Gas Leak London — Gas Safe Emergency Engineers

1. Stop — don't use any switches, sockets, lighters or phones inside the property. 2. Open windows and doors if possible. 3. Turn off the gas at the meter (the lever handle near the meter — turn it 90 degrees so it's perpendicular to the pipe). 4. Leave the property. 5. Call the National Gas Emergency line: 0800 111 999 (free, 24/7). 6. Once declared safe by the National Grid, call us for the follow-up repair.

Visit gassaferegister.co.uk and enter the engineer's ID card number, or call 0800 408 5500. All Gas Safe engineers carry a photo ID card showing their registration number, the gas appliance categories they're qualified to work on, and the card's expiry date. Ask to see the card before any work begins. Our engineers will show it voluntarily on arrival.

Yes. We carry out CP12 landlord gas safety inspections across all 33 London boroughs. The inspection covers all gas appliances (boiler, hob, gas fire, etc.), the flue system, pipework condition and ventilation requirements. The certificate is emailed on the day of inspection in most cases. We also offer multi-property packages for portfolio landlords.

Not always. A pilot light going out on an older boiler or gas fire can release a brief smell as unburnt gas escapes. Similarly, a gas hob igniter clicking near a trace of gas can smell alarming but isn't a leak. However, treat any persistent gas smell as a genuine leak until proven otherwise — the consequences of getting it wrong are too serious. If in doubt, call 0800 111 999.

Yes. When an unsafe boiler is capped by a Gas Safe engineer (as 'Immediately Dangerous'), it means it cannot be used until repaired or replaced. We can assess the boiler, advise whether repair or replacement is more cost-effective, and carry out whichever option you choose. We'll issue a 'safe to use' sign-off once work is complete.

After the National Gas Emergency line has made the property safe, we can typically reach you within 30–60 minutes across most London boroughs. We prioritise gas work above other call types. Out-of-hours gas emergencies are charged at our standard unsocial hours rate — we'll confirm the callout fee before arriving.

A tightness test (formally: soundness test under IGE/UP/1B:2018) checks that the gas pipework in a property holds pressure without loss — confirming there are no leaks. It's mandatory after any gas pipe repair, new gas appliance installation, or when restoring a gas supply that has been isolated. The test involves pressurising the pipe to 20 mbar with the gas off, then monitoring for any pressure drop over 1 minute. A drop of more than 0.5 mbar indicates a leak. We carry out tightness tests on every gas job as standard.

An 'Immediately Dangerous' notice is a formal classification issued by a Gas Safe engineer when an appliance or installation poses an immediate risk to life. Common reasons: no effective flue, CO detected during operation, gas leak within the appliance, or severe deterioration. An engineer must cap off (isolate) any appliance classified as Immediately Dangerous and advise the occupant not to use it. The notice is documented on the engineer's Gas Safe paperwork. Appliances with an ID notice cannot legally be used until repaired or replaced and re-inspected.

No. Using an unregistered person to carry out gas work is illegal under the Gas Safety (Installation and Use) Regulations 1998 — both for the person doing the work and, in some circumstances, for the property owner who commissioned it. Insurance policies for both buildings and contents are typically invalidated if a claim arises from work carried out by an unregistered person. The risk isn't just legal — it's life-safety. Verify any engineer at gassaferegister.co.uk before work starts.

An unexplained increase in gas consumption can indicate a leak — but most small gas leaks don't lose enough gas to show up clearly on a bill. More commonly, increased bills result from: boiler efficiency decline (scale, aging heat exchanger), increased heating demand from a cold snap, or a faulty programmer running the heating longer than intended. However, if your smart meter shows consistent gas consumption overnight when all appliances are confirmed off, call us for a tightness test — this is a reliable indicator of a slow leak.

A Gas Safe check (CP12) is a safety inspection — it tests that all gas appliances are safe to use, checks flue integrity and ventilation, and identifies any immediately dangerous or at-risk conditions. It takes 30–60 minutes per appliance. A boiler service is a maintenance activity — cleaning the heat exchanger, checking the burner, testing combustion efficiency, replacing worn seals and filters. A service takes 45–75 minutes and improves efficiency and reliability. Both are recommended annually, and we can carry them out in a single visit — ask when booking your CP12.

Yes. We carry out gas safety inspections and CP12 certificates for commercial properties — offices, restaurants, retail units, care homes, schools and HMOs — as well as residential. Commercial gas safety involves different appliance categories (LPG, commercial catering equipment) which require additional Gas Safe competencies. We'll confirm our engineers' specific competency categories for commercial work when you contact us.