat exchanger fail-  
ure due to total dissolved solids in excess of 2,500 ppm  
is a non-warrantable condition. Raypak offers basic  
temperature guidelines for operation of a potable water  
heater on normal to moderate levels of hardness and  
solids but levels of hardness and total dissolved solids  
beyond normal limits for operation will require special  
setup and operation.  
Pool/Spa Water Chemistry  
NOTICE: Chemical imbalance can cause severe dam-  
age to your heater and associated equipment.  
Water Hardness  
Water hardness is mainly due to the presence of cal-  
cium and magnesium salts dissolved in the water. The  
concentration of these salts is expressed in mg/l, ppm  
or grains per gallon, as a measure of relative hardness  
of water. Grains per gallon is the common reference  
measurement used in the U.S. water heater industry.  
Hardness expressed as mg/L or ppm may be divided by  
17.1 to convert to grains per gallon. Water may be  
classified as very soft, slightly hard, moderately hard or  
hard based on its hardness number. The salts in water  
will precipitate out when the water is heated and will  
cause accelerated lime and scale accumulation on a  
heat transfer surface.  
Raypak water heaters can operate lime/scale-free using  
potable water with a hardness not exceeding 20 grains  
per gallon. Proper operation is achieved by setting the  
temperature rise/water flow per the guidelines in the  
installation instructions. If the hardness of the water  
exceeds the maximum level of 20 grains per gallon  
special measures must be taken to adjust flow and tem-  
perature rise. Water should be softened to a hardness  
level no lower than 5 grains per gallon. Water softened  
as low as 0 to 1 grain per gallon may be under-  
saturated with respect to calcium carbonate resulting in  
water that is aggressive and corrosive.  
NOTICE: Failure of a heat exchanger due to lime scale  
build-up on the heating surface, low pH or other  
chemical imbalance is non-warrantable.  
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.  
pH of Water  
pH is a measure of relative acidity, neutrality or alka-  
linity. Dissolved minerals and gases affect water’s pH.  
The pH scale ranges from 0 to 14. Water with a pH of  
7.0 is considered neutral. Water with a pH lower than 7  
is considered acidic. Water with a pH higher than 7 is  
considered alkaline. A neutral pH (around 7) is desir-  
able for most potable water applications. Corrosion  
damage and water heater failures resulting from water  
pH levels of lower than 6 or higher than 8 are non-  
warrantable. The ideal pH range for water used in a  
storage tank or a copper water heater system is 7.2 to  
7.8.  
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 adjacent 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 H for maximum pipe lengths.  
17  
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SECTION C: Installation  
1” NPT  
1-1/4” NPT  
1-1/2” NPT  
2” NPT  
2-1/2” NPT  
Model  
No.  
N
15  
5
P
N
65  
P
N
130  
75  
P
N
P
N
P
503  
753  
35  
150  
100  
55  
360  
180  
90  
N/A  
250  
125  
85  
N/A  
N/A  
300  
225  
150  
110  
90  
N/A  
N/A  
300  
200  
150  
115  
85  
N/A  
N/A  
N/A  
300  
275  
230  
210  
15  
65  
1003 N/A  
1253 N/A  
1503 N/A  
1753 N/A  
2003 N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
35  
35  
15  
25  
25  
60  
10  
15  
15  
25  
60  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
45  
35  
Natural Gas – 1,000 BTU/ft3, 0.60 specific gravity at 0.5 in. WC pressure drop  
Propane Gas – 2,500 BTU/ft3, 1.53 specific gravity at 0.6 in. WC pressure drop  
Table H: Maximum Equivalent Pipe Length  
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 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).  
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.  
The heater must be isolated from the gas supply piping  
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 reconnecting the heater and its manual shut-off  
valve to the gas supply line. FAILURE TO FOL-  
LOW THIS PROCEDURE MAY DAMAGE THE  
GAS VALVE. Over-pressurized gas valves are not  
covered by warranty. The heater and its gas connec-  
tions shall be leak-tested before placing the appliance  
in operation. Use soapy water for leak test. DO NOT  
use an open flame.  
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 pres-  
sure exceeds these values, an intermediate gas pressure  
regulator, of the lockup type, must be installed.  
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.  
The gas valve pressure regulator on the heater is nomi-  
nally preset as noted in Table I.  
Fig. 15: Gas Supply Connection  
18  
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SECTION C: Installation  
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.  
Manifold Gas Pressure  
(High Fire Values)  
Model  
No.  
Natural Gas  
-0.1  
Propane Gas  
-0.1  
503  
753  
-0.1  
-0.2  
-0.1  
-0.3  
0.4  
-0.1  
-0.2  
-0.1  
-0.4  
0.4  
1003  
1253  
1503  
1753  
2003  
0.6  
0.6  
NOTE: Manifold pressures should be + 0.2” WC.  
Table I: Manifold Gas Pressure Settings  
During normal operation, carbon dioxide should be 8.0  
to 9.0% at full fire for natural gas and between 9.0 and  
10.0% for propane gas. Carbon monoxide should be  
‹100ppm.  
Fig. 16: Rear Wiring Box Electrical Connections  
All field wiring connections to the MVB heater are  
made inside the rear wiring box as shown in Fig. 16.  
Pump power should be taken from terminals 2 (Com),  
3 (GND) and 6 (Hot) – ¾ hp and smaller ONLY.  
Power to the MVB heater should be connected to ter-  
minals 1, 2, and 3 as noted in Fig. 16. Sensors,  
interlocks, Enable/disable, and various options are  
wired into terminals 1 – 12 as noted in Fig. 16.  
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.  
Safety wiring must be NEC Class 1.  
Heater must be electrically grounded as required by  
the NEC.  
Field-Connected Controllers  
It is strongly recommended that all individually-  
powered control modules and the heater should be sup-  
plied from the same power source.  
In Canada, CSA C22. 1 C.E.C. Part 1.  
The MVB 503-1503 heaters are wired for 120 VAC, 12  
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.  
NOTICE: Field-supplied isolation relays should be  
installed when field-connected controllers are mounted  
more than 50 equivalent feet (18 Ga) from heater.  
Check the Power Source  
Boiler mounted pumps (up to ¾ hp) get their power  
supply directly from the boiler power supply (connec-  
tions in rear wiring box). Install a circuit breaker sized  
sufficiently for both the heater and the pump. Pumps  
larger than ¾ hp must use a separate power supply and  
run the power through the optional pump contactor  
which is located in the rear wiring box (see Fig. 16).  
Use appropriately-sized wire as defined by NEC, CSA  
and/or local codes. All primary wiring should be 125%  
of minimum rating.  
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. 17.)  
19  
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SECTION C: Installation  
proper electrical installation are not covered by  
warranty.  
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 appli-  
cable manufacturers’ instructions.  
7. Conduit should not be used as the earth ground.  
A
B
C
NOTICE: 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.  
Fig. 17: Wiring Connections  
Check the power source:  
AC = 108 VAC Minimum, 132 VAC MAX  
AB = 108 VAC Minimum, 132 VAC MAX  
BC = <1 VAC Maximum  
Field Wiring Connection  
CAUTION: Label all wires prior to disconnection  
when servicing controls. Wiring errors can cause im-  
proper and dangerous operation. Verify proper  
operation after servicing.  
DANGER: SHOCK HAZARD  
Make sure electrical power to the heater is discon-  
nected to avoid potential serious injury or damage to  
components.  
Fig. 18: Multi-meter  
Making the Electrical Connections  
Refer to Fig. 16-19.  
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.  
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.  
Fig. 19: Wiring Location  
4. Observe proper wire colors while making electri-  
cal connections. Many electronic controls are  
polarity sensitive. Components damaged by im-  
20  
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SECTION C: Installation  
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 neutrali-  
zation before disposal, as required by local codes.  
