Bathroom Fans

Bathroom Fan Replacement: Cost, Installation, & Cleaning Guide

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A bath fan is essential because it removes excess moisture from bathrooms. Most bathroom fans are wired to turn on automatically whenever you enter the bathroom and flip the light switch. Over time, bathroom fans wear out and eventually need to be replaced.

So, how often should bathroom fans be replaced?

You should replace bathroom vent fans every ten years. How long a bathroom exhaust fan lasts depends on use, vent fan quality, and maintenance. You should clean vent fans at least once per year.

Most people don’t replace a bathroom vent fan until it fails, and there’s nothing wrong with that logic. However, most bathroom fans fail long before they actually stop working.

Keeping your new bathroom exhaust fan clean should be important for home maintenance. As dirt and grime build up inside the fan, the blades become heavy and harder to turn, causing excess stress on the motor. The build-up also collects on the motor itself, causing it to overheat – eventually leading to failure.

When to Replace Your Bathroom Fan?

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First, you must recognize the tell-tale signs that your bathroom fan needs to be replaced. Of course, it is a good idea to install a new unit before the existing fan fails.

So, when should you replace a bathroom vent fan? Bathroom vent fans should be replaced if the fan is over ten years old, won’t turn, is slow to turn, or is noisy caused by a broken blade or excessive vibration.

Bathroom fans will often start turning slowly or become very noisy before it completely quits. These are signs that your fan needs cleaning. Unfortunately, you can’t repair bathroom vent fans, only replace them. So maintenance is essential.

Here is how you can tell whether or not your bathroom fan needs replacement:

The Vent Fan Is Noisy When Turned On

Turn your bathroom’s exhaust fan on and off while listening carefully. If the fan is loud or making odd sounds, the fan is nearing the end of its useful life.

  • If you hear a loud squealing sound when the fan starts up, the vent fan motor is likely on the verge of seizing up.
  • If you hear a scraping sound, the fan blade is likely broken or is probably hitting the vent cover or housing walls due to excessive vibration.
  • If you hear a humming sound, the motor is likely having difficulty turning the blade and has seized or is about to seize up.

The Vent Fan Blade Doesn’t Turn

If the fan doesn’t startup as quickly as it did in the past, it will fail shortly. The reason is that the motor is not working as efficiently as it once did and is bound to break down sooner or later.

When you turn the fan on but it doesn’t respond, there may be problems with its electrical wiring or its circuits, especially if the lights in the bathroom turn on without any problem.

The Vent Fan More Than 10 Years Old

This is a more proactive than reactive approach. Vent fan components break down quickly as they age. Vent fans should be replaced every ten years, even if they are still in working order, like smoke detectors.

Older fans use more electricity to operate and can become a fire hazard. The motors inside the fans can overheat relatively quickly. New bathroom fan motors have thermal overloads that shut the fan off if it overheats. An old bathroom fan may not have this feature.

Cost to Replace a Bathroom Vent Fan?

If you noticed that your bathroom exhaust fan no longer functions efficiently or shows signs that it will soon fail, you should have it replaced as quickly as possible. But how much does a usual bathroom exhaust fan cost? Let’s look at the breakdown of the costs of having your bathroom fan replaced.

The average cost to replace a bathroom vent fan is $375. The vent fan unit costs between $15 and $300 depending on the Cubic Feet per Minute (CFM) rating, Sone rating, and lighting options. The CFM rating measures how much airflow is moved in square feet. The Sone rating measures the loudness of the fan.

The CFM rating for bathroom vent fans ranges from 50 to 150 square feet. So, the size of your bathroom will dictate the size of the vent fan you will need.

For a bathroom of 75 square feet, choose a vent fan with a CFM 80 rating. However, larger bathrooms may need a bigger fan or two smaller fans, depending on the arrangement of the bathroom.

The Sone rating for bathroom vent fans ranges from 4.0 to 0. The lower the number, the quieter the fan operates. A rating of 1.0 is equivalent to a modern refrigerator.

