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Can Steam Set Off a Smoke Detector? Facts & FAQ

smoke alarm with white smoke

Smoke detectors respond to sudden changes in temperature, which is one of the ways they’re able to recognize fires. Some units may be more sensitive than others, and a sizzling fajita on the stove or a long, steamy shower may be enough to fire the alarm on some units. Here’s what to do if the smoke detector suddenly goes off without warning, as well as ways to prevent a false alarm.

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Why Does Steam Cause My Smoke Alarm to Sound?

Sudden changes in temperature or a rise in humidity may trip the alarm on your smoke detector, resulting in the alarm sounding. Your smoke detector may be overly sensitive if the batteries are low, or if it’s about time to replace the unit. Battery-powered smoke detectors need to be replaced every ten years, while the backup batteries on hardwired detectors need to be changed every six months. Check the manufacturer’s date on your detector if you’re unsure when you’re due a new one.

What To Do If My Smoke Detector Goes Off?

smoke alarm
Photo Credit: r.classen, Shutterstock

Anytime your smoke detector goes off, you should immediately stop what you’re doing and search for a potential fire. Some dangerous house fires may start unnoticed in the walls, so test your walls and floors to see if they feel warmer than usual.

If you’ve determined there’s no fire, turn on the exhaust vent fan in your kitchen or in your bathroom if you haven’t already. This will help pull the trapped steam out of your house and may relieve the detector. If it still doesn’t turn off, you may have to hit the “test/silent” button on your detector, or temporarily disarm the unit.

Some residential smoke detectors may alert the fire department if they’re connected to your home security system, so make sure to call them and let them know it was a false alarm if so.

It’s also important that you have installed your smoke detectors in appropriate places. You should have a smoke detector in every bedroom, as well as areas outside the bedrooms, but never near a shower where steam could trick the sensor or other places that experience sudden changes in temperature such as stoves. While local codes might require you to install a smoke detector in laundry rooms, make sure it’s on the ceiling or as close as possible, and away from the dryer.

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Nothing’s more annoying than a smoke detector that chronically lets out a piercing false alarm. Factors such as excessive steam and sudden temperature changes may trigger your smoke detector unnecessarily, so turn on the exhaust fan or crack a window before you start cooking on the stove. You should also make sure your smoke detectors are installed as close to the ceiling or on the ceiling if possible, avoiding being directly above areas that receive drastic changes in air and temperature such as the shower.


Featured Photo Credit: gopixa, Shutterstock

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