A.O. Smith Commercial gas water heaters User manual

1
Instruction Manual
PRINTEDINTHEU.S.A 1203 PART NO. 184639-000
KEEPTHISMANUALINTHEPOCKETONHEATERFORFUTUREREFERENCE
WHENEVERMAINTENANCEADJUSTMENTORSERVICEISREQUIRED.
ALLTECHNICALAND WARRANTY QUESTIONS: SHOULDBEDIRECTEDTOTHELOCALDEALERFROMWHOMTHEWATERHEATERWAS
PURCHASED.IFYOUAREUNSUCCESSFUL,PLEASEWRITETOTHECOMPANYLISTEDONTHERATINGPLATEONTHEWATERHEATER.
RESIDENTIAL ELECTRIC
WATER HEATERS
FOR POTABLE WATER
HEATING ONLY
NOT SUITABLE FOR
SPACE HEATING
GAMA certification applies to all
residential electric water heaters
with capacities of 20 to 120 gallons.
Input rating of 12 Kw or less.
LISTED

2
SAFE INSTALLATION, USE AND SERVICE
Your safety and the safety of others is extremely important in the installation, use and servicing of this water heater.
Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn you and
others of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual. It is very
important that the meaning of each safety message is understood by you and others who install, use or service this water heater.
This is the safety alert symbol. It is used to alert you
to potential personal injury hazards. Obey all safety
messages that follow this symbol to avoid possible
injury or death.
All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message and
how to avoid the risk of injury.
IMPORTANTDEFINITIONS
•QualifiedInstaller: A qualifiedinstallermust haveabilityequivalent toalicensed tradesmaninthe fieldsofplumbing, andelectricalinstallation
of these appliances. This would include a thorough understanding of the requirements of the National Electrical Code and applicable local
electrical and plumbing codes (and tools necessary to confirm proper installation and operation of the water heater) as they relate to
the installation of electric water heaters. The qualified installer must have a thorough understanding of the water heater
InstructionManual.
•ServiceAgency: A serviceagency alsomusthaveabilityequivalent toa licensedtradesmanin thefields ofplumbing,andelectricalinstallation
of these appliances. This would include a thorough understanding of the requirements of the National Electrical Code and applicable local
electrical and plumbing codes (and tools necessary to confirm proper installation and operation of the water heater) as they relate to
the installation of electric water heaters. The service agency must have a thorough understanding of the water heater
InstructionManual.
DANGER
WARNING
CAUTION
DANGER indicates an imminently
hazardous situation which, if not avoided,
could result in death or injury.
WARNINGindicates a potentiallyhazardous
situation which, if not avoided, could result
in death or injury.
CAUTION indicatesa potentially hazardous
situation which, if not avoided, may result
in minor or moderate injury.
CAUTION used without the safety alert
symbol indicates a potentially hazardous
situation which, if not avoided, could result
in property damage.
CAUTION

3
GENERAL SAFETY
SAFEINSTALLATION,USEANDSERVICE ..............................2
GENERALSAFETY ..................................................................3
TABLEOFCONTENTS..............................................................3
INTRODUCTION ........................................................................4
Preparing for the New Installation ...................................4
NOTES ......................................................................................4
TYPICALINSTALLATION ..........................................................5
WIRINGDIAGRAMS ..................................................................6
MIXINGVALVEUSAGE ............................................................7
LOCATINGTHENEWWATERHEATER .....................................8
Facts to Consider About Location ...................................8
InsulationBlankets ...........................................................8
INSTALLINGTHENEWWATERHEATER ..................................8
WaterPiping ................................................................. 8-9
Temperature-Pressure Relief Valve........................... 9-10
Filling the Water Heater..................................................10
T&PValve and Pipe Insulation (Selected Models) .........10
TEMPERATUREREGULATION ................................................ 11
TemperatureAdjustment ................................................ 11
FORYOURINFORMATION ..................................................... 12
ThermalExpansion ......................................................... 12
Strange Sounds ............................................................. 12
OperationalConditions................................................... 12
SmellyWater ..................................................................12
“Air” in Hot Water Faucets.............................................12
High WaterTemperature Shut Off System ....................12
PERIODICMAINTENANCE .......................................................12
Anode Rod Inspection.............................................. 12-13
Temperature-Pressure Relief Valve Operation..............13
Draining ..........................................................................13
Drain Valve Washer Replacement .................................13
Service ...........................................................................13
LEAKAGECHECKPOINTS ......................................................14
REPAIRPARTSLIST ...............................................................15
TROUBLESHOOTING ..............................................................16
WARRANTY ..................................................................... Insert
TABLE OF CONTENTS

