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how to fix a noisy bathroom fan

Do you remember back when your bathroom fan removed the moisture and smells from the room without making the commotion it does today? If your bathroom fan noise has ever woken up your family members, you need to know how to fix a noisy bathroom fan.

A loud bathroom fan can be caused by many things. In this article, we will go over the main culprits of the exhaust fan noise that is plaguing your life. Then we will discuss 9 different ways to stop bathroom exhaust fan noise.

What Bathroom Fan Parts Can Make Noise

The fan blades are the moving part of the fan. Through normal operation, they will create some sound as they spin. This will be louder or quieter depending on the quality of components used in constructing it.

If the fan is worn out or damaged at all, it may begin to make more noise as it spins. If your fan is making noise now and it didn’t before, you should check for wear or damage on the fan and motor.

Make sure to keep the fan blades clean and clear. Dirt buildup over time can cause the fan to become excessively loud.

The sound of air moving that the fan is pushing also creates noise. Anytime air is moving, it will create some noise, which is unavoidable.

The motor is what does all the work. It is responsible for turning the fan blades that move the air.

If your fan is older, it may have a louder and less efficient fan motor.

Cheap fans also tend to use loud motors that spin fast with small fans. This creates noticeable excess noise.

If your fan has only recently started making noise, it’s possible that it could be from the motor going bad. Eventually, the motor will wear out. This can make the motor noisy and weak as it reaches the end of its lifespan.

Check the motor for any wear or damage after removing the fan cover. If you see any obvious signs of damage, then it may be time for a replacement.

After allowing the fan to run for a while, check for excessive heat buildup. This could be a sign that your motor is on its last legs.

One of the main sources of noise from your bathroom exhaust fan is the ductwork it hooks into. When your fan removes the air from your bathroom, it has to then transport it outside of your house through a vent. The air is carried through the ductwork.

No matter what you do, moving air will always create some level of noise. That being said, there are several ways to minimize the amount of noise that is made from the air moving through the ducts.

The first thing to understand is that higher air pressure means more noise from the air moving. Smaller diameter ducts will create more air pressure, and therefore, more noise.

The quietest bathroom fans on the market are usually built for use with 6” ducts. However, you likely have 4” or even 3” duct currently residing in your ceiling. It could be a major headache and expense to switch to the larger 6” duct.

If your fan is meant to be used with 6” but you have 4” duct currently, you can still hook it up by using a reducer. The problem is that by doing so, you will increase the air pressure and the noise your fan makes. This means you will not achieve the low sone rating that your fan is advertising.

Another important thing to remember with ductwork is that it should be as straight as possible. Hard turns or multiple turns will all increase the air pressure and the noise that the fan makes.

If your duct requires taking a turn or several, try to lessen the impact by lengthening the turn. For example, instead of using a 90-degree corner, you can achieve the same angle by using 45-degree connectors instead.

Hangers/Mounting Brackets
A lot of noise that your fan may be making could be caused by poor mounting. This may be the result of shoddy initial installation, or it may be from the screws and mounting hardware loosening up over time. Either way, the result is the same.

When the fan is loose, the vibration created by the motor and the fan will not be contained. The entire fan assembly will be allowed to move, which will create excess noise.

To make matters worse, this vibration will be transferred into the ceiling and walls, multiplying the amount of noise it makes.

Take off the fan cover. Gently push on the fan assembly and see if you get any visible movement. If the unit is noticeably loose, you’ll have to determine how your fan is mounted.

It’s possible your fan is mounted with screws from underneath that go into the joist. These would be accessible from the ground.

Often, bathroom exhaust fans are mounted to the joists by hangers above the drywall on the ceiling. To access these hangers, you may need to get into the attic and locate the bathroom.

Types of Bathroom Fan Noises

Knocking noise – If the fan blades are misaligned or obstructed, you will hear a repetitive knocking noise as blades spin.

Humming – Older fans or cheaper fans with inefficient motors can make a humming noise as they run. You may also experience this sound as a motor begins to die out.

Vibration- Vibration noise will be caused if the fan is not securely mounted. As mounting screws and brackets loosen up over time, it can lead to vibration noise.

Grinding – If you have an excessive buildup of dirt, dust, and grime on the fan, it can cause some grinding sounds as the fan spins and grinds all the hard matter up. This will create extra wear on your fan and shorten its lifespan.

