Harman PF-120 - Combustion Blower Chamber Cleaning; Distribution Blower and Air Filter Service

Harman® • PF-120 Owner’s Manual_R3 • 2014 -___ • 10/1419
3-90-08120c
G. Combustion Blower Chamber
Removethecombustionblowerheatshield.Therearetwo
latchesthat hold the shieldin place.Figure 5.11. Flip the
latchesupandpulltheshieldawayfromthefurnace.Itcan
notbefullyremoved,itcanonlybemoveddownoverthe
wireuntilithangsonthejunctionbox.
ThefurnaceMUST be OFF and COOLbeforeyoushould
attempttocleanthecombustionblower.
The wire to the combustion blower doesn’t need to be
disconnectedduringthecleaningprocess.
Loosenthethree(3)thumbscrewsabout4turnseach.Figure
5.12. Hold the motorhead withone handand the blower
platehandlewiththeotherhand.Pulloutwardontheplate
handleuntilthecompleteunitcomesloose.Nowrotatethe
plate counter-clockwise about 1/8turn.This will allowthe
completeassemblytoberemovedfromtheblowerchamber.
Cleantheblowerfanbladesandtheblowerplatesealing
overlap.Figure5.13.
Note:Becarefulnottobendthefanblades,thiswillthrow
thefanbladeoutofbalanceoritmayrubtheinnerchamber,
which may affect the performance of the furnace.Any
horizontalandverticaluepipedirectlyabovetheunitshould
becleanedatthistime.
Note: Thehorizontaluepipedirectlyabovethefurnaceis
therstplaceyashwillsettle,duetotheslowingofue
gasvelocitythroughhorizontalpipe.Cleaningofhorizontal
ventingpipesisveryimportanttotheefciencyofthisfurnace.
Note: Inspection,maintenance and cleaning of the
convection/distributionairltershouldbedoneregularly.
H. Distribution Blower and Air Filter
Inspect and clean (if needed) the furnace cold air return
distribution blower and air filter located just below the
combustionblowerchamber.Thisareashouldbeinspected
monthly or more frequently depending on its installation
location.IftheAirFilterisneedingreplacedusea20”x20”x1”
AirFilter,Harman®part#3-40-20201-12.
Latch
Figure 5.11
Thumb Screws
Figure 5.12
Sealing Overlap
Figure 5.13