A.O. Smith GPSX-50L User manual

1
PRINTEDINU.S.A. 0805 PART NO. 185388-000
KEEP THIS MANUAL IN THE POCKET ON THE HEATER FOR FUTURE REFERENCE
WHENEVER MAINTENANCE ADJUSTMENT OR SERVICE IS REQUIRED.
Power Vented Gas Models
GPSX
with Hot Surface Ignition
& 2"/3"/4" PVC Vent
Capability
Thank you for buying this energy efficient water heater from
A.O. Smith Water Products Company. We appreciate your
confidence in our product.
You should thoroughly read this manual before installation and/
or operation of this water heater. Please pay particular attention
to the important safety and operating instructions as well as the
WARNINGSandCAUTIONS.
CAUTION
TEXT PRINTED OR OUTLINED IN RED CONTAINS
INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ
THOROUGHLYBEFORE INSTALLING AND USING THIS
APPLIANCE.
OWNER'SMANUAL
GET TO KNOWYOUR WATER HEATER 2
GENERALSAFETYINFORMATION 3
INSTALLATION 4-12
OPERATION & LIGHTING INSTRUCTIONS 12-15
MAINTENANCE 15-16
TROUBLESHOOTING 17-18
WARRANTY 19
TABLE OF CONTENTS
PAGE
RESIDENTIAL GAS WATER HEATERS
ADIVISIONOFA.O.SMITH CORPORATION
MCBEE,SOUTHCAROLINA
www.hotwater.com

2
GET TO KNOW YOUR WATER HEATER
(A) VENTPIPE-EXHAUST
(B) ANODE
(C) HOTWATEROUTLET
(D) OUTLET(115 VAC)
(E) FLUEBAFFLE
(F) GAS SUPPLY
(G) MAIN MANUALGAS
SHUTOFF VALVE
(H) GROUNDJOINTUNION
(J) DIRTLEG
(K) OUTERDOOR
(L) UNION
(M) INLETWATERSHUT
OFF VALVE
REPLACEMENTPARTSAND DELIMINGPRODUCTS
Replacement parts and recommended delimer may be ordered
through authorized servicers or distributors. Refer to the Yellow
Pages for your A.O. Smith plumber or contact the A.O. Smith
Water Products Company, 5621 W. 115th Street, Alsip IL 60803,
1-800-433-2545. When ordering parts, provide complete model
and serial numbers (see rating plate), quantity and name of part
desired (as listed in Figure 1). Standard hardware items may be
purchased locally.
FIGURE1
(N) COLDWATERINLET
(O) INLETDIPTUBE
(P) TEMPERATUREAND
PRESSURERELIEFVALVE
(Q) EMBLEMANDRATINGPLATE
(R) INSULATION
(S) VENTTERMINAL
(T) DRAIN VALVE
(U) HSIBURNERASSEMBLY
(V) FLUE
(W) DRAINPAN
(X) GAS VALVE
(Y) CONTROLHARNESS
(Z) INNERDOOR
GAS MODEL
WITH HOT SURFACE IGNITION AND
2”/3”/4” PVC VENT CAPABILITY
TEMPERATURE INDICATORS
NATURAL HOT SURFACE
IGNITER & MAIN BURNER
HOT SURFACE IGNITOR
SENSOR
PROPANE HOT SURFACE
IGNITER & MAIN BURNER
SENSOR
HOT SURFACE IGNITOR
TEMPERATURE
ADJUSTMENT
BUTTONS
*CAUTION
115VACIN
CONTROL
HARNESS
AND INSIDE
OUTER DOOR

3
then call your gas supplier or service agent. Keep area clear
until a service call has been made.
At times you may not be able to smell an LP gas leak. One cause
is odor fade, which is a loss of the chemical odorant that gives LP
gas its distinctive smell. Another cause can be your physical
condition, such as having a cold or a diminishing sense of smell
with age. For these reasons, the use of a propane gas detector
is recommended.
IF YOU EXPERIENCE AN OUT-OF-GAS SITUATION, DO NOT
TRYTORELIGHTAPPLIANCE YOURSELF. Askyour LPdelivery
person to relight pilots for you. Only trained LP professionals
should conduct the required safety checks in accordance with
industry standards.
EXTENDED NON-USE PERIODS
WARNING
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
WEEKS OR MORE). HYDROGEN GAS IS EXTREMELY
FLAMMABLE. Toreducethe risk ofinjury under theseconditions,
itisrecommended that thehotwater faucetbeopened for several
minutes at the kitchen sink before using any electrical appliance
connected to the hot water system. 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
SMOKINGOROPEN FLAMENEARTHE FAUCETATTHE TIME
IT IS OPEN.
INSULATION BLANKETS
Insulation blankets available to the general public for external
use on gas water heaters are not approved for use on your
water heater. The purpose of an insulation blanket is to reduce
the standby heat loss encountered with storage tank heaters.
Your water heater meets and exceeds the National Appliance
Energy Conservation Act standards with respect to insulation
and standby loss requirements, making an insulation blanket
unnecessary.
WARNING
Should you choose to apply an insulation blanket to this heater,
you should follow these instructions (See Figure 1 for
identification of components mentioned below). Failure to follow
these instructions can restrict the air flow required for proper
combustion, potentially resulting in fire, asphyxiation, serious
personal injury or death.
•Do not cover the outer door, thermostat or temperature &
pressure relief valve.
•Do not allow insulation to come within 2 inches of dilution air
inlet on the blower to prevent blockage of the dilution air.
•Do not allow insulation to come within 2" of the floor to prevent
blockage of combustion air flow to the burner.
•Do not cover the instruction manual. Keep it on the side of
the water heater or nearby for future reference.
•Do obtain new warning and instruction labels for placement
on the blanket directly over the existing labels.
•Do inspect the insulation blanket frequently to make certain it
does not sag, thereby obstructing combustion air flow.
GENERAL SAFETY INFORMATION
EXTERNAL DAMAGE
Do not operate the water heater until it has been fully checked
out by a qualified technician, if the water heater:
• Has been exposed to fire or damage.
• Displays evidence of sooting.
• Produces steam or unusually hot water.
If the water heater has been flooded it must be replaced.
CHEMICAL VAPOR CORROSION
WARNING
CORROSION OF THE FLUEWAYS AND VENT SYSTEM MAY
OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN
CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN
FAILUREANDRISKOFASPHYXIATION.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium and
sodium chloride (water softener salt), waxes, and process
chemicals are typical compounds which are potentially corrosive.
Do not store products of this sort near the heater. Also, air which
is brought in contact with the heater should not contain any of
these chemicals. If necessary, uncontaminated air should be
obtained from remote or outside sources. The limited warranty is
voided when failure of water heater is due to a corrosive
atmosphere. (Reference is made to the limited warranty for
complete terms and conditions).
IMPROPER COMBUSTION
WARNING
ATTIC AND/OR EXHAUST FANS OPERATING ON THE
PREMISESWITHAWATER HEATERCAN RESULTIN CARBON
MONOXIDE POISONING AND DEATH.
OPERATION OF THESE FANS CAN PRODUCE A NEGATIVE
DRAFT IN THEAREA OF THE WATER HEATER PREVENTING
THE PRODUCTS OF COMBUSTION FROM EXHAUSTING
THROUGH THE VENT PIPE.
Theventingof the waterheater should beinspectedby aqualified
service technician at the time of installation and periodically
thereafter to ensure a down-draft condition does not exist.
DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND
VENTILATING AIR. ADEQUATE AIR FOR COMBUSTION AND
VENTILATION MUST BE PROVIDED FOR SAFE OPERATION.
LIQUID PETROLEUM MODELS
WARNING
Water heaters for propane or liquefied petroleum gas (LPG) are
different from natural gas models. A natural gas heater will not
function safely on LP gas and no attempt should be made to
convert a heater from natural gas to LP gas.
LP gas must be used with great caution. It is highly explosive
and heavier than air. It collects first in the low areas making its
odor difficult to detect at nose level. If LP gas is present or even
suspected, do not attempt to find the cause yourself. Go to a
neighbor's house, leaving your doors open to ventilate the house,

