When you shower, moisture builds up in your bathroom. That’s why you have a 
bathroom exhaust fan that can vent moisture out and away from your home. Did you know that your bathroom fan could also be dangerous? There are a number of precautions you should take that can save your home and possibly your life.
A local television news story reported that firefighters in Stafford County, VA responded to a number of fires that started in ceiling-mounted bathroom exhaust fans. Although these fans are “Great at preventing steamed-up mirrors, damp walls and fogged widows…and remove odors…they are also a fire hazard,” a firefighter said.
“These fans, over time, build up lint that insulates the motor, exacerbating the heat build-up. The lint provides an easy-to-ignite fuel source which in turn ignites nearby combustible building materials. This buildup of lint within these fans, and on the fan motor, can create a potential fire hazard,” said Mark Doyle, Stafford County Fire and Rescue Department Assistant Chief.
The three most common causes of a bathroom exhaust fan fire are: faulty wiring, running the fan for extended periods of time and overheating the motor, and failing to clean the fan. Most fans have a shaded pole motor which has a very low starting torque. Any additional resistance in the bearing can lead to a locked rotor, thus overheating the motor to temperatures in excess of 340 °F. The typical NEMA Class B motor corresponds to a maximum insulation temperature of 266 °F. When overheated, the wire insulation will fail and cause a fire.
Maintenance of a Bathroom Exhaust Fan
For proper care and maintenance of your bathroom exhaust fan and to avoid dangers, here is what Assistant Chief Doyle recommends for both residential and commercial buildings:
- Inspect and clean all bathroom fans regularly.
- Those fans that are not easily accessible for regular cleaning, or those that appear to have heat damage or those in which the blades do not rotate freely, should be replaced with thermally-protected units.
- Bathroom exhaust fans should not be used for prolonged periods of time and should be turned off when you leave the house. The optimal time to run your bathroom exhaust fan is for 15-20 minutes.
How Often Should I Clean My Bathroom Exhaust Fan?
As you use your fan, dirt and dust is drawn up and coats the grill cover, fan blades and motor. It is recommended that you clean your bathroom exhaust fan every six months to year, depending upon how often you use it.
How to Clean a Bathroom Exhaust Fan
- Turn off the switch or circuit breaker to shut off power.
- Remove the fan cover.
- Clean the fan cover on both sides with your vacuum’s brush attachment.
- Reach your vacuum’s dusting attachment inside the opening to clean around the fan housing and motor. Use a crevice tool if areas are hard-to-reach.
- Reinstall the fan cover onto the attachment clips and press it back in place against the ceiling.
Safety Comes First at Först Consulting Group
At Först Consulting Group, we want everyone to be safe in their own homes. That’s why we offer articles like this one on how dangerous a bathroom exhaust fan can be. If you suspect a construction error or are in doubt about the safety of items within your home or your home’s structure itself, contact us. We provide specialized inspections and can ensure that your home is up to code. This can help prevent disasters like home fires down the road.
Take a moment to review all the ways Först Consulting Group provides services for safety, like our home testing services or home inspections. And if you need assistance in proving or negotiating a claim, we can help there too. Contact us to see how we can help.
See also our post on Safety Steps to Childproofing Your Home.
