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Practical carbon monoxide poisoning prevention


Have you had your heating and cooking appliances checked and serviced recently? Is your home well-ventilated? Find out how to protect your family against carbon monoxide poisoning.

Front of gas boiler showing buttons

What is carbon monoxide and what are the risks?

Energy UK's 'Carbon Monoxide - Be Alarmed!' campaign logo

The advice about carbon monoxide poisoning prevention which follows was supplied by Energy UK, as part of the Carbon Monoxide - Be Alarmed! campaign.

Visit the Carbon Monoxide - Be Alarmed! website for detailed information about staying safe and what to do in the event of an emergency, as well as case studies and downloadable factsheets.

Carbon monoxide is a poisonous gas. You can't see, taste or smell it.
It can be released when fuel (such as gas, oil, coal, coke, petrol or wood) doesn't burn properly because not enough air is available.

Incorrect installation or poor maintenance of appliances can cause this lack of air, as can a partial or full blockage of a chimney, flue or air vent.

In addition, a poorly ventilated room adds to the problem because the carbon monoxide concentration builds up.

Exposure to carbon monoxide can cause serious long-term damage to health, such as nervous system or brain damage, and can kill within minutes.


How to stay safe

As part of its Carbon Monoxide – Be Alarmed! campaign, Energy UK recommends the following measures:

Fit an audible carbon monoxide alarm

Fit a carbon monoxide alarm and check that it works, by pushing the 'test' button, regularly.

Carbon monoxide alarms can be bought from energy suppliers, DIY stores and some supermarkets for as little as £15.

If you're renting a property, your landlord may provide you with a carbon monoxide alarm.

Follow the manufacturer's instructions when deciding where best to position a detector or ask a Gas Safe-registered engineer for advice.

'Black spot' indicators are not recommended, as they are often not as accurate and will not alert or wake you if carbon monoxide is present.

Service your appliances

Renting privately?

If you live in rented accommodation with gas appliances your landlord must provide you with proof that a Gas Safe-registered engineer has safety-checked the appliances within the last 12 months. 

Have all gas appliances checked and serviced annually by a Gas Safe-registered engineer.

Use Which? Local to find recommended engineers in your area and check that they are still Gas Safe-registered at the Gas Safe Register website.

For solid fuel appliances, contact HETAS (0485 634 5626) and for oil appliances contact OFTEC (0845 658 5080).

Don’t block ventilation

It's dangerous to block ventilation to fires and stoves.

Make sure rooms and heaters are well ventilated and not blocked to stop draughts or to dry clothes.

If you have a fire or a stove you should empty and check the ash can daily, clean the flue ways at the back of the boiler weekly and clean the throat plates at the top of the room heater monthly.

Also, check outside vents to ensure that vegetation has not grown over the outlets and blocked air flow.

Birds' nests, falling stonework or rubble, spider webs and leaves can block chimneys and stop or reduce the flow of air. If you have fires or stoves which are in use, hire a chimney sweeper to check and clear the chimney at least once a year, or more often if used heavily.

Know the signs and symptoms of carbon monoxide poisoning

Carbon monoxide can't be seen and does not smell.

Danger signs to look out for around gas and other fuel-burning appliances include:

  • sooting or yellow/brown staining on or around the appliance
  • excessive condensation in the room where the appliance is installed
  • a lazy, yellow or orange-coloured gas flame rather than a sharp blue one
  • pilot lights that frequently blow out.


The six main symptoms of carbon monoxide poisoning are:

  1. headaches
  2. dizziness
  3. nausea
  4. breathlessness
  5. collapse
  6. loss of consciousness. 

In an emergency

If your alarm goes off or you spot other signs of carbon monoxide:

1. Open doors or windows for ventilation.

2. Call the relevant emergency advice line:

  • Gas Emergency Service (24 hours): 0800 111 999
  • Solid Fuel Advice Line: 0845 601 4406
  • Oil (OFTEC): 0845 658 5080.


3. Seek medical advice.

4. Have all appliances serviced and checked by a registered engineer. Don't use them until you're told it's safe to do so.

If you feel unwell
Go to your GP, call NHS Direct on 0845 4647 (NHS 24 in Scotland on 08454 242424) or, if it's urgent, call 999 for an ambulance.