4
AIR REQUIREMENTS
Dilution air temperature must be 100°F or less. In calculating the
free area of a vent opening, the blocking effect of screens, louvers
and grills should be considered. Screens shall not be of a mesh
smaller than 1/4 inch square. If the free area is not known, the
current edition of National Fuel Gas Code ANSI Z223.1/NFPA 54
recommends using figures of 20-25 percent free area for wood
louvers or 60-75 percent for metal grills or louvers.
UNCONFINED SPACE
In buildings of conventional frame, brick or stone construction,
unconfined spaces may provide adequate air for combustion,
ventilation, and dilution air for power venter.
If the unconfined space is within a building of tight construction
(as defined in the most recent revision of the National Fuel Gas
Code Handbook), air for combustion, ventilation, and venter
dilution must be obtained from outdoors. The installation
instructions for confined spaces must be followed.
CONFINED SPACE
When drawing combustion and dilution air from inside a
conventionally constructed building to a confined space, such a
space shall be provided with two permanent openings; ONE
WITHIN 12 INCHES OF THE ENCLOSURE TOP AND ONE
WITHIN 12 INCHES OF THE ENCLOSURE BOTTOM. Each
opening shall have a free area of one square inch per 1000 Btuh
of the total input of all appliances in the enclosure, but not less
than 100 square inches.
If the confined space is within a building of tight construction, air
for combustion, ventilation and power venter dilution must be
obtained from outdoors. When directly communicating with the
outdoors or communicating through vertical ducts, two
permanent openings, located in the above manner, shall be
provided. Each opening shall have a free area of not less than
one square inch per 4000 Btuh of the total input of all appliances
in the enclosure. If horizontal ducts are used, each opening
shall have a free area of not less than one square inch per 2000
Btuh of the total input of all appliances in the enclosure.
INSTALLATION
REQUIRED ABILITY
INSTALLATION OR SERVICE OF THIS WATER HEATER
REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED
TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR
SUPPLY, VENTINGANDGAS SUPPLYARE REQUIRED.
GENERAL
The installation must conform to these instructions and the local
code authority having jurisdiction. In the absence of local codes,
the installation must comply with the current editions of the
National Fuel Gas Code ANSI Z223.1/NFPA 54 and the National
Electrical Code, NFPA 70. The former is available from the
Canadian Standards Association, 8501 East Pleasant Valley
Road, Cleveland, OH 44131, and both documents are available
from the National Fire Protection Association, 1 Batterymarch
Park,Quincy, MA02269.
GROUNDING
The water heater when installed must be grounded in
accordance with local codes, or in the absence of local codes:
In the United States
The National Electrical Code, ANSI/NFPA 70.
HIGH ALTITUDE INSTALLATION
WARNING
STANDARD MODELS ARE FOR INSTALLATION UP TO 7,700
FEET(2,347m)ABOVE SEALEVEL.
IF A STANDARD MODEL IS INSTALLED ABOVE 7,700 FEET
(2,347m), INPUT RATING SHOULD BE REDUCEDATARATE 4
PERCENT FOR EACH 1,000 FEET (305m)ABOVE SEALEVEL
WHICHREQUIRES REPLACEMENTOFTHEBURNERORIFICE
IN ACCORDANCE WITH THE NATIONAL FUEL GAS CODE
(ANSIZ223.1/NFPA54).
FAILURE TOREPLACETHESTANDARDORIFICEWITHAHIGH
ALTITUDE ORIFICE WHEN INSTALLED ABOVE 7,700 FEET
(2,347m) COULD RESULT IN IMPROPER AND INEFFICIENT
OPERATIONOFTHEWATER HEATER,PRODUCINGCARBON
MONOXIDEGASINEXCESSOF SAFELIMITS, WHICHCOULD
RESULT IN SERIOUS INJURY OR DEATH. CONTACT YOUR
LOCALGASSUPPLIERFORANY SPECIFICCHANGES WHICH
MAYBE REQUIREDIN YOURAREA.
LOCATION OF HEATER
The heater is design certified by the Canadian Standards
Association for installation on combustible flooring in a closet
having minimum clearances from combustible material of: 0"
clearance from sides and rear, 5" from the front and 12" from the
top. (Standard clearance.) If clearances stated on the heater
differ from standard clearances, install water heater according
to clearances stated on heater.
Adequate clearance for servicing this appliance should be
considered before installation, such as changing the anodes, etc.
A minimum clearance of 5" must be allowed for access to
replaceable parts such as the thermostats, drain valve and relief
valve.
When installing the heater, consideration must be given to proper
location. Location selected should be as close to the wall as
practicable and as centralized with the water piping system as
possible.
Installation:
Do not install water heater
where flammable products
will be stored or used
unless the main burner and
hot surface igniter are at
least 18” above the floor.
This will reduce, but not
eliminate, the risk of vapors
being ignited by the main
burner or hot surface
igniter.

5
CAUTION
In cold climates provide protection against freeze-up.
THE HEATER SHOULD BE LOCATED IN AN AREA WHERE
LEAKAGEOFTHETANKORCONNECTIONSWILLNOTRESULT
INDAMAGETOTHEAREAADJACENTTOTHE HEATERORTO
LOWER FLOORS OF THE STRUCTURE. When such locations
cannot be avoided, a suitable drain pan should be installed
under the heater, see fig. 1. The pan should have a minimum
length and width of at least 2 inches greater than the diameter of
the heater and should be piped to an adequate drain. Drain
pans suitable for these heaters are available from your dealer.
Water heater life depends upon water quality, water pressure
and the environment in which the water heater is installed.
Water heaters are sometimes installed in locations where
leakage may result in property damage, even with the use of a
drain pan piped to a drain. However, unanticipated damage
can be reduced or prevented by a leak detector or water shut-off
device used in conjunction with a piped drain pan. These
devices are available from some plumbing supply wholesalers
and retailers, and detect and react to leakage in various ways:
• Sensors mounted in the drain pan that trigger an alarm or turn
off the incoming water to the water heater when leakage is
detected.
• Sensors mounted in the drain pan that turn off the water supply
to the entire home when water is detected in the drain pan.
• Water supply shut-off devices that activate based on the water
pressure differential between the cold water and hot water
pipes connected to the water heater.
• Devices that will turn off the gas supply to a gas water heater
while at the same time shutting off its water supply.
WARNING
DO NOT INSTALL THIS WATER HEATER DIRECTLY ON A
CARPETED FLOOR. A FIRE HAZARD MAY RESULT. Instead
the water heater must be placed on a metal or wood panel
extending beyond the full width and depth by at least 3 inches
(76.2mm) in any direction. If the heater is installed in a carpeted
alcove or closet, the entire floor shall be covered by the panel.
Also, see DRAINING.
WARNING
For California installation this water heater must be braced,
anchored, or strapped to avoid falling or moving during
an earthquake. See instructions for correct installation
procedures. Instructions may be obtained from your local dealer,
wholesaler, public utilities or California’s Office of the State
Architect, 400 P Street, Sacramento, CA 95814.
WATER CONNECTIONS
Refer to figure 1 for typical installation. A suitable pipe thread
sealant must be used to prevent leakage.
WATER (POTABLE) HEATING AND SPACE
HEATING
1. All piping components connected to this unit for space heating
applications shall be suitable for use with potable water.
2. Toxic chemicals, such as those used for boiler treatment,
shall NEVER be introduced into this system.
3. This unit may NEVER be connected to any existing heating
system or component(s) previously used with a non-potable
water heating appliance.
4. When the system requires water for space heating at
temperatures higher than required for domestic water
purposes, a tempering valve must be installed. Please refer
to Figure 2 for suggested piping arrangement.
FIGURE2
CLOSED WATER SYSTEM
A closed system will exist if a back-flow preventer (check valve),
or similar device is installed in the cold water line between the
water heater and the street main (or well). Excessive pressure
may develop due to the thermal expansion of heated water
causing premature tank failure or intermittent relief valve
operation. This type of failure is not covered by the limited
warranty. An expansion tank may be necessary in the cold water
supply to alleviate this situation, see fig. 1. Contact the local
plumbing authority.
If the temperature and pressure relief valve on the appliance
discharges periodically, this may be due to thermal expansion
in a closed water supply system. Contact the water supplier or
local plumbing inspector on how to correct the situation. Do not
plug the temperature and pressure relief valve.
GAS CONNECTIONS
The minimum gas supply pressure is 5.0" W.C for natural gas
(11.0" W.C. for propane).
THEHEATER ISNOT INTENDEDFOROPERATIONATHIGHER
THAN14.0''WATER COLUMNSUPPLYPRESSURE. EXPOSURE
TO HIGHER GAS SUPPLY PRESSURE MAY CAUSE DAMAGE
TO THE CONTROL WHICH COULD RESULT IN FIRE OR
EXPLOSION. If overpressure has occurred such as through
improper testing of gas lines or emergency malfunction of the
supply system, the control must be checked for safe operation.
Make sure that the outside vents on the supply regulators and
the safety vent valves are protected against blockage. These
are parts of the gas supply system not the heater. Vent blockage
may occur during ice storms.
IT IS IMPORTANT TO GUARD AGAINST CONTROL FOULING
FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING
MAYCAUSE IMPROPEROPERATION,FIREOREXPLOSION.
All piping must comply with local codes and ordinances or with
the National Fuel Gas Code (ANSI Z223.1/ NFPA-54) whichever
applies. Copper and brass tubing and fittings (except tin lined
copper tubing) shall not be used.
REFER TO FIG. 1 FOR CONNECTION DETAILS. BEFORE
ATTACHING THE GAS LINE BE SURE THAT ALL GAS PIPE IS
CLEAN ON THE INSIDE.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS
SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED DRIP LEG)
MUST BE INCORPORATED IN THE PIPING, FIG. 1. The dirt leg
must be readily accessible. Install in accordance with
recommendations of serving gas supplier. Refer to the current
edition of National Fuel Gas Code, ANSI Z223.1/NFPA.