4
Thank You for purchasing this water heater. Properly installed and
maintained,itshould give you years of trouble free service.
AbbreviationsFoundInThisInstructionManual:
• ANSI-AmericanNationalStandardsInstitute
• ASME-AmericanSocietyofMechanical Engineers
• GAMA-GasApplianceManufacturer’sAssociation
• NEC-NationalElectricCode
• NFPA- NationalFire ProtectionAssociation
• UL-UnderwritersLaboratory
PREPARING FOR THE INSTALLATION
1. Read the “General Safety” sectionofthismanualfirst and then the
entire manual carefully. If you don’t follow the safety rules, the
water heater will not operate properly. It could cause DEATH,
SERIOUSBODILYINJURYAND/ORPROPERTYDAMAGE.
Thismanual containsinstructions fortheinstallation, operation,and
maintenanceof the electric waterheater. It alsocontainswarnings
throughout the manual that you must read and be aware of. All
warningsand allinstructions areessentialto theproper operationof
thewater heater and your safety. Sincewe cannot put everything
on the first few pages, READ THE ENTIRE MANUAL BEFORE
ATTEMPTINGTOINSTALLOROPERATETHEWATERHEATER.
2. Theinstallation must conformwiththeseinstructionsand the local
codeauthorityhavingjurisdictionandtherequirementsofthepower
company. In the absence of code requirements follow NFPA-70
(latestedition).TheNationalElectricCodewhichmay be ordered
from: National Fire Protection Association, 1 Batterymarch Park,
Quincy,MA02269.
3. If after reading this manual you have any questions or do not
understandany portionofthe instructions, callthe local utilityorthe
manufacturerwhose name appears on theratingplate.
4. Carefullyplantheplace whereyouaregoingtoputthewaterheater.
INSTALLATIONORSERVICEOFTHISWATERHEATERREQUIRES
ABILITYEQUIVALENTTOTHATOFALICENSEDTRADESMANIN
THEFIELDINVOLVED.PLUMBINGANDELECTRICALWORKARE
REQUIRED.
Examinethelocation to ensure the water heater complies withthe
“FactstoConsiderAbouttheLocation” section in thismanual.
5. ForCaliforniainstallationthiswaterheatermustbebraced,anchored,
or strapped to avoid falling or moving during an earthquake. See
instructionsfor correctinstallationprocedures. Instructions maybe
obtained from California Office of the StateArchitect, 400P Street,
Sacramento,CA95814.
6. Massachusetts Code requires this water heater to be installed in
accordancewithMassachusetts248-CMR2.00:StatePlumbingCode
and248-CMR5.00.
INTRODUCTION
NOTES

5
TYPICAL INSTALLATION
FIGURE1.
UPRIGHTS COMPACTS
TABLE TOPS
INSTALL VACUUM RELIEF IN COLD WATER
INLET LINE AS REQUIRED BY LOCAL CODES.
INSTALL SUITABLEDRAINPANS UNDERHEATERS
TOPREVENTDAMAGEDUE TO LEAKAGE.REFER
TO WATER HEATER LOCATION ON PAGE 8.
INSTALL THERMALEXPANSION TANK ORDEVICE
IF WATER HEATER IS INSTALLED IN A CLOSED
WATERSYSTEM.
LOWBOYS

6
WIRING DIAGRAMS
TURN OFF THE HEATER ELECTRICALSUPPLY BEFORE SERVICINGANY ELECTRICAL COMPONENTS.
FIGURE2.
A-9
240VOLT“OFFPEAK”NON-SIMULTANEOUS
OPERATION BOTTOMELEMENTONSEPARATE
TIMECLOCKOR “OFFPEAK”METER
C-2
TWOWIRECIRCUITFORSINGLE
ELEMENTHEATERSEQUIPPED
WITHHIGH LIMITCONTROL
A-6
TWOWIRE CIRCUITFOR
NON-SIMULTANEOUSOPERATION,
HASSINGLEHIGH LIMITCONTROL
S-1
THREEWIRECIRCUITFOR
ELECTRICCO.CO-OP
PROGRAMS

7
MIXING VALVE USAGE
FIGURE3.
Water (Potable) Heating: All models are considered suitable for
water(potable)heatingonly. HOTTERWATERCANSCALD:
Water heaters are intended to produce hot water. Water heated to a
temperature which will satisfy space heating, clothes washing, dish
washing,and other sanitizingneedscanscald and permanentlyinjure
you upon contact. Some people are more likely to be permanently
injuredbyhotwaterthanothers. Theseincludetheelderly,children,the
infirm,orphysically/mentallyhandicapped. If anyoneusing hotwater in
yourhomefitsinto oneof thesegroups orif thereisalocalcodeorstate
lawrequiring acertaintemperature wateratthe hotwatertap, thenyou
musttake special precautions. Inadditionto using thelowestpossible
temperaturesetting that satisfies yourhotwaterneeds, a means such
as a *mixing valve, shall be used at the hot water taps used by these
peopleoratthewaterheater. Mixingvalvesareavailablelocalplumbing
contractor. Consult a Qualified Installer or Service Agency. Follow
mixingvalvemanufacturer’sinstructionsforinstallationofthe valves.
Before changing the factory setting on the thermostat, read the
“TemperatureRegulation”section inthis manual.

