Carbon monoxide (CO) is a highly poisonous gas that is responsible for killing around 50 people a year in the UK.

Caused by faulty and unsafe gas appliances, it can easily go undetected due to having no colour, scent or taste, so it is important to be aware of the main signs of CO poisoning, which are:

  • headaches
  • dizziness
  • breathlessness
  • nausea
  • collapse
  • falling unconscious.

It can also result in confusion, a fast and irregular heart rate and seizures.

These symptoms can often be mistaken for food poisoning, viral infections and even the flu, so also be mindful of signs within your home.

Common things to look out for would be:

  • a lazy yellow flame on your gas appliances
  • pilot lights that frequently blow out
  • if your windows are suffering from more condensation than normal
  • or if is there is unusual dark staining around or on your appliances.

If you suspect anyone in your house is experiencing effects of carbon monoxide poisoning, turn off all gas appliances immediately and open the windows to allow fresh air to circulate. Seek medical assistance straight away.

Carbon monoxide and pets

Animals face the same risks as humans when it comes to carbon monoxide and will display similar symptoms. Depending on the level of exposure these will include sleepiness, difficulty in breathing, uncoordinated movements, depression, deafness and seizures.

The first step is to ensure your pet is removed from any source of carbon moxoxide and then contact your vet. Treatment will depend on the severity of the toxicity and the diagnosis your vet.

Prevention is better than cure

The best way to keep your family safe is to minimise the risks of a carbon monoxide leak in your home in the first place. First and foremost ensure your boiler is serviced annually by a Gas Safe registered engineer. This enables early detection of any faults as well as helping to keep the system running efficiently.

If you don’t already have one, fit a carbon monoxide alarm. They are readily available from most well-known DIY stores and typically cost between £20-30.


Making sure your boiler is serviced annually is important to ensure that it continues to function as intended.

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Simple actions you can take to ensure that your gas appliances are working safely and correctly.

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We have taken the questions we're asked most frequently at our Call Centre and answered them here for quick and easy reference.

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