How to Replace a Furnace Blower Motor

All mechanical and electrical devices eventually wear out. A furnace blower motor is no exception. Most furnace repair shops will be more than happy to order the part for you. You can also perform an online search for the motor and perhaps save a few dollars by ordering the motor over the Internet. By following a basic process you can replace this integral part yourself and save some cash in your pocket.

Things You'll Need

• New replacement furnace motor New v-belt Screwdriver Philips and slotted 7/16-inch and ½-inch end wrenches

Instructions

1. Inspect the new motor by removing it from the package and checking it for any damages. Also be sure that the new drive v-belt is in good condition with no tears or crack. Some drive belts may have been sitting in a warehouse for years and the rubber can begin to deteriorate over time.

2. Use the screwdriver and remove the metal panel on the furnace that hides the blower motor. Most furnaces will have an identification tag signifying that the motor is behind the panel. There will be either four or six screws holding the panel in place. Pull the panel from the furnace housing and set it aside.

3. Remove all electrical power from the furnace. Some units may have a built-in power switch for the blower motor that resides behind the panel you just removed. Others may not, which means you will have to shut off the circuit breaker or remove the electrical fuse for the circuit that powers the furnace.

4. Loosen the four mounting bolts that hold the blower motor to the frame by using either one of the end wrenches. Different manufacturers will use a different sized bolt. The 7/16-inch or ½-inch end wrenches are the most common.

5. Push the motor toward the fan once the four bolts are loose enough and remove the v-belt. Even if the belt looks to be in good shape, no cracks or breaks, it is best to replace the belt when replacing the motor.

6. Finish removing the bolts from the motor and set them aside.

7. Pull the power plug assembly from the motor connector. All furnace blowers will have a connector plug built into the motor housing. It should be as simple as plugging a lamp into the wall outlet.

8. Remove the old motor and set the new motor in its place.

9. Plug the electrical connector into the motor socket.

10. Install the bolts loosely onto the motor and frame housing.

11. Install the new v-belt over the two pulleys of the fan and motor. A new replacement motor will come with the drive pulley already installed on the end of the motor shaft.

12. Tighten the bolts with the proper end wrench while pulling back on the motor to tension the v-belt. Proper tensioning of the v-belt will allow the fan to run at the correct speed.

13. Reapply the power to the furnace before replacing the housing cover you removed in step 2.

14. Replace the housing cover on the furnace by installing the screws.

15. Test the new motor by setting the thermostat and allowing the furnace to run for five minutes or more.

Tips & Warnings

• Be sure to consult your warranty on the furnace by the manufacturer. Some warranties may be voided if repair work is performed by non certified personnel.