8
FACTSTO CONSIDERABOUT THE LOCATION
Carefullychoose anindoorlocation forthe newwaterheater,because
the placement is a very important consideration for the safety of the
occupants in the building and for the most economical use of the
appliance.
Whetherreplacing an oldwaterheater or putting thewaterheater in a
newlocation,thefollowing critical points must be observed:
1. Select a locationindoorsas close as practicalorcentralizedto the
water piping system as possible. The water heater should be
locatedin anarea not subject to freezing temperatures.
2. Selectedlocationmustprovideadequateclearances(4”)forservicing
partssuchasthe thermostats,drainvalveandreliefvalve.Adequate
clearancefor servicingthisappliance shouldbeconsidered before
installation,such as changing theanodes,etc.
Installationofthe waterheatermustbeaccomplished insuchamanner
thatifthe tank or any connections should leak,theflowwillnot cause
LOCATING THE NEW WATER HEATER
damagetothe structure. Forthisreason,itisnotadvisable toinstallthe
waterheater inanattic or upperfloor. Whensuchlocations cannotbe
avoided,asuitabledrainpanshouldbeinstalledunderthewaterheater.
Drainpansareavailable from your localplumbingcontractor. Sucha
drainpanmusthavea minimum length and width of at least 2 inches
(51mm)greater thatthewaterheaterdimensionsandmust bepipedto
anadequate drain.
Also, the water heater must be located and/or protected so it is not
subjectto physical damagebya moving vehicle.
INSULATION BLANKETS
Insulationblankets are availabletothe general public forexternaluse
onelectric water heatersbutare not necessarywiththis product. The
purpose of an insulation blanket is to reduce the standby heat loss
encountered with storage tank heaters. Your water heater meets or
exceedstheNationalApplianceEnergyConversationActstandards
withrespecttoinsulationandstandbylossrequirements,makingan
insulationblanket unnecessary.
Should you choose to apply an insulation blanket to this heater, you
should follow these instructions below. Failure to follow these
instructionscanresultin fire, serious personal injury, or death.
•Donotcoverthe temperatureandpressure relief(T& P)valvewith
aninsulationblanket.
•Do not cover the instruction manual. Keep it on the side of the
water heater or nearby for future reference.
•Doobtainnew warning and instructionlabelsforplacement on the
blanketdirectly over theexistinglabels.
INSTALLING THE NEW WATER HEATER
WATER PIPING
HOTTER WATER CAN SCALD:
Water heaters are intended to produce hot water. Waterheated to a
temperature which will satisfy space heating, clothes washing, dish
washing,cleaningandothersanitizingneedscanscaldandpermanently
injureyouuponcontact. Somepeoplearemorelikelytobepermanently
injuredbyhotwaterthanothers. Theseincludetheelderly, children,
the infirm, or physically/mentally handicapped. If anyone using hot
water in your home fits into one of these groups or if there is a local
code or state law requiring a certain temperature water at the hot
watertap, thenyou musttakespecial precautions. Inadditionto using
the lowest possible temperature setting that satisfies your hot water
needs,ameanssuch asa *mixingvalve, shallbeusedatthehotwater
tapsused bythesepeople or at thewaterheater. Valvesfor reducing
pointofusetemperaturebymixingcoldandhotwaterarealsoavailable.
ConsultaQualifiedInstalleror ServiceAgency. Follow manufacturer’s
instructionsfor installation of the valves. Before changingthefactory
settingonthethermostat,readthe“TemperatureRegulation”section in
thismanual.
This water heater shall not be connected to any heating systems or
component(s)used with a non-potable water heatingappliance.
Toxic chemicals, suchasthoseusedforboilertreatmentshallnotbe
introducedinto this system.
Water supply systems may, because of such events as high line
pressure, frequent cut-offs, the effects of water hammer among
others,haveinstalled devicessuchaspressurereducingvalves,check
valves,backflow preventers, etc. to control these types of problems.
Whenthesedevicesare notequipped withaninternalby-pass,and no
othermeasuresaretaken, the devices cause the water system to be
closed. Aswaterisheated, itexpands(thermalexpansion)and closed
systems do not allow for the expansion of heated water.

9
The water within the water heater tank expands as it is heated and
increases the pressure of the water system. If the relieving point of
the water heater’s temperature-pressure relief valve is reached, the
valve will relieve the excess pressure. The temperature-pressure
relief valve is not intended for the constant relief of thermal
expansion. Thisis anunacceptable conditionandmustbecorrected.
It is recommended that any devices installed which could create a
closedsystemhave a by-pass and/or the system have an expansion
tankor devicetorelieve thepressurebuilt by thermalexpansion in the
water system. Expansion tanks are available for ordering through a
local plumbing contractor. Contact the local water supplier and/or a
serviceagencyforassistancein controlling these situations.
NOTE: To protect against untimely corrosion of hot and cold
water fittings, it is strongly recommended that di-electric
unions or couplings be installed on this water heater when
connected to copper pipe.
Figure4 shows the typicalattachmentof the water pipingtothe water
heater. The water heater is equipped with 3/4 inch NPT water
connections.
NOTE: If using copper tubing, solder tubing to an adapter
before attaching the adapter to the cold water inlet connection.
Do not solder the cold water supply line directly to the cold
water inlet, it will harm the dip tube and damage the tank.
FIGURE4.
TEMPERATURE-PRESSURERELIEFVALVE
This heater is provided with a properly certified combination
temperature-pressure relief valve by the manufacturer.
Thevalve iscertifiedby a nationallyrecognizedtesting laboratorythat
maintains periodic inspection of production of listed equipment of
materialsasmeetingtherequirementsforRelief ValvesandAutomatic
Gas Shut-off Devices for Hot Water Supply Systems,ANSI Z21.22 •
CSA4.4,andthe coderequirementsofASME.
Ifreplaced,thevalvemust meet the requirements of local codes, but
not less than a combination temperature and pressure relief valve
certifiedas indicated in the aboveparagraph.
Thevalvemustbemarkedwithamaximumsetpressurenottoexceed
the marked hydrostatic working pressure of the water heater
(150psi= 1,035kPa) anda dischargecapacitynotlessthanthewater
heaterinput rate as shown on themodelratingplate.
For safe operation of the water heater, the relief valve must not be
removedfrom itsdesignatedopening norplugged.
Thetemperature-pressure relief valve must be installed directly into
thefitting ofthewater heaterdesigned fortherelief valve. Positionthe
valve downward and provide tubing so that any discharge will exit
only within 6 inches (153 mm) above, or at any distance below the
structuralfloor. Becertainthatnocontactismadewithanyliveelectrical
part. Thedischargeopening must not be blocked or reduced in size
underany circumstances. Excessive length,over30 feet (9.14m),or
use of more than four elbows can cause restriction and reduce the
dischargecapacityofthe valve.
Novalveorotherobstructionistobeplacedbetweenthe relief valve
andthe tank. Do notconnecttubing directlytodischarge drain unless
a6inchair gap is provided. Topreventbodilyinjury,hazardtolife,or
propertydamage, the relief valve mustbeallowed to discharge water
inquantitiesshould circumstancesdemand. Ifthedischargepipe isnot
connected to a drain or other suitable means, the water flow may
causeproperty damage.

