Troubleshooting a Noisy Bathroom Fan

Troubleshooting a noisy bathroom fan can be difficult - especially if the fan is in a hard-to-reach area, or if you're uncomfortable working with electricity. While many fans simply “plug into” an outlet, others are wired in and you’ll need basic electrical know-how to replace or work on them. It may feel easier to just call in an electrician. While you may ultimately do that, consider doing a little troubleshooting yourself.

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 noisy. 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. You can pull the cover off and see for 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. Forty 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 2.0 phons. When you start shopping for bathroom fans, be sure and look at the sone rating. The smaller the number (sone) the quieter the fan. But wait, a quiet fan is no good if it doesn’t move the air you need. Make sure you check the CFM (cubic feet per minute) rating too to ensure its moving the air, even if you can’t hear it.

Has the Fan Suddenly or Gradually Gotten Noisy?

If your fan has been quiet and suddenly becomes noisy, chances are the motor is going or dust and dirt is interfering with the operation. Since the motor is the part most likely to fail in a ceiling fan, chances are good your recently noisy fan can be blamed on the motor. 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 your canned air and blow it out, then start it up 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.