Bathroom fans are usually easy to overlook, as they operate quietly in the background as we go about our daily tasks. So when you hear loud noises from the bathroom fan motor, that’s a telltale sign of a problem.
Bathroom fan motors become loud and noisy when the motor assembly is dirty with dust and other debris. A worn-out motor shaft paired with a damaged blower wheel or fan blade will also cause loud noises as the fan grinds against the housing around it. Lastly, the fan motor will become loud if worn out from excessive wear or old age.
Your bathroom fan motor is pretty easy to troubleshoot. So, follow this guide to understand what problems can affect it and how you can solve them quickly.
Why Is My Bathroom Fan Motor Making Loud Noises?
Your bathroom fan should only make a gentle humming noise. So when it makes loud noises, that means it’s experiencing one of the following problems:
Dirty Motor Assembly
About this: Your bathroom fan constantly has air flowing through it. However, it doesn’t have a filter to remove dust and other contaminants in the air.
Over an extended period, the bathroom fan, as a whole, experiences a buildup of dust. That buildup can get pretty severe depending on your indoor air quality.
When there’s too much dust inside the bathroom fan or even its vent ducts, problems will start to occur.
What’s wrong: A loud motor is one of the many problems caused by dust buildups in your bathroom fan. That’s because plenty of dust gets trapped in and around the motor assembly, especially at its moving parts like the shaft.
Minor dust build-ups will quickly trap even more dust, causing things to worsen quickly.
When that happens, the fan can’t turn its shaft smoothly. The friction from all the dust will lead to loud noises coming from the motor, especially when it works at higher speeds.
How to fix it: The solution is straightforward if the noise is caused by a dirty motor assembly. Firstly, you’ll have to remove the whole fan from your bathroom ceiling.
Then, separate the fan motor assembly so you can clean it thoroughly.
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You can remove loose and large pieces of dust with a vacuum, though a brush will be necessary for smaller bits.
Once the motor assembly is clean, turn the motor shaft manually to ensure it doesn’t make any more noise.
Then, reassemble the bathroom fan and mount it back to your ceiling.
Worn-Out Motor Shaft
About this: The fan motor is responsible for turning a blade or blower wheel. That’s what generates all the airflow in your bathroom fan.
However, the component that connects the motor to the fan blade or blower wheel is called a motor shaft. The motor turns that shaft which then turns the fan blade attached to it.
What’s wrong: A worn-out motor shaft is another common source of bathroom fan noise. However, being ‘worn-out’ can mean several things for a fan motor shaft.
For example, the shaft is physically damaged or worn out and fails to hold the fan blade in place as they turn. That can cause the fan blade to grind against the side of the bathroom fan, causing loud noises.
Besides that, the shaft cannot turn in equilibrium, causing it to move erratically. That, too, can cause loud noises from the fan motor.
How to fix it: Ideally, you should be able to replace the worn-out motor shaft alone. However, that depends on whether or not you can find the part sold separately.
Not many bathroom manufacturers sell the shaft as a spare part. So, if you can’t get a new shaft for yours, you’ll have to replace the motor instead.
The new motor will come with its own shaft that’s safe to use and won’t make loud noises.
Damaged Blower Wheel Or Fan Blades
About this: Aside from the motor, the fan blade or blower wheel is another core component of your bathroom fan. These parts have plastic blades that force air to move as they get turned by the fan motor.
What’s wrong: The loud noises you hear don’t necessarily come from the fan motor per se. Instead, it comes from the blower wheel or fan blade attached to that motor.
Bathroom fan blades and blower wheels consist of rigid plastic fins. Sadly, those fins can break or become misaligned over time.
When that happens, they fail to turn in perfect balance and will grind against the insides of the bathroom fan housing continuously. That will lead to further damage and even more noise.
How to fix it: The good news is that the blower wheel or fan blades are the most straightforward components to replace in a bathroom fan. That’s because they are cheap, easy to find, and easy to install.
So, remove the existing fan blade or blower wheel in your unit and attach a new one in perfect condition. Be sure to turn the fan manually with your hand to ensure it can spin in a balanced way without hitting the inside of the fan housing.
About this: The motor is the powerhouse of the bathroom fan. It’s powered by electricity and spins the fan at high speeds to create airflow.
When the fan motor is working correctly, your bathroom fan will maximize the ventilation in the space without a problem.
What’s wrong: The final reason your bathroom fan motor is loud and noisy is that it’s worn out. That will happen with old age and extensive wear.
Firstly, you’ll know that’s the case if you’ve had the same bathroom fan for many years. As the motor approaches the end of its lifespan, it struggles to work and becomes noisy.
Meanwhile, a newer motor will suffer the same fate if it struggles to turn the fan blade.
For example, suppose the bathroom fan housing is dirty, and the motor can’t turn the fan blades quickly. In that case, it’ll eventually wear itself out.
How to fix it: Worn-out fan motors can’t be fixed. So, you’ll have to get rid of the one you have and find a compatible replacement.
The new one must be the same size and power to ensure that the bathroom fan can work correctly. A motor that’s too large won’t fit the same housing. Plus, your current vent ducts won’t cope with a more powerful motor than your current one.
Frequently Asked Questions (FAQs)
Troubleshooting your fan loud bathroom fan motor can get a bit challenging. So, here are a few more questions and answers to help you along the way:
Should Bathroom Fans Be Loud?
No, bathroom fans should never be loud. Instead, when the fan is turned on, you should only hear a quiet humming sound.
How Do You Know If Your Bathroom Exhaust Fan Is Clogged?
You’ll know your bathroom exhaust fan is clogged when the motor starts making loud noises, and there’s no airflow at the fan. Those are clear signs of a severe clog that require thorough cleaning.
Can I Just Replace A Bathroom Fan Motor?
Yes, the motor in your bathroom fan is replaceable. However, be sure to buy a fan that’s the same size or smaller. A larger motor won’t fit the fan housing.
Are Bathroom Exhaust Fan Motors Interchangeable?
Yes, bathroom fan motors are interchangeable as long as they’re the same size. Larger fans won’t fit, and the existing ducting likely won’t accommodate a larger motor, producing more airflow.
How Do I Know If My Bathroom Fan Motor Is Bad?
You’ll know the fan motor is bad or worn out when it makes loud noises or can no longer turn at regular speeds.