10
TheDischargePipe:
• Shallnotbe smaller in size than the outlet pipesizeofthe valve, or
haveanyreducing couplings or other restrictions.
• Shallnot beplugged orblocked.
• Shallbe of material listed for hotwaterdistribution.
• Shall be installed so as to allow complete drainage of both the
temperature-pressurerelief valve, and the dischargepipe.
• Shallterminateatanadequatedrain.
• Shallnothaveanyvalve between the relief valve and tank.
Thetemperature-pressurerelief valve must be manually operated at
leastonce ayear. Cautionshouldbe takento ensurethat (1)noone is
infront of oraroundthe outlet ofthe temperature-pressure reliefvalve
dischargeline,and (2) the water manually discharged will not cause
any bodily injury or property damage because the water may be
extremelyhot.
FIGURE5.
If after manually operating the valve, it fails to completely reset and
continues to release water, immediately close the cold water inlet to
the water heater, follow the draining instructions, and replace the
temperature-pressurerelief valve with a new one.
FILLINGTHE WATERHEATER
Never use this water heater unless it is completely full of water. To
preventdamage to the tank, the tankmust befilledwith water. Water
must flow from the hot water faucet before turning “ON” electrical
supplytothe water heater.
To fill the water heater with water:
1. Closethewaterheaterdrainvalveby turningthe handletothe right
(clockwise). The drain valve is on the lower front of the water
heater.
2. Open the cold water supply valve to the water heater.
NOTE: The cold water supply valve must be left open when
the water heater is in use.
3. To insurecomplete fillingofthe tank,allowairtoexitby openingthe
nearest hot water faucet. Allow water to run until a constant flow
isobtained. Thiswillletairout of the water heater and the piping.
4. Checkallwaterpipingandconnectionsforleaks. Repairasneeded.
FIGURE6.
T&P VALVE and PIPE INSULATION (On Selected Models)
Removeinsulation for T&PValveandpipeconnections from carton.
Fitpipe insulation over the incomingcoldwaterline and the hot water
line.Makesurethattheinsulationisagainstthetopcoveroftheheater.
FitT&PValveinsulationover valve.Makesure thatthe insulationdoes
notinterferewiththeleveroroutletoftheT&Pvalve.
Secureall insulationusingtape.
PIPE INSULATION

11
KEEPINGTHETHERMOSTATSETTINGAT120°FWILLREDUCETHE
RISKOFSCALDS.
Figure7showstheapproximate time-to-burn relationship for normal
adult skin. The thermostats on your water heater have a linear
relationshipbetweendegreesof angularrotationandthecorresponding
change in temperature. Thus rotating the temperature adjustment
indicator 30 angular degrees will result in a 10 degree Fahrenheit
changein water temperature.
TEMPERATUREADJUSTMENT
To changethe temperaturesetting:
1. Turn off the heater electrical supply. Do not attempt to adjust
thermostat with power on.
2. Remove the thermostat access panels and covers from the
thermostats.Donotremovetheplasticpersonnelprotectorscovering
thethermostats.
3. Usingaflattipscrewdriver,rotatetheadjustmentknobtothedesired
temperaturesetting.
4. Replacethecoversand accesspanels andturn onheater electrical
supply.
Temperature Time to Produce 2nd & 3rd
Settings Degree Burns on Adult Skin
160°F(71°C) About 1/2 second
150°F (66°C) About 1-1/2 seconds
140°F (60°C) Less than 5 seconds
130°F (54°C) About 30 seconds
120°F (49°C) More than 5 minutes
80°F (27°C) - - - - - - - - - - - - - - - -
FIGURE7.
Dueto the natureofthe typical water heater, thewatertemperature in
certainsituations may vary up to30°F(16.7°C) higher or loweratthe
point of use such as, bathtubs, showers, sink, etc.
Any water heater’s intended purpose is to heat water. Hot water is
neededforcleansing,cleaning,andsanitizing(bodies,dishes,clothing).
Untemperedhot watercanpresent ascaldhazard. Depending onthe
timeelement, andthepeople involved(adults,children,elderly,infirm,
etc.)scaldingmayoccur at different temperatures.
HOTTERWATERCANSCALD:Waterheatersareintendedtoproduce
hot water. Water heated to a temperature which will satisfy space
heating, clothes washing, dish washing, and other sanitizing needs
canscald andpermanentlyinjure youupon contact. Somepeopleare
morelikely tobepermanently injured byhotwater thanothers. These
include the elderly, children, the infirm, or physically/mentally
handicapped. Ifanyoneusinghotwaterinyourhomefitsinto one of
thesegroupsor if there is a local code or state law requiring acertain
temperature water at the hot water tap, then you must take special
precautions. Inadditiontousingthelowestpossibletemperaturesetting
thatsatisfiesyourhot water needs, a means such as a mixing valve,
shall be used at the hot water taps used by these people or at the
water heater. Mixing valves are available from your local plumbing
contractor. Follow manufacturer’s instructions for installation of the
valves. Before changing the factory setting on the thermostat, read
the“TemperatureRegulation”sectionin thismanual.
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER TEMPERATURES DESIRED FOR AUTOMATIC
DISHWASHER AND LAUNDRY USE CAN CAUSE SCALDS
RESULTING IN SERIOUS PERSONAL INJURYAND/OR DEATH.
THETEMPERATUREATWHICHINJURYOCCURSVARIES WITHTHE
PERSON’SAGEANDTHETIMEOFTHEEXPOSURE.THESLOWER
RESPONSETIMEOFCHILDREN,AGEDORDISABLEDPERSONS
INCREASES THE HAZARDSTO THEM. NEVERALLOW SMALL
CHILDRENTOUSEAHOTWATERTAP,ORTODRAWTHEIROWN
BATH WATER. NEVER LEAVEACHILD OR DISABLED PERSON
UNATTENDEDINABATHTUBORSHOWER.
Itis recommendedthatlower watertemperatures beusedto avoidthe
riskof scalding. It is furtherrecommended,in all cases, thatthewater
temperaturethermostat(SeeFigure3)besetforthelowesttemperature
which satisfies your hot water needs. This will also provide the most
energy efficient operation of the water heater. Thermostat(s) are
factory set at 120°F (49°C) unless specified differently by state
requirements.
TEMPERATURE REGULATION

