John Wood JW375T75N-AV User manual

1
Instruction Manual
PRINTED 0814 326007-001
KEEP THIS MANUAL IN THE POCKET ON HEATER FOR FUTURE REFERENCE
WHENEVER MAINTENANCE ADJUSTMENT OR SERVICE IS REQUIRED.
COMMERCIAL GAS WATER HEATERS
• For Your Safety •
AN ODORANT IS ADDED TO THE GAS USED
BY THIS WATER HEATER.
MODELS JW375T75N-AV
and JW375T75P-AV
Series 300, 301
INSTALLATION - OPERATION - SERVICE
- MAINTENANCE - LIMITED WARRANTY
CANADIAN MANUAL
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
Read and understand this instruction
manual and the safety messages
herein before installing, operating or
servicing this water heater.
Failure to follow these instructions and
safety messages could result in death
or serious injury.
This manual must remain with the
water heater.
599 Hill Street West Fergus,
ON Canada N1M 2X1
Low Lead Content
WARNING: If the information in these
instructions is not followed exactly, a fire
or explosion may result causing property
damage, personal injury or death.
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do
not use any phone in your building.
Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
If you cannot reach your gas supplier,
call the fire department.
Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
•
•
•
•

2
SAFE INSTALLATION, USE AND SERVICE......................3
APPROVALS......................................................................3
GENERAL SAFETY INFORMATION..................................4
INTRODUCTION................................................................5
Abbreviations Used .....................................................5
 QualiedInstallerorServiceAgency........................... 5
Preparing for the New Installation ...............................5
INSTALLATION CONSIDERATIONS ............................. 6-9
Rough In Dimensions..................................................6
Thermometers.............................................................7
 FactstoConsiderAboutLocation ............................... 7
High Altitude ................................................................8
 Clearances ..................................................................8
Insulation Blankets ......................................................9
Hard Water ..................................................................9
 CirculationPumps .......................................................9
INSTALLATION REQUIREMENTS .................................. 10
 GasSupplySystems.................................................10
Gas Pressure Requirements.....................................10
 SupplyGasRegulator ...............................................10
Mixing Valves ............................................................10
Water Piping.............................................................. 11
 ClosedWaterSystems.............................................. 11
Thermal Expansion ................................................... 11
Temperature - Pressure Relief Valve......................... 11
Filling the Water Heater.............................................12
Air Requirements.......................................................12
 UnconnedSpace..................................................... 13
 ConnedSpace.........................................................13
 FreshAirOpeningsforConnedSpaces ..................13
Outdoor Air Through Two Openings.......................... 13
Outdoor Air Through One Opening ...........................13
 OutdoorAirThroughTwoHorizontalDucts...............14
 OutdoorAirThroughTwoVerticalDucts ................... 14
 AirFromOtherIndoorSpaces ..................................14
Venting ...................................................................... 14
Gas Piping.................................................................16
Sediment Traps .........................................................17
LIGHTING & OPERATING INSTRUCTIONS .............. 18,19
TEMPERATURE REGULATION ...................................... 20
FOR YOUR INFORMATION............................................. 20
Start Up Conditions ...................................................20
Operational Conditions..............................................21
PERIODIC MAINTENANCE............................................. 22
 VentingSystemInspection ........................................22
 BurnerInspection ......................................................22
Burner Cleaning ........................................................22
Housekeeping ...........................................................23
 AnodeRodInspection............................................... 23
Temperature-Pressure Relief Valve Test ...................23
 TankCleanoutProcedure..........................................24
 Service ......................................................................24
LEAKAGE CHECKPOINTS..............................................25
TROUBLESHOOTING GUIDELINES...............................26
WATER PIPING DIAGRAMS.......................................27-32
NOTES ........................................................................33-34
WARRANTY .....................................................................35
TABLE OF CONTENTS

3
SAFE INSTALLATION, USE AND SERVICE
Theproperinstallation,useandservicingofthiswaterheaterisextremelyimportanttoyoursafetyandthesafetyofothers.
