Where to fit carbon monoxide alarms in your home

Carbon monoxide (CO) alarms are mandatory in England for all private rented properties that have a solid fuel appliance. From October 2022, the requirement also covers rooms with any gas, oil, or solid fuel appliance. Scotland and Wales have similar regulations. Even if not legally required for your situation, fitting one is strongly advised.

CO is slightly lighter than air but behaves roughly neutrally at normal temperatures. Best placement: at head height (ceiling or wall above 1.5m), within 3 metres of the potential source, and in rooms where people sleep.

Minimum recommended: one alarm per floor, and one in each room with a gas appliance. Priority rooms: bedroom nearest the boiler, living room if there is a gas fire, kitchen.

Do NOT fit CO alarms: directly above or next to cooking appliances (false alarms from normal cooking combustion), in damp or steamy areas (bathrooms, boiler cupboards), in areas below -10°C or above 40°C (loft or unheated garage).

Look for alarms complying with BS EN 50291-1 (domestic) with a BSI Kitemark. Basic audible alarm CO detectors cost £15–£25 (Kidde, FireAngel, Aico). Interconnected wireless models (£30–£80 each) trigger all alarms in the house simultaneously — best for multi-storey properties.

CO alarms have a stated lifespan — usually 5–7 years. Most have an end-of-life alert. Write the installation date on the back. Replace the unit when it expires, not just the battery. Test monthly using the test button.