Troubleshooting a Noisy Bathroom Fan

A bathroom  fan with a wire mesh  screen
What You'll Need
Canned air
Hand vacuum

A noisy bathroom fan can be annoying and distracting. Sometimes you're stuck with the sound, but sometimes it's an easy fix. If you're uncomfortable working with electricity, many fans simply plug into an outlet hidden in the ceiling, while others are wired in and you need basic electrical know-how to replace or work on them. Either way, they're not complicated, so before you call in an electrician, consider doing a little troubleshooting yourself.

How Noisy Is It?

It helps to understand how appliances are rated for sound. Rather than decibels, a “sone system” was created to simplify things for consumers. It’s not complicated. 40-phons equal 1-sone. Typical ceiling mount bathroom fans vary from 1.5 to 5-sones. The smaller the number, the quieter the appliance. A refrigerator operates at about 2-phons. When you shop for bathroom fans, be sure and look at the sone rating. The smaller the number (sone) the quieter the fan. A quiet fan is no good if it doesn’t move the air you need. Make sure you check the cubic feet per minute rating (CFM) too to ensure its moving the air, even if you can’t hear it.

Has the Fan Always Been Noisy?

The most common cause of noisy bathroom fans is the size of the fan motor and the turbine. Less expensive fans typically have very fast fan motors with very small turbines. They move a lot of air, but they’re generally very loud. Fans with a more powerful fan motor and a larger fan blade are the quietest fans. If you’ve just moved into a house or apartment and noticed the fan is noisy, it may be operating fine, but it’s simply a less expensive and more effective fan. Pull the cover off and see for yourself. Sometimes you need a screwdriver, or sometimes its just a nut you can unscrew by hand. It's a cheap one? If you want it quieter, you need to replace it. There are bath fans specifically designed to be installed as a retrofit.

Has the Fan Suddenly or Gradually Gotten Noisy?

If your fan has been quiet and suddenly becomes noisy, chances are either the motor is failing or dust and dirt is interfering with the operation. The motor is the part most likely to fail in a ceiling fan. Turn the power to the fan off at the main switch and grab your flashlight. Is there a build up of dust, dirt and crud in the fan?

Use a can of compressed air and blow it out, then clean up any debris with a hand vacuum. Make sure there's nothing that can impede the fan blades or the flow of air. Start up the fan again and see if the noise improves. If not, your fan motor may be dying. The good news is you can just replace the motor without having to replace the entire fan. And, the whole process is pretty simple in most fans. Of course a new motor costs about the same as a new fan, but by replacing the motor, you save yourself having to tear out the old fan.

If you opt for buying an entirely new fan, remember the motor/turbine ratio and make sure you get a fan that’s both quiet and moves air. You’ll pay more for it, but if you like a quiet fan, it’ll be more than worth the cost.

A bath vent fan, half uninstalled.Not sure where to place your bathroom's exhaust fan? Take a look at this.