You may also hear grinding from the motor as an older unit starts to die out. In this case, the grinding will be accompanied by a slowing of the fan, which you should be able to hear.

Rattling – If your fan unit gets loose enough, it may be able to move inside of the hole it’s mounted in. When this happens, you’ll hear the fan assembly ratting around as it operates.

Bathroom exhaust fan knocking noise- If your fan is way out of alignment, it may be hitting the side of the fan housing as it spins, creating a loud knocking noise. This would also happen if there was a sizable piece of debris stuck inside the fan housing.

Squealing – If the moving parts of your fan get too dry, they may start to squeal as they move and create friction from the dry parts rubbing together at high speeds.

Buzzing when off – If you live in a multi-unit building, it is possible to experience buzzing from your fan, even when it is off. This is due to the duct being connected to other people’s fan ducts.

If someone else’s fan is running, the vibration may be carried from their fan, through their duct, and into your duct. The final product is buzzing, which seems to come from your bathroom fan.

Crackling – If your fan blades are loose, you can hear a fast clicking that sounds like crackling. This is from the blade holders coming into contact with the motor housing.

High pitched noise – Often, as a bathroom fan motor reaches the end of its lifecycle, it will start to release a high-pitched whining noise. This is a sign that the motor is no longer good and needs replacing.

How to Fix a Noisy Bathroom Fan

1. Thoroughly Clean Fan and All Moving Parts

If your fan is starting to make, noise doesn’t run out and purchase a new fan until you’ve tried cleaning the one you have now! As dirt and grime build up over the years, they can cause problems for the fan blades.

First, remove the fan cover so that you can access the fan blades and housing.

Using a rag and warm soapy water, clean down the fan blades, the entire fan housing, the motor assembly, and anything else that looks dirty. While you’re cleaning, be sure to keep an eye out for any damage or wear. If there’s damage present, you may need to replace the fan, the motor, or the whole unit.

Once everything is dry, replace your fan cover. Test the fan to see if this has alleviated your noise problems. If so, excellent! Your job is done. If not, then proceed down the list.

2. Absorb the Sound With Sorbothane Rubber

If cleaning your fan down thoroughly didn’t do the trick, you may try absorbing the vibration and sound by using Sorbothane rubber.

Sorbothane is a very soft rubber that is available in easy to work with sheets. It can be purchased with an adhesive backing that makes it simple to apply to your bathroom fan.

Cut the Sorbothane into strips. These can be 1 ½” to 2” wide.

Adhere a strip around your fan in line with where the ceiling or wall will be against the unit when installed. This will effectively decouple the fan from the wall, reducing the amount of vibration and sound transferred.

You can also add some of the Sorbothane to the electrical access plate and the fan motor assembly to help dampen some more of the vibrations.

3. Use Larger Duct

The larger the size duct you use, the less air pressure is created by the air that the fan is expelling. This equates to less air noise.

Newer fans that are designed to be ultra-quiet usually use 6” duct to help achieve this goal.

If you’re upgrading to a larger duct because you’re upgrading to a quieter fan that requires 6” duct, then all you need to do is replace the existing duct.

If you’re keeping your old fan but upgrading to a larger diameter duct, you will need to get an enlarger coupling that will allow you to use the larger duct with your smaller fan outlet.

Head up into your attic and locate where your bathroom fan is.

If installing a new duct on an existing fan, unhook the duct from the outlet on the fan. Install your enlarger coupling on your fan’s outlet.

Remove the existing duct from your fan to the vent in the roof or wall.

You will need to enlarge the vent opening for a new 6” vent. Call a professional if necessary.

Run a new 6” duct from your vent to your fan, being sure to keep it as straight as possible.

4. Straighten Out the Duct

If your ductwork has many kinks or hard turns on its way to the exterior vent, then the extra pressure this causes could be making your fan unnecessarily loud.

Straightening out your ductwork is less surgery than replacing it all with a larger diameter duct. It may not have the same effect, but it will help reduce the air pressure and eliminate some of the air movement noise.

Go into the attic and locate the ductwork for your bathroom fan.

Follow the duct from the fan to the exterior vent. Take note of how many hard turns are in the line.

If there are none, then you won’t be able to make improvements through this method. Often though, you will find several.

