Harman® • PF-120 Owner’s Manual_R3 • 2014 -___ • 10/1419
3-90-08120c
G. Combustion Blower Chamber
Removethecombustionblowerheatshield.Therearetwo
latchesthat hold the shieldin place.Figure 5.11. Flip the
latchesupandpulltheshieldawayfromthefurnace.Itcan
notbefullyremoved,itcanonlybemoveddownoverthe
wireuntilithangsonthejunctionbox.
ThefurnaceMUST be OFF and COOLbeforeyoushould
attempttocleanthecombustionblower.
The wire to the combustion blower doesn’t need to be
disconnectedduringthecleaningprocess.
Loosenthethree(3)thumbscrewsabout4turnseach.Figure
5.12. Hold the motorhead withone handand the blower
platehandlewiththeotherhand.Pulloutwardontheplate
handleuntilthecompleteunitcomesloose.Nowrotatethe
plate counter-clockwise about 1/8turn.This will allowthe
completeassemblytoberemovedfromtheblowerchamber.
Cleantheblowerfanbladesandtheblowerplatesealing
overlap.Figure5.13.
Note:Becarefulnottobendthefanblades,thiswillthrow
thefanbladeoutofbalanceoritmayrubtheinnerchamber,
which may affect the performance of the furnace.Any
horizontalandverticaluepipedirectlyabovetheunitshould
becleanedatthistime.
Note: Thehorizontaluepipedirectlyabovethefurnaceis
therstplaceyashwillsettle,duetotheslowingofue
gasvelocitythroughhorizontalpipe.Cleaningofhorizontal
ventingpipesisveryimportanttotheefciencyofthisfurnace.
Note: Inspection,maintenance and cleaning of the
convection/distributionairltershouldbedoneregularly.
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
combustionblowerchamber.Thisareashouldbeinspected
monthly or more frequently depending on its installation
location.IftheAirFilterisneedingreplacedusea20”x20”x1”
AirFilter,Harman®part#3-40-20201-12.
Latch
Figure 5.11
Thumb Screws
Figure 5.12
Sealing Overlap
Figure 5.13