12
THERMALEXPANSION
Water supply systems may, because of such events as high line
pressure, frequent cut-offs, the effects of water hammer among
others,haveinstalled devicessuchaspressurereducingvalves,check
valves,backflow preventers, etc. to control these types of problems.
Whenthesedevicesare notequipped withaninternalby-pass,and no
othermeasuresaretaken, the devices cause the water system to be
closed. Aswaterisheated, itexpands(thermalexpansion)and closed
systems do not allow for the expansion of heated water.
The water within the water heater tank expands as it is heated and
increases the pressure of the water system. If the relieving point of
the water heater’s temperature-pressure relief valve is reached, the
valve will relieve the excess pressure. The temperature-pressure
relief valve is not intended for the constant relief of thermal
expansion. Thisis anunacceptable conditionandmustbecorrected.
It is recommended that any devices installed which could create a
closedsystemhave a by-pass and/or the system have an expansion
tankor devicetorelieve thepressurebuilt by thermalexpansion in the
water system. Expansion tanks are available for ordering through a
localplumbingcontractor. Contactthe local water heater supplier or
serviceagencyforassistancein controlling these situations.
STRANGESOUNDS
Possiblenoises dueto expansionandcontraction ofsomemetalparts
duringperiods ofheat-upand cool-down donot necessarily represent
harmfulor dangerous conditions.
OPERATIONAL CONDITIONS
SMELLYWATER
In each water heater there is installed at least one anode rod (see
parts sections) for corrosion protection of the tank. Certain water
conditionswillcauseareactionbetweenthisrod and the water. The
most common complaint associated with the anode rod is one of a
“rottenegg smell”inthe hotwater. This odoris derived fromhydrogen
sulfide gas dissolved in the water. The smell is the result of four
factors which must all be present for the odor to develop:
a. Aconcentration of sulfate in the supply water.
b. Little or no dissolved oxygen in the water.
c. Asulfatereducingbacteriawhichhasaccumulatedwithinthewater
heater(this harmless bacteria isnontoxictohumans).
d. An excess of active hydrogen in the tank. This is caused by the
corrosionprotectiveaction of the anode.
Smelly water may be eliminated or reduced in some water heater
modelsby replacingtheanode(s) with oneofless activematerial,and
thenchlorinating thewater heatertankand allhot waterlines. Contact
thelocalwaterheatersupplieror serviceagency forfurther information
concerninganAnodeReplacementKitand thischlorination treatment.
Ifthesmellywaterpersistsaftertheanodereplacementandchlorination
treatment, we can only suggest that chlorination or aeration of the
watersupply be considered to eliminate thewaterproblem.
Do not remove the anode leaving the tank unprotected. By
doing so, all warranty on the water heater tank is voided.
“AIR”INHOTWATERFAUCETS
HYDROGEN GAS: Hydrogen gas can be produced in a hot water
systemthat has notbeenused for alongperiod of time(generallytwo
weeksormore). Hydrogengas isextremely flammableandexplosive.
To prevent the possibility of injury under these conditions, we
recommend the hot water faucet, located farthest away, be opened
for several minutes before any electrical appliances which are
connectedto the hotwatersystem are used(suchas a dishwasheror
washingmachine). Ifhydrogen gas is present, there will probably be
an unusual sound similar to air escaping through the pipe as the hot
waterfaucetisopened. Theremustbenosmoking oropen flamenear
thefaucetat the time it is open.
HIGHWATERTEMPERATURESHUTOFFSYSTEM
Anon-adjustable hightemperature limitcontrol operatesbeforesteam
temperatures are reached. The high limit is in the same area as the
upper thermostat and must be reset manually when it operates.
BECAUSE THE HIGH LIMIT OPERATES ONLY WHEN
ABNORMALLYHIGHWATERTEMPERATURESAREPRESENT,IT
ISIMPORTANTTHATAQUALIFIEDSERVICEAGENTBECONTACTED
TODETERMINETHEREASONFOROPERATIONBEFORERESETTING.
ANODE ROD INSPECTION 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
thewater’stasteor color. Therod mustbe maintainedtokeepthe tank
inoperatingcondition.
Anode deterioration depends on water conductivity, not necessarily
water condition.Acorroded or pitted anode rod indicates high water
conductivityandshould be checked and/or replaced moreoftenthen
an anode rod that appears to be intact. Replacement of a depleted
FOR YFOR Y
FOR YFOR Y
FOR YOUR INFORMAOUR INFORMA
OUR INFORMAOUR INFORMA
OUR INFORMATIONTION
TIONTION
TION
PERIODIC MAINTENANCEPERIODIC MAINTENANCE
PERIODIC MAINTENANCEPERIODIC MAINTENANCE
PERIODIC MAINTENANCE

