Why is my bathroom exhaust fan noisy

You have noticed that there is some loud noise coming from your bathroom exhaust. That means whenever you go to the bathroom can be very irritating unless you repair your bathroom exhaust. The cause of that noise may be different, depending on what the problem is, something can be fixed, and something cannot. In any case, you need to find out the exact cause of the problem before you start thinking about a possible repair or replacing it and buying a new bathroom exhaust. Our advice is to educate yourself about potential breakdowns before you decide to do anything.

All about the noise

Before we get into the essential part of your problem, it would be nice to know a little more about what noise is. To be able to calculate noise, you should know that noise is measured in Teflon, a unit of volume level. The noise of a device is rated according to the Sone system, and the smaller the sone number, the quieter the fan in your bathroom will be. It is probably crucial to you that your exhaust fan to move the air while being very quiet, which is the essence of any bathroom fan. What is the capacity of your device is measured in cubic feet per minute-CFM. A small bathroom requires a low CFM grade and vice versa. Each bathroom exhaust fan must be so strong that it can replace the air inside the toilet eight times in an hour.

What kind of noise you can hear

  • Knocking sounds are very common, and can occur if your exhaust fan blades are unsuitable, or if something interferes with them. Every time the blades roll, you have the opportunity to hear this sound.
  • The sound of engine extinction inside an exhaust fan can occur when your exhaust fan is very old, or you have bought a cheap, low-quality model. It sounds like a moan.
  • If your fan is not correctly mounted, you may hear a vibrating sound. After that, as time passes, the fastening screws and supports are slowly released, and this can produce the sound described above. Grinding sound is created if there is a lot of dirt and dust inside the fan. When dust builds up inside the fan, a sound is heard as the fan shreds matter. You need to regularly maintain and clean your exhaust fan in order to extend its life span and to prevent it from being destroyed.

What can produce noise in an exhaust fan


The motor is an essential part that is responsible for everything that happens inside your exhaust fan. If you own an older exhaust fan, chances are the engine has started to die out. Thanks to the engine, the fan blades can move the air around, which is the primary purpose of this device. This part of the device is rapidly dying out, especially with cheaper, low-quality models. When the engine starts to die out, when it is at the end of its life, you will have the opportunity to hear the noise that will disappear when the engine wears out totally. If you want to know if the engine is responsible for making the noise, you need to remove the fan cover, see how the engine looks. If it looks damaged or if you experience heat buildup, know that it’s time to buy a new engine and replace the old one.


Blades are the moving part of your exhaust fan. While those blades are rotating, blades are triggering air circulation. Depending on the quality of the blades, you can hear a specific sound. If you notice that the fan is damaged or worn, the blades will make more noise as they rotate then usual. If a fan didn’t make any sound before, remove the cover to see if the blades are damaged or dirty. Remember to clean your blades regularly to avoid an accumulation of dirt and dust.


This part is the most common culprit and cause of the noise that has created in your bathroom and comes from exhaust fan-the ductwork it hooks into. Since the primary function of this device is to remove air from your bathroom, it must be transported through a vent. Air flows through the duct, and the volume of air pressure depends on the noise generated during the air movement. The size of the duct through which air is transported plays a significant role. Some standard dimensions are about 6 inches, and if you want to expand the channel you have, know that it can be very complicated and irritating. The ductwork must be very straight because multiple turns will increase the noise and air pressure. If you need to make turns, try to make a compromise, reduce the degrees of angles.

Mounting brackets

If the exhaust fan in your bathroom is not properly installed, it can also produce a lot of noise. Poor installation, loosening, and hardware fixing can cause some noise. When the fan loosens, the vibration generated by the motor and fan will not be retained. If the unit is noticeably loose, you will need to determine how the fan is mounted. Your fan may be fitted with screws under which it enters the bracket and is accessible from the ground. Bathroom exhaust fans are often hinged on hangers above the drywall on the ceiling. To access these hangers, you have to enter the attic and repair it from there.

Today there is a plentiful supply of bathroom exhaust fans in the global market. Some of them have some advantages such as exhaust fans with light and heater. If you think the problem is ductwork, and you don’t have an attic, you need to find a way to replace a bathroom exhaust fan without attic access. The other thing you need to keep in mind is that you need to know how to wire a bathroom exhaust fan. If you feel that you are not proficient in this field, we encourage you to seek help from someone skilled in this field.


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