75
The minimum maintenance on this furnace is as follows:
1. Check and clean air filter each month or more frequently if
required. Replace if torn.
2. Check blower motor and wheel for cleanliness each heating
and cooling season. Clean as necessary.
3. Check electrical connections for tightness and controls for
proper operation each heating season. Service as necessary.
4. Inspect burner compartment before each heating season for
rust, corrosion, soot or excessive dust. If necessary, have
furnace and burner serviced by a qualified service agency.
5. Inspect the vent pipe/vent system before each heating sea-
son for water leakage, sagging pipes or broken fittings.
Have vent pipes/vent system serviced by a qualified service
agency.
6. Inspect any accessories attached to the furnace such as a hu-
midifier or electronic air cleaner. Perform any service or
maintenance to the accessories as recommended in the ac-
cessory instructions.
Cleaning and/or Replacing Air Filter
The air filter type may vary depending on the application or
orientation. The filter is external to the furnace casing. There are no
provisions for an internal filter with this furnace. See “Filter
Arrangement” under the “Installation” section of this manual.
CARBON MONOXIDE POISONING AND FIRE
HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Never operate furnace without a filter or filtration device
installed. Never operate a furnace with filter or filtration
device access doors removed.
!
WARNING
NOTE:
If the filter has an airflow direction arrow, the arrow must
point toward the blower.
To clean or replace filters, proceed as follows:
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow this warning could result in personal
injury or death, or property damage.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF position and
install a lockout tag. There may be more than one
disconnect switch. Lock out and tag switch with a suitable
warning label. Verify proper operation after servicing.
Always reinstall access doors after completing service and
maintenance.
!
WARNING
1. Turn off electrical supply to furnace.
2. Remove filter cabinet door.
3. Slide filter out of cabinet.
4. If equipped with permanent, washable filter, clean filter by
spraying cold tap water through filter in opposite direction
of airflow. Rinse filter and let dry. Oiling or coating of the
filter is not recommended.
5. If equipped with factory specified disposable media filter,
replace only with a factory specified media filter of the same
size.
6. Slide filter into cabinet.
7. Replace filter cabinet door.
8. Turn on electrical supply to furnace.
Blower Motor and Wheel Maintenance
To ensure long life, economy, 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.
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 blower door.
3. All factory wires can be left connected, but field thermostat
and accessory wiring may need to be disconnected depend-
ing on their length and routing.
4. If the vent and combustion air pipe passes through the
blower compartment, it will be necessary to remove the
pipes from the blower compartment.
Disconnect the vent and combustion air pipe by:
a. Loosen the clamps on the vent couplings and combustion
air pipe external to the furnace.
b. Separate the pipes from the couplings and move them
aside.
c. Loosen the clamps on the vent couplings and combustion
air pipe located on the blower shelf.
d. Separate the pipes from the blower compartment and set
aside.
e. Remove the couplings from the pipe adapters and set aside.
f. After servicing the blower, reverse steps a through e.
g. Tighten all clamps 15 lb
−
in.
See Fig. 70 for steps 5 through 14.
5. Remove screws securing blower assembly to blower shelf
and slide blower assembly out of furnace. Detach ground
wire and disconnect blower motor harness plugs from blow-
er motor.
NOTE:
Blower wheel is fragile. Use care.
6. 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.
7. 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.
f. Remove blower wheel from housing.
g. Clean wheel per instructions on degreaser cleaner. Do not
get degreaser in motor.
8. Reassemble motor and blower wheel by reversing items 7b
through 7f. Ensure wheel is positioned for proper rotation.
9. Torque motor mounting bolts to 40 +/
−
10 lb
−
in. when re-
assembling.
PG92S*S