Harman® • PF-120 Owner’s Manual_R3 • 2014 -___ • 10/14
20
3-90-08120c
Clean the flue outlet throat (this is the hole that goes up into
the flue pipe). Figure 5.14.
Note:
The ESP extends into this same area.
CARE MUST BE
TAKEN NOT TO DAMAGE THE ESP DURING CLEANING.
Clean the inner chamber of the blower housing, the furnace
blower plate and sealing overlap. Figure 5.14. Inspect the
tops of the heat exchanger tubes where the chain shaker
mechanism is located. Make sure there are no fly ash
buildups that may block the easy flow of flue gases into the
combustion blower inlet hole. (A flashlight may be necessary.)
Inspect the chain shaker mechanism for proper operation.
Note:
Fly ash can build up to the top edges of the heat
exchanger tubes without affecting operation. The chain
shaker will cause any excess to fall down into the chamber
under the tubes where it can be cleaned out through the fire
box. Figure 5.14.
CLEANOUT OF THE HEAT EXCHANGER, FLUE
PIPE, CHIMNEY, AND DRAFT INDUCER, IF USED,
IS ESPECIALLY IMPORTANT AT THE END OF THE
HEATING SEASON TO MINIMIZE CORROSION
DURING THE SUMMER MONTHS, CAUSED BY
ACCUMULATED ASH.
CAUTION
!
I. Tube Heat Exchangers:
The heat exchanger tubes have an external handle that
operates the cleaning mechanism. Figure 5.15.
This cleaning should be done at least once a week,
although it can be done more frequently. The cleaner the
heat exchangers are, the more efficient the furnace will be.
This cleaning can be done at any time and in any mode of
operation.
The handle has two directions of movement, Right to Left and
In and Out. All inside surfaces of these rectangular tubes can
be cleaned with this range of motion. First, with the handle
pushed in, turn the handle right to left, the full sweep, several
strokes. Second, with the handle pointing straight down, pull
out and push inward several strokes. Third, with the handle all
the way out, turn the handle right to left, the full sweep, several
times. End with the handle pushed inward and pointing down.
The shaker handle should be pushed inward and straight
down during normal operation. Figure 5.15.
Note:
Fly ash can build up to the top edges of the heat
exchanger tubes without affecting operation. The chain
shaker will cause any excess to fall down into the chamber
under the tubes where it can be cleaned out through the fire
box. Figure 5.16.
ESP
Sealing overlap
Figure 5.14
Lower cleanout chamber
Figure 5.16
Chain
Shaker Handle
Figure 5.15
Inspect flue pipes, flue pipe joints and flue pipe seals
regularly to ensure that smoke and flue gases are
not drawn into, and circulated by, the air-circulation
system.
CAUTION
!
Access to flue outlet throat
