/ Home & Energy

How often do you check your smoke alarm?

smoke alarm

Do you have a smoke alarm in your home? If you do, you’re not alone. But how often do you test it and do you even know if it’s up to the job it’s supposed to do?

New Which? research is reassuringly positive about the widespread ownership of this potentially life-saving little product, with 19 out of 20 Which? members telling us that they have an alarm fitted and eight out of ten having more than one around their home.

But ownership is one thing – do you know if your smoke alarm actually works and do you ever test it?

The same Which? research revealed that fewer than one in twenty Which? members checks their alarms regularly enough.

Just 4% of smoke alarm owners told us that they run a weekly alarm check, which is recommended by the London Fire Brigade. Seven in ten owners admitted to checking their alarms only every six months or even less frequently than that. And 2% of owners admitted to never checking their alarms at all.

Which? survey results

With products like this – where being in working order is absolutely critical but impossible to tell – running a check every week is the best way you can make sure your smoke alarm is primed and ready to let you know when there’s a fire. So, why not ink it in to the diary alongside something you do weekly, such as cooking the Sunday roast or putting the bins out?

Don’t Buy smoke alarm

Which? tests shows that you can’t always trust the alarms you find in the shops to sound when you need them to.

When we last tested smoke alarms in November 2013, one of them failed our tests. Then, when we tested carbon monoxide alarms in November 2016, we found three that would let you down.

And now, following our most recent smoke alarms test, yet another product designed to save lives has failed at the one job it’s meant to do.

Our tests suggest that in certain types of fast-flaming fires, such as those caused by plastics and solvents, the Don’t Buy Devolo Home Control Smoke Detector (30%, £53-£163) may not sound. This is what we found with one of the two samples we tested.

A second sample of this Devolo alarm passed all of our fire tests, but only just made it through the flaming plastics fire test, triggering at the very last permitted moment.

Devolo told us that safety is its number one concern and it aims to follow the highest international standards. It went on to say it’s concerned by our results and that the alarm has passed standard safety tests at two certified test labs.

But we’re so worried about the safety implications of this smoke alarm failing our tests that we’re calling on Devolo to remove it from sale while it investigates. We have passed our findings on to Trading Standards.

Do you have a smoke alarm fitted in your home or even more than one? How often do you check it?


I am sure I posted this before but under the social services / county council policy we had two fire /smoke alarms fitted by the Fire Department in three rooms (total 6 detectors ) that flash continuously . As I have said previously we also have a county council ( yearly charge ) emergency alarm connected to the land -line going to a local call-centre who run this service. As I was embarrassed to say I burnt toast on the grill forgetting I had it on unknown to me (at the time ) I did not know the detectors+ the emergency alarms were connected together by radio . This set off an alarm in the call-centre saying the house was on fire and yes the Fire Service called to the small village sirens blazing I had to humbly apolgise for calling them out but it did prove they were working okay. I also have separate detector for the central heating supplied by BG.


Wow, that’s a very safe set-up you have there!

Aileen, Edinburgh says:
26 August 2017

I don’t think the Fire Brigade would have been all that bothered because I’m sure they’d prefer to discover it was a false alarm than turn up too late to save people’s lives due to alarms which don’t work properly or don’t work at all. I live in a rented flat so have no control over which brand of alarms are fitted, but must have woken the neighbours up at 1 am one night when smoke from a very small amount of over-heated hot cooking oil set the whole lot off! If nothing else, at least it proved their efficiency. They’re all connected to the electricity supply, so no danger of being switched off or batteries running out, so I would strongly recommend that other people get similar alarms. You should still test them fairly regularly though just in case there’s a malfunction somewhere.


I thought some of you may be interested to know that the smoke alarms test standard is issued by BSI (formerly the British Standards Institue), so we asked BSI why the standard is so tolerant of tardy alarms and it responded:

‘The standard covers ionisation and optical alarms, and the test fires ensure that whichever type is used, the alarm provides adequate warning when there is a real fire.’

But we’re not convinced this is good enough – we think there needs to be a stricter new standard that only rewards alarms that sound more quickly and have shared our response-time concerns with BSI. BSI has responded to this and said that new smoke alarm standard is being drafted.


I agree, Lauren. It would be good if BSI provided test scores for smoke alarms, like Which? product reviews do.

When I moved home I was disappointed how quiet the existing mains-powered interlinked smoke alarms were, so I replaced them with ones that might wake me up if there was a fire. I also bought some battery-operated ‘Best Buy’ smoke alarms and they are loud. That is important if you follow advice and close all doors at night.


The standard is European, implemented in the UK (as most are) by BSI as BS EN 14604. Standards are automatically reviewed at no more than 5 year intervals. There is a European Draft that closed to comments last year which I imagine will lead to a revised standard when all bodies have considered the responses.

The current standard requires an alarm to sound, under a variety of conditions, when a particular aerosol density has been reached in a smoke tunnel it seems. Various sources of fire are used in the tests.

@ldeitz, I’d be interested to see the results of your tests that suggest tardiness, and the relevant part of the standard that you feel needs addressing. I had a quick look through the standard, but could not see a reference to a time to respond, only reference to a “smoke” (aerosol) density threshold at which the alarm should initiate. May have missed it. I assume your testing is done in accordance with the standard.

The draft for comment does give a maximum response time to slowly developing fires.

I have several times commented on how useful it would be if Which? were active in the BSI and directly involved in the consideration of standards. This is a good example perhaps of where their experience would be of value.


I would be interested to know if smoke and carbon monoxide alarms that perform poorly in Which? tests are non-compliant with the standards or if the standards should be more demanding.