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.
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.
TheCaliforniaSafeDrinkingWaterandToxicEnforcementActrequirestheGovernorofCaliforniatopublishalistofsubstances
known to the State of California to cause cancer, birth defects, or other reproductive harm, and requires businesses to warn of
potentialexposuretosuchsubstances.
ThisproductcontainsachemicalknowntotheStateofCaliforniatocausecancer,birthdefects,orotherreproductiveharm.This
waterheatercancauselowlevelexposuretosomeofthesubstanceslistedintheAct.
DANGER
WARNING
CAUTION
CAUTION
DANGER indicates an imminently
hazardous situation which, if not avoided,
will result in injury or death.
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.
WARNING indicates a potentially hazardous
situation which, if not avoided, could result
in injury or death.
CAUTION indicates a potentially hazardous
situation which, if not avoided, could 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.
APPROVALS
Low Lead Content

4
GENERAL SAFETY INFORMATION

5
ThankYouforpurchasingthiswaterheater.Properlyinstalledand
maintained,itshouldgiveyouyearsoftroublefreeservice.
ABBREVIATIONS USED
AbbreviationsFoundInThisInstructionManual:
• UL-UnderwritersLaboratoriesInc.
• ANSI-AmericanNationalStandardsInstitute
• NFPA-NationalFireProtectionAssociation
• ASME-AmericanSocietyofMechanicalEngineers
• AHRI - Air-Conditioning, Heating and Refrigeration Institute
• CAN - Canada
• EPACT-EnergyPolicyAct
• CSA-CanadianStandardsAssociation
This gas-fired water heater is design certified by Underwriters
LaboratoriesInc.underAmericanNationalStandard/CSAStandard
forGasWaterHeatersANSIZ21.10.3•CSA4.3(currentedition).
QUALIFIED INSTALLER OR SERVICE AGENCY
Installationandserviceofthiswaterheaterrequiresabilityequivalent
tothatofaQualiedAgency(asdenedbyANSIbelow)intheeld
involved. Installation skills such as plumbing, air supply, venting,
gassupplyandelectricalsupplyarerequiredinadditiontoelectrical
testingskillswhenperformingservice.
ANSIZ223.12006Sec.3.3.83:“QualiedAgency”-“Anyindividual,
rm, corporation or company that either in person or through a
representativeisengagedinandisresponsiblefor(a)theinstallation,
testingorreplacementofgaspipingor(b)theconnection,installation,
testing, repair or servicing of appliances and equipment; that is
experiencedinsuchwork;thatisfamiliarwithallprecautionsrequired;
and that has complied with all the requirements of the authority
havingjurisdiction.”
If you are not qualied (as dened byANSI above) and licensed or
certied as required by the authority having jurisdiction to perform a
giventaskdonotattempttoperformanyoftheproceduresdescribed
inthismanual.Ifyoudonotunderstandtheinstructionsgiveninthis
manualdonotattempttoperformanyproceduresoutlinedinthismanual.
PREPARING FOR THE INSTALLATION
1. Read the “General Safety” section, page4of this manual
first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,SERIOUSBODILYINJURYAND/OR
PROPERTY DAMAGE.
 This manual contains instructions for the installation,
operation,andmaintenanceofthegas-f iredwaterheater.It
alsocontainswarningsthroughoutthemanualthatyoumust
readandbeawareof.Allwarningsandallinstructionsare
essentialtotheproperoperationofthewaterheaterandyour
safety.Sincewecannotputeverythingonthefirstfewpages,
READ THE ENTIRE MANUAL BEFORE ATTEMPTING TO
INSTALL OR OPERATE THE WATER HEATER.