6
To prevent damage, care must be taken not to apply too much
torque when attaching gas supply pipe to gas valve inlet. The
thermostat inlet has a pad for use with back up wrench.
Apply joint compounds (pipe dope) sparingly and only to the
male threads of pipe joints. Do not apply compound to the first
two threads. Use compounds resistant to the action of liquefied
petroleum gases. Do not use teflon tape on gas valve fittings.
DISCONNECT THE APPLIANCE AND ITS INDIVIDUAL SHUT
OFF VALVE FROM THE GAS SUPPLY PIPING SYSTEM
DURING ANY SUPPLY PRESSURE TESTING EXCEEDING
1/2 PSI (3.5 kPa). GAS SUPPLY LINE MUST BE CAPPED
WHEN DISCONNECTED FROM THE HEATER. FOR TEST
PRESSURESAT 1/2 PSI (3.5 kPa) OR LESS, THE APPLIANCE
NEED NOT BE DISCONNECTED, BUT MUST BE ISOLATED
FROMTHESUPPLYPRESSURETESTBYCLOSINGTHEMAIN
MANUALGASVALVE.
BEFOREPLACINGTHEHEATERINOPERATION, CHECKFOR
GASLEAKAGE. USESOAPANDWATERSOLUTIONOROTHER
MATERIALACCEPTABLE FOR THIS PURPOSE. DO NOT USE
MATCHES, CANDLES, FLAME OR OTHER SOURCES OF
IGNITIONTOLOCATEGASLEAKS.
RELIEF VALVE (P)-FIG. 1
A NEW TEMPERATURE AND PRESSURE RELIEF VALVE
COMPLYINGWITHTHESTANDARDFORRELIEFVALVESAND
AUTOMATIC GAS SHUT OFF DEVICES FOR HOT WATER
SUPPLY SYSTEMS,ANSI Z21.22 (CURRENT EDITION) MUST
BE INSTALLED IN THE HEATER IN THE MARKED OPENING
PROVIDED. THEVALVE MUSTBE OFASIZE (INPUTRATING)
THATWILLBEADEQUATEFORYOUR SIZEHEATER.
Check the metal tag on the relief valve and compare it to the
heater’s rating plate. The pressure rating of relief valve must not
exceed the working pressure shown on the rating plate of the
heater. In addition the hourly Btu rated temperature steam
discharge capacity of the relief valve shall not be less than the
inputratingoftheheater. NOVALVEISTOBEPLACEDBETWEEN
THE RELIEF VALVE AND TANK. DO NOT PLUG THE RELIEF
VALVE.
The drain line connected to this valve must not contain a reducing
coupling or other restriction and must terminate near a suitable
drain to prevent water damage during valve operation. The
discharge line shall be installed in a manner to allow complete
drainage of both the valve and line. DO NOT THREAD, PLUG
OR CAP THE END OF THE DRAIN LINE.
VENTING
WARNING
NEVER OPERATE THE HEATER UNLESS IT IS VENTED TO
THEOUTDOORSAND HASADEQUATEAIR SUPPLYTOAVOID
RISKS OF IMPROPER OPERATION, FIRE, EXPLOSION OR
ASPHYXIATION.
Make sure the flue baffle and flue restrictor ring are properly
aligned and inserted on top of the flue. This can be checked
through the dilution air inlet of the blower.
VENT PIPE TERMINATION
NOTE: Before installing power venter determine place of vent
pipe termination. See figure 3 on page 7.
IMPORTANT
The vent system must terminate so that proper clearances are
maintained as cited in local codes or the current edition of the
NationalFuel GasCode,ANSIZ223.1/NFPA54,7.3.4e and7.8a,b,
as follows:
1. The exit terminals of a mechanical vent system shall be not
less than 7 feet above grade when located adjacent to public
walkways. (Figure. 3)
2. A venting system shall terminate at least 3 feet above any
forced air inlet located within 10 feet. (Figure 3)
3. The venting system shall terminate at least 4 feet below, 4
feet horizontally from or, 1 foot above any door, window or
gravity air inlet into any building.
The manufacturer also recommends that the vent termination
should not be installed closer than 3 feet from an inside
corner of an L shaped structure and not be less than 1 foot
above grade.
The vent shall terminate a minimum of 12'' above expected
snowfall level to prevent blockage of vent termination.
4. In cold climates, it is recommended that vent termination not
be mounted directly above or within 3 feet horizontally from an
oil tank vent or gas meter to avoid potential freeze-up from
condensation.
Plan the vent system layout so that proper clearances are
maintained from plumbing and wiring.
Vent pipes serving power vented appliances are classified by
building codes as “vent connectors”. Required clearances from
combustible materials must be provided in accordance with
information in this manual under LOCATION OF HEATER and
VENT TERMINAL INSTALLATIONS, and with the National Fuel
Gas Code and local codes.
IMPORTANT
Plan the layout of the vent system from the vent termination to the
appliance considering all of the 90 degree and 45 degree elbows
plus the number of feet of pipe that would be needed to install the
total vent system. Make sure to include the 90 degree elbow if
required at the blower. Review the tables on page 9 to make sure
thattheventsystemiswithintheallowedventconfiguration. Multiple
fittings, 90 or 45 degree, installed in close proximity to each other
could result in intermittent lockouts or prevent the unit from firing.
Plan the layout to locate the fittings as far apart as possible.
CAUTION
Termination of the vent system with a device other than the 2",
22.50 degree schedule 40 elbow (supplied with the unit) or a 3"
or 4", 45 degree schedule 40 elbow (supplied locally) could
affect the system performance and result in a safety hazard. If
the 3" or 4" elbow is used for the vent terminal, then the screens
(supplied with this unit) for those elbows must be used and
installed according to the provided instructions.
VENT TERMINAL INSTALLATION
1. After the point of termination has been determined, use the
cover plate as a template to mark the hole for the vent pipe to
insert through the wall. BEWARE OF CONCEALED WIRING
ANDPIPINGINSIDE OF WALL.
2. If the Vent Terminal is being installed on the outside of a
finished wall, it may be easier to mark both the inside and
outside wall. Align the holes by drilling a hole through the
center of the template from the inside through to the outside.
The template can now be positioned on the outside wall using
the drilled hole as a centering point for the template.

7
3. A) MASONRYSIDE WALLS
Chisel an opening approximately one half inch larger than the
marked circle.
B) WOODEN SIDE WALLS
Drill a pilot hole approximately one quarter inch outside of the
marked circle. This pilot hole is used as a starting point for a
saws-all or sabre saw blade. Cut around the marked circle
staying approximately one quarter inch outside of the line. (This
will allow the vent pipe to easily slide through the opening. The
resulting gap will be covered up by the vent terminal cover
plates.) Repeat this step on inside wall if necessary.
This unit can vent through 2, 3 or 4 inch nonmetallic pipe and fittings.
Use the appropriate vent terminal for the size vent pipe being used.
The vent pipe installation can be started from either the blower
discharge or the termination wall. Keep in mind the total vent system
equivalent length (pipe and elbows) when installing the vent system.
(SEEVENTTABLESAND FIGURES ONPAGES 9-10.)
FIGURE4
The vent terminal should be kept as close as possible to the outside
wall, but you need to allow at least 1.5 inches of pipe past the wall,
for the wall plate and vent terminal to mount on the pipe.
Before the vent terminal is installed, caulk (not supplied) around the
pipe on the exterior wall and install the wall plate (can be held to the
outside wall by placing some of the caulking on the back of the plate).
The wall plate is supplied for decorative purposes only and is
not a requirement for the vent termination (if not needed by the
installer).
SEQUENCEOFINSTALLATION
1. The Power Vent Models come with the blower assembly
installed.
2. After the unit is set in place, make sure the blower
assembly is still mounted securely. Also make sure there
is no damage to the blower.
3. Make sure there is no packing material in the discharge of the
blower or the intake of the dilution air restrictor. See Fig. 5.
4. Make sure that the plastic tubing is still attached from the
air pressure switch to the port on the blower housing.
5. Make sure the ON/OFF switch is in the OFF position and
that the outer harness is connected from the blower control
box to the connector on the bottom side of the gas valve.
If the outer harness is not factory installed, make sure the
ON/OFF switch is in the OFF position and then connect
the outer harness from the blower control box to the
connector on the right side of the gas valve.
FIGURE5
FIGURE 3
WARNING
VENT HOOD(S) MAY BE
EXTREMELY HOT DURING
OPERATION

