Disconnected alarm, lights still flashing on bell box

30 Oct 2020
Reaction score
United Kingdom
Hi all. I’ve used this site a few times but only just now signed up to post something of my own!

I had a smart meter fitted recently and during the installation, the power had to be disconnected. When this happened, the alarm sounded for 15 minutes (presumably because the battery is old/dead).

When the smart meter installation was complete about 45 minutes later, the power was turned back on again. Ever since then, the main panel’s transformer has been buzzing (never happened before this point) and it’s been driving us mad. I’ve tried pressing down on it and tightening screws but to no avail (actually just gets worse).

I’m sick of the alarm - we used to have issues with it years ago and we’ve never used it since we have pets in the house, so I switched off the mains (alarm sounded again), removed the fuse and removed the battery from the internal panel. After 15 minutes, the alarms stopped. At that point, I turned the mains back on but I’m keeping the fuse and battery disconnected.

My issue is not knowing if the external alarm stopped sounding because of a 15 minute timeout, or because the bellbox’s battery died. Because when I go out and look at it, the green lights are still alternating.

Since I would’ve assumed this is because it was a timeout (the alternative in my mind being that the battery doesn’t have the power for the sounder but does have enough for the lights - but I doubt that - mainly because I pulled that theory out my backside), should I be expecting the bellbox to sound again at some point? I would expect the internal battery will eventually die, but that’ll probably take a long time, since it’s only powering the green lights.

Thanks in advance
Sponsored Links
modern bell boxes have there own battery, and thats why the sound during a power cut when the panels battery has failed. There is a nuisance cut off timer on modern bells which is usually around 15 minutes.

replace the panel battery and tighten the screws around the transformer, depending on the panel, the panel could well be damaged.
Thanks for the reply!

I have zero intentions, motivation or requirement to reconnect the alarm at this point (if ever!).

I’m aware of the battery inside the bellbox, I just don’t know what to expect from it from this point onwards, with it never receiving power again and its battery inevitably dyeing.

It stopped sounding after 15 minutes as I expected it to, but now I don’t know what it’ll do next, if I never reconnect the power to it.
it will eventually die, but best to decommission it properly, but then the undesirables will be aware there is no alarm
Sponsored Links
Yeah there is that. To be fair though - if they were close enough to our house to be able to see the bellbox, they’d have already needed to know they were going to rob the place. Can never be too careful though. Thanks for the help


DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local