John Wood Commercial AJWSC User Manual
COMMERCIAL GAS WATER HEATER
INSTALLATION AND OPERATING INSTRUCTIONS
for Signature Series models with prefix JWSC and AJWSC
Read and understand these instructions thoroughly before starting.
WARNING:
If the information in these instructions is
not followed exactly, a fire or explosion
may result causing property damage, personal injury or death.
WARNING:
Improper installation, adjustment, alteration, service, or maintenance can cause
injury or property damage. Refer to this
manual. For assistance or additional information, consult a qualified installer, service agency, or the gas utility.
FOR YOUR SAFETY
• Do not store or use gasoline or other
flammable vapours and liquids in the
vicinity of this or any other appliance.
• Installation and service must be performed by a qualified installer, service
agency or the gas utility.
• 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.
WHAT TO DO IF YOU SMELL GAS
PART NO. 64128 REV. A (07-05)
GSW Water Heating is a division of
A. O. Smith Enterprises Ltd.
TABLE OF CONTENTS
I) Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
User Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
II) Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Code Requirements For Installations In Canada . . . . . . . . . . . . . . . . . . . .
Code Requirements For Installations In The United States . . . . . . . . . . . .
Safety Warning (Flammable Vapours) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Warning (Scalding) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Warning (Carbon Monoxide) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Relief Valve Requirements (T&P). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
III) Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Unpacking The Water Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drain Pan Requirement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Location Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clearances And Accessibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation Checklist. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IV) Lighting & Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
V) Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Safety Shut-off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
L.P. (Propane) Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the Draft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Temperature Regulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Heater Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Burner Flames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Emergency Shut Down. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operational Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Heater Sounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Smoke/Odour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VI) Integrated Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
High Humidity or Dripping Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water or Steam Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operational status codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reading mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installer mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Error mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VII) Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Draining and Flushing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Routine Preventative Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature and Pressure Relief Valve. . . . . . . . . . . . . . . . . . . . . . . . . . .
Pilot Burner and Main Burner Assembly Inspection. . . . . . . . . . . . . . . . . .
Gas Valve Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . .
Anode Rod Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VIII) Combination Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Space Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IX) Troubleshooting Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
X) Parts Reference Illustration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
RETAIN THESE INSTRUCTIONS IN A SAFE LOCATION FOR
FUTURE REFERENCE
– 2 –
Thank you for purchasing a Commercial Water Heater.
Properly installed and maintained, it will provide years of
trouble free service.
This gas-fired water heater has been developed to produce
potable hot water for commercial demands and may also be
used in combination with space heating applications. Any
deviation from these applications could affect your warranty.
User Responsibilities
This manual has been prepared to acquaint you with the
installation, operation and maintenance of your gas fired
water heater and provide important safety information in
these areas. It is your responsibility to ensure that your
water heater is properly installed and cared for.
FAILURE TO FOLLOW THE INSTRUCTIONS IN THIS
MANUAL MAY RESULT IN SERIOUS BODILY INJURY
AND/OR PROPERTY DAMAGE. THOROUGHLY READ
AND UNDERSTAND ALL INSTRUCTIONS BEFORE YOU
ATTEMPT TO INSTALL, OPERATE OR MAINTAIN THIS
HEATER.
Installation and service requires trade knowledge in the
areas of plumbing, electricity, venting, air supply and gas
supply. If you lack these skills or have difficulty understanding these instructions, you should not proceed. Enlist the
help of a qualified service technician to install this water
heater.
Examples of qualified service technicians include those
trained in the plumbing and heating industry, local gas utility personnel or an authorized service person.
Service to the Power Vent System should only be performed by a qualified service technician.
The manufacturer and seller of this water heater will not
assume any liability for any property damage, personal
injury or death resulting from improper sizing, installation or
failure to comply with these instructions.
The warranty on this water heater is in effect only when the
water heater is installed and operated in accordance with
these instructions. A data plate identifying your water heater
can be found at the front of the water heater near the integrated control. When referring to your water heater, always
have the information listed on the data plate readily available.
