How to Fix a Noisy Bathroom Fan?

Bathroom fans are essential in our homes. They help get rid of odors and moisture from the bathroom. When you install a new fan in your bathroom, you may not hear any noises for a while. But after servicing you for an extended period, the sounds may appear.

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Bathroom fan sounds could be so severe that you can hardly sleep while the fan is active. As a homeowner, you need to know how to fix your bathroom fan when it starts making noise. Suppose you have no clue, no need to worry. Continue reading this article to enlighten you on how you can fix your noisy bathroom fan.

You will also learn about various causes of bathroom fan noise and their different types. Fans come in multiple parts, culprits producing the annoying sounds. To start with, let’s look at the various places the noise could come from in a bathroom fan.

Causes of Bathroom Fan Noise

dirty bathroom fan blades

I. Fan Blades

The blades constitute the fan’s moving part. They usually create sounds during regular operations. The noise produced depends on the number of edgesFew blades make more noise because they spin faster. But they create a powerful airflow, keeping your bathroom dry and fresh.

Many blades in a fan make less noise because they spin slowly. When blades are many, they cause the fan to drag, which might be hard on the motor. The fan also uses more energy, increasing your power bill.

If your bathroom’s fan blades start making noise you weren’t hearing before, inspect whether they are clean. Dirt accumulated on the edges may cause uncomfortably loud noise.

II. Fan Duct

Bathroom exhaust fans get hooked into ductworks which carry away air into the outside. Ductworks are usually done inside the vents to transport air outside. The vent gets connected to the bathroom fan to remove the bathroom’s moist air and bad smells.

Ductworks are the leading causes of sounds in a bathroom fan. Unfortunately, moving air always makes some noise, and there’s nothing we can do about it. The best thing to do is reduce the noise the moving air produces while passing through the ducts.

When the air gets subjected to high pressure, it will move faster, making a lot of noise. The ducts, therefore, shouldn’t come with small diameters. If so, they will create more air pressure, causing more noise.

Silent bathroom fans usually use ducts of 6 – inches in diameter. If your fan uses ducts less than this, it could cause noise. Generally, most ducks used with fans are usually 3 – inches or 4 – inches wide. Check if yours is the case. If so, they increase the air pressure, making the fan make some noise. Replace them with wider ducts. It may be a lot of work and money involved, but the hustle will be worth it.

When purchasing a new bathroom fan, check the duct size they are using. You may get a fan that uses a smaller duct size than those installed in your bathroom. In this case, you will need to use a reducer to decrease the duct size. In doing so, the air pressure will increase, meaning that you will experience some noise when the fan is in operation.

Also, ductwork is supposed to be straightMultiple and hard turns usually make the air pressure go up. In return, your fan will produce some sounds. If your duck must take one or several turns, ensure you prolong its length. As a result, you will have lessened the impact.

A great example is using two 45 – degree connectors instead of a 90 – degree corner. You will still achieve the same angle, and you will have prevented the air pressure from increasing.

III. Fan Motor

The motor is the engine of the fan. It is responsible for making the fan operate by spinning the blades or activating other air circulating mechanisms. When a motor works for an extended period, it is likely to wear out, making it produce some noise. That is why old fans make some sounds while in use.

Cheap fans may be friendly to your pocket, but they also come with substandard motors. As a result, they will create excess, annoying noise. If you just bought a fan and start producing some irritating sounds, the motor could be the problem. Such a fan never runs for long before it malfunctions.

If you want to know the motor is bad or weak, check whether your fan builds up excess heat. If so, it’s an excellent sign of a dying engine. Remove the fan’s cover and take out the motor. Then replace it with a new, quality fan motor.

IV. Mounting Brackets or Hangers

Poor mounting could also make your fan produce some noise. Avoid shoddy installations. Check out the installation manual from the manufacturer. If you are not sure what you are doing, consult an expert. Engaging a quack because of their cheap labor may be disastrous, making you spend more in the long run.

With time, the mounting hardware and screws loosen up. In return, the fan and motor vibrate when on, making some sounds that you cannot contain. The whole assembly of the fan starts moving, creating excess noise.