8
FIGURE 6
c.) Install suitable conduit fitting in side of enclosure and
then follow (d.) and (e.) below.
d.) Splice field wiring into existing wiring using code
authorized method (wire nuts, etc.).
e.) Be certain that neutral and line connections are not
reversed when making these connections.
f.) Close panel on the side of control box, make sure that
access panel is secured shut.
CAUTION
LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN
SERVICING CONTROLS. WIRING ERRORS CAN CAUSE
IMPROPERANDDANGEROUSOPERATION. VERIFYPROPER
OPERATIONAFTERSERVICING.
THISUNITISMANUFACTUREDWITHANEXTERNALCONTROL
HARNESSFOR EASIERREPLACEMENTIFTHEHARNESSOR
CONNECTORSGETDAMAGED
Do not plug in power cord until vent system is completely
installed. The Power Vent operates on 110-120 Vac, therefore
a grounded outlet must be within reach of the six (6) foot
flexible power cord supplied with the unit (see fig. 1). The
power cord supplied may be used only where local codes
permit. If local codes do not permit the use of a flexible power
supply cord:
a.) Makesurethe unitisunplugged fromwalloutlet. Remove
screws and open panel on front of control box.
b.) Cut the flexible power cord, leaving enough to be able to
make connections, then remove the strain relief fitting
from box.

9
INSTALLATION OF VENT SYSTEM
CAUTION
FOR INSTALLATION OF ANEW VENTSYSTEM, FOLLOW THE
GUIDELINES IN THE MANUAL. FOR PRE-EXISTING VENT
SYSTEMS,INSPECTTHEVENTFORBLOCKAGEORANYSIGNS
OFDAMAGE. CHECKTOSEE IFTHEVENTPIPEIS PROPERLY
PITCHEDAND ITS JOINTS SECURED. FOLLOW THE VENTING
SPECIFICATIONSINTHISMANUALFORTHE RECOMMENDED
VENTMATERIAL,TERMINATIONANDLOCATION.
(Refer to Figures 3, 4, 5, 7 and 8 as guides).
1. Plantherouteof thevent system.Layoutthetotalventsystemto
use minimum of vent pipe and elbows. The vent piping may be
vented downward away from the blower per the required codes.
If the vent piping is sloped level or upwards away from the
blower, then adequate means for draining and disposing of
the condensate needs to be made by the installer, if condensate
is accumulating in the vent.
2. Refer to table above for allowable vent lengths. Nonmetallic
ventpiping maybeusedifit hasa“HeatDeflectionTemperature”
(HDT@66psi) of at least 157 degrees F. Some typical
nonmetallic vent materials meeting this requirement are
schedule 40 PVC toASTM D2665, schedule 40 CPVC to ASTM
D2846, and schedule 40 ABS to ASTM D2661. The cement
used should be as recommended by the vent pipe
manufacturer. The vent terminal provided is schedule 40 PVC
toASTM D2665 and is a 2", 22.5 degree elbow. If the venting is
made with 3" or 4" pipe, the vent terminal must be a 3" or 4", 45
degree schedule 40 elbow (supplied locally). The supplied
screens for the 3" and 4" elbow must be used and installed
according to the provided instructions when one of these
terminals is used. If a material other than schedule 40 PVC is
used for venting, then an equivalent fitting of that material may
be substituted if the screen in the PVC terminal is removed and
inserted into the new fitting. For water heaters installed in
locations with high ambient temperatures (above 100 degrees
F), it is recommended that schedule 40 CPVC or ABS be used.
3. See the instructions on pages 10 through 12 for the proper
method of cutting and cementing the PVC pipe and fittings.
4. The vent piping should be connected to the blower with a
rubber adapter and secured with hose clamps. The adapter
and clamps are provided with the heater.
5. Even though the flue gas temperature leaving the blower is
between 140°F and 175°F, some installations will have water
condense in the vent piping. If this occurs, then adequate
means of draining and disposing of the condensate needs to
be made by the installer.
FIGURE7
The vent pipe may be installed with a slight downward slope
to drain condensate away from the blower. The pipe may
slope 1/4 inch per five feet of pipe but not more than
1 1/2 inches in the total vent length.
The vent pipe should be properly supported and have
supports located no further apart than 5 feet on vertical runs
and 3 feet on horizontal runs. All pipe and fittings should be
joined by the proper procedures discussed on pages 10 and
11 under the heading: VENT PIPE PREPARATION.
TABLE FOR VENT PIPE LENGTH
TWO INCH DIAMETER PIPE
**Number of 90º Elbows **Number of 45º Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 30 Ft.
One (1) One (1) 1 Ft. 27.5 Ft.
Two (2) None 1 Ft. 25 Ft.
Two (2) One (1) 1 Ft. 22.5 Ft.
Three (3) None 1 Ft. 20 Ft.
Three (3) One (1) 1 Ft. 17.5 Ft.
Four (4) None 1 Ft. 15 Ft.
THREE INCH DIAMETER PIPE
**Number of 90º Elbows **Number of 45º Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 65 Ft.
One (1) One (1) 2 Ft. 62.5 Ft.
Two (2) None 1 Ft. 60 Ft.
Two (2) One (1) 1 Ft. 57.5 Ft.
Three (3) None 1 Ft. 55 Ft.
Three (3) One (1) 1 Ft. 52.5 Ft.
Four (4) None 1 Ft. 50 Ft.
Four (4) One (1) 1 Ft. 47.5 Ft.
***Five (5) None 1 Ft. 45 Ft.
***Five (5) One (1) 1 Ft. 42.5 Ft.
***Six (6) None 1 Ft. 40 Ft.
FOUR INCH DIAMETER PIPE
**Number of 90º Elbows **Number of 45º Elbows Minimum Pipe Maximum Pipe
One (1) None 2 Ft. 90 Ft.
One (1) One (1) 2 Ft. 87 Ft.
Two (2) None 1 Ft. 83 Ft.
Two (2) One (1) 1 Ft. 79 Ft.
Three (3) None 1 Ft. 75 Ft.
Three (3) One (1) 1 Ft. 71 Ft.
** One (1) 90º elbow is equal to two (2) 45º elbows.
*** It is not recommended that more than (4) 90º elbows be used, or a combination of three (3) 90º and two (2) 45º elbows, but as long as the
total length is less than in the chart above, the vent system is acceptable.
Note: For the two inch and three inch vent, one (1) 90º is approximately the same as five (5) feet of pipe. For the four inch vent, one (1) 90º
elbow is approximately the same as eight (8) feet of pipe.

