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CLEANING AND/OR REPLACING AIR FILTER
The air filter arrangement will vary depending on the application.
The filter is exterior to the furnace casing.
NOTE: If the filter has an airflow direction arrow, the arrow
must point towards the blower.
Table 14 – Filter Size Information (In. / mm)
FURNACE
FILTER SIZE (In. / mm)
CASING
WIDTH
Side Return
In. (mm)
14-1/2
16 x 25 x 3/4
(368)
(406 x 635 x 19)
17-1/2
16 X 25 X 3/4
(445)
(406 x 635 x 19)
16 x 25 x 3/4
21 (533)
(406 x 635 x 19)
16 x 25 x 3/4
24 (610)
(406 x 635 x 19)
* Recommended
BLOWER MOTOR AND WHEEL
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 control.
No component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch
for service purposes.
NOTE: The blower wheel should not be dropped or bent as
balance will be affected. The following steps should be performed
by a qualified service agency.
To ensure long life and high efficiency, clean accumulated 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.
Clean blower motor and wheel as follows:
1. Turn off electrical supply to furnace.
2. Remove outer door.
3. For downflow or horizontal furnaces having vent pipes
within the furnace that pass in front of the blower access
door:
a. Disconnect vent connector from furnace vent elbow.
b. Disconnect and remove short piece of vent pipe from
within furnace.
4. Remove two screws from blower access door and remove
blower access door.
5. All factory wires can be left connected, but field thermo-
stat connections may need to be disconnected depending
on their length and routing.
6. Remove two screws holding blower assembly to blower
deck and slide blower assembly out of furnace.
7. Clean blower wheel and motor using a vacuum with soft
brush attachment. Blower wheel blades may be cleaned
with a small paint or flux brush. Do not remove or disturb
balance weights (clips) on blower wheel blades.
8. Vacuum any loose dust from blower housing, wheel and
motor.
42
FILTER TYPE
Bottom Return
14 x 25 x 3/4
Washable*
(356 x 635 x 19)
16 X 25 X 3/4
Washable*
(406 x 635 x 19)
20 X 25 X 3/4
Washable*
(508 x 635 x 19)
24 X 25 X 3/4
Washable*
(610 x 635 x 19)
Specifications are subject to change without notice.
9. If a greasy residue is present on blower wheel, remove
wheel from the blower housing and wash it with an appro-
priate degreaser. To remove wheel:
NOTE: Before disassembly, mark blower motor, and blower
housing so motor and each arm is positioned at the same location
during reassembly.
a. Disconnect power choke wires (if used) and ground wire
attached to blower housing.
b. Remove screws securing cutoff plate and remove cutoff
plate from housing.
c. Loosen set screw holding blower wheel on motor shaft
(160+/−20 in.−lb. when reassembling).
d. Remove bolts holding motor to blower housing and slide
motor out of wheel (40+/−10 in.−lb. when reassembling).
e. Remove blower wheel from housing.
f. Clean wheel and housing.
10. Reassemble motor and blower by reversing steps 9f
through 11a, finishing with 9a. Be sure to reattach ground
wire to the blower housing.
11. Verify that blower wheel is centered in blower housing
and set screw contacts the flat portion of the motor shaft.
Loosen set screw on blower wheel and reposition if neces-
sary.
12. Spin the blower wheel by hand to verify that the wheel
does not rub on the housing.
13. Reinstall blower assembly in furnace.
14. Reinstall two screws securing blower assembly to blower
deck.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in shortened heat
exchanger life.
Heating fan speed(s) MUST be adjusted to provide proper
air temperature rise as specified on the rating plate.
Recommended operation is at the midpoint of the rise range
or slightly above. Refer to "SET TEMPERATURE RISE"
under
START−UP,
ADJUSTMENT,
CHECK.
NOTE: Refer to Table 5 for motor speed lead relocation if leads
were not identified before disconnection.
15. Refer to furnace wiring diagram, and connect thermostat
leads if previously disconnected.
16. To check blower for proper rotation:
a. Turn on electrical supply.
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
unless switch is closed. Exercise caution to avoid
electrical shock from exposed electrical components
when manually closing this switch for service purposes.
b. Manually close blower access door switch.
and
SAFETY
441 01 1422 00
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