User Guide
22
WhencheckingtheTemperature-PressureReliefValveoperation,
makesurethat(1)nooneisinfrontoforaroundtheoutletofthe
Temperature-PressureReliefValvedischargeline,and(2)thatthe
waterdischargewillnotcauseanypropertydamage,asthewater
maybeextremelyhot.Usecarewhenoperatingvalveasthevalve
maybehot.
Tocheckthereliefvalve,lifttheleverattheendofvalveseveraltimes,
seeFigure21.Thevalveshouldseatproperlyandoperatefreely.
Ifaftermanuallyoperatingthevalve,itfailstocompletelyresetand
continuestoreleasewater,immediatelyclosethecoldwaterinlet
tothewaterheateranddrainthewaterheater,seeDrainingAnd
Flushingonpage24.ReplacetheTemperature-PressureReliefValve
with a properly rated/sized new one, see Temperature-Pressure
ReliefValveonpage11forinstructionsonreplacement.
DISCHARGE PIPE
TEMPERATURE-PRESSURE
RELIEF VALVE
FIGURE 21.
IftheTemperature-PressureReliefValveonthewaterheaterweeps
ordischargesperiodically,thismaybeduetothermalexpansion.
NOTE:Excessivewaterpressureisthemostcommoncauseof
Temperature-Pressure Relief Valve leakage. Excessive water
systempressureismostoftencausedby“thermalexpansion”
ina“closedsystem.”SeeClosedWaterSystemsandThermal
Expansiononpage11.TheTemperature-PressureReliefValve
isnotintendedfortheconstantreliefofthermalexpansion.
Temperature-Pressure Relief Valve leakage due to pressure
build up in a closed system that does not have a thermal
expansion tank installed is not covered under the limited
warranty. Thermal expansion tanks must be installed on all
closedwatersystems.
DO NOT PLUG THE TEMPERATURE-PRESSURE RELIEF
VALVE OPENING. THIS CAN CAUSE PROPERTY DAMAGE,
SERIOUS INJURY OR DEATH.
Explosion Hazard
Temperature-Pressure Relief Valve
must comply with ANSI Z21.22-
CSA 4.4 and ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.
RECOMMENDED PROCEDURE FOR PERIODIC
REMOVAL OF LIME DEPOSITS FROM TANK TYPE
COMMERCIAL WATER HEATERS
Theamountofcalciumcarbonate(lime)releasedfromwateris
indirectproportiontowatertemperatureandusage,seechart.
Thehigherthewatertemperatureorwaterusage,themorelime
depositsaredroppedoutofthewater.Thisisthelimescalewhich
formsinpipes,heatersandoncookingutensils.
INSTALLEDINSUITABLEAREA:Toinsuresufficientventilation
and combustion air supply, proper clearances from the water
heatermustbemaintained.SeeFactstoConsiderAboutThe
Location section. Combustible materials such as clothing,
cleaningmaterials,orflammableliquids,etc.mustnotbeplaced
againstoradjacenttothewaterheaterwhichcancauseafire.
ANODE ROD INSPECTION
Property Damage Hazard
•
Avoid water heater damage.
•
Inspection and replacement of anode rod required.
CAUTION
Theanoderodisusedtoprotectthetankfromcorrosion.Mosthot
watertanksareequippedwithananoderod.Thesubmergedrod
sacricesitselftoprotectthetank. Instead of corroding the tank,
waterionsattackandeatawaytheanoderod.Thisdoesnotaffect
water’stasteorcolor.Therodmustbemaintainedtokeepthetank
inoperatingcondition.
Anodedeteriorationdependsonwaterconductivity,notnecessarily
watercondition.Acorrodedorpittedanoderodindicateshighwater
conductivityandshouldbecheckedand/orreplacedmoreoftenthan
ananoderodthatappearstobeintact.Replacementofadepleted
anoderodcanextendthelifeofyourwaterheater.Inspectionshould
beconductedbyaqualiedservicetechnician,andataminimum
shouldbecheckedannuallyafterthewarrantyperiod.
Articially softened water is exceedingly corrosive because the
processsubstitutessodiumionsformagnesiumandcalciumions.
The use of a water softener may decrease the life of the water
heater tank.
Theanoderodshouldbeinspectedafteramaximumofthreeyears
andannuallythereafteruntiltheconditionoftheanoderoddictates
itsreplacement.
NOTE: Articially softened water requires the anode rod to be
inspectedannually.
Thefollowingaretypical(butnotall)signsofadepletedanoderod:
• Themajorityoftherodsdiameterislessthan3/8”.
• Signicantsectionsofthesupportwire(approx.1/3ormoreof
theanoderod’slength)arevisible.
TEMPERATURE-PRESSURE RELIEF VALVE TEST
Burn hazard.
Hot water discharge.
Keep clear of Temperature-
Pressure Relief Valve
discharge outlet.
ItisrecommendedthattheTemperature-PressureReliefValve
should be checked to ensure that it is in operating condition
every6months.