A.O. Smith 185363-001 User manual

1
Instruction Manual
PRINTEDINTHEU.S.A 0905 PART NO. 185363-001
KEEPTHISMANUALINTHEPOCKETONHEATERFORFUTUREREFERENCE
WHENEVERMAINTENANCEADJUSTMENTORSERVICEISREQUIRED.
POWER VENTED GAS MODELS W/HOT SURFACE IGNITION
NOT FOR USE IN MANUFACTURED (MOBILE) HOMES
ALLTECHNICALAND WARRANTYQUESTIONS: SHOULDBEDIRECTEDTOTHELOCALDEALERFROMWHOMTHEWATERHEATERWAS
PURCHASED.IFYOUAREUNSUCCESSFUL,PLEASEWRITETOTHECOMPANYLISTEDONTHERATINGPLATEONTHEWATERHEATER.
RESIDENTIAL GAS WATER HEATERS
• For Your Safety •
ANODORANTISADDEDTOTHEGASUSED
BYTHISWATERHEATER.
C3 Technology® Gas Water Heaters meet the new
ANSI Z21.10.1 standard that deals with the accidental or
unintended ignition of flammable vapors, such as those
emitted by gasoline.
GAMA certification applies to
all residential gas water
heaters with capacities of 20
to100gallonswith inputrating
of 75,000 BTU/Hr. or less.
ADIVISIONOFA.O.SMITHCORPORATION
Ashland City, TN 37015
www.hotwater.com

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.
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.
IMPORTANT DEFINITIONS
•Qualified Installer: Aqualifiedinstallermust have abilityequivalentto a licensedtradesmanin the fieldsofplumbing,
air supply, venting and gas supply, including a thorough understanding of the requirements of the National Fuel Gas
Code as it relates to the installation of gas fired water heaters. The qualified installer must also be familiar with the
designfeaturesand useofflammable vaporignitionresistant waterheaters,and haveathorough understandingof this
instructionmanual.
•ServiceAgency: Aservice agencyalso must haveabilityequivalent toalicensed tradesman inthefields of plumbing,
air supply, venting and gas supply, including a thorough understanding of the requirements of the National Fuel Gas
Code as it relates to the installation of gas fired water heaters. The service agency must also have a thorough
understandingofthisinstructionmanual,and be able to perform repairs strictlyinaccordancewiththeservice guidelines
providedbythemanufacturer.
•Gas Supplier: The Natural Gas or Propane Utility or service who supplies gas for utilization by the gas burning
appliances within this application. The gas supplier typically has responsibility for the inspection and code approval of
gas piping up to and including the Natural Gas meter or Propane storage tank of a building. Many gas suppliers also
offerservice and inspectionof appliances withinthe building.

3
GENERAL SAFETY

4
SAFEINSTALLATION,USEANDSERVICE...............................2
GENERALSAFETY ..................................................................3
TABLEOFCONTENTS ..............................................................4
INTRODUCTION ........................................................................4
Preparing for the New Installation ...................................4
TYPICALINSTALLATION ...................................................... 5-6
LOCATINGTHENEWWATERHEATER .....................................7
Facts to ConsiderAbout Location ............................... 7-8
InsulationBlankets ...........................................................8
CombustionAir and Ventilation forAppliances
Located in Unconfined Spaces........................................8
CombustionAir and Ventilation forAppliances
Located in Confined Spaces........................................ 8-9
INSTALLINGTHEWATERHEATER ......................................... 10
WaterPiping ..............................................................10-11
Temperature-Pressure Relief Valve............................... 11
GasPiping ......................................................................12
SedimentTraps ..............................................................13
BlowerAssembly Installation ........................................13
Vent Pipe Connection to Blower Assembly ................... 14
Venting and Installation ............................................ 14-15
LIGHTING&OPERATINGLABEL ............................................ 20
TEMPERATUREREGULATION ................................................ 21
FORYOURINFORMATION .....................................................22
Start Up Conditions ........................................................22
Condensate .................................................................... 22
Smoke/Odor....................................................................22
ThermalExpansion ......................................................... 22
Strange Sounds.............................................................. 22
OperationalConditions...................................................22
SmellyWater ..................................................................22
“Air” in Hot Water Faucets.............................................22
High Temperature Shut Off System ...............................22
PERIODICMAINTENANCE .......................................................23
Venting System Inspection ............................................23
Burner Inspection ...........................................................23
BurnerCleaning.............................................................. 23
Housekeeping .......................................................... 23-24
Anode Rod Inspection....................................................24
Temperature-Pressure Relief Valve Operation..............24
Draining ..........................................................................24
Drain Valve Washer Replacement ........................... 24-24
Service ...........................................................................25
LEAKAGECHECKPOINTS ......................................................25
REPAIRPARTS .......................................................................26
TROUBLESHOOTING ........................................................ 27-28
NOTES .............................................................................. 29-30
WARRANTY ...........................................................................31
Thank You for purchasing this water heater. Properly installed and
maintained,itshouldgiveyouyears of trouble free service.
