What should I do if I smell gas at home?

If you smell gas at home, act straight away. Open the doors and windows, turn the gas off at the meter if you can reach it safely, avoid anything that could make a spark, and call the National Gas Emergency Service free on 0800 111 999, day or night.

This post walks you through those first few minutes, what to do if your home runs on LPG instead of mains gas, how a gas smell differs from carbon monoxide, and what happens once the emergency engineer has made things safe. You can safely do a few things yourself, but finding and fixing a gas leak is always a job for a Gas Safe registered engineer.

The first steps if you smell gas

Natural gas has no smell of its own. Suppliers add a strong "rotten eggs" smell so you notice a leak quickly. If you catch that smell, do these things in order:

1. Open doors and windows to let fresh air in.

2. Turn off the gas at the emergency control valve, next to your meter, unless the meter is in a cellar or basement.

3. Don't touch light switches, plug sockets or doorbells, either on or off. A small spark can be enough to ignite gas.

4. Put out cigarettes and naked flames, and don't strike a match or lighter.

5. Call 0800 111 999. If the smell is strong, get everyone out and make the call from outside.

Don't look for the leak or try to fix anything yourself. Your job is to make the house safe and get help on the way.

Finding your gas emergency control valve

The emergency control valve is a short lever on the pipe going into your gas meter. In newer homes the meter usually sits in a box on an outside wall. In older terraces and semis it's often under the stairs, beneath the kitchen sink or in the garage.

When the lever runs along the pipe, the gas is on. Turn it a quarter turn so it sits across the pipe, at 90 degrees, and the gas is off. Find yours now, while nothing is wrong, so you aren't searching for it in a hurry.

If your meter is in a cellar or basement, don't go down to it. Gas can build up in low spaces, so leave the house and call from outside.

If your home uses LPG

LPG (liquefied petroleum gas, stored in a tank or bottles outside) isn't covered by the 0800 111 999 line. Call your LPG supplier's emergency number instead. You'll usually find it on the tank, on the cylinder label or on your bill. If there's a fire, call 999.

The first steps are much the same. Ventilate, avoid switches and flames, and turn off the valve on the tank or cylinder and the emergency control valve outside the house if you can reach them safely.

One difference matters. LPG is heavier than air, so it sinks and can collect at floor level and in drains or low spots, rather than drifting up and away. Open doors at ground level as well as windows, and keep well clear of cellars.

A gas smell or carbon monoxide

You can smell a gas leak. Carbon monoxide (CO, a poisonous gas made when a boiler, fire or cooker doesn't burn its fuel properly) has no smell, colour or taste at all. That's why it's so dangerous, and why an audible CO alarm near your gas appliances is so worthwhile.

Signs of CO include headaches, nausea, dizziness and breathlessness that ease when you go outside. If your alarm sounds or you have those symptoms, open the windows, turn off your gas appliances, get outside and call 0800 111 999. Then see a doctor, even if you start to feel better.

With heating and gas fires now back on for the winter, this is the time of year to check your CO alarm works.

What happens when the emergency engineer arrives

The emergency service sends an engineer to make your home safe. They'll find where the gas is escaping and stop it, which can mean turning off your supply or disconnecting a faulty appliance and labelling it not to be used.

Their job is to make things safe, not to repair your boiler, cooker or fire. If the problem is on your side of the meter, you'll need a Gas Safe registered engineer to find the cause, repair it and put your gas back into use. Don't turn the supply back on or use a disconnected appliance until that's been done.

Getting the fault found and fixed

When we're called out after a gas escape, the first job is usually a tightness test. That's a pressure test on your gas pipework that shows whether it's holding gas or letting some escape. From there we trace the leak to the pipe, joint or appliance at fault and repair or replace it.

Common culprits include a worn hose or connection behind a cooker, a loose joint on older pipework, or a gas fire or boiler that hasn't been looked after. Before we turn anything back on, we test it again and explain what we found in plain terms.

If the problem was a cooker, hob or gas fire, our cooker, hob and gas fire safety checks cover the connection, the flame and a carbon monoxide test. For boilers and the wider system, including LPG, see our domestic gas, oil and LPG heating service.

Lowering the risk of a gas leak

Most leaks come from worn appliances and connections, so regular checks matter.

• Have your boiler and other gas appliances checked once a year by a Gas Safe registered engineer.

• Fit an audible carbon monoxide alarm in each room with a gas appliance, and test it monthly.

• Know where your emergency control valve is, and make sure everyone at home can turn it off.

• Never let anyone who isn't Gas Safe registered work on your gas pipes or appliances.

If you rent your home out, your tenants need the same peace of mind. A yearly landlord gas safety certificate covers every gas appliance you provide.

If you ever smell gas, call 0800 111 999 first, every time. Once the emergency engineer has made your home safe, Heatfire can find the fault, carry out the repair and get your heating and hot water back on. Our Gas Safe registered engineers work across Willenhall and the surrounding area, and you can book a visit through our domestic gas, oil and LPG page.