2.The installation must conform with 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orCAN/CSA-B149.1theNaturalGasandPropane
Installation Code. All documents are available from the
CanadianStandardsAssociation,8501EastPleasantValley
Road, Cleveland, OH 44131. NFPA documents are also
available from the National Fire Protection Association, 1
BatterymarchPark,Quincy,MA02269.
3.Ifafterreading thismanualyouhaveanyquestionsordo
notunderstandanyportionoftheinstructions,callthelocal
gasutilityorthemanufacturerwhosenameappearsonthe
rating plate.
4.Carefully plan the place where you are going to put the
water heater.  Correct  combustion, vent action, and vent
pipeinstallationareveryimportantinpreventingdeathfrom
possiblecarbonmonoxidepoisoningandfires,seeFigures
3 and 7.
 Examinethelocationtoensurethewaterheatercomplieswith
the“LocatingtheNewWaterHeater”sectioninthismanual.
5.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California
Office of the State Architect, 400 P Street, Sacramento,
CA 95814.
6.MassachusettsCoderequiresthiswaterheatertobeinstalled
in accordance with Massachusetts 248-CMR 2.00: State
Plumbing Code and 248-CMR 5.00.
INTRODUCTION

6
ROUGH IN DIMENSIONS
TABLE 1. DIMENSIONS AND RECOVERY RATINGS
DIMENSIONS
Models Units A B C D E F G H J K L M
JW375T75N-AV
JW375T75P-AV
Inches
CM
611/8
155.25
581/2
148.6
2911/16
75.4
261/2
67.3
153/16
38.6
4
10.2
141/2
39.4
16
40.6
11/4
3.2
1
NPT
1/2
NPT
1115/16
30.3
RECOVERY RATINGS
Models
Input Approx.
Gal.
Cap.
Approx.
Liter
Cap.
Temp.
Rise
C° 17 22 28 33 39 44 50 56 61 67 72 78
Rating
Btu/Hr
Rating
kW F° 30 40 50 60 70 80 90 100 110 120 130 140
JW375T75N-AV
JW375T75P-AV 75,100 22 74 280 GPH 243 182 146 121 104 91 81 73 66 61 56 52
LPH 916 686 550 456 392 343 305 275 249 230 211 196
Recoveryratingsbasedon80%thermalefciency.
INSTALLATION CONSIDERATIONS
FIGURE 1.

7
THERMOMETERS (Not Supplied)
Thermometersshouldbeobtainedandeldinstalled.
Thermometersareinstalledinthesystemasameansofdetecting
thetemperatureoftheoutletwatersupply.
ThisWaterHeaterhasbeendesigncertifiedascomplyingwith
ANSIZ21.10.3-CSA4.3currenteditionforwaterheatersandis
consideredsuitablefor:
Water (Potable) Heating and Space Heating:All models are
consideredsuitableforwater(potable)heatingandspaceheating.
HOTTERWATERCANSCALD:
Waterheatersareintendedtoproducehotwater.Waterheatedtoa
temperaturewhichwillsatisfyspaceheating,clotheswashing,dish
washing,andothersanitizingneedscanscaldandpermanentlyinjure
youuponcontact.Somepeoplearemorelikelytobepermanently
injuredbyhotwaterthanothers.Theseincludetheelderly,children,
theinrm,orphysically/mentallyhandicapped.Ifanyoneusinghot
waterinyourhometsintooneofthesegroupsorifthereisalocal
coderequiringacertaintemperaturewateratthehotwatertap,then
youmusttakespecialprecautions.Inadditiontousingthelowest
possible temperature setting that satises your hot water needs,
ameanssuchasa*MixingValveshouldbeusedatthehotwater
tapsusedbythesepeopleoratthewaterheater.Mixingvalvesare
availableatplumbingsupplyorhardwarestores.Consultaqualied
installer or service agency. Follow mixing valve manufacturer’s
instructions for installation of valves. Before changing the factory
settingonthethermostat,readthe“TemperatureRegulation”section
in this manual, see Figures 17 and 18.
