Carbon monoxide alarms are the most effective means of detecting the concentration of carbon monoxide gas in the environment and alerting you to the presence of dangerous gases.
Where to place a carbon monoxide detector
In order for your carbon monoxide alarm to work correctly, it is essential you put it in the right place. Here are the things you need to consider when placing a carbon monoxide detector:
You should ideally have a carbon monoxide detector on each floor of your house and definitely in the same room as any fuel-burning appliance, such as a boiler, stove or oven.
Place the alarm at head height. This could be on a shelf or bookcase; it doesn’t have to be fixed on a wall. Ideally, it should be at least 15cm from the ceiling.
Make sure the alarm is at least a metre away from fuel-burning appliances, such as boilers and ovens.
Some carbon monoxide alarms are built into ceiling-mounted multipurpose fire alarms. You should check your smoke detector to see whether it is already fitted with a carbon monoxide detector. If the alarm is located on the ceiling, it should be at least 300 mm from any wall and any ceiling obstruction e.g. light fittings.
Don’t place the detector too near your fireplace or any appliance that produces flames (like your gas hob).
Don’t put the alarm behind furniture, in a cupboard or near external doors or ventilation equipment (such as extractor fans), as this will stop it from working correctly.
Private landlords are bound by law to fit carbon monoxide alarms where necessary, and failure to do so can lead to a fine of up to £5,000. You can find out more about the government guidelines for landlords here (opens in new window).
Carbon monoxide alarm maintenance
You should think of the maintenance of your carbon monoxide alarm in the same terms as your smoke alarm. This means that it’ll require regular checks to ensure that it’s in working order, these should include:
Test the ‘beep’ on the alarm at least once a week. You could set a reminder on your phone to remind you.
Ensure batteries are changed, if necessary, at least once a year, and that you test the function immediately after changing.
Pay attention to any ‘chirps’ from your alarm. These could be a warning of low batteries.
Pay close attention to the alarm’s battery life and when it will need replacing. Most alarms will last between five and seven years, with some lasting for as long as 10 years.
Always read and follow the manufacturer’s instructions when placing, testing, and servicing the alarm.
How many carbon monoxide detectors should I have?
This depends on the size of your home. We recommend you have a carbon monoxide gas detector on every level of your home. These should be in rooms with fuel‑burning appliances as well as outside bedrooms. This includes basements and the garages.
Which carbon monoxide alarm should I buy?
Carbon monoxide alarms work like smoke or fire alarms, going off as soon as they detect surplus carbon monoxide in the air. There are three kinds of carbon monoxide detectors, all of which work slightly differently:
Biomimetic sensor
The alarm is set off by a colour-changing gel, which changes when it absorbs a certain level of carbon monoxide and triggers the warning.
Metal oxide semiconductor
Carbon monoxide reduces the electrical resistance in an electronic circuit, which trips the alarm and sets it off.
Electrochemical sensor
Changes in electrical currents, caused by the presence of carbon monoxide, in a chemical solution are detected by submerged electrodes. This then triggers the alarm.