Fan Models (No Light)CFM SonePrice
Broan-NuTone 688 Ceiling and Wall Ventilation Fan504.0$
Broan-NuTone AE80B Invent Energy Star Qualified Single-Speed Ventilation Fan801.5$$
Broan-NuTone AE110 Invent Flex Energy Star Qualified Single-Speed Ventilation Fan1101.0$$$
Fan Models (With Light)CFMSonePrice
Broan-NuTone 678 Bathroom Ventilation Fan and Light Combination502.5$
Broan-NuTone SPK80L Bluetooth Speaker Bathroom Ventilation LED Light802.5$$
Broan-Nutone QTXE110 Ultra-Silent Ventilation Exhaust Fan1100.7$$$
Fan Models (With Light & Heater)CFMSonePrice
Broan-Nutone 659 Heater, Fan, and Light Combo502.5$
Broan-NuTone 100HL Directionally-Adjustable Bathroom Heater, Fan, and Light Combo1002.0$$
Broan-NuTone QTXN110HL Ceiling Heater, Fan, and Light Combo1100.9$$$

Improvement costs: While improvement costs aren’t necessities, they can increase your expenses depending on the improvements you want to introduce. For example, a speed control switch can cost a hundred bucks, including labor costs.

Labor costs: For those who would prefer to pay someone to do the job for them, you’ll have extra labor expenses to replace your bathroom vent fan. Depending on where you live and your electrician, you could spend about $300 in labor costs for three work hours.

Total costs: If you want to improve your bathroom fans, you could be spending $300 to $500 for each installation. A standard bathroom fan replacement will cost $100 to $120 by choosing a standard vent fan. You can save even more by doing the new installation yourself.

Can You Replace a Bathroom Fan Yourself?

If paying a licensed electrician to replace your bathroom fan is a bit over your budget, considering how expensive labor costs can be, you may want to think about replacing the bathroom fan yourself. But you may be asking one of two questions. Is it easy to change a bathroom fan? Is it possible to do it by yourself?

Yes, you can replace a bathroom fan yourself. It is relatively simple to install a bathroom vent fan if you are handy. If you can install a light fixture or ceiling fan, you can install a bathroom vent fan. However, if you are doing any custom work, it’s best to hire a licensed electrician.

For example, if your bathroom exhaust fan doesn’t come in the standard size that you can find in the nearest store, you’d have to make an entirely new opening in the ceiling or on the wall. If you have to replace the entire unit, you may need to go into your attic to install a new exhaust fan vent pipe.

This leads us to one common problem in home inspections; bathroom fans that are not vented to the exterior.

Do Bathroom Vent Fans Need to be Vented Outside?

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The purpose of a bathroom exhaust fan is to draw air from the bathroom and direct it outdoors. Bathroom fans do this to remove the moist air from the bathroom caused by showering and bathing. However, we often see vent fans installed with no vent pipe to the exterior, especially in older houses. So, do bathroom vent fans need to be vented outside?

Most bathroom vent fans require venting to the outside. Venting a bathroom fan into the attic or ceiling space without a vent pipe to the exterior can cause mold or mildew to form on the ceiling or in the attic. If installing vent piping is not feasible, installing a duct-free vent fan is an option.

Bathroom vent fans work by drawing in air and expelling it outside. The fan doesn’t clean the air; it merely moves the air from one location to another. The fans also draw in the air with odors and airborne contaminants such as dust, so the vent piping is essential.

Vent piping for bathroom vents needs venting to the exterior through a wall or soffit. The vent piping should exit the building with a vent cover installed outside.

Without proper vent piping, you are simply moving moist air from the bathroom into the attic. When this happens, moist air can condense and cause a mold problem in the attic and wood rot to the wood framing.

A duct-free fan could be an option if installing a vent pipe is not possible (for instance, in the first-floor bathroom with no attic access above due to second-floor living space). However, your product options are limited.

The Broan-Nutone 682 Duct-Free Ventilation Fan is a duct-free vent fan that contains a long-lasting charcoal filter. Air draws into the fan, across the filter, then out the other side of the fan. The filter needs to be changed at least once per year under normal use.

How Long Do Bathroom Exhaust Fans Last?

A bathroom exhaust fan can last ten years, but it could also last much longer, depending on how well it is maintained. However, a vent fan’s lifespan can quickly change due to frequent use, regular cleaning, and fan size.

Bathroom fans that are frequently used will wear out faster than those that are not always used. Remember that bathroom fans depend on a motor that will eventually fail due to constant wear and tear. Many people will leave bathroom fans on all day or all night.

Bathroom Vent Fan Fire Risks

Leaving a vent fan on for more than 20 minutes can cause the fan motor to overheat and fail. The lint buildup inside a dirty vent fan is flammable. A dirty fan motor that overheats could short out or start a house fire.