10
VERTICAL VENT THROUGH ROOF
This unit is approved for venting through the roof with the type
vent terminal that is included with the unit. A proper flashing or
“BOOT” should be used to seal the pipe where it exits the roof.
The total vent system should not exceed that which is specified
in the table on page 9.
All of the pipe should be secured as per the instructions in the
“INSTALLATIONOFVENT SYSTEM”onpage9.
VERTICAL VENT TERMINATION
RESTRICTIONS
1. Minimum of twelve (12) inches above the roof or twelve (12)
inches above the anticipated snow level. Provide proper
support for all pipe protruding through the roof.
FIGURE8
2. Four (4) feet from or one (1) foot above any gable, dormer, or
other roof structure with access to interior of building (i.e.-
vent, window etc.).
3. Three (3) feet above any forced air inlet located within ten (10)
feet.
VENT PIPE PREPARATION
1. INITIALPREPARATION
A. Make sure the solvent cement you are planning to use is
designed for the specific application you are attempting.
B. Know the physical and chemical characteristics and
limitations of the PVC and CPVC piping materials that
you are about to use.
C. Know the reputation of your manufacturer and their
products.
D. Know your own qualifications or those of your contractor.
The solvent welding technique of joining PVC and CPVC
pipe is a specialized skill just as any other pipe fitting
technique.
E. Closely supervise the installation and inspect the finished
job before start-up.
F. Contact the manufacturer, supplier, or competent
consulting agency if you have any questions about the
application or installation of PVC and CPVC pipe.
G. Takethe timeand effortto doa professionaljob. Shortcuts
will only cause you problems and delays in start-up. By
far, the majority of failures in PVC and CPVC systems
are the result of shortcuts and/or improper joining
techniques.
2. SELECTIONOFMATERIALS
• Cutting Device - Saw or Pipe Cutter
• DeburringTool,Knife,File, orBeveling Machine (2"and above)
• Brush - Pure Bristle
• Rag - Cotton (Not Synthetic)
• Primer and Cleaner
• Solvent Cement - PVC for PVC Components and CPVC for
CPVC Components
• Containers -Metalor Glasstohold PrimerandCement. Select
the type of PVC or CPVC materials to be used on the basis of
their application with respect to chemical resistance, pressure
rating, temperature characteristics, etc.
• Insertion Tool - Helpful for larger diameter pipe and fittings
(6" and above).
PRIMER
Itisrecommended thatTetrahydrofuran(THF)be used toprepare
the surfaces of pipe and fittings for solvent welding. Do not use
water, rags, gasoline or any other substitutes for cleaning PVC
or CPVC surfaces. A chemical cleaner such as MEK may be
used.
CEMENT
The cement should be a bodied cement of approximately 500 to
1600 centipoise viscosity containing 10-20% (by weight) virgin
PVC material solvated with tetrahydrofuran (THF). Small
quantities of dimethyl formamide (DMF) may be included to act
as a retarding agent to extend curing time. Select the proper
cement; Schedule 40 cement should be used for Schedule 40
pipe. Never use all-purpose cements, commercial glues and
adhesives or ABS cement to join PVC or CPVC pipe and fittings.
SAFETY PRECAUTION: PRIMERS AND CEMENTS ARE
EXTREMELY FLAMMABLE, AND MUST NOT BE STORED OR
USED NEAR HEAT OR OPEN FLAME. ALSO, USE ONLY IN A
WELL-VENTILATEDAREA.
APPLICATORS
Select a suitable pure bristle type paint brush. Use a proper
width brush or roller to apply the primer and cement (see chart
below). Speedy application of cement is important due to its fast
drying characteristics. IMPORTANT NOTE: A dauber type
applicator should only be used on pipe sizes 2" and below. For
larger diameter pipe, a brush or roller must be used.

11
RECOMMENDEDBRUSH*SIZE FORPRIMER
ANDCEMENTAPPLICATIONS
Nominal Pipe Size Brush Width
(IPS) (INS.)
2 1-1/2
3 1-1/2 - 2-1/2
*USEONLYNATURAL BRISTLE
3. MAKINGTHEJOINT
A.Cutting
Pipe must be squarely cut to allow for the proper interfacing
of the pipe end and the fitting socket bottom. This can be
accomplishedwitha miterboxsaw or wheeltypecutter. Wheel
type cutters are not generally recommended for larger
diameters since they tend to flare the corner of the pipe end.
If this type of cutter is used, the flare on the end must be
completely removed.
NOTE: Power saws should be specifically designed to cut plastic
pipe.
STEPA
B. Deburring
Use a knife, plastic pipe deburring tool, or file to remove burrs
from the end of small diameter pipe. Be sure to remove all
burrs from around the inside as well as the outside of the
pipe. A slight chamfer (bevel) of about 10°-15° should be
added to the end to permit easier insertion of the pipe into the
end of the fitting. Failure to chamfer the edge of the pipe may
remove cement from the fitting socket, causing the joint to
leak.
STEPB
C. Test dry fit of the joint
Tapered fitting sockets are designed so that an interfaced fit
should occur when the pipe is inserted about 1/3 to 2/3 of the
way into the socket. Occasionally, when pipe fitting
dimensions are at the tolerance extremes, it will be possible
to fully insert dry pipe to the bottom of the fitting socket. When
this happens, a sufficient quantity of cement must be applied
to the joint to fill the gap between the pipe and fitting. The gap
must be filled to obtain a strong, leak-free joint.
D. Inspection, cleaning, priming
Visually inspect the inside of the pipe and fitting sockets and
remove all dirt, grease or moisture with a clean dry rag. If
wiping fails to clean the surfaces, a chemical cleaner must
be used. Check for possible damage such as splits or cracks
and replace if necessary.
Depth-of-entry
Marking the depth of entry is a way to check if the pipe has
reached the bottom of the fitting socket in Step F. Measure
the fitting depth and mark this distance on the pipe O.D. You
may want to add several inches to the distance and make a
second mark as the primer and cement will most likely destroy
your first one.
Apply primer to the surface of the pipe and fitting socket with
a natural bristle brush (see chart on page 11). This process
softens and prepares the PVC or CPVC for the solvent
cementing step. Move quickly and without hesitation to the
cementing procedure while the surfaces are still wet with
primer.
E. Application of solvent cement
• Apply the solvent cement evenly and quickly around the
outside of the pipe at a width a little greater than the depth
of the fitting socket.
• Apply a light coat of cement evenly around the inside of the
fitting socket. Avoid puddling.
• Apply a second coat of cement to the pipe end.
NOTE: Cans of cement and primer should be closed at all times
when not in use to prevent evaporation of chemicals and
hardening of cement. They are also very flammable and should
be kept away from heat or flame.
STEPE
F. Joint assembly
Working quickly, insert the pipe into the fitting socket bottom
and give the pipe or fitting a 1/4" turn to evenly distribute the
cement. Do not continue to rotate the pipe after it has hit the
bottom of the fitting socket. A good joint will have sufficient
cement to make a bead all the way around the outside of the
fitting hub. The fitting will have a tendency to slide back while
the cement is still wet so hold the joint together for about 15
seconds.
STEPF

12
G. Cleanup and joint movement
Remove all excess cement from around the pipe and fitting
with a dry cotton rag. This must be done while the cement is
still soft.
The joint should not be disturbed immediately after the
cementing procedure, and sufficient time should be allowed
for proper curing of the joint. Exact drying time is difficult to
predict because it depends on variables such as temperature,
humidity and cement integrity. For more specific information,
you should contact your solvent cement manufacturer.
STEPG
T & P VALVE and PIPE INSULATION
Remove insulation for T & P Valve and pipe connections from
carton.
Fit pipe insulation over the incoming cold water line and the hot
water line. Make sure that the insulation is against the top cover
of the heater.
FitT& Pvalveinsulation overvalve. Makesure thattheinsulation
does not interfere with the lever of the T & P valve.
Secure all insulation using tape.
OPERATION
WARNING
NEVER OPERATE THE HEATER WITHOUT FIRST BEING
CERTAIN IT IS FILLED WITH WATER AND A TEMPERATURE
ANDPRESSURERELIEFVALVE ISINSTALLEDINTHERELIEF
VALVE OPENING OF THE HEATER. DO NOT ATTEMPT TO
OPERATEHEATERWITHCOLDWATERINLETVALVECLOSED.
TO OPERATE THE WATER HEATER
FILLING
1. Close the heater drain valve by turning handle clockwise
Fig. 1 (T)
2. Open a nearby hot water faucet to permit the air in the system
to escape.
3. Fully open the cold water inlet pipe valve (allowing the heater
and piping to be filled. Fig. 1(M)
4. Close the hot water faucet as water starts to flow from the
faucet.
5. The heater is ready to be operated.

