Carbon Monoxide Alarm — UK Guide 2026
Since October 2022, every UK rented property with a gas appliance must have a CO alarm. Here is the law, correct placement and best models.
Step-by-step method
1. UK law summary
CO alarm in every room with a gas or solid-fuel appliance. Landlord's responsibility. Fine £5,000 for non-compliance.
2. Placement rules
Head-height on the wall, 1–3m horizontal distance from appliance. NOT directly above a boiler (thermal draft) and NOT next to windows or doors.
3. Best models
Kidde 10Y29 — 10-year sealed battery, £22. FireAngel CO-9X — digital display, £28. Nest Protect — combined smoke+CO with app, £120.
4. Testing
Press test button monthly. Digital models show real-time PPM — anything above 30ppm sustained = evacuate.
Frequently asked questions
How long do CO alarms last?+
7–10 years for sensor life. Sealed-battery models expire on that timeline; replace the whole unit.
What if my CO alarm goes off?+
Evacuate immediately, ventilate, call 0800 111 999 or 999 if anyone feels ill (headache, dizziness, nausea).