FACTS TO CONSIDER ABOUT THE LOCATION
Carefully choose an indoor location for the new water heater,
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 water heater. This water heater is not
foruseinmanufactured(mobile)homesoroutdoorinstallation.
Whetherreplacinganoldwaterheaterorputtingthewaterheater
inanewlocation,thefollowingcriticalpointsmustbeobserved:
1.Selectalocationindoorsascloseaspracticaltothegasventor
chimneytowhichthewaterheaterventisgoingtobeconnected,
andascentralizedwiththewaterpipingsystemaspossible.
2.Selected location must provide adequate clearances for
servicingandproperoperationofthewaterheater.
Installationofwaterheatermustbeaccomplishedinsuchamannerthat
ifthetankoranyconnectionsshouldleak,owwillnotcausedamageto
thestructure.Forthisreason,itisnotadvisabletoinstallwaterheater
inanatticorupperoor.Whensuchlocationscannotbeavoided,a
suitable metal drain pan should be installed under the water heater.
MetalDrainpansareavailableatyourlocalhardwarestore.Sucha
metal drain pan must have a minimum length and width of at least
2”(51mm)greaterthanwaterheaterdimensionsandmustbepiped
toanadequatedrain.Thepanmustnotrestrictcombustionairow.
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.
INSTALLATIONS IN AREAS WHERE FLAMMABLE LIQUIDS
(VAPORS)ARELIKELYTOBEPRESENTORSTORED(GARAGES,
STORAGEANDUTILITYAREAS,ETC.):Flammableliquids(suchas
gasoline,solvents,propane[LPorbutane,etc.]andothersubstances
suchasadhesives,etc.)emitammablevaporswhichcanbeignitedby
agaswaterheater’spilotlightormainburner.Theresultingashback
andrecancausedeathorseriousburnstoanyoneinthearea,aswell
aspropertydamage.Ifinstallationinsuchareasisyouronlyoption,then
installationmustbeaccomplishedinawaythatthepilotameandmain
burnerameareelevatedfromooratleast18inches.Whilethismay
reducechancesofammablevapors,fromaoorspillbeingignited,
gasolineandotherammablesubstancesshouldneverbestoredor

8
usedinthesameroomorareacontainingagaswaterheaterorother
openameorsparkproducingappliance.NOTE:Flammablevaporsmay
bedrawnbyaircurrentsfromotherareasofthestructuretotheappliance.
Also,thewater heatermustbe located and/orprotected so itisnot
subjecttophysicaldamagebyamovingvehicle.
Thiswaterheatermustnotbeinstalleddirectlyoncarpeting.Carpeting
mustbeprotectedbymetalorwoodpanelbeneaththewaterheater
extendingbeyondthefullwidthanddepthofthewaterheaterbyatleast
3”(76.2mm)inanydirection,orifthewaterheaterisinstalledinan
alcoveorcloset,theentireoormustbecoveredbythepanel.Failure
toheedthiswarningmayresultinarehazard.
HIGH ALTITUDE
Waterheaterscoveredinthismanualhavebeentestedandapproved
forinstallation atelevations upto 7,700feet (2,347m) abovesea
level.Forinstallationabove7,700feet(2,347m),thewaterheater’s
Btuinputshouldbereducedattherateof4percentforeach1,000
feet(305m)abovesealevelwhichrequiresreplacementoftheburner
oriceinaccordancewiththeNationalFuelGasCodeANSIZ223.1/
NFPA54or the NaturalGasandPropane Installation CodeCAN/
CSAB149.1.Contactyourlocalgassupplierforfurtherinformation.
Failuretoreplacethestandardoricewiththeproperhighaltitude
orice when installed at elevations above 7,700 feet (2,347 m)
couldresultinimproperandinefcientoperationofthewaterheater,
producingcarbonmonoxidegasinexcessofthesafelimits.This
couldresultinseriousinjuryordeath.Contactyourlocalgassupplier
foranyspecicchangesthatmayberequiredinyourarea.