Venting  
CAUTION: Proper installation of flue venting is criti-  
cal for the safe and efficient operation of the heater.  
General  
Appliance Categories  
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 IV vent system. Using im-  
proper venting materials can result in personal injury,  
death or property damage.  
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-  
positive vent static pressure and with a vent gas tem-  
perature that avoids excessive condensate production in  
the vent.  
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) or Z-Flex  
(800-654-5600). Pipe joints must be positively sealed.  
Follow the vent manufacturer’s installation instructions  
carefully.  
Category II – A heater which operates with a non-  
positive vent static pressure and with a vent gas tem-  
perature 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.  
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.  
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.  
See Table J for appliance category requirements.  
Use insulated vent pipe spacers where the vent passes  
through combustible roofs and walls.  
Note: For additional information on appliance catego-  
rization, see appropriate ANSI Z21 Standard and the  
NFGC (U.S.), or B149.1 (Canada), or applicable provi-  
sions of local building codes.  
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 J: Venting Category Requirements  
21  
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SECTION C: Installation  
Vent Terminal Location  
U.S. Installations  
NOTICE: During winter months check the vent cap  
and make sure no blockage occurs from build-up of  
snow or ice.  
Refer to the latest edition of the National Fuel Gas  
Code.  
Vent termination requirements are as follows:  
1. Condensate can freeze on the vent cap. Frozen  
condensate on the vent cap can result in a blocked  
flue condition.  
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.  
2. Give special attention to the location of the vent  
termination to avoid possibility of property dam-  
age or personal injury.  
2. The vent must not be less than 7 ft above grade  
when located adjacent to public walkways.  
3. Terminate vent at least 3 ft above any forced air  
inlet located within 10 ft.  
3. Gases may form a white vapor plume in winter.  
The plume could obstruct a window view if the  
termination is installed near windows.  
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.  
4. Prevailing winds, in combination with below-  
freezing temperatures, can cause freezing of con-  
densate and water/ice build-up on buildings, plants  
or roofs.  
5. Terminate vent at least 6 ft away from adjacent  
walls.  
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. DO NOT terminate vent closer than 5 ft below  
roof overhang.  
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. The vent terminal requires a 12 in. vent terminal  
clearance from the wall.  
8. Terminate vent at least 1 ft above grade, including  
normal snow line.  
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 cre-  
ate a nuisance or hazard or could be detrimental to  
the operation of regulators, relief valves, or other  
equipment.  
9. Multiple direct vent installations require a 4 ft  
clearance between the ends of vent caps located on  
the same horizontal plane.  
Canada Installations  
8. Locate and guard vent termination to prevent acci-  
dental contact by people or pets.  
Refer to latest edition of B149.1.  
A vent shall not terminate:  
9. DO NOT terminate vent in window well, stairwell,  
alcove, courtyard or other recessed area.  
1. Directly above a paved sidewalk or driveway  
which is located between two single-family dwell-  
ings and serves both dwellings.  
10. DO NOT terminate above any door, window, or  
gravity air intake. Condensate can freeze, causing  
ice formations.  
2. Less than 7 ft (2.13 m) above a paved sidewalk or  
paved driveway located on public property.  
11. Locate or guard vent to prevent condensate from  
damaging exterior finishes. Use a rust-resistant  
sheet metal backing plate against brick or masonry  
surfaces.  
3. Within 6 ft (1.8 m) of a mechanical air supply inlet  
to any building.  
4. Above a meter/regulator assembly within 3 ft (0.9  
m) horizontally of the vertical centre-line of the  
regulator.  
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.  
22  
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SECTION C: Installation  
5. Within 6 ft (1.8 m) of any gas service regulator  
vent outlet.  
Vertical Venting (Category IV)  
CAUTION: This venting system requires the installa-  
tion 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.  
6. Less than 1 ft (305 mm) above grade level.  
7. Within 3 ft (0.9 m) of a window or door which can  
be opened in any building, any non-mechanical air  
supply inlet to any building or the combustion air  
inlet of any other appliance.  
Installation  
The maximum and minimum venting length for this  
Category IV appliance shall be determined per the  
NFGC (U.S.) or B149.1 (Canada).  
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).  
The diameter of vent flue pipe should be sized accord-  
ing to Part 11 of the NFGC (U.S.) and Part 7 and  
Appendix B of B149.1 (Canada). The minimum flue  
pipe diameter for conventional venting using Category  
IV, stainless steel AL29-4C vent is: 6 in. for Models  
503-1003; and 8 in. for Models 1253-2003.  
Venting Installation Tips  
Support piping:  
NOTICE: A vent adapter (field-supplied) may be re-  
quired to connect the Category IV vent to the heater.  
horizontal runs - at least every 5 ft  
vertical runs - use braces  
under or near elbows  
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 terminal.  
The horizontal portions of the vent shall also be sup-  
ported for the design and weight of the material  
employed to maintain clearances and to prevent physi-  
cal damage or separation of joints.  
WARNING: Examine the venting system at least once  
a year. Check all joints and vent pipe connections for  
tightness, corrosion or deterioration.  
Venting Configurations  
For heaters connected to gas vents or chimneys, vent  
installations shall be in accordance with Part 7, Venting  
of Equipment, of the NFGC (U.S.), or B149.1 (Canada),  
or applicable provisions of local building codes.  
Vertical Vent  
Height1(Ft)  
Air Inlet  
Max. Length** (Ft)  
Certified  
Vent  
Material  
Combustion Air  
Intake Pipe  
Material  
Vent Size  
(in.)  
Model  
Min.  
Max.  
15*  
75  
6” Ø 8” Ø 10” Ø  
503  
753  
6
8
45  
100  
45  
N/A  
85  
Galvanized Steel,  
PVC,  
1003  
1253  
1503  
1753  
2003  
75  
Category IV  
(AL29-4C)  
40  
0
ABS,  
CPVC  
75  
N/A  
75  
75  
*
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.  
Vent lengths are based on a lateral length of 2 ft. Refer to the latest edition of the NFGC for further details.  
1
** Subtract 10 ft per elbow. Max. 4 elbows.  
Table K: Category IV Vertical Venting  
23  
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SECTION C: Installation  
Termination  
Common Venting  
The vent terminal should be vertical and should termi-  
nate outside the building at least 2 ft above the highest  
point of the roof 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 horizontal dis-  
tance 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 B149.1 (Can-  
ada). Gas vents supported only by flashing and  
extending above the roof more than 5 ft should be se-  
curely braced to withstand snow and wind loads.  
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 L provides boiler discharge vent pressures  
at vent pressure switch and volumes of flue products at  
full fire for the calculation of appropriate vent sizing  
for common venting.  
WARNING: Vent connectors serving any other appli-  
ances 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.  
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 heaters.  
NOTE: For extractor sizing, typical CO2 levels are  
8.5% for natural gas and 9.5% for LP gas and flue tem-  
perature 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
1003  
1253  
1503  
1753  
2003  
* NOTE: Data for 100% firing rate.  
Table L: Vent Pressure and Volume of  
Flue Products Data  
Fig. 20: Vertical Venting  
24  
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SECTION C: Installation  
Fig. 21: Typical Common Venting  
Horizontal Through-the-Wall Direct  
Venting (Category IV)  
Fig. 23: 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.  
Fig. 22: Horizontal Through-the-Wall Venting  
25  
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SECTION C: Installation  
installed horizontally through the wall to the outdoors.  
Adequate combustion and ventilation air must be sup-  
plied to the equipment room in accordance with the  
NFGC (U.S.) or B149.1 (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 arrange-  
ments:  
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.  
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:  
Fig. 24: Horizontal Through-the-Wall Direct Venting  
CAUTION: This venting system requires the installa-  
tion 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.  
1. The vent must be installed with a condensate drain  
located in proximity to the heater as directed by  
the vent manufacturer.  
Installation  
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.  
