Knowing what to do in an emergency could save lives. Whether you’re at home or out and about, there are some essential things to do if you suspect a gas leak.

If you think you have a gas leak or can smell gas, leave the house and phone the National Gas Emergencies number immediately on 0800 111 999.

If you’re at home, and you can do it safely, turn off your gas supply. The gas mains tap should be beside your gas meter. Move the handle a quarter turn until it's at 90 degrees from the pipe to shut off the gas supply.

Detecting a gas leak – what are the symptoms?

The most obvious sign of a leak is the smell of gas. You could also be feeling ill as a result of a gas leak.

The symptoms include:

  • Feeling lightheaded
  • Dizziness
  • Nausea
  • Headaches

If you’re suffering from these symptoms and suspect a leak, you should go outside immediately. If you feel better in fresh air, you could be suffering from the effects of a gas leak.

These are also some of the symptoms of carbon monoxide poisoning.

What to do if you smell gas


  • Open doors and windows to allow fresh air in.
  • Turn off the gas at the mains tap, which is usually near the meter. Move the handle a quarter turn until it's at 90 degrees from the pipe to shut off the gas supply.
  • Leave the property.
  • Phone the National Gas Emergencies number on 0800 111 999. Only use a mobile phone from outside the property. The number is free and available 24 hours a day.
  • Follow the advice given by the emergency adviser.
  • Wait outside for a gas engineer to arrive.
  • If you are feeling unwell, visit your GP or hospital immediately. Tell them you may have been exposed to a gas leak or carbon monoxide poisoning.


  • Smoke, light a match or use any other naked flame.
  • Turn any electrical switches on or off.
  • Use doorbells, mobile phones or any other electrical switches which could cause a spark.

Gas leak prevention

There are lots of things you can do to be gas safe and help prevent a gas leak.

You should always get appliances installed by a Gas Safe registered engineer. A gas detector alarm could help keep you and your family safe by alerting you to leaks.

You should also have a Carbon Monoxide (CO) detector installed in your home. Carbon monoxide is colourless, odourless and can be fatal.

You can find out more about how to prevent leaks with our guide to gas safety.

You should also have an gas safety check or service carried out on your appliances.

If you live in rented accommodation, make sure your landlord provides you with a gas safety certificate.