Protect your warranty: Regularly service your water
heater as directed in the "Maintenance" section of this manual.
Retain your original receipt as proof of purchase.
Do not discard this manual. You or future users of this
water heater will need it for reference.
– 3 –
Your safety and the safety of others is very important.
We have provided many important safety messages in this manual and on your appliance.
Always read and obey all safety messages.
All safety messages will tell you what the potential hazard is, tell you how to reduce the
chance of injury, and tell you what can happen if the instructions are not followed.
This is the safety alert symbol.
This symbol alerts you to potential hazards that can kill or hurt you and others.
All safety messages will follow the safety alert symbol and either the word
“DANGER” or “WARNING”.
DANGER
WARNING
You can be killed or seriously injured if you don’t immediately follow
instructions.
You can be killed or seriously injured if you don’t follow instructions.
The California Safe Drinking Water and Toxic Enforcement Act requires the Governor of California to
publish a list of substances known to the State of California to cause cancer, birth defects, or other
reproductive harm, and requires businesses to warn of potential exposure to such substances.
WARNING: This product contains a chemical known to the State of California to cause cancer, birth
defects, or other reproductive harm.
This appliance can cause low-level exposure to some of the substances listed, including formaldehyde, carbon monoxide, and soot.
I) INTRODUCTION
This water heater is design-certified by CSA International as
a Category I, non-direct vented water heater which takes its
combustion air either from the installation area or from air
ducted to the unit from the outside.
In addition to the installation instructions found in this manual, the water heater must be installed in accordance with
all local and provincial or state codes or, in the absence of
such, with the latest editions of the following specifications.
For Installations in Canada:
“Natural Gas and Propane Installation Code” CAN/CSAB149.1 and “Canadian Electrical Code (CAN/CSA
C22.1), Part I” available from:
Canadian Standards Association,
5060 Spectrum Way,
Mississauga, Ontario, Canada
L4W 5N6
For Installations in the United States:
“National Fuel Gas Code” ANSI Z223.1 (NFPA 54) and
“National Electrical Code” (NFPA 70)” available from:
American National Standards Institute,
25 West 43rd Street,
New York, NY 10036
Massachusetts code requires this water heater to be
installed in accordance with Massachusetts Plumbing and
Fuel Gas Code 248 CMR Section 2.00 and 5.00.
Check your phone listings for the local authorities having
jurisdiction over your installation.
Safety Warning (Flammable Vapours)
There is a risk of property damage, personal injury or death
from the by-products of combustion (e.g., flue gases), in
using fuel-burning appliances such as water heaters. Areas
that may not be suitable for water heater installation include
those where flammable liquids, gasoline, solvents, adhesives etc. are stored, or where engine-driven equipment or
vehicles are stored, operated or repaired. These, and simi-
lar products, should not be stored or used near the water
heater or air intake. Due to the nature of air movement,
flammable vapours can be carried some distance from the
point of storage. The gas-fired water heater igniter or burner flame can ignite these vapours causing a flashback, fire
or explosion, which may result in severe property damage,
serious personal injury or death. If flammable liquids or
vapours have spilled or leaked in the area of the water
heater, leave the area immediately and call the fire department from a neighbor’s home. Do not attempt to clean the
spill until all ignition sources have been extinguished.
II) SAFETY
WARNING
Flammable Vapours
FLAMMABLES
FIRE AND EXPLOSION HAZARD
Can result in serious injury or death
Do not store or use gasoline or other flammable vapours and liquids
in the vicinity of this or any other appliance. Storage of or use of gasoline
or other flammable vapours or liquids in the vicinity of this or any other
appliance can result in serious injury or death.
Vapours from flammable liquids will
explode and catch fire causing death or
severe burns.
Do not use or store flammable products
such as gasoline, solvents or adhesives in
the same room or area near the water heater.
Keep flammable products:
1. far away from heater;
2. in approved containers;
3. tightly closed; and
4. out of children’s reach.
This water heater has a main burner and an
automatic ignition system. The ignition system:
1. can come on at any time; and
2. will ignite flammable vapours.