These installations utilize the heater-mounted blower to  
vent the combustion products to the outdoors. Com-  
bustion air is taken from inside the room and the vent is  
Horizontal  
Vent Length (Ft)*  
Air Inlet  
Max. Length (Ft) **  
Combustion Air  
Intake Pipe  
Material  
Certified Vent Vent Size  
Model  
Material  
(in.)  
Min.  
Max.  
6”Ø 8” Ø 10” Ø  
503  
753  
6
45  
100  
N/A  
85  
Galvanized Steel,  
PVC,  
1003  
1253  
1503  
1753  
2003  
Category IV  
(AL29-4C)  
0
75  
ABS,  
CPVC  
N/A 45  
8
* 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.  
Table M: Category IV Horizontal Vent & Horizontal Direct Vent  
26  
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SECTION C: Installation  
3. The vent must be insulated through the length of  
the horizontal run.  
arrangement that does not exceed the lengths shown in  
Table K.  
The vent cap is not considered in the overall length of  
the venting system.  
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.  
Care must be taken during assembly that all joints are  
sealed properly and are airtight.  
The vent must be installed to prevent the potential ac-  
cumulation 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.  
WARNING: No substitutions of flue pipe or vent cap  
material are allowed. Such substitutions would jeopard-  
ize the safety and health of inhabitants.  
2. The vent must be installed with a slight upward  
slope of not more than 1/4 inch per foot of hori-  
zontal run to the vent terminal.  
Direct Vent - Vertical  
3. The vent must be insulated through the length of  
the horizontal run.  
Termination  
The vent cap MUST be mounted on the exterior of the  
building. The vent cap cannot be installed in a well or  
below grade. The vent cap must be installed at least 1 ft  
above ground level and above normal snow levels.  
The vent cap MUST NOT be installed with any com-  
bustion air inlet directly above a vent cap. This vertical  
spacing would allow the flue products from the vent  
cap to be pulled into the combustion air intake installed  
above.  
This type of installation can cause non-warrantable  
problems with components and poor operation of the  
heater due to the recirculation of flue products. Multi-  
ple vent caps installed in the same horizontal plane  
must have a 4 ft clearance from the side of one vent  
cap to the side of the adjacent vent cap(s).  
Fig. 25: Direct Vent - Vertical  
CAUTION: This venting system requires the installa-  
tion 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.  
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.  
Installation  
WARNING: No substitutions of flue pipe or vent cap  
material are allowed. Such substitutions would jeopard-  
ize the safety and health of inhabitants.  
These installations utilize the heater-mounted blower to  
draw combustion air from outdoors and vent combus-  
tion products to the outdoors.  
The stainless steel flue direct vent cap must be fur-  
nished by the heater manufacturer in accordance with  
its listing (sales order option D-15).  
The total length of air supply pipe cannot exceed the  
distances listed in Table K. Each elbow used is equal to  
10 ft of straight pipe. This will allow installation in any  
27  
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SECTION C: Installation  
Outdoor Installation  
Outdoor models are self-venting when installed with  
the optional factory-supplied outdoor vent kit. Addi-  
tional vent materials are required as outlined in the  
Outdoor Vent Kit instructions. A special vent cap and  
air intake elbow are offered in accordance with CSA  
requirements. These must be installed directly on the  
vent pipe as illustrated in Fig. 26.  
Care must be taken when locating the heater outdoors,  
because the flue gases discharged from the vent cap  
can condense as they leave the cap. Improper location  
can result in damage to adjacent structures or building  
finish. For maximum efficiency and safety, the follow-  
ing precautions must be observed:  
1. Outdoor models must be installed outdoors. They  
must use the outdoor vent cap and air intake elbow  
available from the manufacturer (sales order op-  
tion D-11).  
Fig. 26: Outdoor Venting  
2. Periodically check the venting system. The  
heater’s venting areas must never be obstructed in  
any way and minimum clearances must be ob-  
served to prevent restriction of combustion and  
ventilation air. Keep area clear and free of com-  
bustible and flammable materials.  
Freeze Protection  
When installing this heater in an outdoor location that  
is susceptible to freezing, sales option B-22 should be  
installed to energize the heater pump at a present out-  
door air temperature and circulate water to reduce the  
possibility of freezing and damage to the heat ex-  
changer or headers.  
3. Do not locate adjacent to any window, door walk-  
way, or gravity air intake. The vent must be  
located a minimum of 4 ft horizontally from such  
areas.  
Controls  
4. Install above grade level and above normal snow  
levels.  
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.  
5. Vent terminal must be at least 3 ft above any  
forced air inlet located within 10 ft.  
6. Adjacent brick or masonry surfaces must be pro-  
tected with a rust-resistant sheet metal plate.  
WARNING: Turn off the power to the heater before  
installation, adjustment or service of any heater con-  
trols. Failure to do so may result in heater malfunction,  
property damage, personal injury, or death.  
NOTICE: Condensate can freeze on the vent cap. Fro-  
zen condensate on the vent cap can result in a blocked  
flue condition.  
NOTICE: The vent cap and air intake hood must be  
furnished by the heater manufacturer in accordance  
with its listing (sales order option D-11).  
CAUTION: This appliance has provisions to be con-  
nected to more than one supply source. To reduce the  
risk of electric shock, disconnect all such connections  
before servicing.  
CAUTION: Risk of electric shock: More than one  
disconnect switch may be required to de-energize the  
equipment before servicing.  
28  
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SECTION C: Installation  
The Raypak modulating temperature control is pro-  
vided to maintain the desired system water temperature.  
The control has various modes of operation which are  
listed below.  
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)  
Operating Modes  
BOIL OUT - Actual heater outlet water temperature  
BOIL START - Starting boiler water temperature  
BOIL SUP - Actual system supply water temperature  
Mode 1 – Setpoint operation using parallel piping. The  
heater outlet water temperature is controlled to the  
boiler target setpoint.  
Mode 2 – Setpoint operation using primary / secondary  
piping. The control modulates the heater to satisfy a  
remote header sensor. The heater is turned off based on  
boiler max and boiler differential (factory default H7  
boilers).  
BOIL TARGET - Target temperature that the heater is  
trying to maintain  
‘BURNER’ DELAY - Heater delay from the start of  
the ignition sequence until it fires  
DIFF - The operating differential of the heater; The  
heater outlet water temperature is allowed to rise above  
the BOIL TARGET temperature by 1/2 of this differ-  
ential before the heater shuts off  
Mode 3 – Dedicated DHW operation using parallel  
piping. A call for heat is determined by the DHW sen-  
sor. The heater outlet water is controlled to the boiler  
target temperature (factory default WH7 water heaters).  
MODE - Operating mode of the heater  
Mode 4 – Outdoor reset and reset override operation  
using parallel piping. The heater is operated as in Mode  
1. However the target temperature is based on outdoor  
reset. The outdoor reset temperature can be remotely  
overridden.  
OUTDR - Outdoor air temperature  
OUTDR DESIGN - Design outdoor air temperature  
used in the heat loss calculation  
Mode 5 – Outdoor reset and reset override operation  
using primary/secondary piping. The heater is operated  
as in Mode 2. However, the target temperature is based  
on outdoor reset. The outdoor reset temperature can be  
remotely overridden.  
OUTDR START - Starting outdoor air temperature  
PUMP DLY - Sets the operating time of the pump  
once the CFH is satisfied  
TANK -Current DHW tank temperature (Mode 3)  
Mode 6 – This mode is used for remote control mode.  
The Boil Max setting is the heater shutdown tempera-  
ture.  
TANK DIFF - Storage tank differential (Mode 3)  
TANK TARGET - Target temperature in the DHW  
storage tank (Mode 3)  
Definitions  
UNITS - Selects the temperature units to be displayed  
(oF or oC). For example, if the heater target temperature  
is set to 160°F and the differential is set to 10°F, on  
temperature rise, the heater will shut off at 165oF.  
