If you smell gas right now, stop reading this article, leave the property, and call 0800 111 999 from outside. That's the National Gas Emergency Service. They come out free and they come out fast.
If you're reading this for future reference, here's the full sequence — and the things NOT to do that most people get wrong.
The sequence (in order)
1. Get everyone out
Don't investigate. Don't check the cooker. Don't look for the leak. Open the front door, get everyone (including pets) outside, and don't go back in.
2. Open windows and doors as you leave
If you can do it on your way out without delaying — open windows and doors to ventilate. Don't go back in to do it.
3. Turn off the gas at the meter (if it's safe)
The emergency control valve is usually next to your gas meter. Turn the handle 90 degrees so it's perpendicular to the pipe. If your meter is inside and you can reach it without going through gas-affected rooms, do it. If not, leave it.
4. Call 0800 111 999 from outside
This is the National Gas Emergency Service line. It's free, 24 hours a day, 365 days a year. They'll dispatch an engineer to make the property safe — usually within an hour for confirmed leaks.
5. Wait outside until they say it's safe
Even if the smell goes away. Even if you think you've sorted it. Wait for the National Gas engineer to confirm the property is safe to re-enter.
What NOT to do
Don't touch any electrical switches
This includes: turning lights on, turning lights off, using a doorbell, using a thermostat, plugging anything in, unplugging anything. Electrical switches create tiny sparks. Tiny sparks ignite gas.
Don't use phones inside the property
Mobile phones, landlines, anything. Get outside first, then call. Same reason — sparks.
Don't light anything
Matches, lighters, candles, gas hobs (especially gas hobs — even if the gas hob isn't the source of the leak). And don't smoke anywhere near the property until it's confirmed safe.
Don't look for the leak yourself
Gas leak detection requires specialist equipment (electronic sniffers, soap-water tests, pressure tests). You can't do this safely with your nose. Leave it to the engineer.
Don't reset your boiler
If you suspect the leak is coming from your boiler and it's showing an error code, do not reset it. The error code might be precisely the safety lockout designed to prevent disaster. Wait for the engineer.
Carbon monoxide is different
Important distinction: natural gas has a smell (added by the supplier specifically so you can detect leaks). Carbon monoxide has no smell at all. CO is what comes out of an incomplete combustion process — usually a faulty flue or blocked vent.
Symptoms of CO poisoning: headaches, dizziness, nausea, drowsiness, confusion. If multiple people in your house feel ill at the same time and feel better outside, that's CO until proven otherwise.
Every UK home with a gas appliance should have a working CO alarm. Cost is around £20-£30. Most insurance policies require one. If you don't have one, get one this week.
After the emergency
Once the National Gas engineer has made it safe, they'll typically isolate the leak at the meter and tell you the appliance/pipe needs replacing or repairing. They don't do that work themselves — that's where a Gas Safe engineer (us, or someone like us) comes in.
Bring in a Gas Safe registered engineer (check the register at gassaferegister.co.uk if you're unsure) to repair the cause and reinstate your gas supply safely.
If you're reading this and have NEVER had a gas safety check, book one. £75 once a year for total peace of mind. We do them in 45 minutes.
We're Gas Safe registered engineers.
Book a service, get a quote, or call our emergency line. We work countrywide.