Vapours:
1. cannot be seen;
2. are heavier than air;
3. go a long way on the floor; and
4. can be carried from other rooms to the
water heater by air currents.
Do not install this water heater where flammable products will be stored.
WARNING
FLAMMABLE VAPOURS
FLAMMABLES
– 4 –
Safety Warning (Scalding)
Hot water produced by this appliance can cause severe
burns due to scalding. The hazard is increased for young
children, the aged or the disabled when water temperatures
exceed 52°C (125°F). Use tempering valves, also known as
mixing valves, in the hot water system to reduce the risk of
scalding at point-of-use such as lavatories, sinks and
bathing facilities. Such precautions must be followed when
this heater is operated in combination with dishwashing or
space heating applications.
Safety Warning (Carbon Monoxide)
As with all fuel burning equipment, this heater requires an
adequate supply of air for combustion and ventilation. An
insufficient air supply can result in poor combustion or the
re-circulation of the flue gases. Such a condition can cause
soot build-up and present a fire hazard. Flow reversal of flue
gases can cause an increase of carbon monoxide inside of
the dwelling that could result in serious bodily harm or death
from asphyxiation.
MAKE SURE THE FLOW OF COMBUSTION AND VENTILATION AIR IS NOT RESTRICTED.
Relief Valve Requirements (T&P)
All water heaters must be fitted with a proper temperature
and pressure relief valve. These valves must be certified as
meeting the requirements of the “Standard For Relief
Valves For Hot Water Supply Systems, ANSI
Z21.22/CSA 4.4”.
If this water heater has been exposed to flooding, freezing,
fire or any unusual condition, do not put it into operation until
it has been inspected and approved by a qualified service
technician.
THESE CONDITIONS CAN RESULT IN UNSEEN INTERNAL DAMAGE and are not subject to warranty coverage.
CAUTION
Hydrogen gas can be produced in a hot water system
served by this heater that has not been used for a long
period of time (generally two (2) weeks or more).
Hydrogen gas is extremely flammable and can ignite
when exposed to a spark or flame. To reduce the risk of
injury under these conditions, it is recommended that the
hot water faucet be opened for several minutes at the
kitchen sink before using any electrical appliance connected to the hot water system. Use caution in opening
faucets. If hydrogen is present, there will probably be an
unusual sound such as air escaping through the pipe as
the water begins to flow. There should be no smoking or
open flame near the faucet at the time it is open.
DANGER
DANGER
Carbon Monoxide Warning
• Follow all vent system requirements by
the local authorities having jurisdiction
over your installation.
• Failure to do so can result in death, explosion or carbon monoxide poisoning.
– 5 –
Unpacking the Water Heater
Important: Do not remove any permanent instructions,
labels, or the data label from outside of the water heater or
on the inside of panels.
• Remove exterior packaging and place installation components aside.
• Inspect all parts for damage prior to installation and startup.
• Completely read all instructions before attempting to
assemble and install this product.
If you observe damage to the water heater or any of its components, DO NOT ASSEMBLE OR INSTALL IT OR MAKE
ANY ATTEMPT TO FIX THE DAMAGED PART(S). Contact
the place of purchase for further instructions.
• After installation, dispose of packaging material in the
proper manner.
Location Requirements
• Select a location near the center of the water piping system. The water heater must be installed indoors and in a
vertical position on a level surface. DO NOT install in
bathrooms, bedrooms, or any occupied room normally
kept closed.
• Locate the water heater as close to the gas vent as practical. Consider the vent system piping and combustion air
supply requirements when selecting the water heater
location. The venting system must be able to run from the
water heater to termination with minimal length and
elbows.
• Locate the water heater near the existing gas piping. If
installing a new gas line, locate the water heater to minimize the pipe length and elbows.
• The water heater should be located in an area not subject
to freezing temperatures. Water heaters located in
unconditioned spaces (i.e. attics, basements, etc.) may
require insulation of the water piping and drain piping to
protect against freezing. The drain and controls must be
easily accessible for operation and service. Maintain
proper clearances as specified on the data plate.