13
FORYOUR SAFETYREADBEFORE OPERATING
WARNING: If you do not follow these instructions exactly, a fire or
explosion may result causing property damage, personal injury or loss
of life.
A. This appliance does not have a pilot. It is equipped
with an ignition device which automatically lights
theburner. Do NOT try to lightthe burner by hand.
B. BEFORE OPERATING smellall aroundtheappliance
area for gas. Be sure to smell next to the floor
because some gas is heavier than air and will settle
on the floor.
WHATTODOIFYOU SMELLGAS:
• Do not try to light any appliance.
• Do not touch any electric 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.
C. Use only your hand to push in the gas control
buttons. Never use tools. If the control buttons will
not push in, don’t try to repair them, call a qualified
service technician. Force or attempted repair may
result in a fire or explosion.
D. Do not use this appliance if any part has been
under water. Immediately contact a qualified
installer or service agency to replace a flooded
water heater. Do not attempt to repair the unit! It
must be replaced!
OPERATINGINSTRUCTIONS
1. Set thermostat to the lowest setting by first pressing the COOLER and HOTTER buttons together
and holding for 1 second. Then press the COOLER button until the WARM indicator light appears.
2. Set the ON/OFF switch on the blower control box to the “OFF” position.
3. Turn off all electric power to the appliance if service is to be performed.
BEFORE OPERATING: ENTIRE SYSTEM MUST BE FILLED WITH WATERANDAIR PURGED FROMALLLINES.
1. STOP! Read the safety information above,
on this label.
2. Set the thermostat to the lowest setting by first
pressing the COOLER and HOTTER buttons
together and holding for 1 second. Then press the
COOLER button until the WARM indicator light
appears.
3. Turn the “ON/OFF” switch on the blower control box
to the “OFF” position.
4. This appliance is equipped with a device which
automatically lights the burner.
DONOTTRYTOLIGHTTHEBURNER BYHAND.
5. Wait five (5) minutes to clear out any gas.
If you then smell gas, STOP! Follow “B”
in the safety information above on this label. If
you don’t smell gas, go to the next step.
6. Turn on all electrical power to the appliance.
7. Set thermostat to desired setting by first pressing
the COOLER and HOTTER buttons
together and holding for 1 second. Then press
the HOTTER button.
8. If the appliance will not operate, follow the
instructions“TOTURNOFFGAS TOAPPLIANCE”
and call your technician or gas supplier.
9. WATERTEMPERATUREADJUSTMENT
is approximately 120°F.
CAUTION: Hotter water increases the risk
of scald injury. Consult the instruction
manual before changing temperature.
WARNING: TURNOFFALLELECTRIC
POWERBEFORESERVICING
TO TURNOFFGAS TOAPPLIANCE

14
TEMPERATURE REGULATION
WARNING
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER TEMPERATURES REQUIRED FOR AUTOMATIC
DISHWASHER AND LAUNDRY USE CAN CAUSE PAINFUL
SCALDING WITH POSSIBLE SERIOUS AND PERMANENT
INJURY. THE TEMPERATURE AT WHICH INJURY OCCURS
VARIES WITH THE PERSON'S AGE AND THE TIME OF
EXPOSURE. THESLOWERRESPONSE TIME OFCHILDREN,
AGED OR DISABLED PERSONS INCREASES THE HAZARDS
TOTHEM. NEVER ALLOW SMALLCHILDREN TO USEAHOT
WATERTAPORTO DRAWTHEIR OWNBATHWATER. NEVER
LEAVE A CHILD OR DISABLED PERSON UNATTENDED IN A
BATHTUBORSHOWER.
THE WATER HEATER SHOULD BE LOCATED IN AN AREA
WHERE THE GENERALPUBLIC DOES NOT HAVEACCESS.
It is recommended that lower water temperatures be used to
avoid the risk of scalding. It is further recommended, in all cases,
that the water temperature be set for the lowest temperature
which satisfies your hot water needs. This will also provide the
most energy efficient operation of the water heater. The water
temperature setting was factory set at the lowest temperature;
Pressing the “COOLER” button decreases temperature and
pressing the “HOTTER” button increases the temperature.
SETTING THE WATER HEATER TEMPERATURE AT 120°F
(APPROX. " " MARK ON TEMPERATURE SETTING OF GAS
VALVE) WILL REDUCE THE RISK OF SCALDS. Some states
require settings at specific lower temperatures.
Figure 9 shows the approximate water temperatures produced
at various thermostat settings. Short repeated heating cycles
caused by small hot water uses can cause temperatures at the
pointofuse toexceedthe thermostatsettingby upto30°F (17ºC).
If you experience this type of use you should consider using
lower temperature settings to reduce scald hazards.
Valves for reducing the point-of-use temperature by mixing cold
and hot water are available. See figure 2. Also available are
inexpensive devices that attach to faucets to limit hot water
temperatures. Contact a licensed plumber or the local plumbing
authority.
To avoid anyunintentionalchanges inwatertemperature settings,
the control has a tamper resistant feature for changing the
temperature setting. To change the temperature setting follow
these instructions:
1. “Wake Up” the temperature indicators by holding down both
“COOLER” and “HOTTER” temperature adjustment buttons
at the same time for one second (See Figure 9). One or two of
the temperature indicators will light up. These indicators will
only remain on for 30 seconds if no further buttons are
pressed. After 30 seconds the control will go back to “Sleep”
mode.
2. Release both of the temperature adjustment buttons.
A. To decrease the temperature press and release the
“COOLER” button until the desired setting is reached.
B. To increase the temperature press and release the
“HOTTER” button until the desired setting is reached.
NOTE: Holding down the button will not continue to lower or
raise the temperature setting. The button must be pressed and
released for each temperature change desired.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL
TOSHUTOFF,TURNOFFTHEMANUALGAS CONTROLVALVE
TOTHEAPPLIANCE. SEE FIGURE1(G).
Time to Produce
Display 2nd & 3rd Degree
Temperature Setting A B C Burns on Adult Skin
C - Flashing = approx. 160°F About 1/2 seconds
C = approx. 150°F About 1-1/2 seconds
B = approx. 140°F Less than 5 seconds
A = approx. 130°F About 30 seconds
= approx. 120°F More than 5 minutes
WARM = approx. 80°F - - - - - - - - - - - - - - -
FIGURE9
TEMPERATURE INDICATORS
TEMPERATUREADJUSTMENTBUTTONS

15
WATER HEATING IGNITION SEQUENCE
(Make sure gas and electric power are connected properly)
1) The ignition control module is powered and monitors the
system, waiting for a call for heat from the thermostat.
2) The thermostat calls for heat by reading a resistance value
within a given range directly proportional to water
temperature.
3) The control Module:
a) Checks the pressure switch for an open circuit.
b) Energizes the blower.
c) Checks the pressure switch for a closed circuit to prove
draft.
d) Sends line voltage to the hot surface igniter with a
20 second warm up period.
e) Opens the gas valve and checks the sensing rod for
flame.
4) The burner heats the water to the desired thermostat setting.
a) The resistance in the thermostat rises to the value
selected by the temperature setting.
b) The control module closes the gas valve and 5 seconds
later, removes power from the blower.
5) Cycle is completed.
FIGURE10
CONTROLSEQUENCE-HOTSURFACEDIRECTIGNITION
Pre-purge 5 seconds.
HSI Warm-up 20 seconds.
Ignition Activation Period 4 seconds.
Flame Recognition Period 1 second.
Ignition Trial 4 seconds.
Interpurge 5 seconds.
Post-purge 5 seconds.
Retries 2
Reset from Lockout 1 hr.
Flame Sensing (Nominal)
HSI Off/Run Mode 4.0µV DC
MAINTENANCE
WARNING
DISCONNECT FROM ELECTRICAL SUPPLY BEFORE
SERVICINGUNIT.
FOR YOUR SAFETY, WATER HEATER SERVICE SHOULD BE
PERFORMED ONLY BYAQUALIFIED SERVICE TECHNICIAN.
READTHEGENERALSAFETYINFORMATIONSECTION FIRST.
USERS OF THISAPPLIANCE SHOULD BEAWARE THAT GAS
COMPONENTS WEAR OUT OVER A PERIOD OF TIME. THE
GASCARRYINGCOMPONENTSOFTHISAPPLIANCESHOULD
BEINSPECTED FORPROPER OPERATIONPERIODICALLYBY
AQUALIFIEDSERVICETECHNICIAN.
MAIN BURNER -FIG. 1
Check main burner every 12 months for proper flame
characteristics. This is done by removing door(s) on heater, fig. 1.
The main burner should provide complete combustion of gas;
ignite rapidly; give reasonably quiet operation; cause no excessive
flame lifting from burner ports. Make sure that the flow of
combustion and ventilation air is not blocked.
If proper flame characteristics are not evident, check for
accumulation of lint or other foreign material that restricts or
blocks the air openings in the heater or burner. Also check AIR
REQUIREMENTS.
WARNING
SOOT BUILD-UP INDICATES A PROBLEM THAT REQUIRES
CORRECTIONBEFORE FURTHERUSE. Consultwithaqualified
service technician.
Should the main burner or burner air openings require cleaning,
turn the blower switch to “OFF” position and allow the burner to
cool. Remove the burner and clean with a soft brush. Clean
main burner orifice with a suitable soft material.
HIGH TEMPERATURE LIMIT SWITCH
(Single-Use Type Energy Cut Off)
The thermostat has a built-in limit switch which will actuate in
case of excessive water temperatures. The heater cannot be
operated until the Gas Control Valve is replaced It is important
that a serviceman be called to determine the reason for limit
operation and thus avoid repeated thermostat replacement.
Lower the temperature adjustment setting on new control.

