Reinstalling one smoke alarm is making the other one beep!

[Guest Jonathan]

Hi,

I hope you can help with this weird situation! We have two smoke alarms which are wired up to the electrics with battery back-ups also inside, one at the top of the stairs and one at the bottom. (Can't see any branding on them.)

The one at the top of the stairs started beeping. I disconnected it and we've been using a portable battery-only one for a while instead. When that one started beeping to indicate the battery was running out (and it's a FireAngel which says battery not replaceable), that was my prompt to sort the top of the stairs one.

So I bought a new back-up battery for that today, taking care to buy the exact one it recommends on the alarm itself. As soon as I reattached it to the ceiling, the other alarm at the bottom of the stairs - which has never made a sound before - set off beeping, or double-beeping every minute for a while!

What does this mean?!

Could it be a problem with the electrics or the alarm(s)? We've had the house and alarms from new-build in early 2005 but they do have a sticker on saying to 'replace unit by Aug 2016'.

Many thanks indeed for any advice.

[Safelincs]

Without knowing the brand it is difficult to help. I am guessing that the second alarm also needs a new battery.

[green-foam]

I would guess that it is an incompatibility between the two detectors.

From what you have said you have two different brands of device. I would suggest you change either one or both so that they are the same make / model

As they are due to expire in 2016 you could change them both now. Safelincs do supply mains (with battery back up) smoke alarms for around £20 Click here

[Guest Jonathan]

Thanks for the replies. The temporary portable alarm was a different brand but the two mains alarms at the top and bottom of the stairs are exactly the same (they say Aico Ltd Ei Electronics Ei 141 inside) and they have worked fine together since 2005 until now! So very odd.

I'll certainly try changing the battery in the one at the bottom of the stairs too (the battery says March 2016 on it), but it's odd that it would only notify me it needed changing the second I re-installed the other one at the top!

I've just taken down the beeping one from the bottom of the stairs - and the one at the top of the stairs (with its new back-up battery) beeped...!