Fig. 4—Model 394HAD Upflow
b. Remove blower and control access doors.
c. Release filter retainer from clip at front of furnace
casing. (See Fig. 4.) For side return, clips may be used on
either or both sides of the furnace.
d. Slide filter out.
e. Furnaces are equipped with permanent, washable filters.
Clean filters with tap water. Spray water through filter in
opposite direction of airflow.
f. Rinse and let dry. Oiling or coating of filter is not
recommended or required.
g. Reinstall filter.
h. Replace access doors.
i. Restore electrical power to furnace.
B. Blower Motor and Wheel
For long life, economy, and high efficiency, clean accumulated dirt
and grease from the blower wheel and motor annually.
The following steps should be performed by a qualified service
Some motors have prelubricated sealed bearings and require no
lubrication. These motors can be identified by the absence of oil
ports on each end of the motor. For those motors with oil ports,
lubricate motor every 5 years if motor is used on intermittent
operation (thermostat FAN switch in AUTO position), or every 2
years if motor is in continuous operation (thermostat FAN switch
in ON position).
Remember to disconnect the electrical supply before removing
Clean and lubricate as follows:
1. Remove 2 screws from blower access door (downflow
furnace only). Remove blower access door.
2. Remove vent pipe enclosure (downflow furnace only) and
disconnect short piece of vent pipe from relief box.
3. Disconnect wires from auxiliary limit on blower housing
4. Remove control box.
5. Remove electrical leads from numbered side of blower
6. Remove screws holding blower assembly to blower deck
7. Squeeze side tabs of blower speed selector and pull it out of
8. Loosen screw in strap holding motor capacitor to blower
9. Mark blower wheel, motor, and motor support in relation to
10. Loosen setscrew holding blower wheel on motor shaft.
11. Remove bolts holding motor mount to blower housing and
12. Lubricate motor (when oil ports are provided).
13. Remove blower wheel from housing.
Fig. 5—Model 396HAD Downflow
(downflow furnace only).
speed selector. (See Fig. 4 and 5.) Note location of wires for
and slide blower assembly out of furnace.
housing and slide capacitor out from under strap.
blower housing before disassembly to ensure proper reas-
slide motor and mount out of housing. Disconnect ground
wire attached to blower housing before removing motor.
a. Remove dust caps or plugs from oil ports located at each
end of motor.
b. Use a good grade of SAE 20 nondetergent motor oil and
put 1 teaspoon, 5 cc, 3/16 oz, or 16 to 25 drops in each
oil port. Do not over-oil.
c. Allow time for total quantity of oil to be absorbed by
d. Wipe excess oil from motor housing.
e. Replace dust caps or plugs on oil ports.
a. Mark cutoff location to ensure proper reassembly.