According to a 2014 report from Countryside Fire Protection District, three house fires were linked to bathroom exhaust fans costing more than $100,000 in smoke and property damages. 1

In Ohio, Columbus fire crews reported nine structure fires caused by bathroom vent fans in 2018. As of April 2019, the same district reported eight structure fires caused by bathroom vent fans, totaling over $330,000 in smoke and property damages. 2

How Often to Clean a Bathroom Exhaust Fan?

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Now I know you probably think, “like you need one more thing to clean.” Well, it’s not too bad and should only take you a few minutes to clean. Yes, bathroom fans need to be cleaned because that is one way of keeping them well-maintained and operating efficiently.

You may be wondering, how often does a bathroom vent fan need to be cleaned? Bathroom vent fans need to be cleaned once a year. In bathrooms not used often, you can likely get by once every two years.

Here are some easy steps to clean your bathroom vent fan.

Turn Off the Power to Your Fan

Before you begin cleaning your bathroom vent, you need to shut off the power to the bathroom fan at the wall switch. You may need to shut off the power to the bathroom at the circuit breaker. You may need a flashlight, so have one close by.

You can confirm power is off to the vent fan with a non-contact voltage pen like the Klein Non-Contact Voltage Tester.

Remove the Vent Fan Cover

Using a stepladder, you’ll need to remove the cover on the vent fan. Some vent fan covers are held in place with screws. However, most have large pin clips that slide in place.

Simply slide the cover down to access the clips to remove the pin clips. Press the clips in on both sides to release the hooks.

Clean the Vent Fan Cover with Soapy Water

If needed, once the cover has been removed, wash it in a deep sink with mild soapy water. Use a rag to scrub off hard to remove dirt. Set the vent cover aside to air dry.

Clean the Vent Fan Blades with a Damp Cloth

Remove the fan blade from the motor. Wash the fan blade in a deep sink with mild soapy water. Like before, use a rag to remove hard dirt. Set aside to air dry. If you can’t remove the blade, use a vacuum wand attachment to remove as much dirt as possible. Use a damp cloth to remove caked-on dirt from the blade off.

Vacuum Dust From the Fan Assembly

Using a wand attachment on your vacuum cleaner, vacuum inside and outside the vent. Carefully vacuum dirt and dust from the motor assembly. If you don’t have a wand attachment, a brush attachment should work just fine.

Reattach the Fan Blade to the Motor

If you did not remove the blade, you could skip this step. Now that the housing is clean, it’s time to reassemble the vent fan.

Dry and reattach the vent fan blade if you remove it by pushing the fan blade into place on the motor arm to secure it in place. Be sure the blade is securely on so that it doesn’t hit the fan cover when in use.

Reinstall the Vent Cover

Dry and reinstall the vent fan cover. The clips slide back into place. Slide the cover back up snug to the ceiling. Secure the screws if needed.

Finally, Test the Vent Fan

Once assembled, turn the power on at the breaker or wall switch and test the vent fan. Allow the fan to run for a couple of minutes to verify nothing is loose.

Cleaning bathroom fans also helps them to last longer. The more clogged a bathroom exhaust fan is, the harder its motor has to work. This can very well shorten its lifespan.

That said, I suggest that you clean your bathroom exhaust fans thoroughly at least once a year so that you can remove all of the grime, hair, or particles that have built up. You also have to consider how often you use the bathroom as fans in bathrooms rarely used may not need regular cleaning.

If we are talking about the bathroom you often use, it is best to clean it once a year or maybe even twice, depending on how fast the grime builds up.

Frequently Asked Questions

Can You Replace Just the Fan on a Bathroom Exhaust Fan?

It is possible to replace just the fan blade or fan motor on a bathroom exhaust fan if you have one of the same fan models. However, depending on the model and age of your bathroom exhaust fan, it may be more cost-effective to replace the entire unit.

When replacing just the fan motor, it is important to make sure that the new fan motor is compatible with your bathroom exhaust fan model. Otherwise, you may end up damaging your bathroom exhaust fan and having to replace the entire unit anyway.

Are Bathroom Fans Interchangeable?

Bathroom fans are generally made to be interchangeable, so you can just remove the old fan and install the new fan. If you get a fan that has a larger CFM rating, the fan may not be interchangeable. It’s best to remove the fan cover and measure the opening to verify that the new fan replacement you purchase is the same size.

Whatever type of fan you choose, the size of the fan should match your existing opening or you’ll need to alter the opening to get the fan to fit.

How Do You Fix a Noisy Bathroom Fan?