Once the heater shuts off, it will not come on again  
until the temperature falls to 155oF.  
The following items are common to Modes 1 thru 5.  
They are not required for Mode 6 – the mode for exter-  
nal heater control.  
% OUT - Current percent modulation rate of heater  
BOIL DSGN - Design boiler water temperature used  
in heat loss calculations  
WWSD - Selects the outdoor temperature that shuts  
the heater off, no matter what the demand. NOTE: The  
WWSD segment is displayed on the LCD.  
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  
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  
BOIL MAX - Highest outlet water temperature that  
the control is allowed to use as a target temperature  
29  
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SECTION C: Installation  
system operation by means of three push buttons (Item,  
,). Item advances the display, while ,are used  
in the adjust menu.  
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 dis-  
played. Pressing the scroll button “scrolls” through the  
displayed values in the “VIEW” menu.  
Fig. 27: Modulating Temperature Control  
User Interface  
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.  
When the modulating temperature control is powered  
up, the control turns on all segments in the display for  
Fig. 28: Modulating Temperature Control Display  
Default  
Item  
Modes  
Range  
Boiler  
Water Heater  
BOIL TARGET  
1, 2  
3
4, 5  
140 ºF  
---  
180 ºF  
---  
160 ºF  
---  
OFF, 70 – 220 ºF  
OFF, 70 – 200 ºF  
OFF, 70 – 220 ºF  
BOIL MAX  
1, 2, 4, 5, 6  
3
200 ºF  
---  
---  
180 ºF  
120 – 225 ºF, OFF  
120 – 200 ºF, OFF  
BOIL MIN  
1 - 5  
1 - 5  
1 - 5  
1 - 5  
3
135 ºF  
1:30  
1
135 ºF  
1:30  
1
OFF, 80 – 180 ºF  
0:00 to 3:00 Min.  
1 (Low), 2 (Med), 3 (High)  
2 – 42 ºF  
‘BURNER’ DELAY  
BOIL MASS  
DIFF  
10 ºF  
---  
10 ºF  
120 ºF  
5 ºF  
3:00  
---  
TANK TARGET  
TANK DIFF  
PUMP DLY  
OUTDR START  
OUTDR DSGN  
BOIL START  
BOIL DSGN  
WWSD  
OFF, 70 – 190 ºF  
2 – 10 ºF  
3
---  
All  
4, 5  
4, 5  
4, 5  
4, 5  
4, 5  
All  
---  
3:00  
70 ºF  
-10 ºF  
135 ºF  
180 ºF  
70 ºF  
ºF  
OFF, 0:20 to 9:55 Min., ON  
35 – 85 ºF  
---  
-40 – 32 ºF  
---  
35 – 150 ºF  
---  
70 – 220 ºF  
---  
35 – 100 ºF, OFF  
ºF or ºC  
UNITS  
ºF  
MODE  
2
3
1, 2, 3, 4, 5, 6  
Table N: Modulating Temperature Control Default Setpoints  
30  
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SECTION C: Installation  
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, simultaneously press  
and hold all three buttons for 1 second. The menu  
name, “ADJUST” will be displayed in the menu field.  
6. A 24 VAC signal is sent from the NO contacts of  
the Low Water Cut Off to the common terminal of  
the Blocked Vent Switch.  
During a blocked vent condition a 24 VAC signal  
is sent from the NO open contacts of the Blocked  
Vent Switch to pin P3-5 of the UDB board to indi-  
cate a safety fault.  
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 or button to make the adjustment.  
7. During normal operation of the heater the 24 VAC  
signal exits the NC contacts of the Blocked Vent  
Switch and is sent to the common terminal, of the  
Low Gas Pressure Switch (if equipped).  
In the absence of other information, the values pro-  
vided in Table N should be used as default settings.  
During a low gas pressure condition 24 VAC is  
sent from the NC contacts of the Low Gas Pres-  
sure Switch to pin P3-6 of the UDB board to  
indicate a safety fault.  
Heater Sequence of Operation  
Model 503 - 1503  
1. The black (hot) wire lead, located at the right-  
middle front inside the control compartment, goes  
directly to the main power switch.  
8. 24 VAC is sent from the NO contacts of the Low  
Gas Pressure Switch to the common terminal of  
the High Gas Pressure Switch (if equipped).  
2. When the main power switch is placed in the  
“ON” position, the 120 VAC terminal block in the  
control compartment, the N.O. contacts of pump  
relay, the N.O. contacts of blower relay, the  
120/24 VAC transformer, and terminals L1 and F1  
of the ignition module are powered.  
During a high gas pressure condition 24 VAC is  
sent from the NO contacts of the High Gas Pres-  
sure Switch to pin P3-7 of the UDB board to  
indicate a safety fault.  
9. 24 VAC is sent from the NC contacts of the High  
Gas Pressure Switch to the common terminal of  
the Auto Reset High Limit (if equipped) and to en-  
ergize the coil of optional alarm relay.  
3. The 120/24 VAC transformer sends a 24 VAC hot  
power signal to the 24V Terminal Block .  
4. 24 VAC is sent from the 24V Terminal Block to  
the NO pump contacts on the modulating tempera-  
ture control (pin #13), to pin TP2 of the optional  
alarm relay, to terminal R of the alarm circuit on  
the modulating temperature control (pin #24) and  
the green “Power On” LED on the front of the  
heater will illuminate.  
If the Auto Hi Limit opens, 24 VAC is sent from  
the NO contacts of the Auto Hi Limit to pin P3-3  
of the UDB board to indicate a safety fault.  
10. 24 VAC is sent from the NC contacts of the Auto  
Reset Hi Limit to the common terminal of time de-  
lay relay.  
5. 24 VAC power is sent from 24V Terminal Block  
to Pin P1-1 of the UDB board, the 24 VAC termi-  
nal of the ignition control module, the NC contact  
of the manual high limit, and L1 of the Low Water  
Cut Off (if equipped).  
11. 24 VAC is sent from the NC contacts of time delay  
relay to the common terminal of the burner switch  
located on the front exterior panel of the heater.  
12. Power then travels to the enable/disable connec-  
tion and to the Ht D (heat demand) connection of  
the modulating temperature control.  
24 VAC is sent from the NC contacts of the man-  
ual high limit to pin P3-1 & P3-2 of the UDB  
board.  
Power splits from the enable/disable and goes to  
the stage contact of the modulating temperature  
control (pin #15).  
Upon loss of water in the heater, the Low Water  
Cut Off (if equipped) will send a 24 VAC signal to  
pin P3-4 of the UDB board to indicate a safety  
fault.  
13. When the stage contact closes on the modulating  
temperature control, 24 VAC is sent to the com-  
mon terminal of the flow switch and to pin P1-3  
31  
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SECTION C: Installation  
(CFH) of the UDB board. In addition, the amber  
“Call-for-Heat” LED on the front of the heater will  
illuminate.  
contacts of the air pressure switch to pin P4-10 of  
the UDB board to indicate insufficient air pressure.  
When the 24 VAC signal is sent to P4-10 the same  
signal then de-energizes the coil of the time delay  
relay to remove a heat demand from the modulat-  
ing temperature control and restart the ignition  
sequence after the 5 second time delay.  
14. The pump contact on the modulating temperature  
control closes sending 24 VAC to the pump switch  
located on the front exterior panel of the heater.  
15. When the pump switch is closed, 24 VAC is sent  
to the coil of the pump relay.  
21. After receiving 24 VAC at the heater interlock,  
power then travels to the P Switch terminal of the  
ignition module.  
16. The pump relay energizes and closes the contacts,  
starting the heater pump.  
The ignition module employs a 15 second pre-  
purge before the next sequence.  
17. Upon sufficient flow, the flow switch closes and  
sends 24 VAC to the common terminal of the air  
pressure switch, TH terminal of the ignition mod-  
ule, coil of the ignition lockout relay and the NO  
contacts of the ignition lockout relay.  
