Carbon Monoxide Detector Guide UK¶

Essential guide to carbon monoxide detectors in UK homes - placement, legislation, BS 50291 compliance, and best brands.

UK Regulations and CO Detector Requirements¶

Carbon monoxide detectors are legally required in all rented properties in England under the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022. Landlords must install CO alarms in rooms containing a solid-fuel appliance (wood, coal, biomass) and any room with a gas boiler, fire, or cooker. The alarm must comply with BS 50291-1. Since October 2022, CO alarms must also be installed in all rented rooms with a fixed combustion appliance. Domestic owner-occupiers are strongly advised to fit them - over 40 people die annually from CO poisoning in the UK. Aico, FireAngel, and Kidde are the leading brands, with prices from £18 for a basic model to £45 for a digital-display unit.

Placement and Installation Best Practice¶

Install CO alarms at head height (1.5m to 2m from floor) on a wall or ceiling, at least 1m away from fuel-burning appliances but in the same room. Do not place behind curtains or furniture where airflow is blocked. In a bedroom with a gas fire or flue, fit the alarm near the sleeping area. Avoid locations directly above sinks or stoves where steam triggers false alarms. The sensor lasts 7-10 years depending on the model. Electrochemical sensors are considered the most accurate. Test weekly using the test button and vacuum dust from vents monthly. Replace the entire unit when the end-of-life warning sounds.

Specifications and Comparison¶

CO Alarm Model	Sensor Type	Lifespan	Price
FireAngel CO-9X	Electrochemical	10 years	£22
Aico Ei208	Electrochemical	10 years	£35
Kidde 10COLLD	Electrochemical	10 years	£25
Ei Electronics Ei3018	Digital display	10 years	£42

FAQ¶

Where should I fit a carbon monoxide detector?: In every room with a solid-fuel appliance, gas boiler, gas fire, or gas cooker, at head height and at least 1m from the appliance.
Are CO detectors compulsory in UK Owner-Occupied homes?: Not yet, but building regulations strongly recommend them. Fitting CO alarms is considered best practice and may become mandatory in future.
How often should I replace a CO detector?: Replace the unit when its end-of-life alarm sounds, typically after 7-10 years. Battery-only units may need battery changes every 1-2 years. For more information see our Smoke Alarm Installation Guide UK.

Last updated: 2026-05-31.

External Resources¶

For further information consult authority guidelines at the Electrical Safety First.