One of the duties of a building maintenance worker is to make sure the electrical systems in the building are well-maintained and operating normally. This includes making sure the exhaust fans in the building's bathrooms are kept in working order.  One sign a bathroom fan motor is going bad is that it will usually start to make a lot of noise just before it stops working. You should be able to replace the fan motor on your own even if you are new to working on building maintenance projects. Here is how to replace the motor on a bathroom exhaust fan. 

Turn Off Electricity

Make sure the electricity going to the fan is turned off before you start to work. You should turn the fan off at the circuit breaker box. You should also put a piece of masking tape over the circuit breaker to make sure another maintenance worker doesn't come along and switch the breaker back to the "on" position while you are working.

Remove Grille Cover

Unscrew the grille cover on the front of the fan and set it aside. Some exhaust fans have spring-loaded covers and don't have any screws. Pull the cover down until you can see the springs. Pinch the arms of the springs together to pull the bottom of the spring out of the frame so you can remove the fan.

Remove Fan

You will see the fan motor as soon as you take off the grille cover. Disconnect the electrical harness clip going to the motor. There are usually a couple of clips holding the bracket for the motor and fan to the fan's housing. Push the clips open and drop the bracket, motor, and fan out of the fan's housing. The motor and fan can be put together as one unit or two separate parts. If the parts are separate, there will be a clip holding the fan to the shaft of the motor. Remove the clip and separate the fan from the motor.

There are normally two bolts holding the bottom of the motor to the bracket. Remove the nuts on the bolts and take the motor off of the bracket.

Buy New Motor

The fan will usually be covered in dirt and debris from years of usage. Clean the debris off with a rag so you can read the label on the fan. The label will give you the model number and the amount of amperage the fan motor needs to operate. Use this information to purchase a replacement motor that is compatible with the one you are replacing.

Install New Fan

Connect the bottom of the new motor to the bracket and reconnect the fan to the shaft on the motor. Insert the unit back into the housing. Make sure you hear and/or feel the bracket clicking back into the clips to make sure it's installed correctly. Replace the grille cover and turn the electricity back on. The fan should kick back on without any noise coming from it.

If you need help, consider contacting a commercial electrical contractor at a company like ABC Electric Co.