Smoke Alarm Beeping or Going Off? Smoke and Heat Alarm Guide

A working smoke alarm gives you precious extra minutes to get out if a fire starts, often while you’re asleep. The government’s fire safety in the home guidance says to test your alarms at least monthly and never to disconnect an alarm or take its batteries out because it went off by mistake. Here’s how to look after smoke and heat alarms, what a chirp or false alarm usually means, and when a mains-wired alarm needs a registered electrician.

Smoke alarm or heat alarm: which goes where?

• Smoke alarms detect smoke early. Fire services recommend at least one on every floor, ideally on the ceiling of a hallway or landing, plus rooms where a fire could start, such as a living room.
• Heat alarms react to a fast rise in temperature and ignore cooking fumes and steam. The London Fire Brigade advises a heat alarm in the kitchen rather than a smoke alarm.
• Keep smoke alarms out of kitchens and bathrooms, where steam and cooking set them off and can damage them.
• Interlinked alarms all sound together when one detects a fire, so you hear the warning wherever you are. They’re especially useful in bigger homes or where someone may be slow to wake or move.
• A carbon monoxide alarm is a separate device. Smoke and heat alarms do not detect carbon monoxide.

If the alarm goes off and there could be a fire

Treat every alarm as real until you’ve checked from a safe place. If you see smoke or flames, or the door feels warm, get everyone out, close doors behind you if you can, and call 999. Don’t stop to collect belongings and don’t go back in. Never cover or silence an alarm and carry on if you aren’t sure what caused it.

Simple monthly and yearly care

1. Test every alarm once a month. Press and hold the test button until it sounds. Use a sturdy step ladder with someone steadying it, or a broom handle on the button, rather than standing on a chair.
2. If a battery alarm doesn’t sound, fit a new battery of the type the manufacturer specifies and test again. If it still doesn’t sound, replace the alarm.
3. Change replaceable batteries once a year, on a date you’ll remember. Ten-year sealed-battery alarms don’t need battery changes.
4. Keep them clean. Gently vacuum the outside with a soft brush nozzle every few months to clear dust. Don’t paint over an alarm or stick anything on it.
5. Replace the whole alarm after 10 years, or sooner if the manufacturer says so. Most have a date on the side or back. The sensors wear out with age.
6. Never borrow the battery for the TV remote or a toy. An alarm without a battery can’t warn you.

Why is my smoke alarm chirping?

A single chirp every minute or so usually means the battery is low. The GOV.UK guidance says to replace the battery straight away. On a ten-year sealed alarm, a chirp normally means the unit has reached the end of its life and needs replacing. Some alarms use a different beep pattern for a fault or end of life, so check the manufacturer’s leaflet for what yours means.

False alarms from toast, steam or dust

1. First check there’s no fire anywhere in the home.
2. Open a window or door to clear smoke or steam, and press the test or hush button to silence the alarm. Many alarms reset themselves after a short time.
3. If one alarm keeps going off from cooking or showers, it’s probably in the wrong place. Move it further away or, in a kitchen, swap it for a heat alarm. Don’t remove it and leave the space unprotected.
4. If an alarm goes off for no reason, it may be dusty or past its replacement date. Clean it, check the date, and replace it if needed.

Mains-wired alarms

Many newer homes have alarms wired into the lighting or a dedicated circuit, usually with a backup battery. You can test them, clean them and, if the manufacturer’s instructions say it’s a user task, change the backup battery. Beyond that:

• Don’t unscrew a mains alarm from its wiring base, open the mounting plate, or touch the wires.
• The London Fire Brigade advises that mains-powered alarms should be installed by a qualified electrician. Fitting, moving, replacing or adding mains alarms is electrical work for a registered electrician working to Part P of the Building Regulations.
• If a mains alarm’s green power light is off, it may have lost power. If the RCD or a breaker has tripped, you may reset it once only, with dry hands and a dry floor. If it trips again, leave it off and call an electrician. Our guide to an RCD or trip switch that has gone off explains how.
• Never touch an alarm, light fitting or switch that has water coming through it. Turn off the water at the inside stopcock first and follow our water leak near electrics guide.

If water has got into an alarm or ceiling

Turn off the inside stopcock first. It’s usually under the kitchen sink, in a cupboard or under the stairs; here’s how to find and turn off your stopcock. The outside or boundary stop tap is usually owned by the water company (Anglian Water or Essex & Suffolk Water). It may need a special key, so don’t dig it up or force it. If you think the leak is on their side, check whether neighbours are affected and contact your water company. Nothing here conflicts with the Water Supply (Water Fittings) Regulations 1999.

Smoke alarms and gas safety

A smoke alarm won’t warn you about a gas leak or carbon monoxide. If you smell gas or suspect carbon monoxide, leave the property, open doors and windows if it’s safe, don’t use switches or flames, turn the gas off at the meter only if it’s safe, and call the National Gas Emergency Service on 0800 111 999. Get medical advice if anyone has headaches, dizziness, nausea or breathlessness. Our guide to carbon monoxide warning signs has more detail.

Under the Gas Safety (Installation and Use) Regulations 1998, only a Gas Safe registered engineer may work on gas pipework or appliances. With your boiler, stick to the user-manual checks: the timer, thermostat and power, the reset button, repressurising with the filling loop as the manual describes, and thawing a frozen outside condensate pipe with warm (not boiling) water. Never remove the casing or touch gas valves, burners or the flue. Repeated lockouts or pressure loss need a Gas Safe engineer, and you can check one on the Gas Safe Register.

Renting? Who sorts the alarms

In England, private landlords must make sure there’s a working smoke alarm on every storey used as living accommodation, and a carbon monoxide alarm in any room with a fixed combustion appliance (except gas cookers). They must check the alarms work at the start of each new tenancy and repair or replace faulty ones once told. If you rent and an alarm is faulty, missing or chirping, tell your landlord in writing. Our guide to renting with no heating or hot water covers keeping a record of repair requests.

When to stop and call us

• A mains-wired alarm needs fitting, moving, replacing or adding to.
• A mains alarm’s power light is off, it keeps sounding with no cause, or it chirps after the backup battery has been changed.
• The RCD or breaker trips again after one reset.
• You notice a burning smell, scorching, buzzing or heat around an alarm, light fitting or switch. See our burning smell or hot socket guide.
• Water is coming through a ceiling near an alarm or light.

Our domestic electrical services cover mains-wired and interlinked alarm installation, replacement and fault-finding by registered electricians.

Sources

• GOV.UK: fire safety in the home
• London Fire Brigade: smoke alarms and heat alarms
• Greater Manchester Fire and Rescue Service: smoke and heat alarms
• GOV.UK: smoke and carbon monoxide alarms, guidance for landlords
• Gas Safe Register

This is general safety guidance. If you’re unsure, stop and call a qualified engineer.