- Instruction Manual Residential Gas Water Heater

13
CLOSED WATER SYSTEMS
Water supply systems may, because of code requirements or such
conditionsashighlinepressure,amongothers,haveinstalleddevices
suchaspressurereducingvalves,checkvalves,andbackowpreventers.
Devices such as these cause the water system to be a closed system.
THERMAL EXPANSION
Aswaterisheated,itexpands(thermalexpansion).Inaclosedsystem
thevolumeofwaterwillgrowwhenitisheated.Asthevolumeofwater
growstherewillbeacorrespondingincreaseinwaterpressuredue
tothermalexpansion.Thermalexpansioncancauseprematuretank
failure(leakage).Thistypeoffailureisnotcoveredunderthelimited
warranty.Thermalexpansioncanalsocauseintermittenttemperature-
pressurereliefvalveoperation:waterdischargedfromthevalvedueto
excessivepressurebuildup.Thisconditionisnotcoveredunderthe
limitedwarranty.Thetemperature-pressurereliefvalveisnotintended
fortheconstantreliefofthermalexpansion.
A properly sized thermal expansion tank should be installed
on all closed systems to control the harmful effects of thermal
expansion..
FIGURE 10.
NOTE: To protect against untimely corrosion of hot and cold
water ttings, it is strongly recommended that di-electric unions
or couplings be installed on this water heater when connected
to copper pipe, see Figure 2 also.
CHEMICAL VAPOR CORROSION
CORROSION OF THE FLUEWAYS AND VENT SYSTEM MAY OCCUR IF
AIR FOR COMBUSTION CONTAINS CERTAIN CHEMICAL VAPORS. SUCH
CORROSION MAY RESULT IN FAILURE AND RISK OF ASPHYXIATION.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium and
sodiumchloride(watersoftenersalt),waxes,andprocesschemicals
aretypicalcompoundswhicharepotentiallycorrosive.
Donotstoreproductsofthissortneartheheater.Also,airwhichis
brought in contact with the heater should not contain any of these
chemicals. If necessary, uncontaminated air should be obtained from
remote or outside sources. The limited warranty is voided when failure
ofwaterheaterisduetoacorrosiveatmosphere.(Seelimitedwarranty
forcompletetermsandconditions).
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,cleaning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
physicallyordevelopmentallydisabled.Ifanyoneusinghotwatertsinto
oneofthesegroupsorifthereisalocalcodeorstatelaw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,
shallbeusedatthehotwatertapsusedbythesepeopleoratthewater
heater,seeFigure2.Valvesforreducingpointofusetemperatureby
mixingcoldandhotwaterarealsoavailable:
Consult a Qualied Installer or ServiceAgency. Follow  manufacturer’s
instructions for installation of the valves. Before changing the factory
setting on the thermostat, readthe “Temperature Regulation” section in
this manual.
Thiswaterheatershallnotbeconnectedtoanyheatingsystemsor
component(s)usedwithanon-potablewaterheatingappliance.
All piping components connected to this unit for space heating
applicationsshallbesuitableforusewithpotablewater.
Toxicchemicals,suchasthoseusedforboilertreatmentshallnotbe
introduced into this system.
Whenthesystemrequireswaterforspaceheatingattemperatureshigher
thanrequiredfordomesticwaterpurposes,atemperingvalvemustbe
installed.PleaserefertoFigure2forsuggestedpipingarrangement.
INSTALLING THE NEW WATER HEATER