Smelling gas right now? Call National Gas Emergency: 0800 111 999 — free, 24/7
Gas emergency — London
Gas leak in London?
If you can smell gas, follow the immediate safety steps below and call National Gas Emergency first. Once the property is declared safe, our Gas Safe registered engineers repair the fault and reinstate your gas supply.
If you can smell gas — do this NOW:
Do NOT operate any electrical switches — no lights, no sockets, no doorbells
Open windows and doors — ventilate the property immediately
Turn off the gas meter if you know where it is (quarter-turn handle)
Leave the building — take everyone with you, leave the door open
Do NOT re-enter the building
Call National Gas Emergency: 0800 111 999 (free, 24/7)
Only contact a Gas Safe engineer AFTER National Gas Emergency has attended and declared the property safe.
After National Gas Emergency
What happens after a gas leak is made safe
Gas tightness test
Our Gas Safe engineer performs a full gas tightness test on all pipework to confirm the extent of any leaks and identify every fault location.
Fault identification
We identify the source — failed pipe joint, corroded pipework section, faulty appliance connection or cracked hob burner — before any repair work begins.
Repair and reinstatement
The fault is repaired, a further tightness test confirms the system is sound, and the gas supply is reinstated. A new gas safety record is issued.
Appliance safety check
If a gas appliance caused or contributed to the leak, we assess whether it is safe to return to service or must be replaced before the supply is reinstated.
London landlords
Gas leak in your rental property
As a London landlord, you are legally obliged to have gas pipework and appliances maintained in a safe condition. After a gas leak, you must engage a Gas Safe engineer to repair the fault before the supply can be reinstated. We attend landlord gas leak repairs as a priority across all London boroughs.
Common questions
Gas leak London: frequently asked
What should I do if I smell gas in my London home?
If you smell gas: (1) Do not operate any electrical switches — no lights, no plugs, no doorbells. (2) Open windows and doors immediately. (3) Turn off the gas supply at the meter if you know where it is. (4) Leave the building and keep others away. (5) Call National Gas Emergency on 0800 111 999 — this is free, 24/7, and the first call you must make. They will attend to make the property safe. After National Gas Emergency has attended and the property is declared safe, contact a Gas Safe engineer to repair the fault and restore the gas supply.
Who do I call first for a gas leak in London — National Gas Emergency or a plumber?
Always call National Gas Emergency (0800 111 999) first — not a plumber. National Gas are the statutory authority responsible for making gas escapes safe. They are free, attend 24/7, and will isolate the gas supply if necessary. After they have made the property safe, a Gas Safe registered engineer repairs the fault and reinstates the gas supply.
What does a Gas Safe engineer do after a gas leak in London?
After National Gas Emergency has attended and either capped or isolated the supply, a Gas Safe engineer: carries out a full gas tightness test on all pipework; identifies the source of the leak (failed joint, corroded pipe, faulty appliance); carries out the repair; and performs a further tightness test to confirm the system is safe before restoring the gas supply. If a gas appliance caused the leak, the engineer will assess whether it can be repaired or must be replaced.
As a landlord, what are my responsibilities after a gas leak in my London rental?
Landlords must have all gas pipework and appliances repaired by a Gas Safe registered engineer before the gas supply can be reinstated. They must also ensure tenants are not occupying a property without a gas supply beyond what is reasonable — alternative heating and hot water must be provided. After reinstatement, a new gas safety certificate (CP12) should be issued to confirm the system is safe.