CLEARANCES
Minimum clearances between the water heater and combustible
constructionare0inchatthesidesandrear,4”(102mm)atthe
front,and6”(153mm)fromtheventpipe.Clearancefromthetop
ofthejacketis12”(305mm)onmostmodels.
FIGURE 2.
A gas water heater cannot operate properly without the correct
amountofairforcombustion.Donotinstallinaconnedareasuch
asacloset,unlessyouprovideairasshowninthe“LocatingThe
NewWaterHeater”section.Neverobstructtheowofventilation
air.Ifyouhaveanydoubtsorquestionsatall,callyourgassupplier.
Failuretoprovidetheproperamountofcombustionaircanresult
in a re or explosion and cause death, serious bodily injury, or
propertydamage.
FIGURE 3.
Ifthiswaterheaterwillbeusedinbeautyshops,barbershops,
cleaning establishments, or self-service laundries with dry
cleaning equipment, it is imperative that the water heater or
water heaters be installed so that combustion and ventilation
air be taken from outside these areas.
Propellantsofaerosolspraysandvolatilecompounds,(cleaners,
chlorinebasedchemicals,refrigerants,etc.)inadditiontobeing
highlyammableinmanycases,willalsochangetocorrosive
hydrochloricacidwhenexposedtothecombustionproductsof
thewaterheater.Theresultscanbehazardous,andalsocause
productfailure.

9
INSULATION BLANKETS
Do not obstruct water heater air intake
with insulating blanket.
Gas and carbon monoxide detectors
are available.
Install water heater in accordance with
the instruction manual.
Breathing carbon monoxide can cause brain damage or
death. Always read and understand instruction manual.
Breathing Hazard - Carbon Monoxide Gas
Insulation blankets are available to the general public for
external use on gas water heaters but are not necessary
with these products. The purpose of an insulation blanket is
to reduce the standby heat loss encountered with storage
tankheaters.Thewaterheaterscoveredbythismanualmeet
or exceed the Energy Policy Act standards with respect to
insulation and standby heat loss requirements, making an
insulationblanketunnecessary.
Should you choose to apply an insulation blanket to this
heater,youshouldfollowtheseinstructions.SeetheFeatures
and Components section of this manual 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applyinsulationtothetopofthewaterheater,as
this will interfere with safe operation of the draft hood.
• DO NOTcoverthethermostatortheTemperature-
Pressure Relief Valve.
• DO NOTallowtheinsulationtocomewithin2inches(5
cm)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fromthe
manufacturer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the
combustionairflow.
HARD WATER
Wherehardwaterconditionsexist,watersofteningorthethreshold
type of water treatment is recommended. This will protect the
dishwashers,coffeeurns,waterheaters,waterpipingandother
equipment. See the Maintenance Section in this manual for
sedimentandlimescaleremovalprocedures.
CIRCULATION PUMPS
Acirculatingpumpisusedwhenasystemrequiresacirculating
loop or there is a storage tank used in conjunction with the
water heater. See Water Piping Diagrams in this manual for
installationlocationofcirculatingpumps.
SeetheCirculationPumpWiringDiagramsbelowforelectrical
hookup information. Install in accordance with the current
edition of the National Electrical Code, NFPA 70 or the
CanadianElectricalCode,CSAC22.1.
Allbronzeorstainlesssteelcirculatingpumpsarerecommended
forusedwithcommercialwaterheaters.
Somecirculatingpumpsaremanufacturedwithsealedbearings
anddonotrequirefurtherlubrication.Somecirculatingpumps
must beperiodicallyoiled.Refer to the pumpmanufacturer’s
instructionsforlubricationrequirements.