• The operation of air-moving devices such as exhaust
fans, ventilation systems, clothes-dryers, fire-places, etc.,
can affect the proper operation of the water heater. Note:
Special attention must be given to the location of these
devices and the conditions they may create. Flow reversal of flue gases may cause an increase of carbon
monoxide inside of the dwelling.
In Earthquake Zones
Note: The water heater must be braced, anchored, or
strapped to avoid moving during an earthquake. Contact
local utilities for code requirements in your area.
Important: If installing over carpeting, the carpeting must
be protected by a metal or wood panel beneath the water
heater. The protective panel must extend beyond the full
width and depth of the water heater by at least 76mm (3 in.)
in any direction, or if in an alcove the entire floor must be
covered by the panel. The panel must be strong enough to
carry the weight of the water heater when full of water.
Figure 2 may be used as a reference guide to locate the
specific clearance locations. A minimum of 610mm (24 in.)
of front clearance and 102mm (4 in.) on each side should be
provided for inspection and service.
Clearances and Accessibility
Notice: Minimum clearances from combustible materials
are stated on the data plate located on the front of the water
heater.
III) INSTALLATION
WARNING
Excessive Weight Hazard
Use two or more people to move and install
water heater. Failure to do so can result in
back or other injury.
IMPORTANT:
This water heater must be installed strictly in accordance
with the instructions enclosed, and local electrical, fuel
and building codes. It is possible that connections to the
water heater, or the water heater itself, may develop
leaks. IT IS THEREFORE IMPERATIVE that the water
heater be installed so that any leakage of the tank or related water piping is directed to an adequate drain in such a
manner that it cannot damage the building, furniture, floor
covering, adjacent areas, lower floors of the structure or
other property subject to water damage. This is particularly important if the water heater is installed in a multi-story
building, on finished flooring or carpeted surfaces. GSW
WILL NOT ASSUME ANY LIABILITY for damage caused
by water leaking from the water heater, pressure relief
valve, or related fittings. Select a location as centralized
within the piping system as possible. In any location
selected, it is recommended that a suitable drain pan be
installed under the water heater. This pan must limit the
water level to a MAXIMUM depth of 45mm (1 3/4 in.) and
have a diameter that is a minimum of 50mm (2 in.) greater
than the diameter of the water heater. Suitable piping shall
connect the drain pan to a properly operating floor drain.
When used with a fuel-fired heater, this drain pan must not
restrict combustion air flow.
– 6 –
Figure 1 Drain Pan Installation
Pipe to
adequate
drain
45mm max.
(1¾ in.)
At least 50mm (2 in.) greater than
the diameter of the water heater.
• If the water heater is installed in a restaurant or food service location where the floor is cleaned frequently, NSF
International requires the water heater to maintain
152mm (6 in.) of clearance above the floor. To comply
with the NSF International requirement, install leg extension kit. For availability contact 1-888-479-8324
• The water heater is certified for installation on a combustible floor.
GAS SUPPLY
Read the data plate to be sure the water heater is made
for the type of gas you will be using in your application.
This information will be found on the data plate located near
the integrated control. If the information does not agree with
the type of gas available, do not install or attempt to start.
Call your dealer.
Note: An odourant is added by the gas supplier to the gas
used by this water heater. This odourant may fade over an
extended period of time. Do not depend upon this odourant
as an indication of leaking gas.
Gas Piping
This gas piping must be installed in accordance with all local
and provincial or state codes or, in the absence of such, the
latest edition of “Natural Gas and Propane Installation
Code” CAN/CSA-B149.1 (Canada), or “National Fuel Gas
Code” ANSI Z223.1 (NFPA 54) (U.S.A.).
DANGER
Explosion Hazard
• Use a new CSA or AGA approved gas supply line.
• Install a gas supply shut-off valve.
• Do not connect a natural gas water heater
to a L.P. gas supply.
• Do not connect a L.P. gas water heater to
a natural gas supply
• Failure to follow these instructions can
result in death, an explosion or carbon
monoxide poisoning.
