Carbon Monoxide (CO) Alarm Regulations
The Smoke and Carbon Monoxide Alarm (England) Regulations 2015, as amended in October 2022, require all private and social landlords in England to install a working carbon monoxide alarm in every room used as living accommodation that contains a fixed combustion appliance, with the sole exception of gas cookers. The rules are set out in SI 2015/1693 as amended by SI 2022/707, and are enforced by local housing authorities.
What the 2022 amendment changed
Before October 2022, CO alarms were only required in rooms containing a solid fuel burning appliance, a coal fire or wood-burning stove, for example. The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 extended the requirement to cover all fixed combustion appliances, which means rooms containing a gas boiler, gas fire, or oil boiler now also require a CO alarm. Gas cookers remain the one explicit exclusion, though fitting one in a kitchen with a gas hob is strongly recommended as a matter of good practice.
The same 2022 amendment also updated the smoke alarm requirements for rented homes and brought social housing landlords under the same rules as the private rented sector for the first time.
Landlord duties under the regulations
Under the current rules, landlords must:
Install at least one working CO alarm in every room used as living accommodation that contains a fixed combustion appliance (excluding gas cookers).
Ensure the alarm is in proper working order on the day a new tenancy begins.
Repair or replace any alarm found to be faulty, as soon as reasonably practicable, following a report from the tenant or their representative.
Tenants are responsible for testing alarms periodically during the tenancy and replacing batteries. If replacing the battery does not resolve the fault, the tenant reports it to the landlord and the repair obligation passes to the landlord.
From working with self-managing landlords across the UK, we know that the most common oversight is a gas boiler installed in a utility room or dedicated boiler cupboard, a room that is technically living accommodation under the regulations. If the door opens into a habitable area, the room counts and a CO alarm is required.
Alarm type and placement
The regulations do not mandate a specific brand or model, but alarms must comply with British Standard BS 50291. Where battery-powered alarms are chosen, the government guidance recommends sealed-for-life units rather than those with replaceable cells.
Government guidance places alarms at head height, approximately one to 1.5 metres from the appliance, positioned to avoid draughts from windows, doors, or extractor fans, which can disperse CO before it reaches the sensor.
Enforcement and penalties
Local housing authorities enforce the regulations. Where a local authority has reasonable grounds to believe a landlord has not complied, it must serve a remedial notice requiring the landlord to install or repair alarms within 28 days. If the landlord fails to comply with the remedial notice, the authority can carry out the work at the landlord's expense and impose a civil penalty of up to £5,000 per breach.
A missing or faulty alarm may also support a tenant claim under the fitness for human habitation standard, and carbon monoxide is classified as a Category 1 hazard under the Housing Health and Safety Rating System, meaning enforcement under HHSRS can run alongside the specific CO alarm regime.
Which tenancies are excluded
The regulations apply to the vast majority of private and social rented tenancies in England. The main exclusions are shared accommodation where the tenant shares facilities with the landlord or a member of the landlord's family, and tenancies let on a long lease of more than seven years. Student halls of residence have their own separate fire safety codes.
August's compliance checklist tracks your CO alarm obligations alongside gas safety certificates, EICRs, and other landlord compliance requirements in one place.
For the full practical requirements, including alarm placement, the inspection checklist for new tenancies, and the rules in Scotland and Wales, see the landlord guide to carbon monoxide alarm regulations.
Frequently asked questions
Do I need a CO alarm if my property has a gas boiler?
Yes. Since 1 October 2022, a CO alarm is required in any room used as living accommodation that contains a fixed combustion appliance, which includes gas boilers and gas fires. The gas cooker is the only explicit exclusion. If your boiler is in a utility room or cupboard that connects to living accommodation, you need an alarm there too.
What happens if I do not have a CO alarm in my rental property?
If a local authority has reason to believe you are not complying, it must serve a remedial notice giving you 28 days to install or repair the alarm. If you do not comply, the authority can carry out the work at your expense and issue a civil penalty of up to £5,000. Non-compliance also affects any HHSRS assessment of the property.
Who is responsible for testing CO alarms during a tenancy?
Landlords must ensure alarms are in working order at the start of each new tenancy. During the tenancy, tenants are responsible for periodic testing and for replacing batteries. If the alarm remains faulty after a battery replacement, the tenant notifies the landlord, who must then repair or replace the unit as soon as reasonably practicable.
Does the gas cooker exclusion mean I do not need a CO alarm in my kitchen?
The regulations do not require one for a gas cooker. However, government guidance and industry bodies recommend fitting one in any kitchen with a gas hob or cooker, since gas cookers are a recognised source of CO. The exclusion reflects a technical legislative boundary, not a safety recommendation.
Disclaimer: This page is for general informational purposes only and does not constitute legal advice. Landlord and tenant law is subject to change. The information reflects the legal position in England as at May 2026. Always seek independent legal advice where needed.
