How to Replace an Attic Fan Motor

The motor of an attic fan runs on a constant basis, as otherwise the flow of air out of the house from the attic will be impaired.

A defective motor in a wall-mounted attic fan must be replaced not only because the fan won't turn, but also due to the risk of an electrical fire being started. A few tools commonly found around the home will be needed, as will a replacement motor that is rated similarly to that of the motor being replaced. The replacement motor can be acquired from a hardware store or select home and garden shops.

Pull the fuse or trip the circuit breaker that supplies electrical power to the attic. If the attic fan uses a power cord instead of being wired to an electrical socket, pull the cord out of the AC outlet. Remove the screws surrounding the attic fan with a Phillips screwdriver. Pull the back grille off the attic fan with your hands. Place the grille aside.

Locate the drive belt that is attached to the motor shaft's hub at one side of the motor. Pull the drive belt's loop off the hub -- the belt must be slightly stretched to accomplish this. Pull the loop at the other end of the belt off the hub at the back end of the fan blade assembly. Place the drive belt aside for now.

Remove the screws surrounding the motor with the Phillips screwdriver. The screws are in the brackets attached to each side of the motor. Pull the motor part of the way out of the fan. Loosen the screws on the two electrical contacts on the back end of the motor with the Phillips screwdriver.

Unwind the two electric wires from around the screws. Pull the motor completely out of the fan, and dispose of it in an eco-friendly way.

Shake the can of lubricating spray for two seconds. Spray a burst of lubrication at the motor shaft's hub. Loosen the screws on the two electrical contacts on the back end of the replacement motor with the Phillips screwdriver. Wind the end of the two wires around the screws, in the same manner as they were wound around the defective motor. Tighten the screws.

Place the motor in the fan in the position that the defective one occupied earlier. Attach the screws to hold the motor in place.

Loop an end of the drive belt around the hub at the back end of the fan blade assembly. Stretch the belt so that you can loop the other end around the hub attached to the motor shaft. Place the grille back on the attic fan. Reattach the screws. Return power to the attic fan.

Things You Will Need

  • Phillips screwdriver
  • Lubricating spray
  • Replacement motor

Warning

  • Regularly check your attic fan to ensure that it is running smoothly and that there are no obvious problems, such as a "burning" smell or a broken fan blade.

About the Author

Marshal M. Rosenthal is a technology maven with more than 15 years of editorial experience. A graduate of Brooks Institute of Photography with a Bachelor of Arts in photographic arts, his editorial work has appeared both domestically as well as internationally in publications such as "Home Theater," "Electronic House," "eGear," "Computer and Video Games" and "Digitrends."