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035-17405-000 Rev. B (0801)
BLOWER CARE
Even with good filters properly in place, blower wheels and
motors will become dust laden after long months of opera-
tion. The entire blower assembly should be inspected annu-
ally. If the motor and wheel are heavily coated with dust, they
can be brushed and cleaned with a vacuum cleaner.
The procedure for removing the direct drive blower assembly
for cleaning is as follows:
Upflow / Horizontal Installations
1.
Turn off electrical power supply to the furnace at discon-
nect switch. Remove access doors.
2.
Remove the two auxiliary limit wires on the left side of
the blower deck inside the blower compartment.
3.
Remove blower assembly mounting screws and slide the
blower assembly out of the slots in the deck. If the two
shipping screws were not previously removed, also
remove and discard these two screws located on each
front corner of the blower assembly.
4.
Note the wire/terminal location and then remove the
blower wiring from the furnace control. Remove the pro-
tective boot and disconnect run capacitor wires. Remove
the screws securing the electrical panel to the blower
housing. Pull blower assembly out of the unit. When
cleaning or servicing the blower assembly, DO NOT
remove or change the balance clips on the blower wheel.
5.
To reassemble, reverse the procedure, restore power to
the furnace and verify operation.
Downflow Installations
1.
Disconnect the electrical supply to the furnace and
remove the access doors.
2.
Remove the two wires leading to the auxiliary limit switch
mounted on the top of the blower housing.
3.
Remove the four top panel screws and lift the top panel
enough to disengage and remove the flue chase assem-
bly. Prior to removing the vent pipe, first remove the
screw attaching the vent pipe to the flue collar.
4.
Remove blower assembly mounting screws and slide the
blower assembly out of the slots in the deck. If the two
shipping screws were not previously removed, also
remove and discard these two screws located on each
front corner of the blower assembly.
5.
Note the wire/terminal location and then remove the
blower wiring from the furnace control. Remove the pro-
tective boot and disconnect run capacitor wires. Remove
the screws securing the electrical panel to the blower
housing. Pull blower assembly out of the unit. When
cleaning or servicing the blower assembly, DO NOT
remove or change the balance clips on the blower wheel.
Unitary Products Group
6.
To reassemble, reverse the procedure, restore power to
the furnace and verify operation.
Burner Removal/Cleaning
The main burners should be checked periodically for dirt
accumulation.
If cleaning is required, follow this procedure:
1.
Turn off the electrical power to the unit and turn off gas
supply at the shutoff valve.
2.
Remove the blower and burner compartment access
doors.
3.
Unplug igniter from the wire harness and remove the
igniter/bracket assembly from the burner air shield. Han-
dle the ignitor carefully as it is fragile and easily broken.
4.
Note the location and then disconnect the sensor and
rollout switch wires located on the top of the air shield
and remove the shield.
5.
Remove the two screws securing each burner to the
burner assembly. Note the orientation of the burner
(flanged side down) before removing. Burners may be
cleaned by rinsing in hot water or by using a vacuum
cleaner.
6.
To reassemble, reverse the procedure, restore power to
the furnace and verify operation.
CLEANING THE HEAT EXCHANGER
Lower Heat Exchanger Access
1.
Turn off the electrical power to the unit and turn off gas
supply at the shutoff valve.
2.
Remove the blower and burner compartment access
doors. Disconnect the gas supply piping at the union to
permit removal of the entire burner and gas control
assembly from the vestibule panel. Use the wrench boss
on the gas valve when removing or installing this piping.
3.
Unplug the igniter from the wire harness. Disconnect
sensor and rollout switch wires located on top of the air
shield. Identify and note the location of all leads for ease
of reinstallation. Also disconnect the wires at the side
rollout switches (upflow only) and the gas valve wires.
4.
Remove the screws holding the burner assembly to the
vestibule panel and remove this assembly. Handle the
assembly carefully since it contains the igniter which is
fragile and easily broken. The lower portion of the heat
exchanger will now be exposed. To clean the burner
assembly, use a vacuum cleaner, or remove the burners
as outlined in burner cleaning, and clean in hot water.
5.
6.
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