22. After 15 seconds of combustion chamber pre-  
purge, pin S1 sends 120 VAC to the Hot Surface  
Igniter.  
If the flow switch does not close, a 24 VAC signal  
is sent to pin P4-9 of the UDB board to indicate an  
insufficient flow condition.  
23. The Hot Surface Igniter will be energized for ap-  
proximately 30 seconds and must exceed 3.1 amp  
draw during heat up.  
When the 24 VAC signal is sent to P4-9 the same  
signal then de-energizes the coil of time delay re-  
lay to remove a heat demand from the modulating  
temperature control and restart the ignition se-  
quence after the 5 second time delay.  
24. Once the ignition module determines the proper  
operation of the Hot Surface Igniter, a 24 VAC  
signal is output from the Valve pin on the module  
to energize the gas valve.  
25. The gas valve is energized and the blue “Burner  
On” LED on the front of the heater energizes.  
Upon ignition lockout, the module energizes the  
ignition lockout relay and sends a 24 VAC signal  
to pin P4-12 (ignition lockout) of the UDB board.  
26. The remote sensor is now trying to rectify the  
flame. If the flame is not rectified within 4 seconds,  
the ignition module will shut down the gas valve  
and lock out.  
18. When 24 VAC is received at TH on the ignition  
module, the contacts between pins F1 and F2 close  
and send 120 VAC to pin 1 of the blower relay.  
27. When burner flame is rectified, the gas valve will  
remain at 50% fire for the remainder of the ninety  
(90) second delay after the CFH was initiated and  
then modulate in relationship to the output signal  
to the combustion air blower from the modulating  
temperature control.  
19. The coil of the blower relay energizes closing the  
NO contacts sending 120 VAC to energize the  
combustion air blower motor.  
The combustion air blower will operate at 50% of  
capacity for approximately ninety (90) seconds be-  
fore the modulating signal from the modulating  
temperature control will control the fan speed in  
relationship to the system water temperature.  
28. When the CFH is satisfied, the heater will return to  
a standby condition awaiting the next CFH.  
Model 1753 – 2003  
20. Once sufficient air pressure is achieved in the  
heater and the air pressure switch closes the NO  
contacts, 24 VAC is sent to the heater interlock  
connection on the ignition module.  
1. The black (hot) wire lead, located at the right-  
middle front inside the control compartment, goes  
directly to the main power switch.  
2. When the main power switch is placed in the  
“ON” position, the 120 VAC terminal block in the  
control compartment, the N.O. contacts of the  
If air pressure is insufficient or lost during heater  
operation a 24 VAC signal is sent from the NC  
32  
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SECTION C: Installation  
pump relay and the blower receives power but  
does not energize at this time and terminal L1 the  
ignition module is powered.  
sure Switch to Pin P3-7 of the UDB board to  
indicate a safety fault.  
8. 24 VAC is sent from the NC contacts of the High  
Gas Pressure Switch to energize the alarm relay  
coil and to the common terminal of the Auto Reset  
High Limit (if equipped).  
3. The 120/24 VAC transformer sends a 24 VAC hot  
power signal to the 24V Terminal Block.  
4. 24 VAC is sent from the 24V Terminal Block to  
pin L1 of the Low Water Cut Off, the 24 VAC  
terminal of the ignition control module, the green  
LED on the front of the heater to signify “Power  
On”, terminal R (pin #24) of the modulating tem-  
perature control, the NC contacts of the manual  
high limit, pin P3-1 of the UDB board, pin P1-1 of  
the UDB board, pin J5-5 of the UGB board, the  
NC contacts of the alarm relay, the red LED on the  
front of the heater to signify “Service” if in alarm  
mode and the NO pump contacts on the tempera-  
ture controller.  
If the Auto Hi Limit opens, a 24 VAC is sent to  
Pin P3-3 of the UDB board to indicate a safety  
fault.  
9. 24 VAC is sent from the NC contacts of the Auto  
Reset Hi Limit to the common terminal of time de-  
lay relay.  
10. 24 VAC is sent from the NC contacts of time delay  
relay to the common terminal of the burner switch  
located on the front exterior panel of the heater.  
11. Power then travels to the enable/disable connec-  
tion and to the Ht D (heat demand) connection of  
the modulating temperature control.  
24 VAC is sent from the NC contacts of the man-  
ual high limit to pin P3-2 of the UDB board and to  
the common terminal of the Low Water Cut Off (if  
equipped).  
Power splits from the enable/disable and goes to  
the stage contact of the modulating temperature  
control.  
Upon loss of water in the heater, the Low Water  
Cut Off will send a 24 VAC signal to pin P3-4 of  
the UDB board to indicate a safety fault.  
12. When the stage contact closes on the modulating  
temperature control, 24 VAC is sent to the com-  
mon terminal of the flow switch and to pin P1-3  
(CFH) of the UDB board. 24 VAC is now sent di-  
rectly to the amber LED on the front of the heater  
to signify a “Call For Heat”.  
5. A 24 VAC signal is sent from the NO contacts of  
the Low Water Cut Off to the common terminal of  
the Blocked Vent Switch.  
During a blocked vent condition a 24 VAC signal  
is sent from the NO open contacts of the Blocked  
Vent Switch to Pin P3-5 of the UDB board to indi-  
cate a safety fault.  
13. The pump contact on the modulating temperature  
control closes sending 24 VAC to the pump switch  
located on front exterior panel of the heater.  
6. During normal operation of the heater, the 24  
VAC signal will exit the NC contacts of the  
Blocked Vent Switch and is sent to the common  
terminal, of the Low Gas Pressure Switch (if  
equipped).  
14. When the pump switch is closed 24 VAC is sent to  
the coil of the pump relay.  
15. The pump relay energizes and closes the contacts,  
starting the heater pump.  
During a low gas pressure condition, 24 VAC is  
sent from the NC contacts of the Low Gas Pres-  
sure Switch to Pin P3-6 of the UDB board to  
indicate a safety fault.  
16. Upon sufficient flow, the flow switch closes and  
sends 24 VAC to the common terminal of the air  
pressure switch, the lockout relay coil and the NO  
contacts of the lockout relay. A 24 VAC signal is  
also sent from the common terminal of the air  
pressure switch to pin F1 of the ignition module.  
7. 24 VAC is sent from the NO contacts of the Low  
Gas Pressure Switch to the common terminal of  
the High Gas Pressure Switch (if equipped).  
If the flow switch does not close, a 24 VAC signal  
is sent to pin P4-9 of the UDB board to indicate an  
insufficient flow condition.  
During a high gas pressure condition, 24 VAC is  
sent from the NO contacts of the High Gas Pres-  
33  
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SECTION C: Installation  
When the 24 VAC signal is sent from the flow  
switch to P4-9, the same signal then de-energizes  
the coil of the time delay relay to remove a heat  
demand from the modulating temperature control  
and restart the ignition sequence after the five-  
second time delay.  
23. After 15 seconds of combustion chamber pre-  
purge, pin S1 sends 120 VAC to the Hot Surface  
Igniter.  
The Hot Surface Igniter will be energized for ap-  
proximately 30 seconds and must exceed 3.1 amp  
draw during heat up.  
Upon ignition lockout, the module energizes the  
lockout relay and sends a 24 VAC signal to pin  
P4-12 (ignition lockout) of the UDB board.  
24. During HSI heat-up, the UGB board is monitoring  
current draw across pins J4-1 and J4-3.  
25. Once the ignition module determines the proper  
operation of the Hot Surface Igniter, a 24 VAC  
signal is output from Valve pin on the ignition  
module to energize the gas valve.  
17. When 24 VAC is received at F1 of the ignition  
module, it is then routed to the “TH” terminal of  
the ignition module.  
