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7. Mark blower wheel, motor, and motor support in relation to

blower housing before disassembly to ensure proper reas-
sembly.

8. Loosen setscrew(s) holding blower wheel on motor shaft.

9. Remove bolts holding motor and motor mount to blower

housing and slide motor and mount out of housing. (Do not
remove motor belly band unless replacing motor.) Discon-
nect ground wire attached to blower housing before remov-
ing motor.

10. Remove blower wheel from housing.

a. Mark cutoff location to ensure proper reassembly.

b. Remove screws holding cutoff plate and remove cutoff

plate from housing.

c. Lift blower wheel from housing through opening.

11. Clean blower wheel and motor using a vacuum with soft

brush attachment. Do not remove or disturb balance weights
(clips) on blower wheel blades.

CAUTION:

The blower wheel should not be dropped or

bent as balance will be affected.

12. Reinstall blower wheel by reversing items 10 a. through c.

Be sure wheel is positioned for proper rotation.

13. Reassemble motor and blower by reversing items 5 through

9. If motor has ground wire, be sure it is connected as
before.

CAUTION:

Be sure motor is properly positioned in

blower housing. The motor wires must exit the motor
below horizontal centerline of motor after blower assem-
bly has been reinstalled in the furnace. This applies to
upflow and downflow installations.

14. Reinstall blower assembly in furnace.

15. Reinstall control. (See item 12 for reassembly of vent pipe

and flue enclosure for downflow furnaces.)

16. Connect blower electrical leads to control. Please note that

connections are polarized for assembly. DO NOT FORCE.

C.

Cleaning Heat Exchanger

The following steps should be performed by a qualified service
technician:

NOTE:

Deposits of soot and carbon indicate the existence of a

problem which needs to be corrected. Take action to correct the
problem.

If it becomes necessary to clean heat exchanger because of carbon
deposits, soot, etc., proceed as follows:

1. Turn gas and power to furnace to OFF.

2. Remove control and blower access doors.

3. Remove vent pipe enclosure on downflow furnace only and

disconnect vent pipe from relief box.

4. Remove 2 screws that secure relief box. (See Fig. 5 or 6.)

5. Disconnect wires to the following components. Mark wires

to aid in reconnection of:

a. Draft safeguard switch.

b. Inducer motor.

c. Pressure switch(es).

d. Limit overtemperature switch(es).

e. Gas valve.

f. Hot surface ignitor.

g. Flame-sensing electrode.

h. Wiring connectors leading to control.

6. Remove 8 screws that secure flue collector box to center

panel. Be careful not to damage sealant.

7. Remove complete inducer assembly from furnace, exposing

flue openings.

8. Using field-provided small wire brush, steel spring cable,

reversible electric drill, and vacuum cleaner, clean cells as
follows:

a. Assemble wire brush and steel spring cable.

(1.) Use 48 in. of 1/4-in. diameter high-grade steel

spring cable (commonly known as drain clean-out
or Roto-Rooter cable).

(2.) Use 1/4-in. diameter wire brush (commonly known

as 25-caliber rifle cleaning brush).

NOTE:

The materials needed in items (1.) and (2.) can usually be

purchased at local hardware stores.

(3.) Insert twisted wire end of brush into end of spring

cable, and crimp tight with crimping tool or strike
with ball-peen hammer. TIGHTNESS IS VERY
IMPORTANT.

(4.) Remove metal screw fitting from wire brush to

allow insertion into cable.

b. Clean each heat exchanger cell.

Fig. 6—Model 331JAV Downflow

A93394

PRESSURE
SWITCHES

VENT PIPE
ENCLOSURE

CONTROL

DRAFT
SAFEGUARD
SWITCH

AUXILIARY

LIMIT

SWITCH

MANUAL
RESET
LIMIT
SWITCHES

RELIEF

BOX

MOUNTING

SCREWS

—4—

Summary of Contents for 330JAV

Page 1: ...ted States follow all safety codes including the National Fuel Gas Code NFPA No 54 1996 ANSI Z223 1 1996 In Canada refer to the current edition of the National Standard of Canada CAN CGA B149 1 and 2...

Page 2: ...commercial sources may also be used to prevent ESD damage CARE AND MAINTENANCE For continuing high performance and to minimize possible equip ment failure it is essential that periodic maintenance be...

Page 3: ...ter through filter from opposite direction of airflow e Rinse and let dry Oiling or coating of filter is not recommended or required f Place filter in furnace g Replace blower and control access doors...

Page 4: ...alified service technician NOTE Deposits of soot and carbon indicate the existence of a problem which needs to be corrected Take action to correct the problem If it becomes necessary to clean heat exc...

Page 5: ...ctors leading to control 13 Reconnect vent pipe to relief box When applicable replace vent pipe enclosure 14 Replace blower door only 15 Turn power and gas to ON 16 Set thermostat and check furnace fo...

Page 6: ...connect and reconnect of red wire Fig 9 Heating and Cooling Application Wiring Diagram for Single Stage Thermostats and Single Speed Condensing Units A97443 115 V FUSED DISCONNECT SWITCH WHEN REQUIRED...

Page 7: ...condition E Troubleshooting Refer to service label See Fig 12 Page 10 contains a trouble shooting guide This guide can be a useful tool in isolating furnace operation problems Beginning with the word...

Page 8: ...itches ALS1 2 used on some horizontal and some downflow models 7 This wire must be connected to furnace sheet metal for control to prove flame 8 Factory connected when LGPS not used RED LS FRS2 RED RE...

Page 9: ...DOWNFLOW ONLY SWITCH DID NOT CLOSE OR REOPENED Check for Proper vent sizing and condensate pitch with side wall vent Low inducer voltage 115v Blower motor and capacitor Defective inducer motor Defect...

Page 10: ...eck for proper orifice size Control will attempt to light burners 4 times approximately 1 minute between attempts Code 34 Voltage is present at the gas valve for 7 sec during each ignition trial Syste...

Page 11: ...11...

Page 12: ...video based formats and materials All include video and or slides plus companion book Classroom Service Training plus hands on the products in our labs can mean increased confidence that really pays d...

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