13
Thewater heatershouldbe drainedif beingshutdown duringfreezing
temperatures. Alsoperiodicdraining andcleaningofsedimentfromthe
tankmay benecessary.
1. Turn electricalsupply“OFF”.
2. CLOSE the cold waterinletvalvetothe water heater.
3. OPEN a nearby hot water faucet and leave open to allow for
draining.
4. Connect a hose to the drain valve and terminate to an adequate
drain.
5. OPEN the water heaterdrainvalve to allow for tankdraining.
NOTE: If the water heater is going to be shut down and
drained for an extended period, the drain valve should be
left open with hose connected allowing water to terminate
to an adequate drain.
6. Close the drainvalve.
7. Follow the instructionsinthe “Filling theWaterHeater” section.
DRAINVALVEWASHER REPLACEMENT
(See Figure 9)
1. Follow “Draining” instructions.
2. Turning counter clockwise ( ), remove the hex cap below the
screw handle.
3. Remove the washer and put the new one in place.
4. Screw the handle andcapassemblyback into the drain valveand
retightenusingawrench.DONOTOVERTIGHTEN.
5. Follow instructions inthe“Filling TheWaterHeater” section.
6. Check for leaks.
FIGURE 9.
SERVICE
Ifaconditionpersistsoryouareuncertainabouttheoperationof the
water heater contact a service agency.
Use this guide to check a “Leaking” water heater. Many suspected
“Leakers”are not leaking tanks. Oftenthesourceof the water canbe
foundandcorrected.
If you are not thoroughly familiar with your water heater and safety
practices,contacta qualified installerto check the water heater.
anoderodcan extend the life of your water heater. Inspection should
beconductedby a qualified technician, and at a minimum should be
checkedannuallyafterthewarrantyperiod.
TEMPERATURE-PRESSURE
RELIEFVALVEOPERATION
Thetemperature-pressurerelief valve must be manually operated at
leastonceayear.
Whencheckingthetemperature-pressure reliefvalve operation,make
surethat(1) noone isinfrontoforaroundthe outletofthetemperature-
pressurereliefvalvedischargeline, and (2) that the water discharge
will not cause any property damage, as the water may be extremely
hot,see Figure 8.
FIGURE8.
If after manually operating the valve, it fails to completely reset and
continues to release water, immediately close the cold water inlet to
the water heater, follow the draining instructions, and replace the
temperature-pressurerelief valve with a new one.
If the temperature-pressure relief valve on the appliance weeps or
discharges periodically, this may be due to thermal expansion. You
may have a check valve installed in the water line or a water meter
with a check valve. Consult your local water supplier or service
agencyfor further information. Donotplug the temperature-pressure
reliefvalve.
DRAINING

14
LEAKAGE CHECKPOINTS
Readthismanual first. Then before checking the water heater make
suretheelectricalpower supplyhasbeenturned“OFF”beforechecking
thetank for leakage.
*A. Condensation and dripping may be seen on pipes if the water
temperatureis low inhumidweather orpipeconnections may be
leaking.
*B. Theanoderodfitting maybeleaking.
C. Smallamounts of water from temperature-pressure relief valve
maybedue to thermal expansion or high waterpressureinyour
area.If the valveisnot piped toan open drainthereleased water
couldbe mistakenfor aleakingheater.
*D. Thetemperature-pressurereliefvalve maybeleaking atthetank
fitting.
E. Water on the side of the tank may be condensation due to the
panelor insulationnotbeing inplace.
F. Water from a drain valve may be due to the valve being slightly
opened.
*G. The drainvalvemay beleakingat the tankfitting.
*H. Water in the water heater bottom or on the floor may be from
condensation, loose connections, or the relief valve. DO NOT
replace the water heater until a full inspection of all possible
water sources is made and necessary corrective steps taken.
Leakagefromother appliances, water lines, or ground seepage
shouldalso be checked.
* To checkwherethreaded portion enters tank, insertcottonswab
between jacket opening and fitting. If cotton is wet, follow
“Draining”instructions in the“PeriodicMaintenance” sectionand
thenremovefitting. Put pipe dope or teflon tape on the threads
andreplace. Thenfollow “FillingtheWaterHeater”instructions in
the“Installing the NewWaterHeater” section.
E
H
A
B
C
A
D
E
G
F

