Smoke Alarm Chinese Water Torture

Smoke Alarm

Last night we experienced what is probably the Smoke Alarm equivalent of Chinese Water Torture – a seemingly unstoppable, almost random intermittent beeping from one of our mains powered Smoke Alarms.

Like all new houses in the UK over the past few years, our house was built with mains powered smoke detectors, one of which is placed in the hall downstairs, and the other in a similar position on the upstairs landing. Being mains powered we’ve not really thought much about them – they are basically just there, and get periodically tested – usually thanks to something cooking.

Anyway, last night, the detector downstairs started beeping. It wasn’t regular, but was fairly frequent – frequent enough to be annoying. I took a look, and written on the case was that it had a battery backup, to ensure the alarm worked even if the mains supply failed, so perhaps it was the battery. We turned off the mains circuit for the smoke detectors, and after a bit of fiddling managed to remove the unit, only to find that the battery was a 9 Volt PP3 and typically we didn’t have any of those sitting around. More than that, with the battery disconnected, the smoke alarm then beeped again a couple of times – obviously some backup of the backup… Ok, new batteries it was, so off I went to one of the local convenience stores, and while I was at it, I got a second battery so we could change the one in the unit upstairs too.

I came back with the new batteries, and we replaced them in both units, and what happened – within a few minutes it started beeping again.

I went and took down the unit, and then looked up on the Internet for any clues as to the problem. The main suggestion I could find was that something was that there was a build-up of dirt and fluff on the sensor – indeed I remembered something similar causing a fire evacuation when I was working at SSE. So out came the vacuum cleaner, and I ran it all around the vents on the unit, and replaced it on the ceiling. About five minutes later it did give a couple more beeps – but since then, nothing, so hopefully it is now all sorted. The unit in question is right outside the kitchen door, so is exposed to a lot more dirt and fluff, so that does explain it – the lesson being, periodically vacuum your smoke alarms!

12 thoughts on “Smoke Alarm Chinese Water Torture”

  1. Our smoke alarm does this regularly as it is powered by the light socket so if it’s not switched on long enough it does a slightly TOO irregular beep. When we do switch it on it still beeps for a little while until it’s up to power. That might explain it.

  2. Just had to ask in response to your article as other readers are begging to know the following answers:

    1. Who does the cooking in your household
    2. How often does the smoke detector go off as a result

  3. 1. We both do, although Beth cooks the majority of the time. I tend to cook on request if Beth is busy with school work, or has a late meeting for example. At other times, when I get home from work Beth has often started to cook dinner already.
    2. Quite frequently – in general you don’t need to have burned anything to set it off.

  4. I suffered the exact same annoyance with a mains-powered smoke alarm in our flat. One day it just started beeping intermittently and was driving us mad! There was no battery back-up to change so I was at a loss what to do. However, reading this post about fluff on the sensor gave me an idea – so I tried blowing on the sensor area to dislodge any dust and thus worked. Hurrah!

    So thanks very much for this helpful advice – hope anyone else who reads this finds it useful, too!

  5. I had/have the same problem as all of you..electric smoke alarm beeping every minute..

    Anyway have changed all the batteries etc..still a beeping sound coming from the ether..cleaned it and still beeping..disconnected the things from the ceiling and isolated power supply still beeping.

    So now I have no smoke alarms visible in house only no paint areas where they were once positioned..what is going on ??

    I now have a dreaded feeling that when our house was being renovated an old smoke alarm may have been left in joists (builders !!) between our living room and bedroom and battery is fading…

    lets hope it dies soon as it has been going on for three days now..I can see myself pulling the ceiling down !!!

  6. I’m so glad I found this webpage. My smoke alarm has been doing this every once in a while, and I thought I had tried everything. Changing the batteries never seems to work. Sometimes testing the alarm seems to work, but not always. Now that I’ve read this, I will try blowing on it first from now on. The odd thing is that this always happens when I’m trying to sleep. I think it knows…

  7. i have exactly the same problem with the ame smoke detector….however, i cannot get it off the wall! can someone PLEASE tell me how to remove it?? it’s really important,as the beeping is drving me mad…

  8. my smoke SHRIEK alarm has been beeping for nearly (3 MONTHS) is that a record breaker !!! weve got soo used to it now xx but funny enough im now on heavy duty valium all day…. have a nervous tick… and before i put my straight jacket and ipod on at nite… i take a megga dose of sleepers ….
    i was wondering if it might better ? to just burn my house down myself ? do you think house insurance covers mental bloody illness ? aaaaaaahhhhhhhhh
    ive been on 3 sites today…. and im gonna try everything ive read …… thanks… wish me luck ……..
    ill let you know if it works ? or if im homeless ?
    beeping lee yours ….

  9. well ive vacuumed the hell outta both alarms…. and 30 mins later they are still BLOODY BEEPING !!!!
    ah man …. ill try knocking the power off ?
    im getting bleep bleep real pissed bleeping off !!!

  10. I’m also glad I found this website, I was up at 4am fiddling with our bleeping smoke alarm on the landing (whilte the husband slept soundly I might add..) then gave up and it stopped after a while. However this morning the downstairs one started bleeping. Then that one stopped after a couple of hours. Having read all of the comments I then decided to give it a hoover, which I did and the thing started to bleep again!! Aaaggghhh help!!

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