If you smell gas or suspect a leak right now: turn off the emergency control valve at your gas meter, open all windows and doors, put out any naked flames, do not touch light switches or plug sockets, leave the property, and call the National Gas Emergency Service on 0800 111 999. Once you’re safe, call us on 020 7183 4810 and we’ll get a Gas Safe registered engineer to your South West London home to trace and fix it.
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Natural gas is odourised specifically so leaks can be noticed early, but pinpointing exactly where one is coming from needs proper equipment, not guesswork. Here’s what to look out for and what happens once we’re on site.
Signs of a possible gas leak
- A sulphur or rotten-egg smell, even faint or coming and going, anywhere in the property or near the meter.
- Your boiler repeatedly locking out on a supply or pressure fault code. Can point to a leak upstream starving the appliance of gas.
- A hissing sound near pipework or the meter. Pressurised gas escaping through a damaged joint or fitting.
- Yellow, floppy flames on a cooker or boiler burner instead of a crisp blue. A sign of incomplete combustion and a carbon monoxide risk.
- Headaches, nausea or dizziness that ease when you go outside. A classic sign of gas or carbon monoxide exposure indoors.
What to do right now if you smell gas
- Turn off the gas at the meter. Turn the emergency control valve handle 90 degrees until it’s perpendicular to the pipe.
- Open windows and doors to ventilate the property.
- Put out any naked flames — cigarettes, candles, open fires.
- Don’t touch electrical switches, sockets or doorbells. Even a small spark can ignite gas vapour.
- Leave the building with everyone in the property, including pets.
- Call the National Gas Emergency Service on 0800 111 999, then call us on 020 7183 4810 from outside.
Why finding a leak needs professional equipment, not a DIY check
| The DIY approach | What actually goes wrong |
|---|---|
| “I’ll sniff around and follow the smell” | Small or concealed leaks behind walls or under floors often can’t be located by smell alone, and searching with a lighter or match is extremely dangerous. |
| “I’ll lift the floorboards to check the pipe myself” | Proper leak detection uses electronic sniffers and acoustic equipment to pinpoint the exact joint, avoiding unnecessary damage to floors and walls. |
| “I’ll tighten the fitting myself and see if it stops” | Working on gas pipework is illegal for anyone who isn’t Gas Safe registered, and a fitting that looks tightened can still be leaking. |
| “No smell now, so it must be fine” | A slow leak can fluctuate, and carbon monoxide from incomplete combustion has no smell at all — only proper testing confirms it’s safe. |
What it costs to ignore it
A gas leak is one of the few household faults where waiting is genuinely dangerous, not just costly — beyond the immediate risk, an undetected leak can also mean gas is being wasted continuously, and a supplier-installed warning notice on your meter can leave your home without gas at all until it’s professionally resolved. Getting it traced and fixed properly, first time, is the only way to be certain it’s actually safe.
How Olia’s Plumbing & Heating handles it
- Test. We check your pipework for pressure loss to confirm whether there’s an active leak.
- Trace. Electronic and acoustic equipment locates the exact source, without unnecessary damage to floors or walls.
- Repair. The faulty joint, valve or pipework section fixed by a Gas Safe registered engineer.
- Retest and certify. A full retest confirms zero pressure loss before we restore your supply.
- Clear any warning notice. If Cadent or SGN have isolated your supply, we handle the fix and documentation to get it reinstated.
- Gas Safe registered, 24/7 emergency response
- Non-invasive detection — no unnecessary cutting into walls or floors
- Fixed price agreed before any repair work starts
- Covering South West London and the surrounding area
Get a gas leak traced and fixed safely.
24/7 emergency response across South West London.
Frequently Asked Questions
How do you find a leak without damaging my walls or floors?
We use electronic gas sniffers and acoustic detection equipment that can trace a leak through small gaps and service ducts, so we know exactly where to look before anything is opened up.
How long does a gas leak survey usually take?
A typical domestic survey takes around 45–90 minutes depending on the property and pipework. Call 020 7183 4810 for an estimate specific to your home.
What should I do while I wait for the engineer?
Keep the gas turned off at the meter, windows open, and stay outside in fresh air. Don’t use any electrical switches or appliances in the property.
Can there be a leak with no smell at all?
Yes — a small or intermittent leak can be hard to smell, and carbon monoxide from a combustion fault has no odour at all. If you have any doubt, call 020 7183 4810 and we’ll check properly.
What if my gas supply has been isolated with a warning notice?
We can trace and repair the fault and provide the documentation needed to get your supply reinstated by Cadent or SGN.
Book gas leak detection in South West London
Call 020 7183 4810 for 24/7 Gas Safe registered gas leak detection and repair.
Related services: Gas Leak Repair South West London · Gas Engineer South West London · Why Is Gas Safety Necessary · Landlord Gas Inspection South West London
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Peyman
CEO & Founder — Gas Safe Registered Engineer
Peyman is the founder of Olia's Plumbing & Heating, a London based team with over 15 years of hands on experience in boiler installation and repair, central heating, gas work and emergency plumbing. He personally oversees jobs across Central and West London and writes these guides to help homeowners understand their heating systems.
- Gas Safe Registered
- 15+ years experience
- Covering all of London
