Carbon Monoxide & Smoke Alarm Rules 2026: Landlord & Homeowner Legal Duties

The 2026 rules at a glance

The rules depend on two things: which UK nation you are in, and whether you are a landlord or an owner-occupier. There is no single "UK law" — each nation legislates separately, and most online guides quietly assume England.

• England (landlords): legally required since 1 October 2022 — a smoke alarm on every storey and a CO alarm in any room with a fixed combustion appliance (excluding gas cookers).
• Scotland (everyone): legally required since 1 February 2022 — interlinked smoke alarms plus a CO alarm by any fuel-burning appliance, in owner-occupied and rented homes.
• Wales (landlords): mains-powered interlinked smoke alarms on every storey, plus CO alarms, under the Renting Homes regime (in force from 15 July 2022).
• Northern Ireland (landlords): smoke, heat and CO alarm rules for private tenancies, in force from 1 September 2024 (existing tenancies by 1 December 2024).

The current law: the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 (England)

The headline change for England came into force on 1 October 2022. The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 updated the original 2015 rules and significantly widened CO protection.

Before October 2022, a CO alarm was only required where there was a solid fuel appliance — a coal fire or wood burner. The phrase in the regulations was changed to "fixed combustion appliance other than a gas cooker".

In plain terms: a CO alarm is now required wherever there is a gas boiler, oil boiler, gas fire, wood burner or similar. This is the single most misunderstood point — many landlords still believe gas boilers are exempt. They are not.

The 2022 rules also extended the duties to social housing providers, so housing associations are now in scope alongside private landlords.

Where smoke alarms must go

The England rule is straightforward: at least one smoke alarm on every storey of the home that has a room used as living accommodation.

• Mount alarms on the ceiling, ideally in circulation spaces — halls and landings — where smoke from any room will reach them.
• A mezzanine is not counted as a separate "storey" for these purposes.
• Bathrooms and toilets do not count as living accommodation, but the storey they sit on still needs an alarm.

Heat alarms (which respond to temperature, not smoke) are the right choice for kitchens, where cooking fumes would constantly trigger a smoke alarm. England's landlord regulations specify smoke alarms by storey; Scotland, Wales and Northern Ireland explicitly require a kitchen heat alarm too (see the four-nations table below).

Where carbon monoxide alarms must go

A CO alarm is required in any room containing a fixed combustion appliance. That means the room with your boiler, your gas fire, your wood burner or your oil-fired heater.

For where to mount it, British Standard BS EN 50292 (the siting standard, current version BS EN 50292:2023) recommends placing the alarm:

• A horizontal distance of 1 to 3 metres from the appliance.
• At roughly head height, or on the ceiling at least 300mm from any wall or light fitting.
• Not in an enclosed space (such as inside a cupboard housing the boiler) or directly above a sink or window.

Gas cookers are excluded from the England requirement. The Government's reasoning was that gas cookers cause fewer CO incidents than boilers, that requiring two alarms in one small kitchen was impractical, and that a boiler in the same room would trigger the requirement anyway. Note the exclusion is England-specific — Wales does include gas cookers in its CO rule.

An alarm tells you there is already a problem. It does not stop CO being produced. If yours sounds, get fresh air, switch the appliance off and read the signs of carbon monoxide from your boiler; if you also smell gas, see what to do if you smell gas and call the National Gas Emergency line on 0800 111 999.

Landlord legal duties in England

If you let residential property in England, the regulations place specific, dated obligations on you.

• Alarms must be in working order on the day a new tenancy begins. The simplest way to evidence this is to test them with the tenant present at check-in and log it.
• Once a tenant reports a fault, you must repair or replace the alarm as soon as reasonably practicable.
• The duty applies regardless of the alarm's age — there is no exemption for "the alarm was fine when I fitted it".

These alarm duties sit alongside your separate annual gas-safety obligation. Every let property with gas appliances needs a Gas Safety Certificate (CP12) renewed yearly by a registered engineer. Many landlords cover both the certificate and breakdown protection with a single landlord boiler cover plan.

Penalties and enforcement

Enforcement in England sits with the local housing authority (your council). The process is graduated rather than instant.

• If the council believes you are in breach, it serves a remedial notice giving you 28 days to put things right.
• You may make written representations against the notice within 28 days, which suspends it while the council considers them.
• If you ignore the notice, the council can arrange the work itself and impose a financial penalty.
• The penalty is up to £5,000 per breach — and it is charged per breach, not per property, so multiple failings can stack.
• You can appeal to the First-tier Tribunal against a penalty charge notice.

Do homeowners and owner-occupiers need alarms?

This is the question most landlord-focused guides ignore entirely.

If you own and live in your home in England, Wales or Northern Ireland, there is no legal duty to fit smoke or CO alarms. The landlord regulations simply do not reach owner-occupiers.

However, fitting them is strongly recommended by the fire services, gas-safety charities and building-safety guidance — and at roughly £20–£30 for a sealed CO alarm, the cost is trivial against the risk.

In Scotland the position is different and binding: since 1 February 2022 the alarm standard applies to every home, and it is the owner's responsibility to meet it. Owner-occupiers in Scotland are legally required to comply.

