Advice About Carbon Monoxide

Invisible, Silent ... and Deadly - The Facts

Gas is a very safe fuel. But, as with all fuels, it should be treated with respect. Around 40 people die each year from carbon monoxide poisoning caused by faulty or poorly installed gas appliances.

Carbon monoxide is a gas which is highly poisonous to people and animals, but it can be difficult to recognise because it has

  • No colour
  • No smell
  • No taste

If your appliances burn any fossil fuel (such as gas, coal or oil) carbon monoxide can be produced if they have not been installed properly or regularly maintained.

Gas safety is everyone’s concern. By looking after your appliances you can be sure that they are safe. If appliances are regularly maintained, they should also last longer and run more efficiently. Appliances which are not cared for can put you and your family at risk.

Choosing appliances

There is plenty of advice available to help you choose a safe new appliance. British Gas have trained staff in all their showrooms to help you select an appliance which best meets your needs. It may cost you less than you think to replace an old appliance with a modern safer one.

Only buy appliances which have been tested for safety. Take care if you are considering buying a second-hand appliance. Make sure that the dealer will give you a written guarantee and always ask for a copy of the installation and user instructions.

Installing your appliances

Appliances which have not been properly installed can be lethal. Gas fitting is a job for experts. Never be tempted to do it yourself — one mistake could cost lives.

Always use a Gas engineer who is registered on the GAS SAFE register. This is not only common sense — it is also the law. Please see their website under our useful links or give them a call on 0800 4085500.


All gas appliances need air to work safely. The air ‘breathed in’ by appliances in your home comes from many different places. You must take care not to block any ventilation. This is vital for any conventional/open flue appliances that use air from within the room they are situated for combustion purposes.

When an appliance is fitted, ask where the air supply will come from — and never block it. Always check that air-bricks or vents are unobstructed and that they are in accordance with the manufacturers requirements regarding size and minimum air requirements for the appliance it serves to burn correctly.

When insulating or doing any building work on your home, take care not to restrict ventilation.

Your chimney or flue

Gas appliances also need to ‘breathe out’ and get rid of waste gases. These usually escape outside through a chimney or flue.

If the flue or chimney is blocked, waste gases may build up in your room. This can be fatal.

Flues must be checked before an appliance is fitted and every year when it is serviced. If flues are not checked for integrity, there is a real threat that the products of combustion could come back into the room. Therefore, extra care must be taken with open/conventional flued appliances.

Maintaining your appliances

Just like your car, gas appliances should be regularly maintained so they run safely and reliably. Heating appliances such as fires, water heaters and boilers, should be serviced once a year, and other appliances every two years by a GAS SAFE Registered engineer.

Regular maintenance also makes your appliances last longer and run more efficiently. Unserviced appliances can cost you more to run.

Appliance check-up

By choosing your appliances with care, having them professionally installed and regularly maintained you can be sure they are safe. But there are some important points you should watch for which may show your appliance is not working properly.

If you notice any of these signs you should stop using the appliance immediately and seek help from National Grid or a GAS SAFE Registered Installer. You should always act on any advice that they give you. Unfortunately, some people ignore the danger signs below and the advice of qualified engineers with tragic consequences.

  • Staining, sooting or discoloration on the appliance or on the decoration around the appliance.
  • A yellow or orange flame instead of the normal blue.
  • A strange smell when the gas appliance is working.

If you smell gas, think you have a gas leak, or if you are worried that fumes containing carbon monoxide are escaping from a gas appliance, please call the free National Grid emergency line immediately on 0800 111 999(this is a 24 hour emergency line).


  • open all doors and windows to ventilate the property
  • do not turn on/off any electrical switches.
  • extinguish all naked flames, do not smoke, strike matches or do anything, which could cause ignition.
  • If there are any electrical security entry phones/locks, please open door manually.

For more advice on gas safety in the home, you can visit the British Gas Safety website. There are pages covering each room in the home and specific advice for parents, kids, students and landlords, as well as an interactive safety quiz and games. You could also visit the Health and Safety Executive gas safety pages from the useful link above or call free on 0800 300 363.

Last updated on: 23/04/2015 - 12:40