AbbreviationsFoundInThisInstructionManual:
• CSA-Canadian StandardsAssociation
• ANSI-AmericanNationalStandardsInstitute
• NFPA- NationalFire ProtectionAssociation
• ASME-AmericanSocietyofMechanical Engineers
• GAMA-GasApplianceManufacturer’sAssociation
• UL- Underwriters Laboratories Inc.
This gas-fired water heater is design certified by Underwriters
LaboratoriesInc. underAmericanNationalStandard/CSAStandardfor
GasWaterHeatersANSIZ21.10.1 • CSA4.1 (current edition).
PREPARING FOR THE INSTALLATION
1. Read the “General Safety” section, page 3ofthis manual first and
thenthe entire manualcarefully. If you don’tfollowthe safety rules,
thewater heater will not operate properly. It could cause DEATH,
SERIOUSBODILYINJURYAND/ORPROPERTYDAMAGE.
Thismanualcontainsinstructions fortheinstallation, operation,and
maintenanceofthegas-firedwaterheater. Italsocontainswarnings
throughout the manual that you must read and be aware of. All
warningsandall instructions are essential to the proper operation
ofthewaterheater andyoursafety. Sincewecannot puteverything
on the first few pages, READ THE ENTIRE MANUAL BEFORE
ATTEMPTINGTOINSTALLOROPERATETHEWATERHEATER.
2. The installation must conform with these instructions and the local
code authority having jurisdiction. In the absence of local codes,
installationsshallcomplywiththeNationalFuelGasCodeANSIZ223.1/
NFPA54andtheNationalElectricalCode,NFPA70.Thesepublications
are available from The National Fire Protection Association, 1
BatterymarchPark,Quincy,MA02269.
3. The water heater when installed must be grounded in accordance
withthe local codes, or in the absence of localcodes:IntheUnited
States,theNational ElectricCode.ANSI/NFPA70.
4. If after reading this manual you have any questions or do not
understandany portionofthe instructions,callthe localgasutility or
themanufacturer whose name appears on the rating plate.
5. Carefullyplantheplace whereyou aregoing toput thewater heater.
Correct combustion,vent action,andvent pipe installationarevery
important in preventing death from possible carbon monoxide
poisoningandfires,seeFigures1and2.
Examinethelocationtoensurethewaterheatercomplieswiththe
“Locatingthe New Water Heater” sectioninthismanual.
6. ForCaliforniainstallationthiswaterheatermustbebraced,anchored,
or strapped to avoid falling or moving during an earthquake. See
instructionsfor correctinstallationprocedures. Instructions may be
obtained from California Office of the StateArchitect, 400 P Street,
Sacramento,CA95814.
7. Massachusetts Code requires this water heater to be installed in
accordancewithMassachusetts248-CMR2.00:StatePlumbingCode
and248-CMR5.00.
8. Complies with SCAQMDrule#1121anddistrictshavingequivalent
NOxrequirements.
INTRODUCTION
TABLE OF CONTENTS

5
TYPICAL INSTALLATION
GET TO KNOW YOUR WATER HEATER - GAS MODELS
A Vent Pipe–Exhaust
B Vent Terminal
C Vent Adapter-Rubber Boot
D Blower Assembly
E Cold Water Inlet
F Inlet Water Shut-off Valve
G Union
H Inlet Dip Tube
J Anode**
FIGURE1.
