II.
BLOWER MOTOR AND WHEEL MAINTENANCE
To ensure long life, economy, and high efficiency, clean accumu-
lated dirt and grease from blower wheel and motor annually.
The inducer and blower motors are pre-lubricated and require no
additional lubrication. These motors can be identified by the
absence of oil ports on each end of the motor.
The following items should be performed by a qualified service
technician.
Clean blower motor and wheel as follows:
1. Turn off electrical supply to furnace.
2. Remove main furnace door and blower access panel.
3. Disconnect blower motor wires from furnace control board.
Field thermostat connections may need to be disconnected
depending on their length and routing.
4. Remove control box mounting screws, and position control
box, transformer, and door switch assembly to right side of
furnace casing.
5. If condensate trap is located in left- or right-hand side of
furnace casing, proceed to item 6, otherwise remove trap
and tubing as described below. (See top left of Fig. 8.)
a. Disconnect field drain connection from condensate trap.
b. Disconnect drain and relief port tubes from condensate
trap.
c. Remove condensate trap from blower shelf.
6. Remove screws securing blower assembly to blower shelf
and slide blower assembly out of furnace.
7. Clean blower wheel and motor by using a vacuum with soft
brush attachment. Be careful not to disturb balance weights
(clips) on blower wheel vanes. Do not bend wheel or blades
as balance will be affected.
8. If greasy residue is present on blower wheel, remove wheel
from the blower housing and wash it with an appropriate
degreaser. To remove wheel:
a. Mark blower wheel location on shaft before disassembly
to ensure proper reassembly.
b. Loosen setscrew holding blower wheel on motor shaft.
NOTE:
Mark blower mounting arms and blower housing so each
arm is positioned at the same hole location during reassembly.
c. Mark blower wheel orientation and cutoff plate location
to ensure proper reassembly.
d. Remove screws securing cutoff plate and remove cutoff
plate from housing.
e. Remove bolts holding motor mounts to blower housing
and slide motor and mounts out of housing. Disconnect
capacitor and ground wire attached to blower housing
before removing motor. Motor mounts need not be
removed from motor.
f. Remove blower wheel from housing.
CAUTION:
UNIT DAMAGE HAZARD
Failure to follow this caution may result in noise or
furnace component failure.
The blower wheel should not be dropped or bent as
balance will be affected.
g. Clean wheel per instructions on degreaser cleaner. Do
not get degreaser cleaner in motor.
9. Reassemble motor and blower wheel by reversing items 8b
through 8f. Ensure wheel is positioned for proper rotation.
Be sure to reattach ground wire. Tighten setscrew to 140 to
160 in.-lb torque.
10. Reinstall blower assembly in furnace.
11. Reinstall control box, transformer, and door switch assem-
bly on blower shelf.
12. Reinstall condensate trap and tubing if previously removed.
a. Reinstall condensate trap in hole in blower shelf.
b. Connect condensate trap drain tubes. See Fig. 8 or tubing
diagram on main furnace door for proper tube location.
NOTE:
Ensure tubes are not kinked or pinched, as this will affect
operation.
(1.) Connect 1 tube (blue or blue and white striped)
from collector box.
(2.) Connect 1 tube (violet or unmarked) from inducer
housing.
(3.) Connect 1 tube (relief port, green or pink) from
collector box.
c. Connect field drain to condensate trap.
13. Reconnect wires.
Refer to furnace wiring diagram, and connect thermostat leads if
previously disconnected. (See Fig. 16.)
NOTE:
Refer to Table 1 for motor speed lead reconnection if
leads were not identified before disconnection.
CAUTION:
UNIT DAMAGE HAZARD
Failure to adjust the heating speed may shorten heat
exchanger life.
Heating speed selection MUST be adjusted to provide
proper temperature rise as specified on the rating plate.
WARNING:
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Blower access door switch opens 115-v power to furnace
control. No component operation can occur. Caution must
be taken when manually closing this switch for service
purposes.
14. Turn on electrical supply. Manually close blower access
door switch. Use a piece of tape to hold switch closed.
Check for proper rotation and speed changes by performing
a component self-test as shown at the bottom of SERVICE
label. (See Fig. 17.)
15. If furnace is operating properly, remove tape to release
blower access door switch, replace blower access door, and
replace main furnace door.
III.
CLEANING BURNERS
The following items should be performed by a qualified service
technician. If the burners develop an accumulation of light dirt or
dust, they may be cleaned by using the following procedure:
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
COLOR
SPEED
FACTORY
ATTACHED TO
Black
High
Cool
Yellow (When Present)
Medium High
Spare
Blue
Medium Low
Heat
Red
Low
Spare
White
Common
Com
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