Fan noise is typically caused by a dirty fan or failing motor. There are a few things that you can do to fix a noisy bathroom fan. These include:

  • Check to see if the fan blades are clean. If they are dirty, then they will need to be cleaned. You can do this by using a brush or vacuum attachment to remove the dirt and debris from the blades.
  • Another thing that you can do is to check the fan motor. If it is loose, then you will need to tighten it.
  • If your bathroom fan is still noisy after doing these things, then you may need to replace it. Bathroom fans typically last for around 10 years. So, if your bathroom fan is older than that, then it may be time to replace it anyway.

What Causes a Bathroom Exhaust Fan to Stop Working?

Bathroom fans generally stop working because the fan motor fails. There are a few things that can cause a bathroom exhaust fan to stop working.

  • One thing that can happen is that the fan motor can burn out. This usually happens after years of use.
  • Another thing that can happen is that the fan blades can become damaged or dirty. This can cause the fan to work less efficiently and eventually stop working altogether. Dirt build-up on the fan blades becomes heavy and can stress the motor causing it to fail.
  • If the bathroom exhaust fan is not properly vented, then it can also cause the unit to stop working. Improve venting can cause stress on the motor and over time cause it to fail.
  • You can also check the circuit breaker or the light switch to verify the fan is getting power. The fan will not work without electricity. This is rare but can happen if the switch fails or the breaker trips.
  • Check the bathroom GFCI to see if it is tripped. Sometimes, depending on how the fan is wired, if the GFCI has tripped the fan will not operate until it is reset.

How Do I Know What Bathroom Fan I Have?

You can determine what type of fan you have by the fan’s model number. Most bathroom fans have a product label on the inside of the fan housing. The sticker should have a serial number and model number along with the CFM rating.

If the sticker is not on the inside of the fan housing, it may be on the back of the fan which won’t be visible without removing the fan.

How Do I Know What Size Replacement Bathroom Fan I Need?

You should purchase a replacement bathroom fan that has the same CFM rating. If you don’t know what the CFM rating is, the rule of thumb is 1 CFM per 1 square foot of floor space. If your bathroom is 50 square foot, then purchase a fan with a 50 CFM rating. Fans will typically range from 50 CFM to 110 CFM, with 50 CFM being the lowest rating.

Why is the Bathroom Fan So Loud?

Some bathroom fans are loud because of the type of motor it has. Bathroom fan loudness is measured in Sones. A sone is a unit of loudness and the lower the sone the quieter the fan is. Typically sone ratings for bathroom fans range from 1.0 to 4.0, with 4.0 being the loudest. Cheaper fans generally have a 4.0 sone rating, while more expensive fans may have a 1.5 or 1.0 sone rating.

Another reason your bathroom fan can be loud is that it needs cleaning or is about to fail. If the loudness is accompanied by a rattling or squealing sound, the fan motor is under stress and is struggling to turn.

Is Higher CFM Better for Bathroom Fan?

There’s no real added benefit to getting a bathroom fan with a higher CFM rating than what you need. A higher CFM will move more air, but will also use more electricity to do so. You’re better off keeping the CFM rating the same and opting for a bathroom fan with a lower sone rating which will be quieter to operate.

Can You Use WD40 on a Bathroom Fan?

WD-40 is an excellent lubricant for exhaust fans since it will also aid in the breakdown of any residual dirt, dust, or grease. Other lubricants such as silicone spray can be used to lube an exhaust fan if necessary. Spindle the fan blades a few times with your hand and remove any surplus lubricant from the motor.

If using WD40, it’s best to clean off the excess. WD40 is a lubricant and can actually make the problem worse by attracting more dirt and debris. Using a penetrating oil like Liquid Wrench along with a can of compressed air can clean without excess lubricant.


As mentioned, cleaning your bathroom fan can significantly affect its lifespan because grime and dirt buildup can slow the fan and force it to work harder, to the detriment of its motor’s health. So, if you keep your bathroom fan maintained well by cleaning it thoroughly annually or bi-annually, you can extend its lifespan.

Of course, fan size also plays a role here because larger bathrooms need larger exhaust fans. If you use a small fan in a large bathroom, the fan needs to operate longer and fail quicker. That’s why you should go with an exhaust fan that is just right for the size of your bathroom if you want it to operate efficiently. 

In that regard, while it may be possible for you to replace your bathroom fan all by yourself without the help of a professional, you will find that it is not as easy as it may look.

Even a licensed electrician may need 3 hours to get the job done. You may need more time to get it done, and you could miss an important step and install the fan incorrectly. Having an electrician install your bathroom vent fan can yield peace of mind that you did the job correctly.


Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.