K Hot Water Outlet
L Outlet Receptacle (115 VAC)
M Temperature-Pressure Relief Valve
N Flue
O Flue Baffle Assembly**
P Insulation
Q Control Harness
R Rating Plate
S Gas Supply
T Manual Gas Shut-off Valve
U Ground Joint Union
V Drip Leg (Sediment Trap)
W Drain Valve
X Gas Valve-Thermostat
Y Drain Pan
Z Air Intake Screen - Base Pan
AA Inner Door
BB Outer Door
CC HSI Burner Assembly
DD Air Intake Screen -
Blower Assembly
EE FV Sensor Assembly
NATURAL HOT SURFACE IGNITER & MAIN BURNER
HOT
SURFACE
IGNITOR
SENSOR
PROPANE HOT SURFACE IGNITER&MAIN BURNER
TEMPERATURE INDICATORS
TEMPERATUREADJUSTMENT BUTTONS
HOT
SURFACE
IGNITOR
SENSOR
*CAUTION: 115 VAC IN CONTROL HARNESS
AND INSIDE OUTER DOOR
* ALL PIPING MATERIALS TO BE SUPPLIED BY CUSTOMERS.
** LOCATED UNDER THE BLOWER ASSEMBLY.
GAS MODELS
WITH HOT SURFACE IGNITION
& 2", 3" OR 4" PVC VENT CAPABILITY

6
TYPICAL INSTALLATION
FIGURE2.
MIXING VALVE USAGE
Thisappliancehasbeendesign certified as complying withAmerican
NationalStandard/CSAStandardfor waterheatersand is considered
suitablefor:
Water (Potable) Heating and Space Heating: All models are
consideredsuitableforwater (potable) heating and space heating.
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 sanitizing needs canscaldandpermanently injure
you upon contact. Some people are more likely to be permanently
injured by hot water than others. These include the elderly, 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, then you musttakespecialprecautions. In addition to using
the lowest possible temperature setting that satisfies your hot water
needs, a means such as a *Mixing Valve, shall be used at the hot
watertapsusedby these people or at the water heater. Mixingvalves
areavailableat plumbingsupplyorhardwarestores.Consulta Qualified
Installer or Service Agency. Follow mixing valve manufacturer’s
instructionsforinstallation of the valves. Before changing the factory
settingon thethermostat,readthe “TemperatureRegulation” sectionin
thismanual, see Figure 20.

7
FACTSTO CONSIDERABOUT THE LOCATION
Carefullychoose anindoorlocation for thenewwater heater, because
the placement is a very important consideration for the safety of the
occupantsinthebuildingandforthemosteconomicaluseoftheappliance.
This water heater is not for use in manufactured (mobile) homes
or outdoor installation.
Whetherreplacing an old water heater or putting the water heater in a
newlocation, thefollowingcritical points mustbeobserved:
1. Selectalocationindoorsasclose aspractical tothe ventterminal or
locationtowhichthewaterheaterventpipingisgoingtobeconnected,
andas centralized withthewater piping system aspossible.
2. Selected location must provide adequate clearances for servicing
andproper operation ofthewater heater.
Installationofthe waterheater mustbeaccomplishedinsuchamanner
that if the tank or any connections should leak, the flow will not cause
damagetothe structure. Forthis reason,it isnotadvisabletoinstallthe
waterheater in anatticor upper floor. Whensuch locationscannotbe
avoided,asuitabledrainpanshouldbeinstalledunderthe waterheater.
Drainpansare availableatyourlocalhardwarestore. Sucha drainpan
musthaveaminimumlengthandwidthofatleast2"(5.1cm)greaterthat
thewater heater dimensionsandmustbe piped to anadequatedrain.
Thepanmust not restrictcombustion air flow.
Water heater life depends upon water quality, water pressure and the
environment in which the water heater is installed. Water heaters are
sometimesinstalled in locationswhereleakage may resultinproperty
damage, even with the use of a drain pan piped to a drain. However,
unanticipateddamagecanbereducedorpreventedbyaleakdetectoror
watershut-offdeviceusedinconjunctionwithapipeddrainpan.These
devices are available from some plumbing supply wholesalers and
retailers,and detectandreactto leakageinvarious ways:
• Sensorsmounted inthedrain panthattrigger analarmor turnoffthe
incomingwater to thewaterheater when leakageisdetected.
