Gas leak or smell of gas in north and east London

These steps come from Cadent, which runs the gas network for north London:

1. Open doors and windows.
2. Do not turn light switches or electrical things on or off. Do not light a flame. Do not use anything that could spark.
3. Turn off the gas at the mains tap, called the emergency control valve, near the meter. The handle turns a quarter turn.
4. If the leak is in a cellar or basement, do not go in. Leave the building.
5. Once you are safe, call 0800 111 999.
6. Wait for the emergency engineer to give the all clear before going back in.

If you feel dizzy, sick or have a headache, get fresh air. If symptoms are severe, call 999.

The emergency service engineer makes the situation safe. They do not usually repair your appliances. Cadent says they may advise that extra work is needed on ovens, boilers or fires, and that you need a Gas Safe registered engineer for that. So the order is always: emergency service first, then the repair.

If the smell is outside, in the street or from a neighbour's property, still call 0800 111 999 and avoid naked flames nearby.

Many of the Victorian houses in Hackney, Islington and Stoke Newington were split into flats, and the gas meters went wherever there was space. Under the stairs, in a front cellar or vault, in a cupboard in the shared hall, or all together in a basement. Find your emergency control valve now, while nothing is wrong, and make sure everyone in the flat knows which one is yours. Our guide to finding it explains what to look for.

If the emergency engineer finds a leak they cannot clear, they may cap the supply or turn off an appliance and leave a warning notice and a label saying it must not be used. Do not turn it back on. Keep the notice, take a photo of it, and send that to us when you book, because it says what was found. If you rent, tell your landlord or agent straight away, since gas pipework and the appliances they provide are their responsibility to repair. Once the leak is repaired, the engineer tests the whole installation for tightness, purges air from the pipes and relights each appliance so you know everything is working safely.

A smell of gas and a carbon monoxide alarm are two separate warnings. Carbon monoxide comes from appliances burning badly and has no smell. If your CO alarm sounds, open windows, turn off the appliances if you can, get out into fresh air, and call 0800 111 999. If anyone feels very unwell, call 999. See our page on carbon monoxide alarms.