16
VENTING SYSTEM
HAVEVENTING SYSTEMCHECKEDEVERYSIX MONTHSFOR
OBSTRUCTIONSAND/OR DETERIORATION INVENT PIPING.
BLOWER ASSEMBLY MAINTENANCE
CAUTION
The air flow restrictor screen on the inlet side of the blower unit
should be checked periodically for any accumulation of dust and
lint. Any build up of dirt in the screen can result in insufficient
dilution air and excessive vent temperatures that could cause
heat damage to the PVC pipe or cause the thermal switch to
safely shut the unit down. Should this happen, the build up of the
lint/dirt needs to be cleaned.
The venter must be inspected four times a year. Points of
inspection are:
1. MOTOR - Motor must rotate freely.
2. WHEEL - Wheel must be clean of soot, ash, lint or any other
coating which inhibits either rotation or air flow. Remove all
foreign material from vent system before operating.
3. The pressure switch part inside the power venter must be
open and free from deposits of soot, carbon, etc.
For safety and satisfactory operation it is recommended that the
heater be checked once a year by a competent service person.
T & P VALVE
At least once a year, the temperature and pressure relief valve
must be checked to ensure that it is in operating condition. Lift
the lever at the top of the valve several times until the valve seats
properly and operates freely.
DANGER
THE WATER PASSING OUT OF THE VALVE DURING THIS
CHECKING OPERATION MAY BE EXTREMELY HOT. AVOID
CONTACT AND DISCHARGE SAFELY TO PREVENT WATER
DAMAGE.
If temperature and pressure relief valve on the appliance
discharges periodically, this may be due to thermal expansion
in a closed water system. Contact the water supplier or local
plumbing inspector on how to correct this situation. DO NOT
PLUG the temperature and pressure relief valve.
DRAINING (T)-FIG. 1
If the heater is to be shut off and exposed to freezing
temperatures, it must be drained. Water, if left in the tank and
allowed to freeze, will damage the heater.
• Turn off the gas and cold water inlet valve to the heater.
• Open a nearby hot water faucet and the heater drain valve.
• BE CAREFUL TO GRASP THE DRAIN VALVE HANDLE SO
THAT THE HAND IS NOT EXPOSED TO HOT WATER. IF
DESIRED, A HOSE MAY BE CONNECTED TO THE DRAIN
VALVETOCARRYTHEWATERAWAY.
DANGER: THEWATER MAYBEHOT.
• The drain valve must be left open during the shutdown period.
• To restart heater, refer to the FILLING instructions under
OPERATION.
Periodically open the drain valve and allow the water to run until
it flows clean. This will help prevent sediment build-up in the
tank.
It is normal for lime and scale deposits to form within the tank.
Such deposits will not be removed by periodic draining. It is
necessary to chemically delime the affected parts in water areas
where such deposits are encountered.
CONDENSATION
Water vapor can condense on the cooler surfaces of the tank
forming droplets, which drip into the fire or run out on the floor.
This is common at the time of startup after installation, during
periods of time when incoming water is very cold, or the heater
may be undersized for the requirements.
Droplets from the bottom of the flue may be due to corrosive
combustionproductsor improper venting. Checkwithyour dealer
for more information.
CATHODIC PROTECTION - ANODE (FIG. 1)
The anode rod is used to protect the tank from corrosion. Most
hot water tanks are equipped with an anode rod. The submerged
rod sacrifices itself to protect the tank. Instead of corroding the
tank, water ions attack and eat away the anode rod. This does
not affect the water's taste or color. The rod must be maintained
to keep the tank in operating condition.
Anode deterioration depends on water conductivity, not
necessarily water condition. A corroded or pitted anode rod
indicates high water conductivity and should be checked and/or
replaced more often than an anode rod that appears to be intact.
Replacement of a depleted anode rod can extend the life of your
water heater. Inspection should be conducted by a qualified
technician, and at a minimum should be checked annually after
the warranty period.

17
TROUBLE SHOOTING
Please check guidelines below. For your safety, water heater service should be performed only by a qualified service technician.
Read the GENERAL SAFETY INFORMATION section first.
PROBLEM SOLUTION
An open earth groundcircuit to the 1. Check that the earth ground connection is
ignition system. properlyconnected.
2. Check that the ground conductor on the
waterheateris properly connected.
Wiring error or a high resistance to 1. Checkforproper connection of line
earthground. neutralandhotwires.
2. Check that the water heater is securely
connectedtoearthground.
Pressureswitch remainedclosedlonger 1. Pressure switch wiring is incorrect.
than 5 seconds after the call for 2. Replacepressureswitch.
heatbegan.
Pressureswitchremainedopenlonger 1. Pressure switch wiring is incorrect.
than 5 seconds after the combustion 2. Pressure switch tubing not connected
blowerwasenergized. correctly.
3. Air intake or exhaust obstructed.
Error in the hot surface ignitor circuit. 1. Check that all wiring is correct and secure.
2. Replacehotsurfaceignitor.
System in lockout. 1. Gas supply is off or too low to operate.
2. Hotsurfaceignitornotpositioned
correctly.
3. Lowvoltage to the water heater.
4. Electric polarity to unit is incorrect - test
andcorrect.
Probleminthegasvalvedrivercircuit. 1. Turnpowertothewaterheaterofffor
10 seconds and the back on.
2. Replacegascontrolvalve.
Problem with the internal circuit. 1. Turnpowertothewaterheaterofffor
10 seconds and then back on.
2. Replacegascontrolvalve.
Problem with the internal circuit. 1. Turnpowertothewaterheaterofffor
10 seconds and then back on.
2. Replacegascontrolvalve.
Flame signal sensed out of 1. Replacegascontrolvalve.
propersequence.
ECOactivated. 1. Replacegascontrolvalve.
One ofthetemperature adjust 1. Press and release each of the buttons
buttons stuck closed. once.
2. Replacegascontrolvalve.
Water temperaturesensoris 1. Check that all wiring is correct and secure.
eitheropen or short circuited. 2. Replacegascontrol valve.
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
LEDSTATUS
WATER HEATERCONTROL
WARNING: DO NOTBY-PASSANYCONTROLSTOMAKEHEATER OPERATE.
OPERATEONLYASWIREDFROMFACTORY.

18
TROUBLE SHOOTING (Continued)
PROBLEM CAUSE SOLUTION
1) Blower will not run.
A) “ON/OFF” control switch turned off. Turn switch to the “ON” position.
B) Blower unplugged. Plug blower back into 115 Vac. outlet.
C) No power at outlet. Repair service to outlet.
D) Thermostat defective. Replace thermostat.
E) Control harness defective. Replace control harness.
F) High limit control circuit open. Replace thermostat.
NOTENOUGH G) Blower motor defective. Replace Blower Assembly.
HOTWATER Thermostat problems.
A) Thermostat set too low. Turn temperature control higher.
B) Thermostat or ECO defective. Replace thermostat.
Others
A) Heater undersized. Reduce hot water use.
B) Low gas pressure. Contact dealer.
C) Incoming water is unusually cold. Allow more time for heater to reheat.
D) Leaking hot water pipes or fixtures. Have plumber check and repair leaks.
A) Defective air flow restrictor. Take unit out of service immediately, call the
manufacturer’s representative.
B) Not enough dilution air to mix with Proper dilution air must be provided for
VENTPIPE TOOHOT flue gases. combustion and dilution of flue temp.
(ABOVE170°F) Refer to “INSTALLATION” section.
C) Dilution air too hot for mixing with Supply air is too hot. Check for heat sources
flue gases. around and/or blockage of dilution air intake.
D) Wrong burner orifice. Install correct orifice.
A) Dirt in burner ports Turn off heater and gas, clean burner head.
B) Combustion air path restricted. Check dilution air intake, exhaust venting, and
YELLOWFLAME air openings in bottom base pan for
obstructions or blockage.
C) Not enough dilution air for proper Check dilution air intake for obstructions
combustion. or blockage.
A) Water on the floor under heater. See “CONDENSATION” section.
B) Water dripping from blower assembly. Install condensate drain hose (supplied locally)
CONDENSATION on drain port of rubber boot of blower assembly
or provide a drip “TEE” in the vent pipe to catch
the condensation. See figure 1 and the
Installation of Vent System instructions.
Improperly sealed, hot or cold supply Tighten threaded connections.
connections, relief valve, drain valve
WATERLEAKS or thermostat threads.
Leakage from other appliances or water Inspect other appliances near water heater.
water lines.
Condensation of flue products. Refer to “CONDENSATION” section.
Thermal expansion in closed water Install thermal expansion tank (DO NOT plug
LEAKINGT&P system. T&Pvalve).
Improperly seated valve. Check relief valve for proper operation
(DO NOT plug T&P valve).
HOTWATERODORS High sulfate or mineral content in Drain and flush heater thoroughly then refill.
(Referto CATHODIC water supply.
PROTECTION Bacteria in water supply. Chlorinate water supply.
WATERTOOHOT Thermostat set too high. Refer to HIGHTEMPERATURE REGULATION.
WATERHEATERSOUNDS Condensation dripping on burner. Refer to CONDENSATION above.
SIZZLING-RUMBLING Sediment at bottom of heater tank. Clean sediment from tank. Refer to DRAINING
instruction in Maintenance section of manual.
SOOTING Improper combustion. Refer toAIR REQUIREMENTS on page 4.
HEATERLIGHTS Outlet polarity is reversed. Test polarity and correct.
BUTGOESOUT
IN4-5 SECONDS

