Instruction manual

3. Downflow/horizontal only.
a. Disconnect vent connector from furnace flue collar. (See
Fig. 7.)
b. Disconnect and remove vent pipe enclosure. Push bot-
tom side backward to release tabs.
c. Disconnect and remove short piece of vent pipe from
within furnace.
NOTE: Vent pipe is screwed and RTV sealed to relief box.
4. Disconnect blower leads from furnace control. Notice wire
color and location for reassembly. Also, disconnect auxil-
iary limit switch leads (downflow/horizontal only, if
present).
All other factory wires can be left connected, but field
thermostat connections may need to be disconnected de-
pending on their length and routing.
5. Remove screw securing control box support to furnace.
6. Hang control box and transformer assembly to front of
furnace casing.
7. Remove screws holding blower assembly to blower deck
and slide blower assembly out of furnace.
8. Clean blower wheel and motor using a vacuum with soft
brush attachment. Do not remove or disturb balance weights
(clips) on blower wheel blades. The blower wheel should
not be dropped or bent as balance will be affected.
9. 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, motor, and blower housing
so motor and each arm is positioned at the same 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.
f. Remove blower wheel from housing.
10. Reassemble motor and blower by reversing items 9a
through 9f. Be sure to reattach ground wire.
11. Reinstall blower assembly in furnace.
12. Reinstall control box and support assembly in furnace.
13. Reconnect blower leads to furnace control and auxiliary
limit switch leads (downflow/horizontal only).
Refer to furnace wiring diagram, and connect thermostat
leads if previously disconnected. (See Fig. 12.)
NOTE: Refer to Table 1 for motor speed lead relocation if leads
were not identified before disconnection
CAUTION: Heating speed selection MUST be adjusted
to provide proper temperature rise as specified on the
rating plate. Failure to adjust the heating speed may
shorten heat exchanger life.
14. Reinstall internal vent pipe and enclosure on
downflow/horizontal furnaces only by reversing items 3a
through 3c.
NOTE: A releasing agent such as PAM cooking spray or equiva-
lent (must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) and RTV sealant
(G.E. 162, 6702, or Dow-Corning 738) are needed before starting
installation. DO NOT substitute any other type of RTV sealant.
G.E. 162 (P771-9003) is available through RCD in 3-oz tubes.
15. Reinstall vent connector to furnace flue collar. After fully
assembling vent connector to furnace flue collar, securely
fasten vent connector to flue collar with 2 field-supplied,
corrosion-resistant, sheet metal screws located 180 degrees
apart and midway up the collar.
16. 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 between
heating and cooling by jumpering R to W and then R to Y
on furnace control thermostat terminals.
Fig. 7—Model 331AAV Downflow
A99092
PRESSURE
SWITCHES
VENT PIPE
ENCLOSURE
CONTROL
FLUE
COLLAR
DRAFT
SAFEGUARD
SWITCH
AUXILIARY
LIMIT
SWITCH
MANUAL
RESET
LIMIT
SWITCHES
RELIEF
BOX
MOUNTING
SCREWS
TABLE 1—SPEED SELECTOR
COLOR SPEED
FACTORY-
ATTACHED
TO
Black High Cool
Yellow (When Present) Medium High Spare
Blue Medium Low Heat
Red Low Spare
White Common Com
Orange (When Present) Medium Spare
—4—