What worsens the situation is that the produced noise gets amplified when transferred into the walls and ceiling. Sort out this problem by first removing the fan cover. Then press the fan assembly gently to check for any movements. If you see it moving, know that your mounting has a problem. You will have to remove the fan and fix it again. Ensure it is firmly secured such that it doesn’t move an inch when pushed aside.

Because it’s a bathroom fan, it gets mounted by hangers to the joists, usually over the ceiling’s drywall. The only way to accessing the hangers is by going into the attic above your bathroom.

The above causes of bathroom fan noise come in different sounds. As a result, you can identify the fan problem by the noise type produced without a checkup. As a homeowner, you must learn the different sounds produced by your bathroom fan. In return, you can tell the problem quickly, making you attend to it before it gets worse.

To help you out, here is the insight into various noises produced by a bathroom fan;

Noise Types Produced by a Bathroom Fan

bathroom fan blades

i. Humming Sound

When you hear this sound, it means that you are dealing with a cheap or old fan. Also, substandard motors produce humming sounds as they run. The engine may be of top-notch quality, but it may wear out or die when used for a long time. While in this state, it produces the humming noise.

ii. Knocking Noise

This kind of sound gets produced when the blades are obstructed or misaligned. When the blades spin, they create the knocking noise repetitively.

iii. Vibration

Loose screws and brackets cause it to make noise. It would help if you mounted a fan securely. If not, it vibrates when in use. Keep on checking if your fan gets firmly fixed because the screws loosen up with time.

iv. Rattling Noise

very loose fan produces the rattling sound. It gets caused by the fan dancing within the installation area or hole. When the fan runs, its assembly starts rattling. You should reinstall the fan securely to eliminate this problem.

v. Squealing Sound

When you hear this noise coming from your fan, it means that most of its parts are dry. It gets brought about by friction between dry parts. When the fan speed increases, the squealing sound also increases, becoming a nuisance. Oil your fan’s components to get rid of this problem.

vi. Knocking Noise from a Bathroom Exhaust Fan

Bathroom exhaust fans usually make a knocking sound when they get misaligned. When such a fan spins, it hits its housing, making a loud noise. Also, large debris stuck inside your bathroom fan’s housing could cause the knocking noise. Realign the fan and remove all obstructions stuck inside its housing to remove the noise.

vii. Crackling Noise

It is one of the most annoying sounds you can hear from your bathroom fan. It comes from loose blades. When the screws securing the edges become loose, the blades start producing a fast clicking sound when the fan runs.

It is the kind of noise that makes you close your ears or gnaw your teeth. The sound’s sharpness is on another level. When the loose blade holders and motor housing come into contact, they produce a crackling noise.

viii. Buzzing Sound – Even When Off

Have you ever heard your bathroom fan produce a buzzing noise even when you’ve switched it off? Your duct gets connected with others from a different house. It is common in neighborhoods with multi-unit buildings.

Ducts from various houses get connected. When your neighbor puts on his bathroom fan, it vibrates. The vibration then gets transferred to your device through his duct. The result is the buzzing sound.

ix. High Pitched Noise

It is another noise type you will not like to hear. Its sound can get on your nerves! When you hear this kind of sound from your bathroom fan, get ready to buy a new one. It means that your fan is worn out and almost dead!

Now that you are aware of the different kinds of sounds your bathroom fan can produce, it is time to learn how to fix them. Below is a detailed guide on how to do so.

How to Repair a Noisy Bathroom Fan

installing bathroom fan

Use the following steps to eliminate sounds from your bathroom fan.

Step 1: Clean the Entire Fan Thoroughly

As days pass by, an active fan accumulates dirt and grime. When the buildup is too much, especially on the blades, it can cause the fan to produce sounds when running. Before thinking of changing any part or installing a new fan, try cleaning the fan.

Access the blades and the housing by removing the fan cover. Use warm soapy water and a clean rag to clean the blades, motor assembly, housing, and everything else that’s dirty. As you do the cleaning, look out for any wear or damages. If the damage is manageable, you may need to repair it. If not, you will have to replace the entire fan.

