There is no legal or BSI requirement to test the CO detectors with a test gas. A weekly check with the test button is fully sufficient if you choose a quality CO detector. The test gas is offered as a 'belts and braces' option.

Yes, this CO alarm has been Kitemarked to EN 50291-1: 2010 and has been awarded a CE mark. It should be installed in line with the manufacturers guidance.

CO detectors should be installed near potential sources of carbon monoxide, essentially any fuel-burning appliances such as boilers, cookers and ovens, fireplaces (both open and enclosed burners), and portable generators. As you are likely to be most affected by CO in areas of your home that you spend the most time in it is advisable to install alarms in those areas as well, such as the living room and bedrooms. It is also worth noting that while one detector is better than no detectors at all, larger homes may require several detectors to cover the property fully.

Also note that carbon monoxide has been proven to spread into neighbouring properties through open windows and, in semi-detached or terrace houses, through loft spaces. If your property has an attached garage with a connecting door through to the house, it is recommended to fit a CO alarm inside the house leading from that doorway.

Battery powered carbon monoxide alarms can typically be installed wall-mounted or left free-standing on flat, level surface.

• Near an appliance: they should be placed within 1 to 3 metres horizontally from the appliance and between the height of the appliance to 150mm below the ceiling – i.e., not above a stove where it would be in the path of steam or fumes.
• In living spaces: they should be positioned close to where the occupant's head is likely to be most of the time – e.g., on your bedside table.

Combined smoke & CO alarms or mains-powered CO alarms are typically installed on the ceiling and should be at least 30cm away from any wall, light fitting, or other obstruction.

Do not install CO alarms within 3 metres of doors or windows, above radiators, or immediately close to anything that gives off steam or fumes like a cooker or shower room. Similarly, it is not recommended to install detectors in dusty areas such as workshops or garages.

For more information, please check the manufacturer's instructions – you can download the PDF manual from the relevant product page on our site. You can also watch our video guide to positioning CO detectors.

Most legislation advises at least one carbon monoxide alarm is fitted near new or replacement fuel-burning appliances that are fixed installations, though rented properties (both social and private sector) often require CO alarms be provided by landlords even if no appliances are being installed or replaced. Examples include boilers, coal fires, wood burners, and gas ovens and cookers, though an exception is often made in legislation for gas appliances solely used for cooking.

However, any and all materials can give off CO when burning, including gas cookers. Carbon monoxide can also spread from neighbouring properties or outside sources such as vehicle fumes. Because of this, Safelincs strongly recommends the installation of carbon monoxide detectors in every home, and also at head-height in bedrooms to protect occupants while sleeping.

Landlords, please see our pages for English, Welsh, and Scottish alarms or our landlord guidance page for more information.