Smoke and CO Alarm Rules for Landlords: Where They Go

Two rules, and they work differently from each other:

Smoke alarms — one on every storey that has a room used as living accommodation. Not one per room, and not one per property. A three-storey house needs three. A loft conversion used as a bedroom makes that storey count.

Carbon monoxide alarms — one in every room used as living accommodation that contains a fixed combustion appliance. This is per room, not per storey.

The two rules get conflated constantly. Smoke alarms are counted by storey; CO alarms are counted by appliance location.

Under the original 2015 Regulations, a carbon monoxide alarm was only required in rooms containing a **solid fuel** appliance — a wood burner or an open fire. Plenty of London flats had none, entirely lawfully.

The **Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022**, in force from **1 October 2022**, widened this to **any fixed combustion appliance**. That brings in gas boilers and gas fires, which is most of the housing stock.

So a flat with a gas boiler in the kitchen needed no CO alarm in 2021 and has needed one since October 2022. If nobody revisited that property's alarms in the last four years, it is very likely non-compliant right now.

The exception: gas cookers. A gas cooker is explicitly excluded. A kitchen whose only gas appliance is the cooker does not require a CO alarm. A kitchen with a gas cooker *and* a wall-mounted boiler does — because of the boiler, not the cooker.

The duties do not stop at installation:

• **At the start of every new tenancy**, you must make sure each alarm is in working order. This is your job, on the day the tenancy begins — not something to be inferred from an installation years earlier.
• **During the tenancy**, if a tenant reports a faulty alarm, you must investigate and repair or replace it **as soon as reasonably practicable**.
• **Keep records.** There is no prescribed format, but if a local authority asks you to demonstrate compliance, a dated test record is the difference between a straightforward answer and an argument.

Day-to-day testing between tenancies is generally the tenant's responsibility, but the duty to provide working alarms at the outset and to fix reported faults is firmly yours.

A local authority that has reasonable grounds to believe you are in breach serves a **remedial notice** giving 28 days to comply. Ignore it and the authority can arrange the work itself and impose a penalty charge of up to **£5,000**.

The wider exposure is worse than the fine. Alarm compliance is the first thing examined after a fire or a CO incident, and it bears directly on both your insurance position and any civil claim.

A fire safety check covers alarm siting, type and operation against BS 5839-6, including carbon monoxide alarms, and gives you a dated certificate for your records.

• Fire Safety Check from £65 inc VAT, certificate issued same day
• Fire alarm installation at £219.99 per alarm for mains-powered interlinked units
• Fire Risk Assessment from £84 where the property is an HMO or has communal areas

If your gas safety certificate is also due, booking both in one visit saves arranging tenant access twice. We cover all 32 London boroughs and the M25 corridor — call 07426 409342 or book online.