Figure 3 Gas Piping
– 7 –
Figure 2 Minimum Clearance Locations
Sides
Top to
ceiling
Vent
Front View
Top View
Sides
Back
Front 610mm (24 in.)
min. for service
Ground
Joint
Union
Manual Gas
Shut-off
Valve
Drip Leg
Check with
local utility for
min. height
Note: If using a flexible gas connector, make sure its rating
tag matches or exceeds the input of the water heater.
Tables 1, 2, and 3 provide a sizing reference for commonly
used gas pipe materials. Consult the “Natural Gas and
Propane Installation Code” or “National Fuel Gas Code”
for the recommended gas pipe size of other materials.
Follow the instructions below and reference Figure 3 for gas
piping installation.
Note: When installing gas piping, apply sealing compounds
approved for use with natural and propane gas.
1. Install a readily accessible manual shut-off valve in the
gas supply line as recommended by the local utility. The
owner/operator must be shown the location of this valve
and be given instructions on how to use it to shut off the
gas to the heater.
2. Install a drip leg (if not already incorporated as part of
the water heater) as shown. The drip leg must be no
less than 76mm (3 in.) long for the accumulation of dirt,
foreign material, and water droplets.
3. Install a ground joint union between the gas valve and
the manual shut-off valve. This is to allow easy removal
of the gas valve.
4. Turn the gas supply on and check for leaks. Use a chloride-free soap and water solution (bubbles forming indicate a leak) or other approved method.
Gas Pressure
Important: The gas supply pressure must not exceed the
maximum supply pressure as stated on the water heater’s
data plate. Minimum supply pressure should also be maintained per the data plate.
L.P. Gas Capacity
Size , (in) 10 20 30 40 50 60 70 80 90 100 125 150
1/2 275 189 152 n/a n/a n/a n/a n/a n/a n/a n/a n/a
3/4 576 393 315 267 237 217 196 185 173 162 146 132
1 1071 732 590 504 448 409 378 346 322 307 275 252
1-1/4 2205 1496 1212 1039 913 834 771 724 677 630 567 511
Maximum capac ity of gas pipe in thousands of BTU per hour of undiluted liquified petroleum gass es (at 11 inches
water column pressure). Based on a Pressure Drop of 0.5 Inch W ater Column.
Nominal Iron Pipe
Length of pipe, Feet
Example: Input BTU requirements of the water heater, 199,000 BTUH
Total pipe length, 80 feet - 1" IPS required.
L.P. Gas Capacity
Size , (in) 10 20 30 40 50 60 80 100 125
5/8 206 141 n/a n/a n/a n/a n/a n/a n/a
3/4 348 239 192 164 146 132 n/a n/a n/a
7/8 536 368 296 253 224 203 174 154 137
Maximum capac ity of gas pipe in thousands of BTU per hour of undiluted liquified petroleum gass es (at 11 inches
water column pressure). Based on a Pressure Drop of 0.5 Inch W ater Column.
Copper Tubing OD
Example: Input BTU requirements of the water heater, 199,000 BTUH
Total pipe length, 50 feet = 7/8" IPS required.
Length of pipe, Feet
Natura l Ga s Pipe Ca pacity (Cu. ft./hr)
Size , in. 10 20 30 40 50 60 70 80 90 100 125 150 175 200
1/2 132 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a
3/4 278 190 152 130 115 105 96 n/a n/a n/a n/a n/a n/a n/a
1 520 350 285 245 215 195 180 170 160 150 130 120 110 100
1-1/4 1050 730 590 500 440 400 370 350 320 305 275 250 225 210
1-1/2 1600 1100 890 760 670 610 560 530 490 460 410 380 350 320
Cu. Ft. Per Hr. Required =
Gas Input of Water Heater (BTU/HR)
Heating Value of Gas (BTU/FT 3)
The gas input of the water heater is marked on the water heater data plate. The heating value of the gas (BTU/ft3) may
be determined by consulting the local natural gas utility.
Capacity of gas pipe of different diameters and lengths in cu. ft. per hr. with pressure drop of 0.3 in. and s pecific
gravity of 0.60 (natural gas).
