User Guide

23
Limeaccumulationnotonlyreducesthelifeoftheequipmentbut
alsoreducesefciencyoftheheaterandincreasesfuelconsumption.
The usage of water softening equipment greatly reduces the
hardnessofthewater.However,thisequipmentdoesnotalways
removeallofthehardness(lime).Forthisreasonitisrecommended
thataregularschedulefordelimingbemaintained.
Thetimebetweencleaningwillvaryfromweekstomonthsdepending
uponwaterconditionsandusage.
Thedepthoflimebuildupshouldbemeasuredperiodically.Heaters
equippedwith cleanouts will have about 2” of lime buildupwhen
theleveloflimehasreachedthebottomofthecleanoutopening.A
schedulefordelimingshouldthenbesetup,basedontheamount
oftimeitwouldtakefora1”buildupoflime.Itisrecommendedthat
thewaterheaterinitiallybeinspectedafter6months.
Example1:
Initialinspectionafter6monthsshows1/2”oflimeaccumulation.
Therefore,theheatershouldbedelimedonceayear.
Example2:
Initialinspectionafter6monthsshows2”oflimeaccumulation.
Therefore,theheatershouldbedelimedevery3months.
FIGURE 22.
DELIMING SOLVENTS
UN•LIMEisrecommendedfordeliming.UN•LIMEis a patented
foodgradeacidwhichissafetohandleanddoesnotcreatethe
harmfulfumeswhichareassociatedwithotherproducts.
UN•LIMEmaybeobtainedfromyourdealer,distributororwater
heatermanufacturer.OrderPartNumber9005416105,1gallon,
packed 4 gallons per case or Part Number 9005417105, 5
galloncontainer.
NOTE:Un•LimeisnotavailableforuseinCanada.
Hydrochloric base acids are not recommended for use on glass
lined tanks.
Observehandlinginstructionsonlabelofproductbeingused.
TANK CLEANOUT PROCEDURE
Thefollowingpracticeswillensurelongerlifeandenabletheunitto
operateatitsdesignedefciency:
1. Onceamonththeheatershouldbeushed.Openthedrainvalve
andallowtwogallonsofwatertodrainfromtheheater.Inletwater
valveshouldremainopentomaintainpressureintank.
2. Acleanoutopeningisprovidedforperiodiccleaningofthetank.
Gasmustbeshutoffandheaterdrainedbeforeopeningcleanout.
Tocleanheaterthroughcleanoutopening,proceedasfollows:
1. Drain heater.
2. Removeoutercoverplatefromlowersideofheaterjacket.
3. Removesix(6)hexheadscrewssecuringtankcleanoutplate
andremoveplate.
4. Removelime,scale,orsedimentusingcarenottodamagethe
glasslining.
5. Inspect cleanout plate gasket, if new gasket is required, see
replacementpartslistforitemnumber.
6. Installcleanoutplate.Besuretodrawplateuptightbytightening
screwssecurely.
7. Replaceouterjacketcoverplate.
FIGURE 23.
9. Insomewaterareasthesedimentmightnotberemovedbythis
methodandmayresultinthewaterheatermakingrumblingor
boiling noises. To dissolve and remove these more stubborn
mineral deposits,A. O. Smith UN•LIME Professional Delimer
should be used.
DELIMING USING FLO-JUG METHOD
UN•LIMEinthe5gallonsizeisrecommendedfordelimingofthe
100 models.  UN•LIME with the necessary hoses and ttings to
delimeyourheaterisalsoavailableasakit:Up-N-DownTransfer
Kit.ContactyourlocalA.O.Smithdealer,distributoror,A.O.Smith
Corporation,Telephone:(800) 433-2545, Fax:(800) 433-2515 or
Website:www.hotwater.com.
PREPARE THE WATER HEATER
TodelimethewaterheaterusingtheFlo-Jugmethod,rstprepare
theheaterfordelimingasdescribedinthe“Why?When?andHow?”
booklet,FormNo.4800.Theninstallthelongplasticmaleadapter
ttingintothedrainvalveopeningofthewaterheater.Useteon
tapeandhandtightenonly.Donotovertighten.
PREPARE THE UP-N-DOWN TRANSFER KIT
ThenextstepisthepreparationontheUp-N-DownTransferKit,if
youhavenotalreadydoneso:
1. Withthe5gallonUp-N-Downcontainerintheverticalposition,unscrew
theplasticventcapinthehandleandpiercetheplasticmembrane
overtheventbossunderthecaptoallowthecontainertovent.
Note:Ifyourcontainerdoesnot have the vent cap and vent
boss,drilla3/16”(4.76mm)holeinthehandle.Whenyouhave
nisheddelimingyouwillbeabletoplugthisdrilledventwiththe
stainlesssteelscrewthatissuppliedwiththekit.
2. Removethecontainer’scapandcutplasticmembranelocatedin
the3/4”IPTopeningincap.Takecaretonotdamagethethreads.
3. Findthe3/4”maleadapter,applyteontapetothethreadedend
andscrewitintothe3/4”IPTopeninginthecap.