19
THISWARRANTYISAPPLICABLETOTHEORIGINALOWNERONLY. Ifthe
glasslinedtankinthiswaterheatershallproveuponexaminationbyA.O.
Smith Corporation (the warrantor) to have leaked during the warranty
period in normal residential use, due to natural corrosion from potable
water therein, the warrantor will furnish the ORIGINAL OWNER a
replacement A. O. Smith water heater of equivalent size and current
model,or areplacementpartfor anythermostator thermocouplewhich
failsinnormaluse,inaccordance withthe warrantyterms andconditions
specifiedbelow. THEA.O.SMITHREPLACEMENTMODELORPARTWILL
BEWARRANTEDFORONLYTHEUNEXPIREDPORTIONOFTHEORIGINAL
WARRANTY. The warranty period will be determined by the original
installationdateofthewaterheater. PROOF-OF-PURCHASEANDPROOF-
OF-INSTALLATIONARENECESSARYTOVALIDATETHISWARRANTY.
Thiswarrantyis nottransferableandappliesto modelslistedinTable1.
TABLE1
WARRANTYPERIOD
MODEL TANK1PARTS2
GPSX 6 YEARS 6YEARS
When the water heater has been used for other than single family
residentialapplication:1. The tankwarrantyshall bereduced to1year.
2.Thepartswarranty shallbe reducedto 1year forall models. Returned
partswhich meetanyofthefollowingconditionsare notcoveredby this
warranty:1) improperinstallationorremoval; 2)damagedby otherthan
normal wear; 3) replaced for cosmetic purposes; or 4) returned with
defaceddate codes.
CONDITIONSANDEXCEPTIONS
This warranty shall apply only when the water heater is installed and
operatedinaccordance with:1)all localfirecodesand plumbingcodes,
ordinancesand regulations;2) theprintedinstructions providedwith it;
3) good industry practices; and 4) proper safety practices such as but
not limited to a properly sized drain pan if installed in an area where
leakagefromconnections ofthe tankwouldresultindamageto thearea
adjacent to the heater. In addition, a new temperature and pressure
reliefvalve, certifiedby theAmericanGasAssociationmust havebeen
properlyinstalled andpipedto thenearestdrain.
This warranty shall apply only when the heater is:
• ownedby theoriginal purchaser;
• usedattemperatures notexceedingthemaximum calibrated
settingof itsthermostat;
• not subjected to excessive water pressure fluctuations and
notsubject toanoperating pressuregreaterthan 150P.S.I.;
• filled with potable water, free to circulate at all times and with the
tankfree ofdamaging watersedimentorscaledeposits;
• usedin anon-corrosiveandnon-contaminated atmosphere;
• usedwith factoryapproved anode(s)installed;
• initsoriginal installationlocation;
• inthe UnitedStates,its territoriesor possessions,and
• sized in accordance with proper sizing techniques for residential
water heaters;
• bearinga ratingplate whichhas notbeen altered,defaced or
removedexcept asrequiredby thewarrantor;
• not used in a closed system without a properly sized and installed
thermalexpansiontank;
• firedat thefactory ratedinputusing thefuel statedin thefaceof the
ratingplate;
• operatedwith theinnerand outercombustion chamberdoors
inplace;
• maintainedinaccordance withtheinstructions printedinthemanual
includedwith theheater.
Anyaccident tothewater heaterorany partthereof(including freezing,
fire, floods, or lightning), any misuse, abuse or alteration of it, any
operationof itin amodified form,or anyattempt torepair tankleaksor
parts, will void this warranty.
SERVICEANDLABORRESPONSIBILITY
UNDERTHISLIMITEDWARRANTY,THEWARRANTORWILLPROVIDE
ONLYAREPLACEMENTWATERHEATERORPARTTHEREOF. THEOWNER
ISRESPONSIBLEFORALLOTHERCOSTS. Suchcostsmayincludebut
arenotlimitedto:
a. Labor charges for service, removal, or reinstallation of the water
heateror partthereof.
LIMITED RESIDENTIAL GAS WARRANTY
b. Shipping anddeliverychargesforforwarding thenew waterheater
or replacement part from the nearest distributor and returning the
claimed defective heater or part to such distributor except in the
state of California where such charges are the manufacturer’s
responsibility.
c. All cost necessary or incidental for handling and administrative
charges,andforany materialsand/or permitsrequired forinstallation
ofthe replacementheaterorpart.
LIMITATIONONIMPLIED WARRANTIES
Impliedwarranties, includingany warrantyofmerchantability imposed
onthesale ofthisheaterunder statelawarelimitedto oneyearduration
fortheheater oranyof itsparts. Somestatesdo notallowlimitationson
how long an implied warranty lasts, so the above limitations may not
applyto you.
CLAIMPROCEDURE
Any claim under this warranty should be initiated with the dealer who
soldtheheater,orwithanyotherdealerhandlingthewarrantor’sproducts.
If this is not practical, the owner should contact: A. O. Smith Water
ProductsCompany, 5621 West 115th Street,Alsip,Illinois, 60803(800)
323-2636.
Thewarrantorwill onlyhonorreplacementwith identicalorsimilarwater
heater or parts thereof which are manufactured or distributed by the
warrantor.
Dealer replacements are made subject to in-warranty validation by
warrantor.
PROOF-OF-PURCHASEANDPROOF-OF-INSTALLATIONDATESARE
REQUIREDTOSUPPORTWARRANTYFORCLAIMFROMORIGINAL
OWNER. THISFORMDOESNOTCONSTITUTEPROOF-OF-PURCHASE
ORPROOF-OF-INSTALLATION.
DISCLAIMERS
NOEXPRESSEDWARRANTYHASBEENORWILLBEMADEINBEHALF
OFTHEWARRANTORWITHRESPECTTOTHEMERCHANTABILITYOF
THE HEATER OR THE INSTALLATION, OPERATION, REPAIR OR
REPLACEMENTOFTHEHEATERORPARTS. THEWARRANTORSHALL
NOTBERESPONSIBLEFORWATERDAMAGE,LOSSOFUSEOFTHE
UNIT,INCONVENIENCE,LOSSORDAMAGETOPERSONALPROPERTY,
OROTHERCONSEQUENTIALDAMAGE. THEWARRANTORSHALLNOT
BELIABLEBY VIRTUEOFTHIS WARRANTYOROTHERWISEFOR
DAMAGETOANYPERSONSORPROPERTY,WHETHERDIRECTOR
INDIRECT,ANDWHETHERARISINGINCONTRACTORINTORT.
Some states do not allow the limitation or exclusion of incidental or
consequential damages, so the above limitation or exclusion may not
applyto you.
Thiswarrantygivesyouspecificlegalrights,andyoumayalsohave other
rightswhichvaryfrom stateto state.Should governmentalregulationsor
industrystandardsprohibittheManufacturerfromfurnishingacomparable
modelreplacementunder thiswarranty,the Ownerwillbefurnishedwith
theclosest comparablewaterheatermeeting thecurrentgovernmental
regulationsandindustrystandards.Asupplementaryfeemaybeassessed
to cover the additional cost associated with the changes made to meet
applicableregulationsandstandards.
Fillout andkeep withwater heater.
IMPORTANTINFORMATION
ModelNumber____________________________________________
SerialNumber_____________________________________________
InstallationInformation:
DateInstalled_____________________________________________
Company’sName_________________________________________
StreetorP.O.Box _________________________________________
City,State,and ZipCode ___________________________________
PhoneNumber_______________Plumber’sName_______________

20
5621 W. 115TH STREET,ALSIP, IL 60803
PHONE: [phone] FAX: [phone]
www.hotwater.com E-mail: [e-mail]
REPLACEMENT PARTS