15
REPAIR PARTS LIST
DRAINPAN 17
12
16
8
11
14 14
7
1 3
6
4
23
910
15
Key No. Part Description
1 Upper Heating Element (If Dual Element Unit)
2 Lower Heating Element
3 Element Gasket
4 Lower Thermostat (If Dual Element Unit)
5 Upper Thermostat w/ECO (If Dual Element Unit)
6 Lower Thermostat w/ECO (If Single Element Unit)
7 Outer Door(s)
8 Inlet Tube
9 Drain Valve
10 Drain Valve Washer
11 Anode Rod
12 Anode Outlet/Heat Trap (If Applicable)
13 Temperature-Pressure Relief Valve
14 External Heat Trap Nipples (If Applicable)
15 Pipe Insulation (If Applicable)
16 T&P Insulation (If Applicable)
17 Drain Pan w/Side Drain
* Instruction Manual
*Not Illustrated
Now that you have purchased this water heater, should a need
ever exist for repair parts or service, simply contact the company
it was purchased from or the manufacturer listed on the rating
plate on the water heater.
Be sure to provide all pertinent facts when you call or visit.
Selling prices will be furnished on request or parts will be
shipped at prevailing prices and you will be billed accordingly.
The model number of your Water Heater will be found on the
rating place located above or adjacent to outer door.
WHEN ORDERING REPAIR PARTS, ALWAYS GIVE THE
FOLLOWINGINFORMATION:
• MODEL NUMBER
• SERIAL NUMBER
• PART DESCRIPTION
THIS ISAREPAIR PARTS LIST, NOTAPACKING LIST.
5
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16
Theseguidelines should beutilizedby a qualifiedserviceagent.
TROUBLESHOOTING GUIDELINES
Improperlysealed,hot orcold supply connection,
relief valve or drain valve.
Leakage from other appliances or water lines.
Thermal expansion in closed water system.
Improperly seated valve.
High sulfate or mineral content in water supply.
Bacteria in water supply.
Power supply to heater is not on.
Thermostat set too low.
Heater undersized.
Incoming water is usually cold (Winter).
Leaking hot water from pipes or fixtures.
High temperature limit switch activated.
Thermostat set too high.
High temperature limit switch activated.
Scale accumulation on elements.
Sediment build-up on tank bottom.
Tighten threaded connections.
Inspect other appliances near water heater.
Install thermal expansion tank
(DO NOT plug T&P valve).
Check relief valve for proper operation
(DO NOT plug T&P valve).
Drain and flush heater thoroughly, then refill.
Chlorinate water supply.
Turn disconnect switch on or contact
electrician.
Refer to temperature regulation.
Reduce hot water use.
Allow more time for heat to reheat.
Have plumber check and repair leaks.
Contact dealer to determine cause. See
temperature regulation.
Refer to temperature regulation.
Contact dealer to determine cause. See
temperature regulation.
Contact dealer to clean or replace elements.
Drain and flush heater thoroughly, then refill.
Problem Cause Solution
WATERLEAKS
(See Leakage Checkpoints on 14)
LEAKINGTEMPERATURE
ANDPRESSURE
RELIEFVALVE
HOTWATER ODORS
(CAUTION: UNAUTHORIZED REMOVAL OF THE
ANODE(S) WILL VOID THE WARRANTY FOR
FURTHER INFORMATION, CONTACT YOUR
DEALER)
NOTENOUGH
OR
NOHOT WATER
HOT WATER TOO HOT
WATERHEATERSOUNDS

17
RESIDENTIAL ELECTRIC WARRANTY
THIS WARRANTY IS APPLICABLE TO THE ORIGINAL
OWNER ONLY. In accordance with the warranty terms
and conditions specified below.
A. O. Smith Water Heaters (the warrantor) will furnish the
ORIGINAL OWNER, 1) a replacement A. O. Smith water
heater of equivalent size and current model if the glasslined
tank in this water heater leaks and, 2) a replacement part
for any component part which fails.
THE A. O. SMITH WATER HEATERS REPLACEMENT
MODELOR PART WILLBE WARRANTED FOR ONLYTHE
UNEXPIRED PORTION OF THE ORIGINAL WARRANTY.
The warranty period will be determined by the original date
of purchase of the water heater, or in the absence of a Bill
of Sale verifying said date, from the date of manufacture
indicated on rating plate affixed to this water heater. This
warranty is not transferrable and applies to models listed
below:
When the water heater has been used for other than single
family residential application;
1. The tank warranty shall be reduced to 1 year for 6 year
models and to 3 years for 10 year models.
2. The parts warranty shall be reduced to 1 year for all
models.
CONDITIONS AND EXCEPTIONS
This warranty shall apply only when the water heater is
installed and operated in accordance with 1) all local fire
codes and plumbing codes, ordinances and regulations, 2)
the printed instructions provided with 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 leakage from the tank or its connections would result
in damage to the area adjacent to the heater. In addition, a
new temperature and pressure relief valve, certified by the
CanadianGasAssociationmust havebeen properly installed
and piped to the nearest drain.
This warranty shall apply only when the heater is:
• owned by the original purchaser;
• installed for indoor operation only;
• used at temperatures not exceeding the maximum
calibrated setting of its thermostat;
• used at water pressure not exceeding the working
pressure shown on the heater;
• filled with potable water, free to circulate at all times
and with the tank free of damaging water sediment
or scale deposits;
• used in a non-corrosive and non-contaminated
atmosphere;
• used with factory approved anode(s) installed;
• in its original installation location;
• in the United States, its territories or possessions,
and Canada;
• sized in accordance with proper sizing techniques
for residential water heaters;
• bearing a rating plate which has not been altered,
defaced or removed except as required by the
warrantor;
• used in an open system or in a closed system with
aproperly sized and installedthermal expansion tank;
• connected to the proper voltage or:
• operated at the factory rated input;
• installed with no attempted, nor actual modification
or alteration of the water heater’s design in any way,
including but not limited to, the attachment of non-
company approved appliances or equipment.
Any accident to the water heater or any part thereof
(including freezing, fire, floods, or lightning), any misuse,
abuse or alteration of it, any operation of it in a modified
form, any operation of the water heater on desalinated
(deionized) water, or any damage caused by attempts
to repair tank leaks or parts, will void this warranty. This
warranty does not cover water heaters replaced for
cosmetic reasons or for reasons of noise, taste, odor,
discolored and/or rusty water. This warranty does not
apply to water heaters used to heat pools, whirlpools or
hot tubs or used for space heating where its sizing does
not conform with specifications of the heating component
manufacturer.
This warranty gives you specific legal rights, and you
may have other rights which vary under the laws of each
state. If any provision of this warranty is prohibited or
invalid under applicable state law, that provision shall be
ineffective to the extent of the prohibition or invalidity
Series Tank Parts
Conservationist®10-year 10-year
PXHT, PXHS
ProMax®10-Year Models 10-year 6-year
PCRT, PCRS, PCT, PCS, PCL, PCJ, PLJC, PLSC
ProMax®6-Year Models 6-year 6-year
ECRT, ECRS, ECT, ECS, ECL,
ECJ, ELJC, ESTT, ELSC

