What to Do If You Smell Gas: Steps to Take Right Now

If you can smell gas in your home right now, stop reading and call the National Gas Emergency Service on 0800 111 999. The line is free, it is answered 24 hours a day, and the call handlers will talk you through everything below. Come back to this page once you are safely outside.

Still here? Then let us walk through what to do if you smell gas, step by step, so that if it ever happens you can act quickly without having to think. As a Gas Safe registered firm working in and around Bristol since 2004, we get asked about this a lot, and the honest answer is that the right actions are simple. The hard part is remembering them under pressure.

The number to save now: National Gas Emergency Service, 0800 111 999. Free, 24/7, for anywhere in the UK. Put it in your phone under "Gas Emergency" before you need it.

What to do if you smell gas: the six steps

Open doors and windows. Get fresh air moving through the property. Gas disperses quickly once it has somewhere to go.
Do not touch any electrical switches. That means lights, sockets, appliances, doorbells, anything. Leave every switch exactly as it is, whether on or off. Flicking a switch can create a spark.
Put out any naked flames. Candles, the hob, cigarettes. Extinguish them straight away.
Turn off the gas at the meter, if it is safe to reach. The emergency control valve is a lever on the pipe next to your meter. Turn it a quarter turn so the lever sits at 90 degrees to the pipe. If the meter is in a cellar or somewhere you would have to linger in the smell to reach, skip this step and move on.
Get everyone outside. People and pets. Leave the front door open behind you if you can.
Call 0800 111 999 from outside. Use your mobile in the street or a neighbour's phone. Do not make the call from inside the property.

Then wait outside for the emergency engineer. Do not go back in, even for keys, a coat or a charger. Nothing in the house is worth it.

What not to do when you smell gas

Most of the danger in a gas leak comes from ignition, so the list of things to avoid is really a list of things that make sparks or flames.

Do not turn lights on or off, in either direction.
Do not smoke, strike a match or use a lighter.
Do not use your phone, laptop or any electrical item inside the property.
Do not ring the doorbell to warn a neighbour. Knock instead.
Do not try to find the leak yourself, and never test for one with a flame.
Do not assume a faint smell is nothing. Weak smells can come from small leaks that get worse, or from a leak further away than you think.

How to find and use your emergency control valve

It is worth locating this valve on a calm day rather than during an emergency. In most homes the gas meter is in one of a few places: a white or brown box on an outside wall, a cupboard in the hallway or kitchen, under the stairs, or occasionally in a cellar or garage. Flats often have banks of meters in a communal cupboard, so check which one is yours and consider labelling it.

The emergency control valve is the lever on the pipe just before or after the meter. When the lever runs in line with the pipe, the gas is on. Turn it a quarter turn, so it sits across the pipe, and the gas is off. It should move by hand. If yours is stiff, painted over or seized, mention it next time an engineer visits, because a valve you cannot turn is no use in an emergency.

Rule of thumb: lever in line with the pipe means gas on. Lever across the pipe means gas off. A quarter turn is all it takes.

What happens after you call 0800 111 999

The call handler will ask where you are, what you can smell and whether anyone feels unwell. They will confirm the safety steps and send an emergency engineer to make the property safe. That usually means finding the source, isolating it and, where necessary, capping off the supply or a particular appliance.

One thing that surprises people: the emergency engineer's job is to make things safe, not to carry out repairs. If a pipe, boiler, hob or fire is at fault, it will be disconnected and labelled, and you will need a Gas Safe registered engineer to repair or replace it and restore your supply. Always check the engineer's Gas Safe ID card before any work starts, whoever you call.

If the smell is outside, or you are not sure it is gas

Call 0800 111 999 anyway. A gas smell in the street, in a shared hallway or drifting from a neighbour's property is still an emergency, and the network operator would far rather attend a false alarm than miss a real leak. Natural gas has no smell of its own; the distinctive rotten egg odour is added deliberately so leaks get noticed. Trust your nose.

While we are on the subject of things you cannot smell: carbon monoxide has no odour at all, which is why every home with a gas appliance should have a working carbon monoxide alarm. If your CO alarm sounds, treat it with the same urgency. Get out, get fresh air, and if anyone has a headache, feels dizzy or sick, call 999 and mention carbon monoxide.

A note for landlords and letting agents

If a tenant reports a gas smell, tell them to follow the steps above and call 0800 111 999 immediately. Do not ask them to wait for your usual contractor. Once the property has been made safe, you will need a Gas Safe registered engineer to investigate and repair, and it is sensible to have the affected appliance checked and the paperwork updated at the same time. A gas incident is also a good prompt to confirm the property's annual gas safety record is current across your portfolio, because that is the document you will be asked about afterwards.

After the emergency: getting your gas back on

Once the emergency engineer has made everything safe, the repair work, whether that is a faulty appliance, a damaged pipe or an old boiler that has reached the end of the road, needs a Gas Safe registered engineer. That is the point where a local firm comes in. We cover Bristol and the surrounding villages with our own engineers, no call centre, and we quote a fixed price after seeing the job. If your supply has been capped and you need it investigated, repaired and reinstated, call us on the number at the top of the page or use the callback form and we will get you booked in.

And if you take one thing from this article, make it this: save 0800 111 999 in your phone today. The five seconds it takes now is the head start you will want later.