Nominal Iron Pipe
Length of Pipe, Feet
After the length of pipe has been determined, select the pipe siz e which will provide the maximum cubic feet per hour
required for the gas input rating of the water heater. By formula:
Table 1
Table 2
Table 3
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Gas Leak Testing
Important: This water heater and its gas connection must
be leak tested before placing the appliance in operation.
• If the code requires the gas lines to be tested at a pressure exceeding 14 in. w.c. (3.5 kPa), the water heater and
its manual shut-off valve must be disconnected from the
gas supply piping system and the line capped.
• If the gas lines are to be tested at a pressure less than 14
in. w.c. (3.5 kPa), the water heater must be isolated from
the gas supply piping system by closing its manual shutoff valve.
U.L. recognized fuel gas and (CO) detectors are recommended in all applications and should be installed using the
manufacturer’s instructions and local codes, rules, or regulations.
Note: Air may be present in the gas lines and could prevent
the burner from lighting on initial start-up. The gas lines
should be purged of air by a qualified service technician
after installation of the gas piping system.
Air Requirements
Important: Air for combustion and ventilation must not
come from a corrosive atmosphere. Any failure due to corrosive elements in the atmosphere is excluded from warranty coverage.
Installations in or for certain places including, but not limited
to, those listed below will require outdoor air for combustion
to reduce the risk of chemical exposure:
• Beauty shops
• Photo processing labs
• Buildings with indoor pools
• Water heaters installed in laundry, hobby or craft rooms
• Water heaters installed near chemical storage areas
Combustion air must be free of acid-forming chemicals.
These chemicals are found in aerosol sprays, detergents,
bleaches, cleaning solvents, air freshener, paint and varnish
removers, refrigerant, and many other commercial products. When burned, vapours from these products form highly corrosive acid compounds. These products should not be
stored or used near the water heater or air inlet.
The area in which the heater is located is classified as either
“an unconfined sp
ace” or “a confined space”.
An unconfined space is defined as a space having a vol-
ume not less than 50 cubic feet per 1000 BTU/hour (4.8
cubic meters per kilowatt) of combined input rating of all
appliances using the space. Adjacent open rooms may be
included as part of the unconfined space provided there
are no closeable doors between these rooms. An example of this is an open basement.
A confined sp
ace is one smaller than described above. Air
shall be supplied through permanent openings as described
in Figure 4. At no time shall an air opening have a dimen-
sion of less than 76mm (3 in.) and at no time shall any top
opening be lower than the top of the water heater.
For buildings that are not well sealed (do not have tight fitting doors and windows) natural air infiltration may provide
sufficient air required for combustion and ventilation. For
buildings using tight construction (newer and renovated
structures), the air supply shall be introduced from the outdoors, regardless of whether the space is confined or
unconfined.
Where an exhaust fan or any other air consuming appliance
(e.g. clothes dryer, furnace, etc.) is installed in the same
space as the water heater, sufficient air openings must be
available to provide fresh air when all appliances are operating simultaneously.
Combustion Air “Supply” Ducts
Air supply ducts shall be of galvanized steel or equivalent
corrosion resistant material. A single air duct may not be
substituted when required for upper and lower air openings.
Horizontal upper combustion air ducts shall not slope downward toward the air inlet.
WARNING
An adequate air supply shall be provided for
combustion and ventilation of this water
heater.
An insufficient supply can result in poor
combustion and possible sooting of the
burner, combustion chamber, or flue passageway. This may present a potential fire
hazard or create a serious health hazard by
producing carbon monoxide.
WARNING
Explosion Hazard
Have a qualified service technician make
sure L.P. gas pressure does not exceed 13
in. w.c. (3.24 kPa). Failure to do so can result
in death, explosion, or fire.
WARNING
Exposure to a higher gas supply pressure
may cause damage to the gas valve, resulting in explosion or fire. Consult your local
gas supplier and gas authorities. DO NOT
PUT INTO SERVICE IF OVER-PRESSURIZATION HAS OCCURRED.
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