Specifications

TroubleshootingGuide
29|Page
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REPLACINGTHEHEATEXCHANGER
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Therearemanypossiblecausesofaheatexchangerfailure:
• Contaminated air with  a high level of dust, lint, sand, grease, aerosols or other contaminants,
can become airborne and enter the air intake.The contaminants build up within the fan and
burner assembly causing abnormal flame conditions due to
lack of combustion air, damaging
manycomponentsoftheunit.
• Scalecanbuildupfromveryhardwater.Limescalewillformontheinsideoftheheat
exchangertubesreadilyathightemperatures.Thisscaleprohibitsheatfromreachingthewater
whichcausesexcessiveheatwithintheheatexchanger
copper,anditwilleventuallyburnand
leak.
Alongwithchangingtheheatexchanger,itisimportanttoidentifytheCAUSEoftheneedfor
replacement,andfixtheproblemsoitdoesnotoccuragain
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1) TOOLS
‐Gatherthefollowingmaterialstogether:
a. Degreaserinapumpactionbottle
b. Sheetof100GritSandpaper
c. #2 PhilipsScrewDriver
d. Needle‐NosedPliers
e. DuctTape
f. Flashlight
g. AirCompressor
h. OldTowels,atLeastThree
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2) PREPARETHEUNIT
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a. POWER
‐Disconnectpowertoyourunit.
b. GAS
‐Shutoffthegassupplytotheunit.
c. WATER
–Draintheunit.Refertop.21forinstructions.
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3) REMOVEMANIFOLD/GASASSEMBLY,BURNER
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a. Followsteps1‐7oftheprevioussection,“CleaningtheCombustionComponents”.Thiswill tell
youhowtoremovethePCB,manifold/gasassembly,andburner
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4) WIRES
‐Thereareseveralwireclipsthatneedtoberemovedtofreetheheatexchanger
a. LocatethebrownwireclipconnectedtotheGFI,anddisconnectit.
b. Onthebottomlef t, disconnecttheceramicheatingelements(whitewires).
c. Locatethewhitebypassva lveclipontheleft‐
handsideofthecombustionchamberwith
red/blackwires.Disconnectit.
d. Upwardstowardtheleftside,removeablueconnectiontotheover‐heatcutofffuse
e. Removethetwospadeconnectionsonthehighlimitswitch.
f. Disconnecttheigniterplug(purplewiresandblueplug)atthe
bottomright.
g. Alongthebottom,disconnecttheplugintotheproportionalvalve(red&whitewires).
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