Installing and Maintenance

  • A smoke alarm is a warning device that detects smoke at the earliest stages of a fire. When it detects a fire, it will make a piercing noise to alert or wake you

  • Smoke alarms can cost as little as £5 and are available from DIY stores, electrical shops and many supermarkets and high-street retailers

  • There are two ways that smoke alarms detect fires. Both types are effective but there are some differences

Ionisation alarms

These alarms are the cheapest and the most widely available from most supermarkets, DIY stores and other high street retailers. They are sensitive to free burning fires e.g. chip pan fires.

Optical alarms

These are more expensive because they are more effective at detecting slow burning fires such as overheated electrical wiring. They are less likely to go off accidentally or when you're cooking, and are best for ground floor hallways or for homes on one level.

If you are installing more than one smoke alarm, you may want to consider having one ionisation and one optical alarm for the best protection. However, whichever model you choose, look out for one which has a British Standard Kitemark symbol which indicates that the detector is an approved model.

Smoke alarm maintenance

You should have at least one working smoke alarm on every level of your home.

To keep your smoke alarm in good working order, you should:

  • Test it once a week, by pressing the test button until the alarm sounds

  • Vacuum the alarm twice a year and wipe over with a damp cloth to remove any dust

  • Change the battery once a year (unless it's a ten-year alarm)

  • Replace the whole unit every ten years


If the alarm fails to operate or continues to chirp:

Alarm hard wired to mains electric – contact an electrician or if in rented accommodation your landlord who will be able to give you further advice.

Find out more about alarms and their positioning (PDF, 2.2MB)

Why does my alarm keep going off?

False alarms can be annoying but they are easy to prevent. Whatever you do, don't remove the battery or disconnect the alarm. Usually the problem is you have placed the alarm too near to the kitchen so it is easily set off when you are cooking. Follow the advice on fitting and try moving the alarm to a less sensitive area or replace it with a hush or silencer button alarm.

But my alarm isn't near my kitchen but is still beeping regularly - what's the problem?

If your smoke alarm starts to 'beep' regularly, you must replace the battery as soon as possible. If it's a 10 year alarm, you should replace the whole unit.

Warning! False alarms can also show that your alarm needs servicing.