Our mains powered smoke alarms have taken to chirping in the wee small hours. Fine during the day but around 3 in the morning they go off for about 10 seconds. I have two questions. 1) Can I fix this and 2) If not, any recommendations for replacements?

Posted 1 week ago

Is there still not a battery in them (power cut back up) this probably needs changed

Posted 1 week ago

They should have battery backup and it’s telling you the battery is at the end of its life. Just open it up and replace the battery.

Posted 1 week ago

There will likely be a back up battery which either needs replacing or if it’s built in the whole alarm needs replacing.

How old is it? 10 years seems to be the recommended life span.

Posted 1 week ago

Happened with ours except a single chirp every 5 minutes making is painstaking to discover which one had a flat battery.

Posted 1 week ago

…and they first start doing it when the temperature drops, which is generally overnight rather than a sensible time for faffing with such things.

I mean I’m very glad they’re there but it’s like they’re made to be infuriating!

Posted 1 week ago

They have a PP3 backup battery. I’m surprised no one has mention this yet.

Posted 1 week ago

I’m surprised that no one has mentioned they still need batteries in case of a power cut.
Sounds like a flat battery.

But seriously do check the model as some are combi smoke /carbon dioxide monitors.

Posted 1 week ago

It’s recommended that smoke alarms are be replaced after 10 years. I don’t know if there’s something built in to measure the degradation or the age and beep to indicate the alarm is at the end of its life.

I’ve read that the time limit on ionisation type alarms is because of the decay of the tiny radioactive source in the detector.  I’m not sure that’s right, as the source is normally Americium 241 which has a half life of 432 years, so 10 years isn’t going to affect the output much.

Posted 1 week ago

Just to point out that they only do this in the very early hours, between 01:00 and 04:00. If it was a battery backup issue I would expect them to beep through the day.

It could be a temperature issue as there wasn’t a peep last night and it wasn’t as cold.

Posted 1 week ago

Aico alarms will chirp regardless of the battery state when they’ve been continuously powered for more than ten years. Might be no choice but to replace.

Posted 1 week ago

We had to replace ours in the buy to let flat, as the batteries were irreplaceable and the head units were deemed as ‘past their best’. They were not cheap from memory – maybe £45 each plus a heat detector and we had 5 units to replace in a 3 bed flat and shared hallway….

Posted 1 week ago

Chirruping alarm = dead battery.

Chirruping alarm at specific times = no idea, I’d guess the same but with some sort of edge case charge that fluctuates with temperature. A smoke alarm doesn’t know what time it is.

One point to bear in mind if replacing the unit, there’s a couple different types of sensor. Units for the kitchen are different from units for the hallway. I forget exact details, I’d have to look it up.

Posted 1 week ago

One point to bear in mind if replacing the unit, there’s a couple different types of sensor. Units for the kitchen are different from units for the hallway. I forget exact details, I’d have to look it up.

yeah, only realised this the other day when poking about at ours as I was considering ways to “smart” them. Heat/fire for the kitchen so it doesn’t go off on burnt toast etc, smoke everywhere else.

Funnily enough didn’t realise they had batteries too (tho makes sense!) until one of ours started chirping at the weekend.

(My conclusion re. making them smart was, “can’t really be bothered”, although looks like Apple have saved me a job… didn’t realise but one of the accessibility features for iPhones is sound recognition – doorbell, smoke alarm, baby crying etc. They’re bringing this feature to their smart speakers (HomePods) soon which is very handy. Awesomely it’ll also save me trying to figure out a way of detecting when the cat has snuck into the garage and gotten himself locked in as it will also detect cat meows! 😃 🐈)

We had to replace ours in the buy to let flat, as the batteries were irreplaceable and the head units were deemed as ‘past their best’. They were not cheap from memory – maybe £45 each

seems expensive unless they’re special units part of some proprietary system… should be able to get a wired Aico (with replaceable battery) for £20-30. Obviously makes sense to replace the whole unit periodically though!

Posted 1 week ago

Aico alarms are not the cheapest option, but they are one of the most recommended ones.

Regulations for them in Scotland are also different from England.
In Scotland, although they can be mains powered, they’ve still got to have a tamperproof backup battery, so idiots can’t easily disable them.

Other option are sealed battery units, which although more expensive, negates the need for additional wiring, and the hassle of needing somebody capable of wiring to change them at end of life.

Posted 1 week ago

In Scotland you need to fit interlinked alarms now so one smoke alarm triggering makes all the alarms in the house sound. It’s a newish regulation but means you have to use the more expensive interlinked ones. It does make the smoke alarms more or less a full fire alarm for the house though. Just make sure you don’t burn that toast!
Probably a good idea if refitting irrespective.
https://www.gov.scot/publications/fire-and-smoke-alarms-in-scottish-homes/

Posted 1 week ago