18
withoutinvalidating theremainderof theaffected provision
or the other provisions of this warranty.
SERVICE AND LABOR RESPONSIBILITY
UNDERTHISLIMITEDWARRANTY,THEWARRANTOR
WILL PROVIDE ONLY A REPLACEMENT WATER
HEATER OR PART THEREOF. THE OWNER IS
RESPONSIBLE FOR ALL OTHER COSTS. Such costs
may include but are not limited to:
a. Labor charges for service, removal, or reinstallation
of the water heater or part thereof.
b. Shipping and delivery charges for forwarding the new
water heater or replacement part from the nearest
distributor and returning the claimed defective heater
or part to such distributor.
c. All cost necessary or incidental for handling and
administrative charges, and for any materials and/or
permits required for installation of the replacement
heater or part.
LIMITATION ON IMPLIED WARRANTIES
Implied warranties, including any warranty of merchan-
tability imposed on the sale of this heater under state
law are limited to one year duration for the heater or
any of its parts. Some states do not allow limitations
on how long an implied warranty lasts, so the above
limitations may not apply to you.
CLAIM PROCEDURE
Any claim under this warranty should be initiated with
the dealer who sold the heater, or with any other dealer
handling the warrantor’s products. If this is not practical,
the owner should contact: A.O. Smith Corporation,
5621 W. 115th Street, Alsip, Illinois 60803. Phone:
1.800.323.2636 or visit our website: www.hotwater.com.
For Canadian customers contact: A.O. Smith
Enterprises LTD., P.O. Box 310, 768 Erie Street,
Stratford, Ontario N5A6T3 or phone: [phone]
Replacement Parts may be ordered through authorized
servicers or distributors. Refer to your local Yellow
Pagesfor whereto call orcontactA.O.Smith Corporation,
5621 W. 115th Street, Alsip, Illinois 60803.
Phone: [phone] or visit our website at:
www.hotwater.com/parts.
The warrantor will only honor replacement with identical
or similar water heater or parts thereof which are
manufactured or distributed by the warrantor.
Dealer replacements are made subject to in-warranty
validation by warrantor.
PROOFOF PURCHASEAND PROOF OF INSTALLATION
DATE ARE REQUIRED TO SUPPORT WARRANTY
CLAIM FROM ORIGINAL OWNER. THIS FORM DOES
NOT CONSTITUTE PROOF OF PURCHASE OR PROOF
OF INSTALLATION.
DISCLAIMERS
NO EXPRESSED WARRANTY HAS BEEN OR WILL BE
MADE IN BEHALF OF THE WARRANTOR WITH
RESPECTTOTHE MERCHANTABILITYOFTHE HEATER
OR THE INSTALLATION, OPERATION, REPAIR OR
REPLACEMENT OF THE HEATER OR PARTS. THE
WARRANTOR SHALL NOT BE RESPONSIBLE FOR
WATER DAMAGE, LOSS OF USE OF THE UNIT,
INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL
PROPERTY, OR OTHER CONSEQUENTIAL DAMAGE.
THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE
OF THIS WARRANTY OR OTHERWISE FOR DAMAGE
TO ANY PERSONS OR PROPERTY, WHETHER DIRECT
OR INDIRECT, AND WHETHERARISING IN CONTRACT
OR IN TORT.
Should governmental regulations or industry standards
prohibit the Manufacturer from furnishing a comparable
model replacement under this warranty, the Owner will be
furnishedwith the closestcomparable water heatermeeting
the then current governmental regulations and industry
standards.A supplementary fee may be assessed to cover
the additional cost associated with the changes made to
meet applicable regulations and standards.
IMPORTANT INFORMATION
Model Number _______________________________
Serial Number _______________________________
INSTALLATION INFORMATION
Date Installed _______________________________
Company’s Name ____________________________
Street or P.O. Box ____________________________
City, State, and Zip Code ______________________
Phone Number ______________________________
Plumber’s Name _____________________________
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19
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