This morning was somewhat eventful. Our bath fan caught on fire. We're all safe and there was minimal damage.
TLDR conclusions:
- Loud shaded pole motors must be promptly replaced.
- Don't spray oil all over a dusty motor.
- Bathroom fans should be cleaned yearly.
- Iowians do not fear fire.
- The apartment management does NOT have a good "safety culture".
- Bath fan plastic is not self-extinguishing.
- Putting out a fire quickly is a good idea.
- Call fire services as quickly as is practicable
- If safe to do so, close doors and shut off electricity & gas as you leave a building on fire.
- Bath fans should have a thermal overload, but do not
I'm staying in an American apartment (in Iowa, built in 1979, 8 two-bedroom units), and our bathroom extractor fan caught on fire.
My roommate noticed the fan wasn't running when the switch was turned on, and a minute later noticed that it was glowing (so he told me that it was glowing...).
I verified the fan switch was OFF, and then removed the cover of the bath fan (giving it more combustion air), and saw that, yes, there were flames. It looked like a candle flame, just much much bigger. Removing the cover could have been a bad idea since it gave it more air, but on the other hand it let us assess the situation.
Next, I called emergency services and ensured that my flatmates knew there was a fire. The cell phone connected to the county services, I gave them my address, and they had to transfer me to the city (30 second delay). The city dispatch had a script to run through. Once I said fire, she asked for my address, told me to pull a fire alarm (the building doesn't have a central alarm system, so I couldn't), asked how many floors there were, and told me to get out of the building. She said NOT to use a fire extinguisher. I ignored her advice. Maintenance had removed the extinguisher from our unit a few months ago (saying that too many kids used them, making messes, and that they are no longer required by the fire code), so I went to the hallway to grab the communal one. I held my breath and used it. The ABC power got everywhere and the fire was immediately extinguished. Finally, I turned off the six electrical breakers in the breaker box (NEC allows there to be up to six independent breakers without a main) closed the bathroom door (to reduce drafts). I knocked on the door of the apartment directly above us, but nobody answered. If there was still a known active fire, I maybe would have kicked down the door to look for people (though maybe that would get me shot???). I then left the building.
The fire brigade arrived four minutes later. They had three engines (maybe one was ladder truck?), and command in a pickup. I said hi to the firelady and explained the situation. They came inside and tore down part of the ceiling and opened up the exhaust port to check for embers. They also used a FLIR camera. One had a SARS-Cov-2 surgical mask on, and the other didn't have a mask. They also brought a big fire extinguisher with them (CO2? Halon?), but didn't use it.
Once everything was clear, they packed up. They noted down my name, birthday, and phone number for notoriety. The apartment management was called by the responding people, but we called, too.
The building was never evacuated. Other tenants seemed seemed unconcerned when I said our bathroom caught on fire.
The maintenance people arrived half an hour later, and replaced the motor and fan blades. They also hired a fire damage repair company to repair the ceiling and sweep up the ABC powder (I still have the taste in my mouth). Since the fan had a metal grill cover, it's likely it would have eventually self-extinguished, but it was still a dangerous situation.
The fire department said that maintenance must replace the spent fire extinguisher by 5PM today, or else there would be a fine. The department has a policy of fining people $500 for needless calls, but they saw there was a real fire, so we didn't incur any fees related to their visit.
I believe the fire's proximate cause was bearing failure in the shaded-pole motor, causing overheating and ignition of oils. The motor (and also its replacement) do not have a thermal overload, as it relies on the coil resistance to limit the stall-current. Last month, we reported to maintenance that the motor was loud. It was visibly dirty. Maintenance saturated the motor with oil, and did not clean the dust. Once the bearings finally seized, the oil-soaked lint caught fire, igniting the plastic in the motor housing and fan blades. This event should prompt them to periodically inspect all bath fans and replace them as needed, but I highly doubt that they will.
PS: As an ancillary note, maintenance once put a bunch of Americium smoke detectors in the dumpster, and they got wet in the rain. They were sounding for about 18 hours, overnight. Maintenance refused to come out and disable them, so I could hear smoke alarms going off ALL night. They were adamant that it was not a safety issue. I constantly wanted to evacuate the building, feeling that another apartment was on fire. I also didn't want to crawl into the dumpster as this was the local maximum of the virus plague. I did call the police with a noise complaint, but they were not servicing noise complaints because of the virus... Nobody else in the apartment even noticed the alarms. Another issue was when we reported our unit's fire extinguisher hadn't been inspected in ten years. Their response was to remove it, but leave behind the sign saying that there was a fire extinguisher in the closet.