After spotlessly cleaning all the dirty parts, leave them for a while to dry. Then return everything in place, including the fan cover. Switch on your fan to test if the noise it was producing earlier has gone. If quiet, you have successfully eliminated the sound from your bathroom fan! If not, proceed to the next step.

Step 2: Use Sorbothane Rubber to Absorb the Sound

Even after cleaning, the noise could still be there. In this case, use a Sorbothane rubber to dampen the sound or vibration. As a soft rubber, Sorbothane comes in sheets easy to use. It gets sold together with an adhesive to reinforce it. The glue makes it easy to apply to the fan.

First, cut the Sorbothane into thin strips of around 1 ½ – 2 – inches wide. Then apply adhesive to each strip and stick it where you will install the fan. It could be on the wall or ceiling. In doing so, you get to decouple your bathroom fan from the top or wall. It means that sound or vibration traveling through the roof or walls will not get transferred to your fan.

Adding the Sorbothane to your fan’s motor assembly and electrical access plate also works like magic in reducing noise.

Step 3: Install Large Duct

Though using Sorbothane will significantly reduce the noise from your fan, the air exited through the ductworks may disturb you with its noise. If the fan pushes out the air through the vent with much pressure, it will produce a loud and annoying sound.

Small ducts increase the air pressure, resulting in the air making some noise as it gets pushed out. Larger ducts decrease the air pressure, equating to less air sound. That’s why manufacturers nowadays are making fans compatible with 6 – inches ducts to make them ultra-quiet.

If your duct is less than 6 – inches in diameter, it is wise to replace it with a new duct measuring 6 – inches. You will also need to replace the fan with an ideal one to use with your new duct. As a result, you will enjoy a peaceful environment when your bathroom fan is in use.

In case you don’t want to replace your old fan or don’t have the money to buy a new one, there is a way out. Use an enlarger coupling to enable you to use the new large duct with your fan’s small outlet. You will need to locate your bathroom first from the attic.

When you find the fan, unhook the old duct from it and install the new one. If using an enlarger coupling, install it on the fan’s outlet. Because the new duct comes in a larger size, you will need to adjust the vent’s size in the wall or roof.

It might be tricky. If you find it confusing, don’t hesitate to engage an expert or professional to do it for you. Then run the new duct from the vent to the fan, ensuring it stays straight as much as possible.

Step 4: Straightening Out the Ductwork

The problem may not be with the size of your duct, but the fact that it’s not straightened out properly. When the duct has many hard turns and kinks, it causes extra pressure to the air has gotten pushed out. The result is the production of unnecessary loud noise.

You cannot compare the process of straightening out the ductwork with replacing a new duct. It will cost you less and take little of your time to straighten the duct. Installing a new duct will require a significant amount of time. The duct cost and professional service fee may leave your pocket dry.

To eliminate the problem, you will have to inspect the ductwork. Start by entering the attic and searching for your bathroom fan’s ductwork. When you locate it, follow it from the fan through the vent to the outside. Note all the hard turns you encounter in the line.

If you don’t find any hard turns, this method is useless. You will generally find one or several hard turns of the duct within the vent.

Remove all the 90 – degree connectors and replace them with two pieces of 45 – degree connectors. It will decrease the air pressure, bringing your fan’s noise down.

Step 5: Adjust Your Fan’s Blades and Housing

When your fan’s blades and housing become loose and out of alignment, it can make all kinds of sounds. If you don’t take action immediately, they can reduce the lifespan of your bathroom fan. Start by switching off the fan’s switch. You may not want to take chances. Otherwise, power can be dangerous.

Then take out the fan’s cover. You can now access and see the blades. Inspect for any damage. Move them gently using your finger, checking everywhere. If you discover any bending, non-straight movement, or hitting the housing while rotating, you need to adjust the blades.

Uninstall the fan and rectify the problems. Then remount it when you finish. Ensure you return every part where it belongs and in the correct manner. Otherwise, the problem may persist or worsen.

