Smoke and carbon monoxide alarms: what landlords must fit

Every rented home in Great Britain needs working smoke alarms, and most need at least one carbon monoxide (CO) alarm. The details differ between England, Scotland and Wales, so check the rules for where your property is.

England: the 2022 rules

The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 were updated from 1 October 2022. They now apply to private and social landlords.

Before October 2022 the CO alarm rule only covered solid-fuel appliances. It now covers gas boilers and gas fires too. The government Q&A booklet says a bathroom or toilet counts as living accommodation, so a room with a boiler in it, such as a bathroom, needs a CO alarm.

The regulations do not say whether alarms must be battery or mains-powered. HMO licence conditions, building regulations for new work, or your council may require more.

Scotland: interlinked alarms

Since 1 February 2022 all homes in Scotland have had to meet the same fire alarm standard. Private landlords already had to meet it under the Repairing Standard.

• One smoke alarm in the room used most for daytime living.
• One smoke alarm in every circulation space (hallway or landing) on each storey.
• One heat alarm in every kitchen.
• All of these must be ceiling-mounted and interlinked, so when one sounds they all do.
• A CO alarm wherever there is a carbon-fuelled appliance, such as a boiler, fire or flue. It does not need to be interlinked.

Interlinked alarms can be sealed long-life battery or mains-wired types.

Wales: mains-wired and interlinked

Under the Renting Homes (Fitness for Human Habitation) (Wales) Regulations 2022, Welsh Government guidance says a home is treated as unfit if it doesn’t have:

• a working smoke alarm on every storey, mains-wired and interlinked; and
• a CO alarm in every room with a gas, oil or solid-fuel combustion appliance.

This has applied to new occupation contracts since 1 December 2022 and to converted contracts since 1 December 2023. Mains-wired alarms are electrical work, so use a qualified electrician.

Testing on day one

In England you must be able to show the alarms worked at the start of the tenancy. A simple way, suggested in government guidance, is to test each alarm with the tenant at check-in and have them sign the inventory to confirm the alarms were tested and working.

Good practice:

• Press the test button on every alarm at check-in.
• Note the expiry date printed on each alarm in your records.
• Show the tenant how to test the alarms, and ask them to test regularly and report faults.

Repairs and replacement

During the tenancy, the landlord is responsible for repairing or replacing faulty alarms once told about them. If an alarm has a replaceable battery, the tenant may change the battery, but the alarm itself remains your responsibility. Sealed-battery alarms typically last around 10 years and carry a “replace by” date on the casing, so plan replacements around that date rather than waiting for the end-of-life chirp.

Penalties

Buying guidance

The rules set out where alarms must go, not which brand to buy. These points come from government and fire service guidance and are manufacturer-neutral.

Smoke alarms

• Sealed long-life batteries. Government guidance says alarms with “sealed for life” batteries are a better option than ones with replaceable batteries. Many sealed alarms last around 10 years. Check the stated life on the packaging.
• Look for BS 5839-6 compliance (the British Standard for fire detection in homes), as referenced in government guidance.
• Position: fix smoke alarms to the ceiling in a circulation space, such as a hall or landing, and follow the manufacturer’s instructions.
• Heat alarms in kitchens avoid false alarms from cooking. They are required in Scotland and sensible elsewhere.

Carbon monoxide alarms

• Standard: choose an alarm that meets BS EN 50291, ideally with a Kitemark.
• Position: government guidance suggests head height, on a wall or shelf, about 1 to 3 metres from the appliance; Devon & Somerset Fire and Rescue Service gives similar advice. Always follow the alarm’s own instructions.
• One per room with an appliance. If you have a boiler in the kitchen and a wood burner in the lounge, you need an alarm in each room.
• Sealed batteries: CO alarms to BS EN 50291 are widely sold with sealed batteries lasting 7 to 10 years.

A CO alarm is not a substitute for servicing. Gas appliances still need their annual gas safety check, and solid-fuel chimneys should be swept regularly (see chimney sweep costs).

Quick checklist

• Smoke alarm on every storey (England), or the interlinked layout in Scotland and Wales.
• CO alarm in every room with a fixed combustion appliance (not gas cookers in England).
• Test every alarm on day one of each tenancy and get it signed off.
• Record expiry dates and replace alarms before they run out.
• Repair or replace promptly when a tenant reports a fault.

For the rest of your safety duties, see the landlord compliance checklist.