Why would a smoke alarm go off twice with no fire?

[Bweave]

Why would a smoke alarm go off at random in the middle of the night, then again half an hour later.

Last night I was up late until about 4.30 and only going to bed then. I was up doing jobs and laundry.

I fell asleep straight away.

I woke to noise a while later and it was the smoke alarm. I got up to check but there was nothing. No smoke no fire.

Worse I live with my mum and I think she has dementia so her tone and facial expressions were not right. She came into my room raging at me thinking there's a fire in my room but there was none. Eventually settled back to sleep at about 6 for some sleep. Was hoping to get about maybe 4 hours sleep before work. Nope. The smoke alarm went off again at 6.15. Followed by my rage and senile temper tantrum to find a fire and clearly it's in my room according to my mother.

I would have been able to manage with 5 hours sleep but it was just so broken. I am dying now. I feel sick.

So how would a smoke alarm go off twice with nothing there to set it off.

Its not the batteries need replacing is it?

Could be a fault; replace.

In my experience it is always a battery that needs renewing

I don't think so. It was put in new this summer. The smoke alarm was new. Battery came with it. I think

Batteries.

Insects in the sensor?

Is it definitely just a smoke alarm? Not one that also goes off for carbon monoxide?

I’ve had this and it was dust. I vacuumed it and that sorted it.

I would say ( almost ) 100% your smoke alarm needs dusting !
Put your vacuum hose on it and give it a good clean . Frightened the life out of us when it first happened but then someone advised us to try dusting it & it worked .

I live in a warmer country, is it hot there at the moment? . Sometimes humidity can make them trip. Could it be that?

Give it a hoover

We had this recently. Thought it was the batteries, but nope. Took it down and gave it a wipe and hoover of the sensor and it's fine.

You are supposed to change them every 10 years though, so check the date on it.

Batteries or a spider
Hope you manage to get some sleep

But also, why do they always pull this shit during the night?!

I’d say dust/insects

Spider

When it happened to us it was a spider. Broken sleep is the worst, OP. You have all my sympathy.

A spider went out for a nighttime stroll, and then went home again

Are the batteries low? Sometimes the alarm will go off to let you know they need changing

This happened to us a couple of weeks ago, during the day fortunately rather than the night.

We took it down and checked it, it was newish and the battery had years left in it. It was probably just dust, but I can't think why as we've had a smoke alarm in that location for years with no issues, and there has been no dusty type work done.

I did not want to risk it giving another false alarm at night so we replaced it.

Ours did it a few months ago during the night, it turned out to be a tiny spider inside presumably walking over the sensor

Dust.

Steam can set them off (if someone is cooking or using the shower) as can dust.

Old neighbour of ours was annoyed with their fire alarm as for over a week it kept 'beeping'. Anyway turned out to be an electrical malfunction with it and a few days it caught fire and burnt his house down. Seen him the other day actually, had a pay out from the insurance and downgraded to bungalow and had his teeth done with the remainder

Change the batteries. If it’s hard wired, get someone in to check the electrics.

If it’s also got a heat sensor and you’ve got it near a radiator then you should move it.