How To Oil A Bathroom Exhaust Fan (6 Step Guide)

Is your bathroom exhaust fan making strange noises?

Is the fan not working as it once used to?

This is a common issue in 21st century homes, which is why it’s time to put your working hat on.

In this guide, you will learn…

how to oil a bathroom exhaust fan
  • How to disconnect a bathroom exhaust fan
  • The inspection process before applying oil
  • How to correctly apply oil

Follow these steps and the fan will be up and running in no time!

Step 1. Pre-Inspection

Before getting started, it’s time to inspect the bathroom exhaust fan. This is also the first step in deciding whether to vent a fan through the attic that I wrote earlier about.

This means taking out a small notepad and jotting down what’s working and what’s not. 

You can’t start oiling the fan without knowing the main issue. Sometimes, there are greater problems to deal with and oiling won’t help. This is why you want to jot down what’s wrong immediately.

This could be something as simple as a weird noise or perhaps the blade isn’t spinning properly.

Whatever the issue is, please make sure to write it down. You need this information for the final inspection.

Without examining the fan, you will never know if the oiling helped. It’s important to have this information in hand as you get started.

Read Also: How To Replace a Bathroom Exhaust Fan Without Attic Access (First Floor?)

Step 2. Disconnect and Remove Cover

According to a study run by Consumer Product Safety Commission (CSPC), all home-based electrical systems should be handled carefully. There’s a safety risk attached to them with electrical shocks.

Keeping this in mind, it’s important to disconnect the main power source before starting.

The primary circuit breaker is often housed in the basement. Find the circuit breaker and turn off the power. Please note, oiling the fan without doing this step is a major safety hazard and incredibly dangerous. Do not attempt to work with the exhaust fan under such conditions.

Once the power has been turned off, it’s time to assess the fan’s outer shell. If the fan looks in good shape, it’s time to remove its covering. 

Usually, all you have to do is pull on the plastic cover. When the cover has come down an inch from the ceiling, you should be able to see two metal clips that are holding the cover in place. All you have to do is squeeze the two metal clips together, and pull out the plastic cover or grill.

Step 3. Remove The Motor

Now remove the motor. In some circumstances, the screws may be covered with paint. Don’t panic! This is normal and shouldn’t be a concern moving forward. Simply peel away at the paint until there’s enough space to work on the screws. This should allow you to remove the motor without doing damage. 

Once the motor is out, it’s important to keep one hand on the fan. If not, the fan will come falling down and crash on the ground below. Support the fan and make sure it’s safely removed in one piece. The best way to do this is to ask for assistance and have the second person keep their hand in place.

Make sure to look up and disconnect the fan’s power supply. There is usually a socket within the fan housing where it is plugged in. If not, the fan is hardwired into the home's electrical system, and you will have to undo the wiring. Also, take the opportunity to remove additional wiring that’s connected to the fan.

Remember to write down where each wire goes! Otherwise, you may be left scratching your head once the oiling is done.

dirty bathroom exhaust fans cause fires

Step 4. Clean the Components

A study on asthma by Environ Health Prospect showed an increased rate in breathing problems due to poor indoor air quality. This shows the importance of cleaning your bathroom exhaust fan before turning it on.

When the exhaust fan doesn’t work properly, it won’t suck the air in. This often has to do with debris lodged inside.

To make sure this isn’t a long-term problem, please take the time to clean each component thoroughly.

The most common mistake people make is to start oiling right away. Yes, you may be eager to begin but it’s important to take a step back and clean everything.

To do this correctly, use a sturdy toothbrush or vacuum cleaner (handheld preferably). This allows you to clean the different components while making sure nothing gets damaged. 

For the blade, you should wash it separately with soap. 

While cleaning, keep an eye out for the shaft that’s holding the motor. This area can go unnoticed and should be cleaned as well.

Once everything has been scrubbed, it’s time to organize each part. You want to lay them down ensuring all sides can be oiled.

Read Also: Top 3 Best Rated Quiet Bathroom Exhaust Fans 

Step 5. Begin Applying Oil

This is what you’ve been waiting for.

It’s time to oil the bathroom exhaust fan. 

To get started, take out your can of WD-40 (or other general use lubricant), and apply it to both ends of the shaft. As mentioned previously, this shaft is found directly on the motor. Take your time and move the shaft around to get all of it. Remember, this has to be oiled properly to make sure the fan works efficiently.

Once you feel there’s enough oil on the shaft, it’s time to spin the blades with your finger. This allows you to see whether or not oil is dripping off of the blades. If yes, please take a small rag or cloth and wipe up the mess. Don’t turn on the fan without checking!

There are times when extra oil damages the fan for good. Don’t let this happen and pay attention throughout the process. It’s easy to apply a bit too much, which is why staying careful is important.

This inspection will also help determine whether or not extra oil is needed. Sometimes, the blades won’t spin as easily as you want them to. This means additional oil is required. If that’s the case, don’t be afraid to add a little bit more in the problem areas.

When do you know to stop?

The best approach is to go slowly and see how the shaft responds. This is why having your finger spinning the blade is important. You have to make sure it’s well-oiled and doesn’t create issues later on. The last thing you need is for the fan to stop working because it wasn’t oiled thoroughly.

And if you would like to replace your bathroom fan, check out our guide on bathroom exhaust fans with lights.

By gradually oiling the shaft, you’re able to make adjustments on the go. You can figure out when and if additional oil is needed. Do this and you will be more than happy with the oiling process.

In some situations, it may only take a few sprays of WD-40 to get the job done. Don’t assume you need a lot of oil to see results. The shaft is a small component and doesn’t take a lot to get back up to speed. Continue to work along the edges and ensure each side is oiled.

The change should be noticeable once the WD-40 is in place. You will notice a change in how the blade spins. It will be smoother, faster, and cleaner than ever before.

After the oil has been applied, allow the parts to dry for a few hours.

Read Also: Top 5 Best Bathroom Exhaust Fans With Humidity Sensors

Step 6. Final Testing

It’s time to finish the job!

You are going to put everything together. This includes the motor, power supply, wiring, and anything else attached to the fan. Don’t rush the assembly because any misstep here may force you to take everything apart again.

After the bathroom exhaust fan is in place, go back to the main circuit breaker and turn the power on.

You will want to run the fan and see if it’s working properly.


What should you check for?

It’s best to start by listening for odd noises (i.e. stuttering, squealing). In fact, experts say modern fans produce less noise and this has to do with their design [3]. So, if noise is coming, this means something has gone wrong.

After testing the noise, determine whether or not the blade is spinning correctly. If yes, this means the exhaust fan is good to go. If not, make sure it was oiled and put together perfectly.

If necessary, take out the notepad from step 1 and see if everything is in order. This is why the pre-inspection is important. It allows you to see if the WD-40 did its job in improving the fan’s performance.

What's The Bottom Line On Oiling A Bath Fan?

So, there you have it.

Properly oiling a bathroom exhaust fan can be a tricky thing to manage. Many homeowners refrain from oiling it and allow the problem to continue for years until it stops working.

Don’t make this mistake and get on top of the problem right away. If you allow it to get worse, the bathroom exhaust fan will eventually break down. The goal should be to oil it as soon as you get the chance to do so.

In most cases, this shouldn’t take longer than a few hours. You can end up saving quite a bit of money with nothing more than your toolbox and a can of WD-40 oil.

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Arie Van Tuijl

Arie Van Tuijl

Arie is a licensed home inspector who owns a residential and commercial inspection company in the state of Virginia. He also does specialty testing such as radon gas, termites, air quality, and mold.

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