HWritten by a qualified plumbing and heating engineer·

I can smell gas — what do I do right now?

Free DIY guide — no sign-up required. written by a qualified plumbing and heating engineer.
DIY Friendly💷 £0£0Immediate
Safety First
⚠️ A gas smell is an emergency. Do not use any electrical switches, light switches, or flames.

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Most likely cause & what to check

1

Do NOT: use any light switches or electrical equipment, light a match or candle, use your mobile phone inside the property, or use the doorbell.

2

DO: get everyone out of the building immediately including pets. Leave doors open as you go to ventilate.

3

Once outside: call the National Gas Emergency Service on 0800 111 999 (free, 24/7). Tell them your address and that you can smell gas.

4

Turn off the gas at the emergency control valve (ECV) if you know where it is and can do so safely — it is usually next to the meter. Turn the handle 90° so it is perpendicular to the pipe (off position).

5

Do not return inside the building until the emergency engineer has attended, found the source, made the supply safe, and confirmed the property is safe to re-enter.

6

Common causes of gas smells: faulty appliance valve left partially open, failed flue, cracked boiler heat exchanger, underground pipe corrosion, or a neighbour's gas leak travelling through foundations.

7

After the emergency engineer visits, you will need a Gas Safe registered engineer to repair the fault before the gas supply is restored.

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