18. After 24 VAC is received at TH on the ignition  
module, the contacts between pins F1 and F2 close  
and send 24 VAC to pin J5-6 of the UGB board.  
26. A 24 VAC signal is sent to the blue LED on the  
front of the heater to signify “Burner Firing” and  
to pin J5-2 on the UGB board to prove flame.  
A signal must be received at this terminal to en-  
able output to the blower.  
27. The gas valve is energized and the burner ignites.  
28. The remote sensor is now trying to sense the flame.  
If the flame is not rectified within 4 seconds, the  
ignition module will shut down the gas valve and  
lock out.  
19. A 24 VAC signal is sent from J6-1 to the blower.  
20. The blower is controlled by a PWM (pulse width  
modulation) signal sent from J6-4 to start the  
blower operating at 50% speed.  
29. When burner flame is rectified, the gas valve will  
remain at 50% fire for the remainder of the ninety  
(90) seconds after CFH and then modulate in rela-  
tionship to the output signal to the combustion air  
blower from the modulating temperature control.  
The combustion air blower will operate at 50% of  
capacity for approximately ninety (90) seconds be-  
fore the modulating signal from the temperature  
control will control the blower speed in relation-  
ship to the system water temperature.  
30. When the CFH is satisfied, the heater will return to  
a standby condition awaiting the next CFH.  
21. Once sufficient air pressure is achieved in the  
heater and the air pressure switch closes the NO  
contacts, 24 VAC is sent to the heater interlock  
connection.  
Ignition Module  
When additional heat is needed, the combustion air  
blower starts to purge air from the combustion chamber  
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 ig-  
niter is verified. The main burner is automatically 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.  
If air pressure is insufficient or lost during heater  
operation, a 24 VAC signal is sent from the NC  
contacts of the air pressure switch to pin P4-10 of  
the UDB board to indicate insufficient air pressure.  
When the 24 VAC signal is sent to P4-10, the  
same signal then energizes the coil of the time de-  
lay relay to remove a heat demand from the  
temperature controller and restart the ignition se-  
quence after the five-second time delay.  
22. After receiving 24 VAC at the heater interlock,  
power then travels to the P Switch terminal of the  
ignition module.  
The ignition module employs a 15 second pre-  
purge before the next sequence.  
34  
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SECTION C: Installation  
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 above  
desired outlet temperature.  
Fig. 29: Ignition Module  
The standard 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.  
Fig. 30: Fixed Setting & Adjustable High Limit  
(Manual Reset)  
The optional 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.  
High Limit - Auto Reset (Optional)  
The heater may be equipped with an optional adjust-  
able auto reset high limit temperature device.  
Code  
On  
Condition  
System OK; No faults present  
Possible control fault; Check power  
Low air  
The optional adjustable auto reset high limit is located  
inside the heater junction box. Adjust the setting to  
approx. 20°F above desired outlet temperature.  
Off  
1 Flash  
Flame in combustion chamber;  
No call for heat  
2 Flashes  
3 Flashes  
4 Flashes  
5 Flashes  
6 Flashes  
Ignition lockout  
Low HSI current  
Low 24 VAC  
Internal fault; Replace control  
Table O: Ignition Module  
Diagnostic LED Flash Codes  
Fig. 31: Adjustable High Limit (Auto Reset)  
Flow Switch  
High Limit - Manual Reset  
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.  
The 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).  
35  
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SECTION C: Installation  
High and 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 removable  
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 proper  
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 LP gas.  
Fig. 32: Flow Switch  
Modulating Temperature Control  
The heater is equipped with a Raypak modulating tem-  
perature control. Refer to information starting on page  
28 for information on the setting and use of this control.  
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 acces-  
sible from the front of the heater (to reset the gas  
pressure switch) or through the removable access pan-  
els on the rear of the heater (to reset the gas pressure  
switch), as necessary. If the gas pressure regulator in  
the valve fails, the high gas pressure switch automati-  
cally shuts down the burner.  
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. 35 to reset a tripped pressure switch. The LED  
will go out when the switch is reset.  
Fig. 33: Modulating Temperature Control  
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. 35: High/Low Gas Pressure Switch  
Air Pressure Switch  
The 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  
mounting assembly, directly behind the junction box.  
Fig. 34: Low Water Cut-Off  
36  
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SECTION C: Installation  
Fig. 36: Air Pressure Switch  
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.  
Fig. 37: Blocked Vent Switch  
UDB Diagnostic Board  
This heater is equipped with a diagnostic board which  
will indicate faults as they occur. It has the ability to  
retain up to 256 faults in history. Refer to the Trouble-  
shooting section for instructions on accessing,  
reviewing and clearing these faults.  
SW1  
SW2  
Fig. 38: UDB Diagnostic Board  
37  
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SECTION C: Installation  
Wiring Diagrams  
Models 503-1503  
38  
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SECTION C: Installation  
Models 1753-2003  
39  
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SECTION C: Installation  
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SECTION D  
Start-up  
For Your Safety  
Pre Start-up  
WARNING: If you do not follow these instructions  
exactly, a fire or explosion may result causing property  
damage, personal injury or loss of life.  
Filling System (Heating Boilers)  
Fill system with water. Purge all air from the system.  
Lower the system pressure. Open valves for normal  
system operation, and fill system through feed pressure.  
Manually open air vent on the compression tank until  
water appears, then close vent.  
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.  
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.  
Air Purge (Domestic Hot Water  
Heaters)  
WHAT TO DO IF YOU SMELL GAS:  
Purge all air from system before lighting heater. This  
can be normally accomplished by opening a down-  
stream valve.  
Do not try to light any appliance.  
Do not touch any electrical switch; do not use any  
telephone in your building.  
Raypak offers an optional air vent for the MVB heaters  
which can be screwed 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.  
Immediately call your gas supplier from  
neighbor’s telephone. Follow the gas supplier’s in-  
structions.  
a
If you cannot reach your gas supplier, call the fire  
department.  
Venting System Inspection  
1. Check all vent pipe connections and flue pipe ma-  
terial.  
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 ser-  
vice technician. Forced or attempted repair may  
result in a fire or explosion.  
2. Make sure vent terminations are installed per code  
and are clear of all debris or blockage.  
Do not use this appliance if any part has been under  
water, immediately call a qualified service techni-  
cian to inspect the appliance and to replace any part  
41  
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SECTION D: Start up  
of the control system and any gas control which has  
been under water.  
Attach Manometers to Measure Pressures  
1. Turn off main gas valve.  
Check around unit for debris and remove combusti-  
ble products, i.e. gasoline, etc.  
2. Attach (1) 12” scale manometer to an upstream  
bleedle valve on the gas supply pipe to the heater  
(Measure point “A” in Fig. 39).  
Pre Start-up Check  
3. Attach (1) 24” scale manometer to the manifold  
pressure tap located on the valve (Measure point  
“C” in Fig. 39).  
1. Verify heater is filled with water.  
2. Check system piping for leaks. If found, repair  
immediately.  
4. Attach (1) 12” scale manometer near the fan-  
proving switch. Pull black cap from air pressure  
switch tee and connect the manometer. NOTE: Re-  
tain caps for reinstallation later.  
3. Vent air from system. Air in system can interfere  
with water circulation. If the heater is equipped  
with the optional air vent, ensure that it is adjusted  
before firing the heater to make sure all air is  
vented prior to start-up.  
4. Purge air from gas line up to heater.  
Initial Start-up  
Tools Needed  
(1) 12-0-12, 24” scale U-tube manometer  
(2) 6-0-6, 12” scale U-tube manometer  
(1) Phillips screwdriver  
(1) Crescent wrench  
(1) Multi-meter  
(1) Amp probe  
Fig. 39: Gas Pressure Measurement Location  
Check Gas Supply Pressure  
1. Slowly turn on main gas shut-off valve.  
2. Read the gas supply pressure from the manometer;  
minimum supply pressure for natural gas is 4.0 in.  