CIRCULATING PUMP WIRING DIAGRAM
STORAGE TANK OR BUILDING RECIRCULATION
FIELD SUPPLIED TEMPERATURE CONTROL
INSTALLED IN THE STORAGE TANK
OR CIRCULATING LOOP RETURN LINE
CIRC
PUMP
MOTOR
L1 HOT
L2 NEUTRAL
120 VAC
POWER
NOTE: USE SEPARATE 120 VAC POWER
SUPPLY FOR PUMP CIRCUIT. DO NOT
SHARE POWER WITH APPLIANCE AS THIS
MAY CAUSE ELECTRICAL LINE NOISE AND
LEAD TO ERRATIC CONTROL SYSTEM
OPERATION.
FIGURE 4.
CIRCULATING PUMP WIRING DIAGRAM
DISHWASHER LOOP WITH TOGGLE SWITCH
FIELD SUPPLIED TEMPERATURE
CONTROL INSTALLED IN THE
CIRCULATING LOOP RETURN LINE
DISHWASHER
TOGGLE
SWITCH
CIRC
PUMP
MOTOR
L1 HOT
L2 NEUTRAL
120 VAC
POWER
NOTE: USE SEPARATE 120 VAC POWER
SUPPLY FOR PUMP CIRCUIT. DO NOT
SHARE POWER WITH APPLIANCE AS THIS
MAY CAUSE ELECTRICAL LINE NOISE AND
LEAD TO ERRATIC CONTROL SYSTEM
OPERATION.
FIGURE 5.

10
GAS SUPPLY SYSTEMS
Low pressure building gas supply systems are dened as those
systemsthatcannotunderanycircumstancesexceed14”W.C.
(1/2PSIGauge).Thesesystemsdonotrequirepressureregulation.
Measurements should be taken to insure that gas pressures are stable
and fall within the requirements stated on the water heater rating plate.
readingsshould betaken with all gas burningequipment off(static
pressure)andwithallgasburningequipmentrunningatmaximumrate
(dynamicpressure).Thegassupplypressuremustbestablewithin1.5”
W.C.fromstatictodynamicpressuretoprovidegoodperformance.
Pressuredropsthatexceed1.5”W.C.maycauseroughstarting,noisy
combustionornuisanceoutages.Increasesorspikesinstaticpressure
duringoffcyclesmaycausefailuretoigniteorinseverecasesdamage
toappliancegasvalves.Ifyourlowpressuresystemdoesnotmeet
theserequirements,theinstallerisresponsibleforthecorrections.
HighPressurebuildingsupplysystemsusepressuresthatexceed
14” W.C. (1/2 PSI Gauge). These systems must use eld supplied
regulatorstolowerthegaspressuretolessthan14”W.C.(1/2PSI
Gauge).Appliancesrequiregasregulatorsthatareproperlysizedforthe
waterheaterinputanddelivertheratingplatespeciedpressures.Gas
supplysystemswherepressureexceeds5PSIoftenrequiremultiple
regulatorstoachievedesiredpressures.Systemsinexcessof5PSI
buildingpressureshouldbedesignedbygasdeliveryprofessionals
forbestperformance.Waterheatersconnectedtogassupplysystems
thatexceed14”W.C.(1/2PSIGauge)atanytimemustbeequipped
withagassupplyregulator.
GAS PRESSURE REQUIREMENTS
Naturalgasmodelsrequireaminimumgassupplypressureof4.5”
W.C.(1.12kPa).Propanegasmodelsrequireaminimumgassupply
pressure of 11” W.C. (2.74 kPa). The minimum supply pressure
is measured while gas is owing (dynamic pressure). The supply
pressure(dynamic)shouldneverfallbelowthespeciedminimum
supplypressure.Thesupplypressureshouldbemeasuredwithallgas
redappliancesconnectedtothecommonmainringatfullcapacity.If
thesupplypressuredropsmorethan1.5”W.C.(0.37kPa)asgasbegins
toowtothewaterheaterthenthesupplygassystemincludingthe
gaslineand/orthegasregulatormayberestrictedorundersized.See
SupplyGasregulatorsectionandGasPipingsectionofthismanual.
