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Home & garden.

Updated: 9 Jun 2021

Five ways to avoid a carbon monoxide build-up

Follow our five point plan to keep your home free from poisonous levels of carbon monoxide.
Matt Stevens

There are steps that you can take to identify whether you might have a problem with carbon monoxide in your home.

Keep your family safe and your home carbon monoxide free by following our five-point plan below.

Make sure you've got the the right equipment for the job: discover the best carbon monoxide detectors that have passed our stringent safety tests.

1. Check for tell-tale signs of carbon monoxide

Carbon monoxide (CO) may be invisible and odour-free, but it does sometimes leave clues that can alert you to a CO build up. Here are four warning signs to look out for:

  • a lazy yellow or orange flame on your hob, rather than a clear blue flame
  • dark staining around your fuel-burning appliances
  • your boiler's pilot light frequently blowing out
  • increased condensation on windows in the room with the fuel burning appliance.

2. Install a reliable carbon monoxide detector

A carbon monoxide detector will alert you to a build-up of carbon monoxide in your home. The best models are sensitive enough to detect small and large doses of the gas, are reliable enough to go off when you need them to, have safe installation instructions and will be loud enough for you to hear them.

You can find out which models are proven to tick all these boxes using our carbon monoxide detector reviews.

3. Ensure all gas appliances are professionally installed and maintained

Protecting your home from carbon monoxide poisoning begins the moment you get your new appliance - such as a gas cooker, oven, boiler or stove - home. 

Find a reliable professional gas installer who has a Gas Safe Register accreditation (formerly Corgi) to install you appliance, and ensure repairs and services are also carried out by an accredited professional. Only Gas Safe Register-accredited engineers and repairers are legally allowed to work with gas appliances, and all fuel-burning appliances should be serviced annually.

Find a local, recommended engineer in your area on Which? Trusted Traders

4. Keep flues, vents and chimneys clear

Keep your chimneys, vents and flues clear. An obstruction such as a bird’s nest could block a chimney and lead to a build-up of carbon monoxide. So if you have a chimney or flue, have it swept once a year.

5. Replace old carbon monoxide detectors

Carbon monoxide detectors don’t last forever. Most will last between five and seven years, with some lasting for 10. At the end of this time, the sensitivity of the sensor inside will start to fail and the alarm will need to be replaced. Most alarms will begin emitting a sound to warn you that it's almost time for a replacement.