Made safe first
The supply is isolated and the area ventilated before any testing starts. Nothing is turned back on until it has passed a tightness test.
Gas leak detection across London.
Gas Safe registered engineers who test your supply, trace the leak, repair it and check every appliance is safe before we leave. For homes and businesses in every London borough.
- Gas Safe registered
- Tightness tested before and after the repair
- Appliances and carbon monoxide checked while we are there
- Every London borough, 24 hours a day
Smell gas right now? Do this first.
Call the National Gas Emergency Service free on 0800 111 999, 24 hours a day. They will make the supply safe. Then call us to find and repair the leak.
Call 0800 111 999Open doors and windows
Let fresh air in to clear the gas.
Turn off the gas at the meter
If you can reach it safely, turn the lever on the emergency control valve so it sits across the pipe.
No switches or flames
Do not turn electrical switches on or off, use doorbells, smoke, or light matches or lighters.
Get outside
Leave the building and make the call from outside. Stay out until you are told it is safe.
Priced before we start
We agree the cost of the investigation with you up front, and price the repair before we do it. No surprises on the invoice.
Found, fixed and signed off
The engineer who finds the leak repairs it, retests the whole installation and checks your appliances, so you are not left waiting for someone else.
Signs of a gas leak or carbon monoxide
Natural gas has a smell added so leaks can be noticed. Carbon monoxide has no smell at all, which is why the other signs matter just as much.
A smell of rotten eggs
The added smell of gas, near the meter, pipework, cooker, boiler or fire. Even a faint smell is worth reporting.
Hissing near pipes
A hiss or whistle near gas pipework or an appliance when nothing should be running.
Lazy yellow flames
Gas flames should burn crisp and blue. Floppy yellow or orange flames can mean the appliance is not burning safely.
Soot and staining
Black or brown marks on or around a boiler, fire or flue, or a pilot light that keeps going out.
Headaches and dizziness
Headaches, nausea, tiredness or breathlessness that ease when you leave the house can be carbon monoxide.
Your CO alarm sounding
Never ignore it. Get everyone into fresh air, turn off gas appliances and call 0800 111 999.
Carbon monoxide: the risk you cannot smell
Carbon monoxide is produced when gas does not burn properly. It has no colour, taste or smell, so it is easy to miss until people start to feel ill.
Fit a carbon monoxide alarm
An audible alarm is the only reliable way to know carbon monoxide is there. We recommend one in every room with a fuel-burning appliance. Test it regularly and replace it by the date shown on the alarm.
In rented homes in England, landlords must fit a carbon monoxide alarm in any room with a fixed combustion appliance, apart from gas cookers.
Know what a healthy flame looks like
A gas flame that is burning safely is crisp and blue. Yellow or orange flames, soot marks or a pilot light that keeps going out mean the appliance is not burning properly and could be producing carbon monoxide.
Stop using it and have it checked by a Gas Safe registered engineer.
How we find a gas leak
Gas work is only ever carried out by Gas Safe registered engineers. We prove whether there is a leak with a pressure test, trace it to the exact joint or fitting, then prove the repair the same way.
Tightness testing
A gauge is connected at the meter and the installation is checked for any drop in pressure over a set time. It tells us for certain whether gas is escaping.
- Proves whether there is a leak
- Whole installation tested
- Repeated after the repair
Electronic gas detection
A sensitive gas detector is run along the pipework, joints, valves and appliance connections to trace where the gas is coming from.
- Pipework and joints
- Valves and meters
- Appliance connections
Leak detection fluid
A specialist fluid is applied to suspect joints and fittings. Bubbles form at the exact point of the leak, confirming it before any repair is made.
- Pinpoints the exact fitting
- Confirms before we repair
- Checks the repair afterwards
Repair, retest and purge
The faulty joint or section is repaired or replaced, the installation is tightness tested again, then purged of air before any appliance is relit.
- Repaired to current standards
- Retested before gas goes on
- Air purged from the pipework
Combustion checks
A flue gas analyser measures how well each appliance is burning, alongside checks on burner pressures and the flame picture.
- Boilers, cookers and fires
- Burner pressures
- Carbon monoxide levels
Flue and ventilation checks
We check flues are sealed, supported and clear, and that rooms with gas appliances have the ventilation they need to burn safely.
- Flue condition and seals
- Terminal position
- Room ventilation
What happens on a gas leak visit
Make safe
The supply is isolated at the meter and the property ventilated. If the emergency service has already capped the supply, we start from there.
Test and trace
A tightness test confirms the leak, then electronic detection and leak fluid pinpoint the exact joint, fitting or appliance.
Repair and retest
The faulty section is repaired or replaced and the whole installation tightness tested again before the gas goes back on.
Check and explain
Appliances are relit and checked for safe operation, and we explain in writing what we found, what we fixed and anything else that needs attention.
Gas work we carry out
- Suspected gas leak investigations
- Gas tightness testing
- Repairs to leaking gas pipework and fittings
- Reconnection after the supply has been capped
- Boiler, cooker, hob and gas fire safety checks
- Carbon monoxide investigations
- Flue and ventilation checks
- Homes, landlords and commercial premises
Testing, tracing and repairs
Tightness tests, gas detection and appliance checks, carried out by Gas Safe registered engineers.
Why use EcoBuild
24 hours a day
Nights, weekends and bank holidays. One number for every London borough, answered by the people who do the work.
Gas Safe registered
You can check us on the Gas Safe Register, and our engineers carry their Gas Safe ID card.
Heating engineers too
If the leak is on a boiler or heating appliance, the same team can repair or replace it without a second callout.
Straight answers
If an appliance is unsafe we will tell you plainly, explain why and give you the options and prices to put it right.
Common questions
I can smell gas. Should I call you or the emergency line?
Call the National Gas Emergency Service on 0800 111 999 first. It is free and open 24 hours a day, and they will make the supply safe. Repairs to pipework and appliances on your side of the meter then need a Gas Safe registered engineer, which is where we come in.
How much does gas leak detection cost?
It depends on the size of the installation and how hard the leak is to trace, so we agree the price with you before we start. If we find the leak we can usually repair it on the same visit.
Can I use my gas while I wait for an engineer?
No. If the supply has been turned off or an appliance has been labelled as unsafe, do not turn it back on or use it until it has been repaired and tested by a Gas Safe registered engineer.
How do I know you are Gas Safe registered?
You can check us on the Gas Safe Register website. Every Gas Safe engineer carries an ID card, and you are entitled to ask to see it.
Do you do gas leak detection for businesses?
Yes. We carry out gas leak investigations and repairs in shops, offices, restaurants and other commercial premises across London, as well as in homes.
Related services
One number, every London borough, 24 hours a day. Call 079 1616 8585 or message us on WhatsApp.
Smell gas?
Call the National Gas Emergency Service on 0800 111 999 first. Once the supply is safe, call us to find and repair the leak.
Call 0800 111 999
