Skip to content 
If your bathroom fan becomes noisy, replacing it isn’t always the answer, there are some basic methods that can be used to repair the fan and save on costs.
Table of Contents
Dirt and grime build up on the fan blades over time, causing the fan to become imbalanced and noisy.
Troubleshooting Noisy Fan
All Moving Parts and the fan must be cleaned thoroughly
#Always isolate the electrical supply to the fan before attempting any work.
Start by removing the fan cover, to access the bathroom fan blades and housing,
Using an approved solvent or cleaning solution, clean all the fan parts. Avoid getting the water into the motor. While you’re cleaning, keep an eye out for any signs of wear or damage. Replacing the entire bathroom fan might be the only solution if there is to much wear and tear on the moving parts.
Once all the parts have been dried completely, reassemble the unit. Check to see if the cleaning of the fan has solved your noise concerns, alternatively….
Use Sorbothane Rubber to Absorb Sound
If cleaning your fan properly didn’t work, you might try applying Sorbothane rubber to absorb the vibration and sound.
Sorbothane is an extremely soft rubber that comes in sheets that are easy to deal with. It is able to stick to the surface due to one side having a glue layer.
Sorbothane should be cut into strips. These can range in width from 1 ½ to 2 inches.
Apply a strip around your fan in the same direction as the ceiling or wall might be.
This effectively decouples the fan from the wall, decreasing vibration and sound transfer.
Have a Question? Ask HVAC Technician
Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.
Sorbothane can be used in the fan unit on the access plates t dampen the vibrations as well.
Make use of a larger duct
Using a larger duct size will decrease the air pressure exhausted by the fan and will therefore reduce the noise level.
The inclusion of 6-inch duct in newer fans that are designed to be ultra-quiet helps to attain this goal.
You only need to replace the present duct if you’re changing to a larger duct since you’re upgrading to a quieter fan that requires 6-inch duct.
An enlarger coupling(also known as a reducer) will be needed if you’re maintaining your existing fan but upgrading to a larger diameter duct. This will facilitate the use of an old fan with larger ductwork.
Find the location of your bathroom fan in your crawl space or attic.
Unhook the duct from the fan’s outlet if you’re putting a new duct on an existing fan. Connect your enlarger coupling to the outlet of your fan.
Remove the existing duct that connects your fan to the roof or wall vent.
For a new 6-inch vent, you’ll need to widen the vent opening. Use a recognized ductwork installer if you are uncertain.
Connect your vent to your fan using a new 6-inch duct, keeping it as straight as possible and make sure all the new joints are sealed up properly again.
Straighten the Ductwork
If your ductwork has a lot of kinks or severe twists on the route to the outside vent, the extra pressure it creates could be making your fan noisy.
It’s less invasive to straighten out you’re ducting than it is to replace it entirely with a larger diameter duct.
It won’t have the same impact, but it will assist in lowering air pressure and lessen noise from air movement.
Locate the ducting for your bathroom fan in the attic.
From the fan to the outdoor vent, follow the duct. Count how many hard twists there are in the line.
If there aren’t any twists or bends, your problem does not stem from here, however, because of the bathroom’s location in the home and the route followed to expel air from the bathroom, there is bound to be at least 1 or 2 bends or twist.
Where possible replace each 90-degree connector in your duct with two 45-degree connectors . This will lower the air pressure and should make your bathroom fan quieter.
housing or fan blades might need adjustments.
The fan housing or blades might fall out of balance or alignment, resulting in a variety of noises. Worse, they will be subjected to more wear and tear, reducing the lifespan of your fan by years.
Make certain the fan is turned off. Remove the cover from the fan.
Gently move the fan blades with your finger to see if there is any visible evidence that they are out of alignment. It must be adjusted if it is not traveling straight or if it is hitting the fan housing.
Uninstall the fan completely, do the necessary and reinstall. If you don’t get everything totally right when you reinstall the fan blades, the bathroom fan may continue being noisy.
Make sure the fan motor and blades are lubricated.
As your fan ages, it will begin to dry up and the friction between the moving parts will rise. This will begin to wear down and harm your fan, shortening its lifespan.
The fan cover should be removed first. Check to see if the fan is turned off.
Clean the fan and the fan housing first. When applying lubricant, make sure there is no debris or dust that could turn into thick sludge or grime. This will exacerbate rather than alleviate your situation.
WD-40 or your preferred lubricant should be used to lubricate the base of the fan blades. When adding lubricant, make sure to spin the blades a few times to ensure that you achieve a nice penetration that reaches deep into the moving portions where the friction is greatest.
Tighten the Screws for Mounting
The screws and mounting hardware on your fan may begin to loosen after years of use. When this happens, your fan will produce excessive noise and vibration, making it appear louder than it actually is.
How you tighten the screws will depend on how your fan is installed.
If your fan is fastened to a joist using screws that run through the fan assembly, you may be able to tighten them without entering the attic.
By removing the fan cover first, Tighten the screws attaching the fan to the joists.
Many fans have hangers fixed above the ceiling drywall that are attached to the ceiling joists. You’ll need to go up into the crawl space or attic and identify the fan hangers for your bathroom there.
Tighten all the screws that connect the fan to the hangers first.
Any movement after tightening the screws means something is still lose. If you detect movement. tighten the troublesome screws some more. Wear and tear might require some if not all the hangers to be replaced.
Swap out the motor
Unfortunately, the motor in your bathroom fan has a limited lifespan. It will eventually reach its expiry date and fail completely. You won’t be able to ignore this awful reality no matter what you do.
Simply because your fan motor has failed does not necessitate the purchase and installation of a completely new fan assembly. You can buy the fan motor as well as other components separately and only replace the one component that has failed.
This method can be a cost saver. It can also be considerably simpler to replace just the fan motor or other singular components rather than the entire assembly.
Change the entire fan
It may be time to retire your old bathroom fan and replace it once you’ve had enough of the noisy troubles it causes. Modern bathroom fans are designed to be whisper silent and quickly exchange the air in your bathroom
Begin by isolating the power to your existing fan to ensure you work safely.
Remove the joist-mounting screws or hangers that hold your fan in place.
These could be beneath the floor or above the ceiling, in which case you’ll need to reach the attic. Check the dimensions of your new fan after removing the old one. To install your new fan, you may need to widen the current hole.
Install the fan by securing it to the joists following the guidelines from the manufacturer.
Some units require screws to be inserted from the bottom. Others will attach to hangers that screw into the joists above the drywall.
After you’ve installed the fan, you’ll need to connect the duct. Place the duct above the fan’s outlet. Secure the duct with foil tape so that there are no leaks. Connect the electricity following the correct color coding. You can hire an electrician if you are unsure about this stage.
Turn on the power and double-check that your fan is properly mounted!
Conclusion
A noisy, irritating bathroom fan can be a real pain to deal with. However, the problem is not always as big as it seems.
A good cleaning and service regularly can save you money and extend the life of your bathroom fan, at the same time ensuring quite operation.
