Are Bathroom Fan Motors Universal?


Recently my bath fan started making a horrible noise that reminded me of the noise my high-school teacher made by dragging her nails over the chalkboard whenever the class didn’t behave. Goes without saying I wanted to stop that as soon as possible.

As I dislike throwing things away unless absolutely necessary, I decided to find out if it is possible to change only the motor. The first thing I had to find out was if bathroom fan motors are universal or not.

Bathroom exhaust fan motors are not universal because motor dimensions, power output, and mounting locations are different across different models.

Nevertheless it is possible to change the motor. Read on and I will share all I learned by replacing mine.

Can You Replace a Bathroom Fan
Motor?

Most of the major manufacturers offer replacement parts for their units. And depending on your model it will take between 5-60 minutes to change. Even when your fan motor is decades-old there is a good chance you can find a replacement motor for it. Even when the original manufacturer has gone out of business, you can probably find some other company that offers aftermarket parts and has a similar motor that will fit.

Some brands offer more efficient brushless motors as an upgrade. As long as the part number matches it should fit nicely in the old enclosure.

When you research the price for the new motor you will quickly realize that you can buy a new fan for almost the same price. While this can be tempting, do think about how you can remove the whole assembly without damaging the finish on the ceiling. Most often replacing the whole fan unit without attic access is close to impossible without damaging the drywall.

How to Find the Correct Motor?

  • Turn off the power
  • Remove the fan cover/grill
  • Vacuum or sweep away the dust
  • Look for the part number on the label or stamped on the housing.

In case you can’t find the model number on the housing, you will have to remove the motor. It is most likely printed on the side of the motor. Keep reading to find out how to remove it.

How Hard is it To Replace Bathroom Fan Motor?

The first aspect that determines how difficult it is to replace the motor is the construction of the fan unit. I was lucky with mine and it was a matter of unscrewing 2 bolts, unplugging the wire, and installing the new motor. It took me around 15 minutes for the whole job from start to finish.

However, before I began to change mine I did some research and found out that some models have motors that are close to impossible to remove while the whole fan unit is in the ceiling. But that is more of an exception than a rule, most are easy to replace.

On top of that, if the motor is hardwired it is very difficult to connect the new wires since the connection has to be made in a very confined space. There is not much room to work and you are working up on a ladder.

The second aspect is your skill and confidence that you can do it. What’s easy as ABC for some people, can be very intimidating for others.

So I don’t want to say it is very easy since it will depend on your skill and experience. However, I feel confident that this is doable for everybody if you follow all safety precautions and take your time.

After removing the grill you will see if the fan is connected with a regular wall plug or if it is hardwired.

In case it is hardwired and you lack previous electrical experience it is wise to turn to a licensed electrician, who can make sure that all connections are made securely.

How do You Replace an Exhaust Fan Motor?

bathroom fan cover removed

If you have a fan similar to the one pictured above you can use the following steps to replace the motor:

Tools you need: Adjustable wrench or a socket set.

  • Turn the fan on and have someone watching it
  • Go to your breaker box and turn off circuit breakers one by one until the fan stops working (Alternatively you can turn off the main fuse, but then you will have the whole house without electricity for the duration of the job)
    turn off circuit breaker
  • Remove the plastic grill/cover
  • Use a circuit tester to confirm that the power is off.
  • Unplug the wire (Proceed with caution if it is hardwired).
    hand holding a us wall plug
  • Unscrew the motor from the housing.
  • For a plate type fan you can’t unscrew the fan, you have to wiggle the whole plate off with a screwdriver as seen in the video below.
  • Now you should see the printed label or stamped product code.
    Try googling the product code, most likely you can find it on Amazon, so you can get it within 24 hours.
  • After the new motor has arrived double-check that the new motor is identical to the old.
  • Install the new motor and tighten the nuts (It’s a good idea to use a little thread lock on those nuts since they can vibrate loose.)
  • Replace the plastic cover
  • Turn on the power and test your new motor.

Does it Make Sense to Replace the Entire Bath Fan?

Before running out to your local home improvement store and buying a new fan consider does It even makes sense to replace the whole unit. Wait…who am I kidding, you will most likely order it online while drinking coffee. Aren’t we getting lazy these days…or is it efficient? I can never decide.

Replacing the whole unit should be the last option. It is recommended only when there is no replacement motor available. It does not make sense since the labor costs for rewiring and drywall work make replacing the entire fan much more expensive. Besides there is not much to gain from replacing the housing, since that does not wear out over time.

One reason you might want to replace the whole unit is that the plastic grille has yellowed over time. The good news is you can buy only the cover for most models, just pop the cover off to find the model of your fan and google that + cover/grille. For most models it will cost only 5-10 bucks.

Earlier we covered that replacing only the motor is no big deal for most models.

If you still insist on changing the whole unit think about how you can remove the entire housing without damaging the drywall or paint. Consider this, even if you damage the drywall a little from one corner you will have to repaint the whole ceiling to get a nice even finish.

Joonas

I like it when I'm able to fix everything that needs fixing around the house. In order to do that, I have to do a lot of research. This site will cover everything I learn and maybe help others do the same.

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