Smoke and CO Alarm Rules for Landlords

Landlords in England must fit at least one smoke alarm on every storey of a rental property that has a room used as living accommodation, and a carbon monoxide alarm in any room used as living accommodation that contains a fixed combustion appliance, such as a gas boiler, gas fire or log burner, but not a gas cooker on its own. Alarms must be confirmed working at the start of every new tenancy, and any alarm reported as faulty during a tenancy must be repaired or replaced as soon as reasonably practicable.

These duties come from the Smoke and Carbon Monoxide Alarm (England) Regulations 2015, significantly widened by an amendment that took effect on 1 October 2022. Before that date, the carbon monoxide requirement only applied to rooms with a solid fuel appliance; it now covers any fixed combustion appliance, which in practice brings in most properties with gas central heating.

Where alarms are required

Smoke alarms must be fitted on every storey of the property where there is a room used wholly or partly as living accommodation. This means a typical two-storey house needs at least one alarm downstairs and one upstairs, even if only one floor contains bedrooms, because the regulation is based on storeys with living space, not specifically on bedrooms. Manufacturer guidance generally recommends fixing smoke alarms to the ceiling in a circulation space, such as a hallway or landing, so they can pick up smoke from any room on that level.

Carbon monoxide alarms must be fitted in any room used as living accommodation that contains a fixed combustion appliance. A fixed combustion appliance is any apparatus that burns fuel, such as gas, oil, coal or wood, to generate heat, and specifically includes:

• Gas boilers, including combi, system and heat-only boilers.
• Gas fires and gas fireplaces, whether real flame or decorative.
• Log burners, wood-burning stoves and multi-fuel stoves.
• Oil-fired boilers and oil-fired heaters.

Gas cookers are the one common appliance specifically excluded from the requirement. In practice, this means the room housing a combi boiler, whether that is a kitchen, airing cupboard or dedicated utility room, needs its own carbon monoxide alarm, as does any lounge with a working gas or wood-burning fire. Manufacturer guidance typically suggests mounting a carbon monoxide alarm at head height, roughly one to three metres from the appliance, though you should always follow the specific instructions supplied with the alarm you install.

Alarms can be mains-powered or battery-operated, and there is no requirement for them to be interlinked, though interlinked systems are common in newer or refurbished properties and can offer better coverage across a larger home.

Testing on tenancy start

You must test every smoke and carbon monoxide alarm and confirm it is in proper working order on the first day of a new tenancy. This is a specific point-in-time duty, distinct from the ongoing duty to repair a fault reported during the tenancy, and it is worth recording clearly, for example in the check-in inventory or a signed statement from the tenant, that alarms were tested and working at the start of the letting.

As a worked example, a landlord letting a two-bedroom flat with a combi boiler in the kitchen would need a working smoke alarm on the single storey the flat occupies, and a working carbon monoxide alarm in the kitchen because of the boiler. If the same flat also had a decorative gas fire in the lounge, it would need a second carbon monoxide alarm in that room too, since the requirement applies per room containing a qualifying appliance, not once per property.

Remediation

If a tenant, or someone acting on the tenant's behalf, reports that a smoke or carbon monoxide alarm may not be working properly, and you find on checking that it genuinely is not, you must repair or replace it as soon as reasonably practicable. There is no fixed number of days set out in the regulations for this, but "as soon as reasonably practicable" is understood to mean promptly, not at the next scheduled visit or when convenient, given that these are life safety devices.

In practice, this means having a way for tenants to report a faulty alarm quickly, and being able to act on it without unnecessary delay, whether that means posting a replacement battery-powered alarm, arranging a same-week visit, or instructing a managing agent or contractor to attend. Landlords who treat alarm faults with the same urgency as a heating breakdown, rather than filing the report for the next routine inspection, are in a much stronger position if anything goes wrong and the response is later scrutinised.

Local authorities can serve a remedial notice requiring you to fix a breach within 28 days, and can arrange for the work to be done themselves and recover the cost from you if you do not comply, on top of which they can issue a civil penalty for non-compliance. Given the safety stakes involved, most landlords act well within that window rather than treating it as a target deadline.

Record keeping

Keep a simple record for each property showing when alarms were last tested, particularly at the start of each tenancy, and any occasion an alarm was reported faulty and when it was fixed. This does not need to be complicated: a dated note or photo taken during the check-in, kept alongside your other compliance certificates, is usually enough to demonstrate compliance if a dispute or local authority inspection arises later.

Being able to show that alarms were working at the start of a tenancy, and that any reported fault was dealt with promptly, matters as much as actually having compliant alarms fitted, since a dispute often comes down to what you can evidence rather than what you remember doing. Our landlord certificates checklist covers how alarm testing fits alongside the other mandatory safety certificates every rental property needs, and our landlord legal responsibilities guide sets out how alarm duties sit within a landlord's wider legal obligations in England.

How Property HQ helps

Property HQ lets you log alarm testing dates and any reported faults against each property, alongside your gas safety, EICR and EPC certificates, so you have a single, dated record to point to if a tenant, letting agent or local authority ever asks whether alarms were checked and working.

Disclaimer

This guide is general information for UK landlords, not legal advice, and covers the position in England. Rules in Wales, Scotland and Northern Ireland differ in detail. Check GOV.UK or the relevant national guidance for your property's location before relying on this summary.