If you smell gas
Checked against its sources: Updated
If you smell gas, open doors and windows, avoid switches and flames, turn off at the meter control valve if you know where it is and can reach it safely, leave, and call 0800 111 999 from outside.12 Northern Ireland and the Isle of Man have their own numbers.
- Covers
- Great Britain, Northern Ireland and the Isle of Man; numbers differ, as shown
- You
- Everything in the first panel. Don't look for the leak or touch any gas fitting beyond the meter control valve.
- A professional
- Finding and fixing the leak, and saying when gas can be used again: the emergency service's engineer, then a Gas Safe registered engineer.
1 What to do
Open doors and windows. Don't touch electrical switches, don't smoke and don't use naked flames. Turn off at the meter control valve if you know where it is and can reach it safely, and don't go into a cellar to do it. Leave the building, keep others out, and from outside call the National Gas Emergency Service on 0800 111 999 (Great Britain). In Northern Ireland call 0800 002 001. On the Isle of Man call 0808 1624 444. Call without delay once you are out.
Wait for the engineer's all-clear before going back in, as the Isle of Man guidance says, and don't use a gas appliance you suspect is unsafe.4 HSE puts it plainly: "It is illegal for anyone to use a gas appliance if they suspect it is unsafe."1 A boiler fault code or reset has no part in this.
2 Why official lists don't match
Official lists vary in order, and none is a single national sequence. The steps above are this reference's one wording, drawn from them.
| Source | Order it gives |
|---|---|
| HSE, Great Britain1 | Calling the emergency number comes first. Then "Open all the doors and windows", then "Shut off the gas supply at the meter control valve (if you know where it is)" |
| SGN, gas network, Great Britain2 | Windows and doors, then meter and appliances, then the call. Don't smoke, use flames or touch switches. Don't go into a cellar, even if the meter is there |
| nidirect, Northern Ireland3 | Meter, then windows and doors, no electrical equipment on or off, then the call |
| gov.im, Isle of Man4 | Call as soon as it is safe, doors and windows where possible, emergency control valve if possible, no switches, flames or smoking, wait for the all-clear |
SGN gives the reason for the switch rule: switching could ignite a leak.2 HSE's own qualifier for the valve is "(if you know where it is)".1 Reaching it safely, and staying out of cellars, are added cautions here, the second from SGN.2
3 Boiler manuals say different things
Boiler user manuals word this section in their own ways. Some order the steps differently, and one Viessmann manual gives no UK emergency number.5 Where a manual differs, use the wording on this page. On LPG, Worcester's manual says to call the number on the tank.6
4 The legal duty
In England, Wales and Scotland, a responsible person who knows or suspects gas is escaping must immediately take all reasonable steps to have the supply shut off. If gas keeps escaping or a smell persists afterwards, they must immediately notify the supplier, and the supply must stay off until steps are taken to prevent a recurrence.7
Repairs afterwards are work for a Gas Safe registered engineer. If anyone has symptoms such as headache or dizziness, or a CO alarm sounds, go to carbon monoxide.
Sources
- Suspected gas leak list in HSE's domestic gas FAQ, page updated March 2023 read 3 November 2026. HSE's page uses an older company name for the same emergency number.
- Smell gas, SGN gas network read 3 November 2026.
- Energy, power supply and utilities, nidirect read 3 November 2026.
- gov.im gas safety advice page read 3 November 2026.
- Gas section of the Vitodens 050-W instructions, Viessmann, 05/2026, p3 read 3 November 2026.
- Worcester Bosch LPG line, Greenstar 4000 instructions, 2020/09 issue, p4 read 3 November 2026.
- Regulation 37: escape of gas, 1998 gas safety regulations read 3 November 2026.