• Sensorsmountedinthedrainpan thatturn offthewatersupplyto the
entirehome whenwateris detected inthedrain pan.
• Water supply shut-off devices that activate based on the water
pressure differential between the cold water and hot water pipes
connectedto thewaterheater.
• Devicesthat willturn offthegas supplytoa gaswaterheater whileat
thesame time shuttingoff its water supply.
INSTALLATIONSINAREASWHEREFLAMMABLELIQUIDS(VAPORS)
ARELIKELYTOBEPRESENTORSTORED(GARAGES,STORAGEAND
UTILITYAREAS,ETC.):Flammableliquids(suchasgasoline,solvents,
propane(LPor butane,etc.) andothersubstances(suchasadhesives,
etc.)emitflammablevaporswhichcanbeignitedbyagaswaterheater’s
hotsurface igniteror mainburner. The resultingflashback andfirecan
cause death or serious burns to anyone in the area. This water is
equipped with a FV sensor for detecting the presence of flammable
vapors, see Figure 3. When the sensor detects those vapors, the unit
willshut downand notoperate.Should thishappen,please refertothe
troubleshootingguideonpages27-28. Eventhoughthiswaterheateris
a flammable vapors ignition resistant water heater and is designed to
reduce the chances of flammable vapors being ignited, gasoline and
otherflammablesubstancesshouldneverbestoredorusedinthesame
vicinity or area containing a gas water heater or other open flame or
sparkproducingappliance.
LOCATING THE NEW WATER HEATER
FIGURE3.
Also, the water heater must be located and/or protected so it is not
subjecttophysical damageby amovingvehicle.
Thiswaterheater mustnot beinstalled directlyon carpeting. Carpeting
mustbeprotectedbymetalorwoodpanelbeneaththeapplianceextending
beyondthefullwidthanddepthoftheappliancebyatleast3"(7.6cm)in
any direction, or if the appliance is installed in an alcove or closet, the
entirefloor mustbecovered bythepanel. Failure toheedthis warning
mayresult in afirehazard.
Minimum clearances between the water heater and combustible
constructionare0inch atthe sidesandrear,5"(12.7cm)fromthefront

8
and 12" (30.5 cm) from the top. (Standard clearance.) If clearances
statedontheheaterdifferfromstandardclearances,installwaterheater
accordingto clearancesstatedonthe heater.
Adequateclearance forservicingthis appliance shouldbeconsidered
beforeinstallation,suchas changingtheanodes, etc.
A minimum clearance of 5" (12.7 cm) must be allowed for access to
replaceablepartssuchas thethermostats,drainvalveand reliefvalve.
Wheninstallingtheheater,considerationmustbegiventoproperlocation.
Locationselected should be asclosetothe wall as practicableandas
centralizedwith the waterpipingsystem as possible.
FIGURE4.
Agaswaterheatercannotoperate properlywithout thecorrect amount
ofairforcombustion. Do notinstallinaconfined areasuchasacloset,
unless you provide air as shown in the “Locating The New Water
Heater”section. Never obstruct the flow of ventilation air. If you have
anydoubtsor questionsatall, callyour gassupplier. Failuretoprovide
the proper amount of combustion air can result in a fire or explosion
andcause death, serious bodily injury,or property damage.
FIGURE5.
Ifthiswater heaterwill beusedinbeautyshops,barbershops,cleaning
establishments,or self-servicelaundrieswith dry cleaningequipment,
it is imperative that the water heater or water heaters be installed so
thatcombustion and ventilationairbe taken fromoutsidetheseareas.
Propellants of aerosol sprays and volatile compounds, (cleaners,
chlorinebased chemicals,refrigerants,etc.) in additiontobeing highly
flammableinmanycases, willalsoreacttoform corrosivehydrochloric
acid when exposed to the combustion products of the water heater.
Theresultscanbe hazardous, and also cause product failure.
INSULATIONBLANKETS
Insulationblankets are available tothegeneralpublic for external use
ongas water heaters but are not necessary withtheseproducts. The
purpose of an insulation blanket is to reduce the standby heat loss
encountered with storage tank heaters. Your water heater meets or
exceedstheNationalAppliance Energy ConversationActstandards
withrespectto insulation and standby loss requirements, makingan
insulationblanket unnecessary.