WC, recommended supply is 7.0 in. WC, mini-  
mum supply pressure for propane gas is 4.0 in.  
WC, recommended supply is 11.0” WC (dynamic  
readings, full fire input).  
NOTICE: Digital manometers are not recommended.  
Preparation  
WARNING: Do not turn on gas at this time.  
3. If the pressure is > 14.0 in. WC, turn off the valve.  
Check Power Supply  
With multi-meter at incoming power, check voltage  
between:  
4. Check if the service regulator is installed and/or  
adjust the service regulator.  
Hot - Common (120 VAC)  
Hot - Ground (120 VAC)  
Common - Ground (< 1 VAC)  
Start-Up  
Blower Adjustment  
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 off power.  
2. Unplug cap at pressure switch and connect ma-  
nometer to the tee.  
3. Close manual firing valve.  
4. Turn power on.  
42  
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SECTION D: Start up  
5. Check blower motor amp draw and the manometer  
attached to fan pressure switch with the blower  
running at 100% speed. The reading should be as  
noted in Tables P and Q for both natural gas and  
propane gas. If not, adjust the air shutter on the  
blower to attain the correct values.  
Manifold Adjustment  
1. Turn off unit.  
2. Open manual firing valves.  
3. Turn on the unit, wait approximately 15 seconds,  
and the igniter should glow (observable through  
the observation port located at the front, bottom of  
the heater). Look into sight glass located at the  
bottom of the front panel to check igniter operation.  
Gas valve should open in 45-60 seconds.  
6. Measure the blower amp draw and compare the  
measured values to the values in Table P. If the  
measured value is different than the values in the  
table (with the noted tolerance), contact the factory.  
NOTE: Connect the amp probe to the 14 Ga.  
black power wire going into the blower.  
4. If burner does not light on first trial. It will go into  
lockout with the standard ignition module. If it is  
equipped with the optional 3-try ignition module,  
it will try for ignition up to three times.  
7. Turn power off.  
8. Disconnect the manometer and reconnect the cap.  
5. Main burner ignition: Check manifold gas pressure  
at gas valve outlet pressure tap (connection “C” in  
Fig. 39). This should read per the values in Table  
R for natural gas and propane gas.  
Setting  
Tolerance  
Model  
Amp Draw  
1.9  
2.9  
503  
753  
+0.0/-0.2  
6. If the pressure reading differs by more than ± 0.2  
in. WC, STOP – Call the factory for directions on  
what to do next!  
+0.0/-0.2  
4.8  
6.3  
1003  
1253  
1503  
1753  
2003  
+0.0/-0.2  
+0.0/-0.2  
+0.0/-0.2  
+0.0/-0.5  
+0.0/-0.5  
CAUTION: Special manifold and air settings may be  
required.  
8.1  
Manifold Gas Pressure Setting*  
13.5  
14.8  
High Fire Values (in. WC)  
Model  
Natural Gas  
-0.1  
LP Gas  
-0.1  
-0.1  
-0.2  
-0.1  
-0.3  
0.4  
Table P: MVB Blower Amp Draw  
503  
753  
-0.1  
1003  
1253  
1503  
1753  
2003  
-0.2  
Air Pressure Setting*  
-0.1  
Model  
(in. WC)  
-0.4  
503  
-2.3  
-2.9  
-3.0  
-3.5  
-4.0  
-4.6  
-4.1  
0.4  
753  
1003  
0.6  
0.6  
* Settings +/- 0.2” WC  
1253  
Table R: MVB Manifold Gas Pressure Settings  
1503  
1753  
2003  
* Settings +/- 0.2” WC  
Table Q: MVB Air Pressure Requirements  
43  
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SECTION D: Start up  
bleedle valve located upstream of the combination gas  
valve on the supply manifold.  
Safety Inspection  
1. Check all thermostats and high limit settings.  
Test point B is a bleedle valve located between the two  
automatic gas valve seats.  
2. During the following safety checks leave manome-  
ters hooked up, check and record.  
Test point C is a bleedle valve located downstream of  
both automatic gas valve seats and upstream of the  
manual valve. Refer to Fig. 40.  
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.  
These tests are to be conducted with the electrical  
power to the heater turned OFF.  
4. Check thermostats for ON-OFF operation.  
5. Check high limits for ON-OFF operation.  
6. While in operation, check flow switch operation  
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).  
7. Check the low gas pressure switch (if provided).  
(For proper adjustment, use the attached manome-  
ters, if available, to set pressure. The scales on the  
switch are approximate only.) Low gas pressure  
switch (if provided) must be set at 3.0 in. WC for  
natural gas and propane gas.  
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.  
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.  
4. Next, close the upstream manual gas valve (field  
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  
bleedle 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.  
Follow-Up  
Safety checks must be recorded as performed.  
Turn heater on. After main burner ignition:  
1. Check manometer for proper readings.  
2. Cycle heater several times and re-check readings.  
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 leaking  
gas valve which must be replaced.  
3. Remove all manometers and replace caps and  
screws.  
4. Check for gas leaks one more time.  
Leak Test Procedure: Dual-Seat Gas  
Valve  
6. Remove rubber tube and manometers. Close each  
test point bleedle valve as the tubes are removed.  
Proper leak testing requires three pressure test points in  
the gas train.  
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.  
Remove the access panel on the rear of the heater to  
access the gas valve for this test. Test point A is a  
44  
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SECTION D: Start up  
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.  
9. Test ignition system safety device:  
a. Open manual gas valve. Turn power on.  
b. Set thermostat to call for heat.  
c. When the heater is in operation, pull cap off of  
tee in air switch hose. The burner should go  
off almost immediately.  
d. Reattach cap on tee. Burner should re-ignite  
after pre-purge time delay. NOTE: Ignition  
control may have to be reset after this portion  
of the test.  
10. To restart system, follow lighting instructions in  
Section E.  
11. Check to see that the high limit control is set above  
the design temperature requirements of the system.  
Fig. 40: Leak Test Procedure  
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:  
12. Check that the heater is cycled with the thermostat.  
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.  
1. Verify that the heater and heat distribution units or  
storage tank are filled with water.  
2. Confirm that the automatic air vent (if used) was  
opened two full turns during the venting procedure.  
13. Observe several operating cycles for proper opera-  
tion.  
3. Verify that air has been purged from the system.  
14. Set the heater thermostat to desired temperature.  
4. Verify that air has been purged from the gas piping,  
and that the piping has been checked for leaks.  
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.  
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.  
45  
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SECTION D: Start up  
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SECTION E  
Operation  
12. If heater fails to start, verify the following:  
Lighting Instructions  
a. There are no loose connections or that the ser-  
vice switch is off.  
1. Before lighting, make sure you have read all of the  
safety information in this manual.  
b. High temperature limit switch is set above wa-  
ter temperature or manual reset high limit is  
not tripped.  
2. Remove upper front panel.  
3. Set the thermostat to the lowest setting.  
4. Turn off all electrical power to the appliance.  
c. Thermostat is set above water temperature.  
d. Gas is on at the meter and the heater.  
5. This appliance is equipped with an ignition device  
which automatically lights the burner. Do not try  
to light the burner by hand.  
e. Incoming dynamic gas pressure to the gas  
valve is NOT less than 4.0 in. WC for natural  
gas or propane gas.  
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.  
To Turn Off Gas To Appliance  
1. Shut off manual gas valve field installed near gas  
inlet connection on back of heater.  
2. Remove upper front panel.  
8. Turn on all electrical power to the appliance.  
3. Set the thermostat to lowest setting.  
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 one time  
(three times on optional 3-try ignition module). If  
flame is not sensed, lockout will commence.  
4. Turn off all electrical power to the appliance if  
service is to be performed.  
