Inducer Fan Motor

Inducer Fan Motor Trouble Shooting

1. Remove burner door to gain access to the induced draft

blower motor.

2. Disconnect the motor wire leads from its connection point

at the induced draft motor.

3. Using a ohmmeter, test for continuity between each of the

motor leads. Touch one probe of the ohmmeter to the

motor frame and the other probe in turn to each lead. If a

reading is obtained to ground, replace the motor.

4. If the windings have a continuity reading, reconnect wires.

Turn power on to the furnace in heating mode. If you have

115V and the motor does not run, replace the induced draft

motor.

5. Inspect the hose. Make sure hose is in good shape

and free of cracks and moisture.

6. Check stainless steel nipple of corrosion or debris

front and back.

7. Check gaskets are free of tears and gaps.

Inducer Fan Motor Trouble Shooting (cont.)

90% Vent Motor

• Rubber Vent

Discharge

• Ball Bearings

–Factory

Installed

Troubleshoot Induced Draft Blower

Troubleshoot Induced Draft Blower

• Verify that each step of the “sequence of operation” has occurred up until induced draft blower should start.

Then, test power being supplied by board once the call for heat has occurred. • Disconnect plug to motor.

• Place one meter lead into the plug that is attached to the black wire from the ICM.

• Place the other meter lead into the plug that is attached to the white wire from the ICM.

• Turn up t-stat to high setting.

Troubleshoot Induced Draft Blower Testing power being supplied by board once the call for heat has occurred. (cont.) Measure voltage being

supplied to induced draft blower by ICM. (should be 115-120 VAC)

If no voltage present, troubleshoot back to ICM board.

Plug E40 on the GMEC96 board.

Plug E109 on the GMVC96 board.

Troubleshoot Induced Draft Blower Capacitor

• If the incoming voltage has been verified, and the blower still will not resume normal operation:

Test the 5uf start capacitor • Turn off power to furnace. • Disconnect brown wires

attached to the capacitor. • Safely discharge capacitor. • Set meter to capacitance/

microfarad setting. (uf or MFD)

Troubleshoot Induced Draft Blower Capacitor

• Test for 5 microfarads across the two probes of capacitor.

• If not 5uf, +/-6%, replace capacitor.

Testing the 5uf Start Capacitor (cont.)

Test Induced Draft Blower Windings- Ohms Test

• Disconnect plug to motor.

• Touch one meter lead to the male terminal inside of the motor plug attached to the white wire from induced draft blower.

• Touch the other meter lead to the male terminal inside of the motor plug attached to the black fan wire.

• Ohm reading should be: Approx. 55.6 to 65.2 ohms.

Set Meter to ohms Setting

Test Induced Draft Blower Windings- Ohms Test

• White to Red: Approx. 120 ohms

• Black to Red: 55.8 to 65.5 ohms

• Black to painted brown: 72.9 to 85.5 ohms

Repeat same test for wire terminals below

Modulating Furnace Inducer Fan Check the motor like any other 3 Phase motor

3 conductors +

ground wire

Set meter to

Ohms and check

from pin to pin.

All should be

equal in Ohms