Why are my smoke detectors going off when I cook?

Question

Seems like every time we cook anything in the oven the fire alarms (in-home system, all connected) go berzerk. is there any way to make them "less sensitive"? We do blow/vaccuum them out gently here and there but it doesn't seem to help.

Answer 1

The obvious (but ultimately unhelpful) answer is that the heat/smoke from your cooking is setting off the alarm. So what you have to do is reduce the heat/smoke getting to the alarm.

There are a number of things you can do:

• If you don't have a smoke alarm in the kitchen close the door while cooking. This will stop the fumes reaching the detector.
• Use the cooker hood's extractor fan to help divert the fumes. If it doesn't have one, consider fitting one.
• If you have a smoke alarm in the kitchen make sure it's of a suitable type. The standard ones are (quite rightly) designed to be sensitive to any smoke/heat. A kitchen one will be less sensitive to heat (for example).
• Clean your cooker. This might reduce the particles being emitted. You might not be able to see them, but they are there.

Answer 2

There is more than one type of smoke detector / fire alarm, so it's really hard to say without knowing what you have.

• Photo : have a light source + detector, and go off if they sense particles in the air. They typically require a bit of smoke or dust to set them off, but a cracked casing can also do it (as it lets light into the detector).

• Ionizing : (most common type) have a radiation source in them, and rely on charged particles to change the voltage across a gap ... but they can be set off by steam, so don't put 'em near showers, and they're not useful if they're near a fan (as the particles won't settle and trip the circuit)

• Aspirating : actively suck in the air and analyze it. It's not typically found in homes.

• Temperature : pretty rare these days. They typically rely on a bi-metal switch for alarms, and something that'll fail completely for sprinker heads, and they're very slow to respond (or they constantly go off on hot days in warehouses) They're more useful for telling firefighters where the fire is than in giving you sufficient warning to escape. (and the only reason I have one is because I was at a swap meet on a hot day, and someone had a dozen of 'em he was trying to keep on ice as they kept going off, so I showed him how to disable them)

• CO / CO2 : if it's in a smoke detector, it's probably more to prevent false positives (so steam doesn't set it off) than something that it alarms on, so is installed along side another sensor.

...

Now, for the actual fixes ... if it's a photo one, odds are, it's damaged and needs to be replaced. If it's ionizing, try hitting it with some canned air or a blast from a compressor to blow out any dust and adjust the sensitivity (but it might be a bad circuit, and then it needs to be replaced). Temperature ones mean you have to find where the switch is, and adjust the trigger, which I don't recommend ... you're better off just not having it near a place that gets really hot.

I'd also follow DA01's hint, and clean the oven. It's quite possible that there's something in there that's burning off, and is enough to set off an ionizing detector.

And, if that fails ... replace the smoke detector. Most companies only rate 'em for 10 years of operation. And the 'test' button only really confirms the battery & alarm, not the detector itself. You need to blow smoke at them or use a candle to really test them.

Answer 3

Ionization detectors are the most prevalent style installed in residences. This is largely due to a lower cost, but they aren't necessarily the best. They have more false positives (nuisance) alarms and are frequently removed or disabled, which does absolutely no good. We had a fatal cooking fire just last year because of this very phenomenon. Couple this with the fact that they take longer to alarm (up to 20+ minutes) in a smoldering fire, illustrates that you are better served by switching to either a dual sensor unit, or a photoelectric style for your home. Here is the text of an email I send out regularly on this subject.

Investigative news footage regarding different types of detectors- http://www.youtube.com/watch?v=pnlkiZC0dd0 and http://youtu.be/cwl1biSvTiY

Interesting program from a father of a fire victim from the OSU fire tragedy in 2003- www.uc.edu/cas/firescience/forms/SmokeDetect.pdf (The first several slide are heartbreaking)

The first 10-15 minutes of this presentation is very informative- www.uc.edu/cas/firescience/Bennett/fire_detector_seminar.asx

Position paper from two different State Fire prevention associations- the Southwest Ohio Fire Safety Council ( www.uc.edu/cas/firescience/forms/SmokeDetectorsSOFSC5-10.pdf )and the Central Ohio Fire Protection Association ( www.libertytwpfire.com/files/MiscDocs/position_paper.pdf )recommend utilizing photoelectric. or dual sensor units.

Do yourself a favor and install photoelectric, it may save your life.

Answer 4

We have this problem at our place and 9 times out of 10 the answer is to turn down the heat and stop burning dinner. Even if the food isn't burned the grease is way too hot and it is vaporizing.

Make sure your oven is clean, we like to do Shake and Bake chicken regularly, but to avoid smoky chicken splatter grease we have to stay on top of cleaning the oven. After cleaning the oven I usually turn it up fairly high to burn off any residual soap. I do this with the windows open.

Range hoods, as have been suggested, will greatly help this problem. Clean the grease filter and if necessary upgrade the fan.

Answer 5

Like the previous user answered, "use the cooker hood's extractor fan to help divert the fumes". Since I don't have an extractor fan, I placed a fan nearby so if I cook anything that tends to create a lot of smoke, I turn it on and/or open doors to let