Should you choose to apply an insulation blanket to this heater, you
should follow these instructions (For identification of components
mentioned below, see Figure 1). Failure to follow these instructions
can restrict the air flow required for proper combustion, potentially
resultingin 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 outer door, thermostator temperature & pressure
reliefvalve.
•Do not allow insulation to come within 2" (5.1 cm) of the floor to
preventblockageofcombustion 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.
•Doobtainnew warning andinstructionlabels from themanufacturer
forplacement on the blanket directly overtheexistinglabels.
•Do inspect the insulation blanket frequently to make certain it
doesnotsag,thereby obstructing combustion air flow.
COMBUSTIONAIRAND VENTILATION FOR
APPLIANCESLOCATED INUNCONFINED SPACES
UNCONFINED SPACE is space whose volume is not less than
50cubicfeet per 1,000 Btu per hour (4.8 cubic meters perkW)of the
aggregateinput ratingofall appliancesinstalledin that space. Rooms
communicating directly with the space in which the appliances are
installed,through openingsnotfurnished with doors,areconsidered a
partof the unconfined space.
Inunconfinedspacesinbuildings,infiltrationmaybeadequatetoprovide
airforcombustion,ventilationanddilutionoffluegases. However, in
buildingsof tight construction (forexample,weatherstripping, heavily
insulated,caulked, vapor barrier, etc.), additional air mayneed to be
providedusingthemethodsdescribedin“CombustionAirandVentilation
forAppliancesLocatedinConfinedSpaces.”
COMBUSTIONAIRAND VENTILATION FOR
APPLIANCESLOCATED INCONFINED SPACES
CONFINEDSPACEisaspacewhosevolumeis lessthan50cubicfeet
per1,000Btuper hour(4.8cmperkW) of theaggregateinput ratingof
allappliances installed inthatspace.

9
Chemicalvaporcorrosionoftheflue,blowerassembly andventsystem
may occur if air for combustion contains certain chemical vapors.
Spraycanpropellants,cleaningsolvents,refrigeratorandairconditioner
refrigerants,swimming pool chemicals, calcium and sodiumchloride,
waxes,bleach and process chemicals are typical compoundswhich
arepotentially corrosive.
A. ALLAIRFROMINSIDEBUILDINGS: (SeeFigure5and6)
The confined space shall be provided with two permanent openings
communicatingdirectly withanadditional room(s) ofsufficientvolume
so that the combined volume of all spaces meets the criteria for an
unconfinedspace. Thetotalinputofallgasutilizationequipmentinstalled
inthecombinedspaceshallbeconsideredinmakingthisdetermination.
Eachopening shall have a minimum free area of one square inchper
1,000Btuperhour(22cm2/kW)ofthetotalinputratingofallgasutilization
equipmentin the confinedspace,butnot less than100squareinches
(645 cm2). One opening shall commence within 12 inches
(31cm)ofthetopandonecommencing within12 inches(31 cm)of the
bottomoftheenclosures.
FIGURE6.
B.ALL AIRFROM OUTDOORS:(SeeFigures7,8and9)
Theconfinedspaceshall be provided with two permanent openings,
one commencing within 12 inches (31 cm) of the top and one
commencingwithin12inches(31cm)fromthebottomoftheenclosure.
Theopeningsshallcommunicatedirectly,orbyducts,with theoutdoors
orspaces (crawl or attic) that freelycommunicate with the outdoors.
1. Whendirectlycommunicatingwiththeoutdoors,each openingshall
havea minimum free area of 1 square inch per 4,000 Btuper hour
(5.5 cm2/kW)oftotalinput rating of allequipmentin the enclosure,
seeFigure7.
FIGURE7.
2. Whencommunicatingwiththeoutdoorsthroughverticalducts, each
openingshall haveaminimum freeareaof 1squareinch per4,000
Btuperhour(5.5cm2/kW)of totalinputrating ofallequipmentinthe
enclosure,see Figure 8.
3. When communicating with the outdoors through horizontal ducts,
eachopening shall have aminimumfreearea of 1 square inchper
2,000Btuper hour(11 cm2/kW))of totalinputratingofall equipment
inthe enclosure, see Figure 9.