The four-nations breakdown

This is where most rank-one guides get it wrong. The UK does not have one law — here is the genuine all-nations picture for 2026.

Nation	Who it binds	Smoke alarms	CO alarms	In force
England	Landlords only	One per storey with living accommodation	Any room with a fixed combustion appliance (gas cookers excluded)	1 Oct 2022
Scotland	All homes (owners + landlords)	Most-used room + every hall/landing, all interlinked, plus a kitchen heat alarm	By any fuel-burning appliance (need not be interlinked)	1 Feb 2022
Wales	Landlords (Renting Homes)	Mains-powered, interlinked, on every storey, plus a kitchen heat alarm	Each room with a gas, oil or solid-fuel appliance (cookers included)	15 Jul 2022
Northern Ireland	Landlords (private tenancies)	Main living room + every circulation space per storey, plus a kitchen heat alarm	Any room/space with a fixed combustion appliance or flue	1 Sep 2024

Note the standout difference: Scotland's interlinked requirement (where one alarm sounding sets them all off) applies to owner-occupiers, not just tenants. If you live in your own Scottish home, this is your duty.

Battery vs mains-powered, and the standards

England does not mandate a power type for the alarm itself — what matters is that it works. Wales is stricter, requiring smoke alarms to be mains-powered and interlinked.

Two product types dominate:

• Sealed 10-year battery alarms — a tamper-proof lithium battery lasts the unit's life; nothing to replace until the whole alarm expires. Ideal for owner-occupiers and many landlords.
• Mains-powered (hardwired) alarms — wired into the lighting or a dedicated circuit with a battery backup; the standard for new builds and required for Welsh smoke alarms.

Look for the British Standard kitemarks when buying:

• BS 5839-6 — the standard for domestic smoke and heat alarm systems.
• BS EN 50291 — the performance standard for domestic CO alarms (current version BS EN 50291-1:2018, which mandates an end-of-life indicator).
• BS EN 50292 — the guidance on selecting and siting CO alarms.

How much do alarms cost?

Prices are indicative UK ranges, last checked in 2026 — always confirm the current price with the retailer.

Item	Indicative cost
Sealed 10-year battery CO alarm (BS EN 50291)	from around £20–£30
Mains/hardwired CO alarm	£40–£110+
Sealed 10-year smoke alarm	£10–£25
Combined smoke + CO alarm	£30–£60
Electrician to fit a hardwired alarm	£60–£120 per alarm (varies)

DIY vs electrician: battery alarms are a screwdriver job most people can do themselves. Mains-wired alarms involve fixed electrical work and should be fitted by a competent, qualified electrician. Never let an unqualified person touch the boiler or gas pipework — that is strictly Gas Safe territory.

Alarm lifespan and when to replace

Alarms do not last forever — the sensing element degrades over time.

• CO alarms: the electrochemical sensor wears out. Most manufacturers specify a life of around 5 to 10 years, then the unit must be replaced (not just the battery). Models meeting the 2018 standard beep and flash an end-of-life warning.
• Smoke alarms: typically replace every 10 years, or sooner if the manufacturer states.

Write the replacement date on the unit when you fit it. A CO alarm that has reached end-of-life is no protection at all, even if its test button still chirps.

Tenant duties

Tenants are not off the hook. While landlords must provide working alarms, the day-to-day upkeep falls to the occupier.

• Test the alarms regularly — the recommendation is weekly via the test button.
• Replace replaceable batteries where the alarm is not a sealed unit.
• Report any fault to the landlord promptly — that report is what triggers the landlord's repair duty.

If you rent and want breakdown peace of mind beyond the landlord's gas-safety obligations, see boiler cover for tenants: who pays.

Carbon monoxide from a faulty boiler — why servicing matters

An alarm is a backstop, not a fix. The real defence against carbon monoxide is a boiler that burns cleanly — and that comes from regular servicing by a registered engineer.

CO is produced when fuel burns incompletely: a blocked flue, a cracked heat exchanger, a poor gas-air mix or inadequate ventilation. A competent engineer checks combustion, flue integrity and ventilation at every service. Any work on the gas supply, burner, flue, sealed combustion circuit, gas valve or PCB must be carried out by a Gas Safe registered engineer only — never attempt it yourself.

You can check an engineer on the Gas Safe Register before they touch your boiler, and a typical annual boiler service cost is a small price for that combustion check. Flue position matters too — see the boiler flue regulations and clearances. To arrange one, you can book a Gas Safe engineer near you.

Many homeowners and landlords roll the annual service into a maintenance plan so the combustion check never gets forgotten. We compare a selected panel of providers — not the whole market — and may earn a commission if you buy through our links, at no extra cost to you. You can compare the best boiler cover for 2026; some plans are FCA-regulated insurance and others are unregulated service or care plans, so always confirm which you are buying, and the current price, on the provider's own page.

This article is general information, not financial or gas-safety advice. We compare a selected panel of providers, not the whole market, and may earn a commission if you buy through our links. Always have gas appliances checked and repaired by a Gas Safe registered engineer; in a gas emergency call 0800 111 999. Prices are indicative UK guides for 2026 — confirm current prices on the provider's own site.