Where should smoke and heat alarms go?
Put a smoke alarm in the hallway and on every landing, and a heat alarm in the kitchen. Many homes also add a smoke alarm in the main living room, where fires often start.
The guidance most installers follow is BS 5839-6, the code of practice for fire alarms in homes. It recommends more cover than the legal minimum, and the right level depends on the size and layout of the property. We'll suggest positions when we price the job and agree them with you before we fit anything.
- Hallway and landings
- Smoke alarms on the escape route, one on every storey.
- Kitchen
- A heat alarm, which won't go off every time you cook.
- Living room
- A smoke alarm is commonly recommended here.
- On the ceiling
- Usually at least 30 cm from walls and light fittings.
- Not in bathrooms
- Steam sets off smoke alarms; heat alarms aren't needed there.
What is an interlinked alarm, and do I need one?
Interlinked alarms talk to each other, so when one detects smoke or heat, they all sound. A fire downstairs at night wakes you upstairs, not just whoever is nearest the kitchen.
The link can be a cable between the alarms or a radio signal. Radio interlink is useful in a finished home, because it avoids running new cable between floors. In England, existing owner-occupied homes don't have to have interlinked alarms by law, although new builds and some building work, such as loft conversions, usually need mains-wired interlinked alarms. Fire services widely recommend them, and they are what we fit as standard.
What alarms do landlords need in England?
Rented homes in England need a smoke alarm on every storey used as living accommodation, and a carbon monoxide alarm in any room with a fixed combustion appliance, such as a boiler or wood burner. Gas cookers are not included.
These rules come from the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022. Landlords also have to check alarms are working at the start of each new tenancy and repair or replace them once they are reported faulty. The law doesn't say alarms must be mains-wired or interlinked, but many landlords choose them because tenants can't remove the batteries. HMO licences can set extra conditions, so check yours. Our landlord electrical safety guide covers the full set of duties.
Where should a carbon monoxide alarm go?
In the same room as each fuel-burning appliance, such as a gas boiler, oil boiler, wood burner or open fire. The exact position depends on the alarm, so we follow the maker's instructions, which commonly say 1 to 3 metres from the appliance.
CO alarms can be sealed battery units or mains-wired, and some mains systems link the CO alarm into the smoke and heat interlink. We fit CO alarms, but we don't do gas work. Boilers and gas appliances need a Gas Safe registered engineer.
If a CO alarm goes off, open the windows, turn off fuel-burning appliances if you can, get everyone outside and call the National Gas Emergency Service on 0800 111 999.
How long do smoke and CO alarms last?
Smoke and heat alarms are often designed to last about 10 years, and the date to replace them is usually printed on the side or back. CO alarms vary by model, often somewhere between 5 and 10 years.
When an alarm reaches the end of its life, the whole unit is replaced, not just the battery. Many alarms give an end-of-life warning, such as a regular chirp that a new battery doesn't stop. Alarms in the same home were often fitted at the same time, so if one is out of date, the rest usually are too, and replacing the set together keeps them matched.
Why does my smoke alarm keep beeping or going off?
A single chirp every minute or so is usually a low backup battery or an end-of-life warning. Repeated false alarms usually mean dust, insects, steam or an alarm in the wrong place.
On an interlinked system, one faulty alarm sets off all the others, so the first job is finding which one started it. Many alarms show this with a light or a different flash pattern.
- Regular chirp
- Low backup battery, or the alarm has reached the end of its life.
- Goes off when cooking
- A smoke alarm too near the kitchen; a heat alarm suits it better.
- Goes off after a shower
- Steam drifting from the bathroom to the landing alarm.
- Random alarms at night
- Dust or insects in the sensor, or a failing unit.
- Whole system sounds
- Find the alarm that triggered first before replacing any.
What affects the price of fitting smoke and heat alarms?
The number of alarms and how the interlink is done have the biggest effect.
You get one fixed price before any work starts. These are the things that move it:
- Number of alarms
- Each smoke, heat or CO alarm adds a unit and fitting time.
- Replacement or new
- Existing wiring and bases make a swap quicker.
- Cable or radio interlink
- Radio avoids running cable between floors.
- Cable routes
- Loft access helps; lifting floorboards takes longer.
- New circuit
- Only needed in some homes; notifiable when it is.