FIGURE8.
4. When ducts are used, they shall be of the same cross-sectional
areaas the free area of the openingsto which they connect. The
minimumshort side dimensionofrectangularair ducts shallnotbe
lessthan3inches(7.6cm), see Figure 9.
FIGURE9.
5. LouversandGrilles:Incalculating freearea,consideration shallbe
givento the blocking effect oflouvers,grillesorscreens protecting
openings. Screens used shall not be smaller than 1/4 inch
(6.4mm) mesh. If the free area throughadesignoflouver or grille
isknown, itshouldbe used incalculatingthe sizeopeningrequired
toprovide the freeareaspecified. If the designandfree area isnot
known,it may beassumedthat wood louverswillbe 20-25 percent
freearea andmetallouvers and grilleswillhave 60-75 percentfree
area. Louvers and grilles shall be fixed in the open position or
interlockedwiththeequipmentsothattheyareopenedautomatically
duringequipmentoperation.
6. SpecialConditionsCreatedbyMechanicalExhaustingorFireplaces:
operation of exhaust fans, ventilation systems, clothes dryers or
fireplacesmaycreateconditionsrequiringspecial attentionto avoid
unsatisfactoryoperation of installedgasutilizationequipment.

10
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.
Thisisanunacceptableconditionandmust becorrected.
Itisrecommended thatany devicesinstalled whichcouldcreateaclosed
system have a by-pass and/or the system have an expansion tank to
relieve the pressure built by thermal expansion in the water system.
Expansion tanks are available for ordering through a local plumbing
contractor. Contactthe localwatersupplier and/or a serviceagencyfor
assistanceincontrollingthesesituations.
NOTE:To protectagainst untimely corrosionof hot andcold water
fittings, it is strongly recommended that di-electric unions or
couplings be installed on this water heater when connected to
copper pipe.
AllgaspipingmustcomplywithlocalcodesandordinancesorwiththeNational
FuelGasCode(ANSIZ223.1/NFPA-54)whicheverapplies.Copperandbrass
tubingandfittings(excepttinlinedcoppertubing)shallnotbeused.
FIGURE10.
WATER PIPING
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,cleaningandothersanitizingneedscanscaldandpermanently
injureyouuponcontact. Somepeoplearemorelikely tobepermanently
injuredbyhotwater thanothers. These includetheelderly,children, the
infirm,or physically/mentallyhandicapped. If anyoneusinghot waterin
yourhome fitsinto oneofthese groupsorif thereisa localcodeor state
lawrequiring a certaintemperaturewater at thehotwater tap, thenyou
musttakespecialprecautions. Inadditiontousingthe lowest possible
temperaturesettingthatsatisfiesyourhotwaterneeds,ameanssuchas
a*mixingvalve, shallbeusedatthehotwater tapsusedbythesepeople
or at the water heater, see Figure 2. Valves for reducing point of use
temperaturebymixingcoldandhotwaterare alsoavailable:
Consulta QualifiedInstallerorServiceAgency. Follow manufacturer’s
instructions for installation of the valves. Before changing the factory
settingon thethermostat,readthe“Temperature Regulation”sectionin
thismanual.
This water heater shall not be connected to any heating systems or
component(s)usedwitha non-potablewaterheating appliance.
Allpipingcomponentsconnectedtothisunitforspaceheatingapplications
shallbesuitablefor use with potable water.
Toxic chemicals, such as those used for boiler treatment shall not be
introducedintothissystem.
Whenthesystemrequireswaterforspaceheatingattemperatureshigher
thanrequiredfordomesticwaterpurposes,atemperingvalvemustbe
installed. PleaserefertoFigure2forsuggestedpipingarrangement.
Watersupplysystemsmay,becauseofsucheventsashighlinepressure,
frequent cut-offs, the effects of water hammer among others, have
installeddevices suchas pressurereducingvalves, checkvalves,back
flow preventers, etc. to control these types of problems. When these
devicesarenotequippedwithaninternalby-pass,andnoothermeasures
aretaken,the devicescausethewatersystem tobeclosed. Aswateris
heated,itexpands (thermalexpansion)andclosedsystemsdonotallow
for the expansion of heated water.
INSTALLING THE NEW WATER HEATER