5. Replace access panel.  
10. If the appliance will not operate, follow the in-  
structions “To Turn Off Gas To Appliance,” and  
call your service technician or gas supplier.  
11. Replace upper front panel.  
47  
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SECTION E: Operation  
48  
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SECTION F  
Troubleshooting  
Does the power switch provide  
power to the control panel?  
Check the switch and/or  
line voltage  
NO  
Step 1  
Is there a Call For  
Heat?  
YES  
NO  
Unit is in standby mode.  
YES  
NO  
Reattach.  
Is Disable connection intact?  
YES  
Step 2  
Step 3  
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  
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  
Replace gas valve  
YES  
NO  
YES  
The unit is okay  
Call our Technical Service Department  
1-800-927-2975 Outside California  
1-800-627-2975 Inside California  
49  
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SECTION F: Troubleshooting  
UDB Fault History  
To view the fault codes in the UDB history file:  
1. Press and hold the switch labeled “SW1” for 5  
seconds to access the fault history. LED 17 will  
begin to flash when the history has been accessed.  
See Fig. 38 on page 37.  
2. Press the switch labeled “SW2” to scroll through  
the recorded faults in history.  
3. When a fault is being displayed, the corresponding  
LED will light AND LED 17 will flash at a rate  
that corresponds to the fault number.  
4. The faults are recorded and displayed on a last in,  
first out basis. The last fault recorded will be the  
first fault displayed. There is no time or date stamp  
associated with these faults.  
5. Continue to push “SW2” to view subsequent faults.  
6. When the history of faults has been exhausted,  
pushing “SW2” again will roll the fault history  
over and it will start again.  
7. To exit the fault history, press and hold “SW1” for  
5 seconds, or wait for 4 minutes and the board will  
automatically exit the history mode (fault LEDs  
will go out).  
To clear the fault history, press and hold both “SW1”  
and “SW2” for 5 seconds.  
NOTE: Once the history has been cleared, it cannot be  
recovered.  
50  
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SECTION G  
Maintenance  
Yearly (Beginning Of Each Heating  
Season)  
Suggested Minimum  
Maintenance Schedule  
Regular service by a qualified service agency and mainte-  
nance must be performed to ensure maximum operating  
efficiency.  
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.  
Maintenance as outlined below may be performed by the  
owner.  
2. Visually inspect venting system for proper function,  
deterioration or leakage. Ensure that condensate drain  
is inspected and ensure that condensate is being di-  
rected to appropriate condensate management system  
or drain, as required by local codes.  
Daily  
1. Check that the area where the heater is installed is free  
from combustible materials, gasoline, and other flam-  
mable vapors and liquids.  
3. Check that area is free from combustible materials,  
gasoline, and other flammable vapors and liquids.  
2. Check for and remove any obstruction to the flow of  
combustion or ventilation air to heater.  
4. Check for and remove any obstruction to the flow of  
combustion or ventilation air to heater.  
5. Follow pre-start-up check in Section D.  
Monthly  
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.  
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.  
2. Visually inspect burner flame.  
7. Check operation of safety devices. Refer to manufac-  
turers’ instructions.  
3. Visually inspect venting system for proper function,  
deterioration or leakage.  
8. Follow oil-lubricating instructions on pump (if re-  
quired).  
Over-oiling  
will  
damage  
pump.  
4. Visually inspect for proper operation of the condensate  
drain in the venting. If leaks are observed repair at  
once.  
Water-lubricated circulators do not need oiling.  
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.  
5. Check air vents for leakage.  
10. Check blower and blower motor.  
51  
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SECTION G: Maintenance  
11. Check for piping leaks around pumps, relief valves  
and other fittings. Repair, if found. DO NOT use pe-  
troleum-based stop-leak.  
2. Test blower air pressure. (See “Blower Adjustment”  
on page 42.)  
3. Test high and low gas pressure interlocks (if equipped).  
(See “Safety Inspection” on page 44.)  
Periodically  
1. Check relief valve. Refer to manufacturer’s instruc-  
tions on valve.  
Semi-Annually  
1. Recalibrate all indicating and recording gauges.  
2. Test low water cut-off (if equipped). Refer to manu-  
facturer’s instructions.  
2. Check flame failure detection system components.  
3. Check firing rate control by checking the manifold  
pressure. (See “Manifold Adjustment” on page 43.)  
Preventive Maintenance  
Schedule  
The following is required procedure in all jurisdictions  
which require CSD-1 and good practice for all MVB instal-  
lations.  
4. Check piping and wiring of all interlocks and shut-off  
valves.  
Annually  
1. Test flame failure detection system and pilot turndown.  
Daily  
2. Test high limit and operating temperature. (See “Post  
Start-Up Check,” page 45.)  
1. Check gauges, monitors and indicators.  
3. Check flame sensors.  
2. Check instrument and equipment settings. (See “Post  
Start-Up Check” on page 45.)  
4. Conduct a combustion test at full fire. Carbon dioxide  
should be 8.0 to 9.0% at full fire for natural gas, and  
between 9.0 to 10.0% for propane gas. Carbon monox-  
ide should be < 100 ppm.  
3. Check burner flame. (Should see light blue flame at  
full input rate).  
Weekly  
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.  
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).  
1. Check igniter. (Resistance reading should be 42-70  
ohms at ambient temperature.)  
6. Perform leakage test on gas valves. (See Fig. 40.)  
7. Test air switch in accordance with manufacturer’s  
instructions. (Turn panel switch to the “On” position  
until blower is proven, then turn the switch to “Off.”  
2. Check flame signal strength. (Flame signal should be  
greater than 1 microamp as measured at the 2 pins on  
the upper left corner of the ignition control).  
8. Inspect burner.  
3. Check flame failure detection system. (See “Post Start-  
Up Check” on page 45.)  
As Required  
4. Check firing rate control by checking the manifold  
pressure. (See “Manifold Adjustment” on page 43.)  
1. Recondition or replace low water cut-off device (if  
equipped).  
5. Make auditory and visual check of main fuel valve.  
2. Check drip leg and gas strainers.  
Monthly  
3. Perform flame failure detection tests.  
1. Check flue, vent, stack, or outlet dampers.  
4. Test safety/safety relief valves in accordance with  
ASME Heater and Pressure Vessel Code Section IV.  
52  
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SECTION H  
Appendix  
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.  
Inside Air Contamination  
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 acid-  
ity levels attack many materials including stainless  
steel, which is commonly used in high efficiency sys-  
tems. The heater can be supplied with corrosion-  
resistant, non-metallic intake air vent material. You  
may, however, choose to use outside combustion air  
for one or more of these reasons:  
Areas where contaminated combustion air commonly  
exists:  
dry cleaning/laundry areas  
metal fabrication plants  
beauty shops  
refrigeration repair shops  
photo processing plants  
auto body shops  
plastic manufacturing plants  
furniture refinishing areas and establishments  
new building construction  
remodeling areas  
1. Installation is in an area containing contaminants  
listed below which will induce acidic condensation.  
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.  
open pit skimmers.  
Check for areas and products listed above before in-  
stalling heater. If found:  
Products causing contaminated combustion air:  
remove products permanently, OR  
install TruSeal direct vent.  
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  
53  
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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  
Mailing Address  
Model Number  
Serial Number  
Date of Installation  
Installation Site  
Contractor/Installer  
City  
State  
Zip Code  
Daytime Telephone Number  
RAYPAK, INC y 2151 Eastman Avenue y Oxnard, CA 93030-9786 y (805) 278-5300 y Fax (800) 872-9725 y www.raypak.com  
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NOTES:  
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Raypak, Inc., 2151 Eastman Avenue, Oxnard, CA 93030 (805) 278-5300 Fax (805) 278-5468  
Raypak Canada Limited, 2805 Slough St., Mississauga, Ontario, Canada L4T 1G2 (905) 677-7999 Fax (905) 677-8036  
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