For each 90-degree connector in your duct now, replace it with two 45-degree connectors instead. This will reduce the air pressure and should help quiet your bathroom fan.

5. Adjust the Housing or Fan Blades

If the fan housing or blades become out of whack, they can cause all kinds of noise. Worse, they will also be subject to greater levels of wear and tear, taking years off of your fan’s lifespan.

Remove the fan cover. Make sure the fan is off.

Gently move the fan blades with your finger and look for any obvious signs of it being out of kilter. If you see it’s not moving straight, or it’s hitting the fan housing, then it needs an adjustment.

You will need to remove the fan and then remount it. Make sure when you re-install the fan blades that you get everything completely straight or the problem will persist.

6. Lubricate the Fan Motor and Blades

As your fan gets on in years, it will start to dry out and moving parts will start to experience increased friction. This will start to cause greater wear and damage, reducing the lifespan of your fan.

Remove the fan cover. Make sure the fan is powered off.

First, clean off the fan and the fan housing. Make sure there is no dirt or dust to become thick grime when you add lubrication. This will make your problem worse instead of better.

Lubricate around the base of the fan blades with WD-40, or your choice of lubricant. Make sure to spin the blades around a few times will applying lubricant to ensure that you get a nice coat that gets deep into the moving parts where the friction is greatest.

7. Tighten the Mounting Screws

As your fan goes through years of operation, the screws and mounting hardware may begin to loosen. When this happens, you will experience excess noise and vibration that makes your fan seem louder than it should be.

There are two ways to go about tightening the mounting screws depending on how your fan is installed.

If your fan is installed by screws being run through the fan assembly and into a joist, then you may be able to tighten them without getting into the attic.

Remove the fan cover. Locate the screws used to install the fan to the joists and tighten them. That’s it, simple!

Many fans are installed to the ceiling joists with hangers that are mounted above the ceiling drywall. In this case, you’ll need to head up to the attic and locate your bathroom fan from above.

Start by tightening all of the screws that mount the fan to the hangers.

You should be able to follow the hangers from your fan assembly to the nearby joists that they are mounted to. Tighten the screws that mount the hangers to the joists.

Check your fan assembly by moving it gently with your hand and looking for any movement. If you see movement, then something is still loose. Find the offending screws and tighten them up!

8. Replace the Motor

Unfortunately, the motor that powers your bathroom fan does have a lifespan. Eventually, it will reach the end of its lifecycle and the motor will die. There is nothing you can do to avoid this sad reality.

Just because your fan motor has died doesn’t mean you need to purchase and install a whole new fan assembly. You can get the new motor by itself and replace the one part that has gone bad.

This approach can save you quite a bit over the cost of an entire fan unit. It can also be much easier to install just a fan motor than a whole new assembly. You’ll have to decide for yourself if this is the right option for you or not.

9. Replace the Whole Fan

When you have had enough of the noise problems generated by your old bathroom fan, it may be time to retire it and get a replacement.

Modern bathroom fans are built to be ultra-quiet and exchange the air in your bathroom very quickly. A replacement may be just the breath of fresh air you needed (pun intended).

Start by disconnecting the power to your existing fan. You don’t want to get shocked by accident!

Remove the screws that mount your fan to the joists. These may be underneath, or they may be up above the ceiling, in which case you’ll get access from the attic.

After removing the old fan, check your new fan for sizing. You may need to enlarge your existing hole to install your new fan.

Set the fan in place and screw it into the joists according to the directions provided with your fan. Some units will screw in from the bottom. Others will mount above the drywall by attaching to hangers that screw into the joists.

Once your fan is mounted, you’ll need to hook up the duct. Slide the duct over the outlet on your fan. Using foil tape, secure the duct so that no air will escape.

Hook up your electric by matching the correct colors together. If you are uncomfortable with this step, you can call an electrician.

Turn on the power and make sure your fan is installed correctly!


A loud, obnoxious bathroom fan can become a real nuisance. After reading this article, you should know how to reduce or eliminate the noise your fan makes. If all else fails, replace it with a new ultra-quiet modern one and experience the bliss of silent bathroom usage.

If your bathroom is quieter and your life more peaceful after receiving the help provided in this article, please be sure to share it so that others can also find some peace in their bathrooms! If you have any questions or comments, leave them in the comment box below so I can get back to you.

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