Asklemmy

I've had a photoelectric alarm set off by steam from a dryer in the next room, through a closed door.

I don't think this is what you're experiencing, but I had an alarm go off randomly for one beep once. Went and looked at it, and a few seconds later a spider crawled out and away from it.

If it's photoelectric, anything that could scatter light could cause it to go off. Is your house dusty?

Since it went off in your hands, have you tried googling the make and model to see if there are any similar complaints or even recalls for them?

Are your smoke detectors linked to each other? Could be faulty wiring in the circuit, or a completely different smoke detector failing and sending out an alarm that triggers the others. The latter happened in my home when I was growing up: the living room smoke detector kept going off a few seconds before the rest of them would chime in, but it turned out it was the one in the nearest hallway that was failing and sending out bad signals. The living room detector was just the next in the circuit.

omg 😭😭😭 The new detector went on off in the living room where the old one did. switched it to the kitchen, put the kitchen detector in the living room, and the new one went off in the kitchen. wtffff

I think you said elsewhere that they are new and that they are photoelectric rather than the radioactive ones.

I'm purely taking a shot in the dark but I'm wondering if you should try sealing up the hole(s) in the wall that you made to run electric and to mount the detector

My thinking is that dust might be getting caught up in a tiny draft through that hole and it's so close to the source that it sets it off. Cause like, if wind hits the side of the house, there can be some positive pressure in the crawlspace which often also means inside the walls.

I guess maybe somehow there could be some stream or condensation as well. If it's right by the front door and the humidity is high, maybe the hot air from outside meets the AC air and causes a tiny amount of condensation. Or if you live in hellscape temperatures, maybe there could be some vapor generated because of the hot air.

update - so I've got two more diagnostic steps. I have another detector of the exact same brand in another room, I'm going to switch them and see what happens. if the detector from my kitchen starts going off by the front door, then I'm going to try another brand that I have elsewhere in the house and move forward from there.

Did you open one up yet? That might give you a clue 🤔

E.g. I don't know exactly how wide the gaps are, but here it looks like small insects could get in. Maybe you have another problem than smoke 🫣

Depends on what kind of detector it is but alot of them use small amounts of radiation and a detector that triggers when the number of particles detected drops below some level.

How smoke detectors work

That being the case any particulate large enough to interrupt the particles could cause it to go off.

For example high humidity misty water from a shower wafting over a detector placed over the bathroom door, etc.

Does it get hot by your front door or in direct sunlight? We have a few in my house that go off if our kitchen gets too hot. We had to move them down the hall slightly and they stopped. A really old one we have upstairs, hardwired into the house electric (built in 86) trips if too much steam builds up in the bathroom and let's loose into the hall.

I’d call the fire department to ask them to come out and make sure that there’s not anything slow burning that’s hidden in the walls. Be sure to mention two separate smoke detectors have been going off. Even if that’s not what it is they’ll be fine with coming out to check.

Call the fire department, they have detectors that they can use to look for gas leaks and other things that can set off a detector.

You can also call your gas provider. One of those two should be able to track it down, it could be a lot of things, but two different smoke detectors going off in the same location is a huge red flag.

Best case, you have something kicking up fine dust, worst case, you have a smouldering electric fire in your wall somewhere.

Don't panic, but also do not ignore this.

Mine went off in high humidity when I showered and forgot to turn on the fan

Try replacing the batteries. That's often the reason for this type of thing.

Spiderwebs or insects can mess with the sensors, likewise with dust. Try spraying some canned air inside. Or if it's a few years old, you may want to replace it.

Dust maybe? Dust can have the same particles as smoke.

~~Look for an expiration date. Radionucleotide style detectors end up failing with false positives when they reach end of life. You might need to have all the old ones replaced.~~

A ghost 👻