Replacing a Furnace Blower Motor

A man works on a furnace.
  • 2 hours
  • Intermediate
  • 100-250
What You'll Need
New motor
Cloth rag
Insulation tape
What You'll Need
New motor
Cloth rag
Insulation tape

Replacing a furnace blower motor is a task that many would not want to take up, believing it is a job for the professionals. However, this is a job you can do yourself, provided you have the right tools.

Step 1 - Turn Off the Power

Turn off the furnace. You need to turn off the power at the circuit breaker and not just by moving the thermostat down.

Step 2 - Locate the Blower

Locate the blower after opening the furnace door. The motor will usually be at the center of the blower.

Step 3 - Remove the Blower

If the blower is restricting access to the motor, unbolt the blower and take it out. If you have unimpeded access to the motor, simply unbolt it from the furnace and remove it. In case something else like the electrical box is in the way, then take that out first and then the blower.

Step 4 - Unplug the Wires

Unplug the wires that connect the motor to the blower unit. You will need to connect the new motor to these wires later. It would be good if you make a note of all that you are doing so that when installing the new motor, you know the exact steps to reverse.

Step 5 - Clean

Properly clean the compartment and the filter. To ensure that motors don’t burn out frequently, you should clean the filter every month.

Step 6 - Remove the Motor

Now unscrew the bolts that mount the motor in the blower. To allow easy removal, loosen the nut by turning the squirrel cage over, and after loosening, turn back the cage and take out the motor.

Step 7 - Remove the Bracket

If you plan to use the existing bracket with the new motor as well, take it off the old motor, clean it, and keep it aside to use it again.

Step 8 - Insert the New Motor

It is very important that the new motor that you install has the same horsepower and RPM. Put the bracket, which you took off the old motor, on to the new one and secure it.

Step 9 - Check Oil Ports

If the new motor has oil parts, make sure that they face out. In addition, the bracket should not block them.

Step 10 - Tighten the Nuts

Place the motor in the center of the blower and tighten the nut you loosened earlier in Step 6. Screw back the bolts you removed in Step 6 to secure the motor in place.

Step 11 - Re-wire

Rewire the motor by connecting the connector to the plug. It is advised that you use the notes on wiring connections that you made while unplugging the wires in Step 4.

Step 12 - Finish

Re-assemble the furnace cover and manually check the free spinning of the fan. Turn on the power supply, switch on the furnace, and check the furnace.