What to Do If You Smell Gas in the House

Last updated: 3 August 2025

Step 1: Do Not Use Any Electrical Switches or Flames

Avoid turning on lights, appliances, or using matches and lighters. A single spark could ignite the gas and cause an explosion.

Step 2: Open Doors and Windows Immediately

Ventilate your home by opening as many windows and doors as possible. This helps to disperse the gas and reduce the risk of ignition.

Step 3: Turn Off the Gas Supply

Locate the gas emergency control valve (usually near your gas meter) and turn it off. Turn the handle 90 degrees so it's perpendicular to the pipe.

Step 4: Evacuate the Property

Leave the building and keep others out until it’s confirmed safe. Don’t use phones or doorbells inside the property — move a safe distance away first.

Step 5: Call the National Gas Emergency Number

Once outside and safe, call 0800 111 999 immediately. This is the National Gas Emergency Service in the UK and operates 24/7.

Step 6: Wait for an Engineer to Arrive

Do not re-enter your home until a Gas Safe engineer has inspected and confirmed it’s safe to return.

How to Prevent Future Gas Leaks

  • Have your boiler and gas appliances serviced annually by a Gas Safe registered engineer
  • Install a gas leak detector or alarm
  • Ensure your gas meter is accessible and you know how to turn it off
  • Check for corrosion or damage to gas appliances regularly

Frequently Asked Questions

Natural gas is odourless, but a chemical called mercaptan is added to give it a distinctive ‘rotten egg’ smell to help detect leaks.
No. Wait until you are safely outside before using your phone to avoid any risk of sparks.
No. Always wait for a qualified engineer to inspect and confirm that it’s safe before using any gas appliances again.