Step 6: Lubricating the Fan Parts

Your bathroom fan’s blades and motor need occasional lubrication. Otherwise, they may dry up and cause friction sounds. Dry parts grinding against each other wear out and get damaged quickly. If you don’t oil the parts immediately, your fan may not live long.

Begin by removing the fan’s cover. Then clean the entire fan. When you add the lubrication to dust and dirt, it results in thick grime. It will worsen the situation.

After the motor and blades are spotlessly clean, use a reliable lubricant like the WD-40 to lubricate them. As you apply the grease to the edges, spin them once in a while. It will help the oil spread evenly to the moving parts. The lubricant will also reach the places with the most significant friction, reducing the noise drastically.

Step 7: Fastening the Mounting Screws

The fan’s mounting hardware and screws loosen with time. That is why fans used for an extended time tend to increase their noise level while running. The loose components make the fan vibrate and produce more noise.

The solution is to tighten the loose parts. You may not need to enter the attic if the screws run through your fan’s assembly, then into the joist. Remove the cover and tighten the screws. It will sort out the problem.

But if your bathroom fan is mounted using hangers into your ceiling’s joist, you will have to go into the attic to tighten the loose screws. Remember to test if the tightening was firm enough by gently shaking the fan. If it moves side to side, some screws are still flexible. Look for the culprit screws and fasten them tightly.

Step 8: Motor Replacement

The reality is that fan motors do not last long. After a certain period, you will have to replace your bathroom fan’s motor. The solution is to install a new one. It doesn’t mean that you need to replace the entire fan when your fan’s motor dies. A quality fan may still have many years of service. You only need to install a new motor.

Step 9: Install a New Fan

If all the above options do not work out to your expectations, or the fan is beyond repair, installing a new fan is the best thing to do. You may also find out that the cost of reducing noise in your bathroom fan is the same as that of a new one. In this case, go for a new fan.

Thanks to the advent of technology, today’s market has got ultra-quiet bathroom fans that circulate air very fast. Replacing your noise-making fan with such an advanced device will be a great decision.

As illustrated above, the noise solutions to your bathroom fan are many. You only need to implement those in your power. It is advisable to leave the technical methods to the experts.

Though this article has given you so much information about noisy bathroom fans and how to eradicate them, you may still have some questions bothering your mind. Here are answers to questions most people ask to enlighten you.


1. Why Does a Bathroom Fan Make So Much Noise?

As described above, various reasons make a bathroom fan produce some noise. An old fan, loose parts, loose mounting, lousy motor, and others attribute to the fan’s sound. Causes have gotten illustrated in this article. Check them out.

2. What Kind of Noise Does a Bathroom Fan Make?

Bathroom fans make various sounds, as shown above. It could be humming, buzzing, vibrating, rattling, squealing, grinding, and others. The details have gotten described in this article.

3. Is the Noise Normal?

If the bathroom fan comes with few blades and rotates very fast, it is normal to produce sound. Also, air pushed with high pressure will always make noise. But if the sounds are any of the types described above, it means something is wrong.

You need to check the problem and have it fixed. Otherwise, your bathroom fan may not allow you to enjoy your sleep or concentrate on your work. Fortunately, there are many ways of reducing a bathroom fan noise, as illustrated in this article.

4. How Quiet Can a Bathroom Fan Become?

The sounds produced by a bathroom fan get measured in sones. The quietest bathroom fan should read 1.0 sones or less. A refrigerator has 1.0 sones, standard TV 4.0 sones, and noise in a typical office is approximately 3.0 sones.


Installing a fan in your bathroom is essential. The fan removes moisture and foul smell, making the space dry and fresh. But when the bathroom fan starts producing some noise, it may interfere with our peace and comfort, as illustrated above.

Fortunately, there are many ways to reduce the fan sounds, as described above. If you have a noise problem with your bathroom fan, use the above guide to reduce it. If you follow the steps to the latter, you will minimize the noise successfully.

In case you can’t perform the sound reduction procedure as explained above due to unavoidable circumstances, engage the services of an expert.