Thegasvalveonallmodelshasamaximumgassupplypressurelimit
of14”W.C.(3.48kPa)Themaximumsupplypressureismeasured
whilegasisnotowing(staticpressure).
SUPPLY GAS REGULATOR
Themaximumallowablegassupplypressureforthiswaterheater
is14.0inchesW.C.(3.48kPa).Installapositivelock-upgaspressure
regulatorinthegassupplylineifinletgaspressurecanexceed14.0
inchesW.C.(3.48kPa) atanytime. regulatorsmustbe sized/used
accordingtomanufacturer’sspecications.
Ifapositivelock-upregulatorisrequiredfollowtheseinstructions:
1. Positivelock-upgaspressureregulatorsmustberatedatorabove
 theinputBtu/hrratingofthewaterheatertheysupply.
2. Positivelock-upgaspressureregulator(s)shouldbeinstalledno
 closerthan3feet(1meter)andnofartherthan8feet(2.4meters)
 ofequivalentlengthfromthewaterheater’sinletgasconnection.
3. Afterinstallingthepositivelock-upgaspressureregulator(s)aninitial
 nominalsupplypressuresettingof7.0”W.C.whilethewaterheater
 isoperatingisrecommendedandwillgenerallyprovidegood
 waterheateroperation.Someadditionadjustmentmayberequired
 latertomaintainasteadygassupplypressure.
4. When installing multiple water heaters in the same gas supply
 system it is recommended that individual positive lock-up gas
 pressureregulatorsbeinstalledateachunit.
MIXING VALVES
Water temperature over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and the physically
or mentally disabled are at highest risk
for scald injury.
Feel water before bathing or showering.
Temperature limiting devices such as
mixing valves must be installed when
required by codes and to ensure safe
temperatures at fixtures.
Waterheatedtoatemperaturewhichwillsatisfyclotheswashing,dish
washing,andothersanitizingneedscanscaldandcausepermanent
injuryuponcontact.Shortrepeatedheatingcyclescausedbysmall
hotwaterusescancausetemperaturesatthepointofusetoexceed
thewaterheater’stemperaturesettingbyupto20°F(11°C).
Somepeoplearemorelikelytobepermanentlyinjuredbyhotwater
than others. These include the elderly, children, the inrm and the
physically/mentally disabled. Table 2 shows the approximate time-
to-burnrelationshipfornormaladultskin.Ifanyoneusinghotwater
providedbythewaterheaterbeinginstalledtsintooneofthesegroups
orifthereisalocalcoderequiringacertainwatertemperatureatthe
pointofuse,thenspecialprecautionsmustbetaken.
In addition to using the lowest possible temperature setting that
satisesdemandoftheapplicationaMixingValveshouldbeinstalled
atthewaterheaterorathotwatertapstofurtherreducesystemwater
temperature. See Figure 6.
Mixing valves are available at plumbing supply stores. Consult
a Qualified Installer or ServiceAgency. Follow mixing valve
manufacturer’sinstructionsforinstallationofthevalves.
TABLE 2.
Water
Temperature °F
Time for
1st Degree Burn
(LessSevereBurns)
Time for Permanent Burns
2nd & 3rd Degree
(MostSevereBurns)
110
(normalshowertemp.)
116 (painthreshold)
116 35 minutes 45 minutes
122 1 minute 5 minutes
131 5seconds 25seconds
140 2seconds 5seconds
149 1second 2seconds
154 instantaneous 1second
(U.S.GovernmentMemorandum,C.P.S.C.,PeterL.Armstrong,Sept.15,1978)
HOT WATER
OUTLET
TO TANK
INLET
CHECK
VALVE
MIXING
VALVE
COLD
WATER
INLET
TEMPERED WATER
OUTLET
12” TO 15”
(30-38 cm)
CHECK
VALVE
FIGURE 6.
INSTALLATION REQUIREMENTS