Carbon monoxide alarm rules for landlords: the law, the signs, and what to tell tenants
By Jordan Valentine-Dunn, Gas Safe registered engineer · 9 July 2026
Landlords must fit carbon monoxide alarms in rented homes across the UK, but the rules differ by nation. England requires an alarm in any room used as living accommodation with a fixed combustion appliance, excluding gas cookers. Scotland and Wales set their own, in places stricter, rules. Wherever you let, test alarms and replace them by their end-of-life date.
What are the carbon monoxide alarm rules for landlords?
All three nations require CO alarms in rented homes, but the detail differs enough to catch out anyone letting across a border. Check the rule for the nation the property sits in, not the one you live 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. Landlords must repair or replace an alarm once told it's faulty.
Scotland
Since February 2022, a CO alarm is required in any room with a carbon-fuelled appliance or a flue, and the rule applies to every home, not just rentals. Cookers and hobs are excluded.
Wales
Under the Renting Homes fitness rules from December 2022, a CO alarm is required in any room with a gas, oil or solid-fuel appliance, with no exclusion for gas cookers, so Wales goes further than England and Scotland on that point.
Does a room with a gas cooker need a CO 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 for a landlord with properties in more than one nation to get caught out, because the appliance is identical and the duty is not. Fitting an alarm anyway removes the doubt, and nothing in any of the three nations' rules stops you going further than the minimum.
What are the signs of carbon monoxide poisoning?
The NHS lists headache, dizziness, nausea or being sick, tiredness and confusion, stomach pain, and shortness of breath. The telling clue is the pattern: symptoms that ease when you leave the building and come back when you return. Carbon monoxide is colourless and odourless, so the alarm and the symptoms are all the warning anyone gets. A headache and tiredness are easy to wave away in winter, which is exactly why the pattern matters more than any single symptom, and why it's worth passing the list to tenants in writing when they move in.
Why is winter the risk season?
The danger peaks in the colder months, when appliances run hardest and homes are shut up against the cold. UK health data shows the large majority of accidental carbon monoxide deaths happen in autumn and winter. That is why an annual gas safety check before the heating season, and a working alarm, matter so much. If a property's check falls due in autumn, book it early, because engineers' diaries fill fast once the heating goes back on.
What should you tell tenants about carbon monoxide?
- Put the symptoms in writing when they move in, along with the leave-the-building clue. A one-page note does the job.
- Show them where each alarm is, how to test it, and ask them to test it regularly.
- Ask them to tell you straight away if an alarm is faulty or out of date. In England you must repair or replace an alarm once you've been told it's faulty.
- Make sure they know the gas emergency line, 0800 111 999, and that a sounding alarm means fresh air first, phone second.
- Ask them never to block or cover air vents; a vent is often there to let an appliance burn safely.
If an alarm sounds or anyone shows symptoms, treat it as an emergency: get everyone into fresh air, turn the appliance off if you safely can, and call the gas emergency line on 0800 111 999. This is general guidance, not legal advice, and the rules differ across the UK nations. Only a Gas Safe registered engineer can carry out the annual gas safety check and issue a valid record.