What are the carbon monoxide alarm requirements for landlords?

Carbon monoxide is colourless and odourless, which is why the law now puts an alarm between a rented home's appliances and the people sleeping in it. The requirements are not the same across the UK, though, and the differences are exactly the kind that catch out a landlord letting in more than one nation. Here are the rules where you let, what alarm to fit and where, and who does what once the tenancy is running.

What does the law require in England?

Since 1 October 2022, a carbon monoxide alarm is required in any room used as living accommodation that contains a fixed combustion appliance, excluding gas cookers. Alarms must be in working order at the start of each new tenancy, and once a landlord is told an alarm is faulty, they must repair or replace it. Enforcement sits with the local authority, which can serve a remedial notice; failing to comply with one can bring a civil penalty of up to £5,000. The duty covers appliances burning any fuel, not just gas, so an open fire or a solid-fuel stove in a living room triggers it just as a boiler does.

How are the rules different in Scotland and Wales?

Does a room with a gas cooker need an alarm?

In England and Scotland, no: gas cookers are excluded from the requirement, and Scotland excludes hobs too. In Wales there is no cooker exclusion, so a kitchen with a gas cooker does need an alarm. This is the easiest place to get caught out across borders, because the appliance is identical and the duty is not. Fitting an alarm anyway removes the doubt: nothing in any of the three nations' rules stops you going further than the minimum, and an alarm costs less than the argument.

What alarm should you fit, and where should it go?

Look for an alarm meeting British Standard EN 50291, which is what the government's guidance for landlords recommends. On placement, the same guidance suggests positioning alarms at head height, on a wall or shelf, roughly 1 to 3 metres from the appliance, and the manufacturer's instructions for the specific alarm take precedence. Every alarm has an end-of-life date printed on the casing, and many last around seven to ten years, so replacement is a when, not an if. A CO alarm is not a smoke alarm and neither substitutes for the other; the smoke alarm rules are a separate duty with their own placement logic.

Who tests the alarm during the tenancy?

In England the landlord must ensure alarms work at the start of each new tenancy; day to day, tenants should test them regularly and report problems, and the landlord's duty to repair or replace bites once told. The handover conversation is worth doing properly: show the tenant where each alarm is and how to test it, put the symptoms of CO poisoning in writing, and make sure they know the gas emergency line, 0800 111 999, and that a sounding alarm means fresh air first, phone second. The NHS lists headache, dizziness, nausea, tiredness and confusion, stomach pain and shortness of breath, and the telling clue is symptoms that ease when you leave the building and return when you come back. Ask tenants never to block or cover air vents, because a vent is often there to let an appliance burn safely.

How does this fit with the annual gas safety check?

The alarm duty is separate from the CP12 duty, but they belong to the same habit. The danger peaks in the colder months, when appliances run hardest and homes are shut up against the cold, and UK health data shows the large majority of accidental carbon monoxide deaths happen in autumn and winter. A working alarm and a current gas safety record are the two layers of protection, so most landlords have the alarms looked at during the annual gas visit while the engineer is already there. Manifold keeps that rhythm running: every property's gas renewal is tracked and chased automatically, and each certificate sits in the landlord portal, so the annual visit that protects the alarms' blind spot never quietly lapses.