Makes we repair
If you smell gas: the steps, in order
The steps for a smell of gas come from Gas Safe Register, in its order. Gas has no smell of its own. A strong smell, like rotten eggs, is added so you notice a leak.
1. Open all the doors and windows
Stay out of rooms that smell of gas.
2. Turn off the gas at the meter, if it's safe
The lever is usually next to the meter. Don't turn it off if the meter is in a basement or cellar, or at an LPG tank.
3. Put out any naked flame
Don't smoke, or strike a match or a lighter.
4. Don't touch the switches
Don't turn any switch on or off, light switches included. Leave plugs, doorbells and phones inside alone too. A spark can light the gas.
5. Get everyone out
Warn anyone else inside, and make sure nobody goes back in.
6. Ring the gas emergency line from outside
Ring the National Gas Emergency Service on 0800 111 999. The call is free, and the line is open 24 hours a day.
Feeling unwell? See your GP or go to hospital straight away. Say you may have breathed in carbon monoxide.
Leave the gas off until a Gas Safe registered engineer has checked it. If the fault is your boiler, ring us.
Sources: Gas Safe Register, the HSE, National Gas and the boiler makers' user guides.
Who to ring, and when
Ring the National Gas Emergency Service first for a smell of gas, a suspected gas leak or a carbon monoxide emergency. The number is 0800 111 999. The call is free, day and night. Don't ring us first.
- Mains gas: the National Gas Emergency Service, on 0800 111 999. It covers England, Scotland and Wales.
- LPG from a tank or a meter: the number on the tank or the meter.
- Bottled gas: your supplier's number.
- Someone feels unwell: NHS 111, if you think you have symptoms of carbon monoxide poisoning.
- Someone is badly affected: 999, or A&E, if they find it hard to breathe, are suddenly confused or have passed out. The same goes if they feel weak, or have chest or muscle pain. Don't drive yourself to A&E. Ask someone to drive you, or ring 999 for an ambulance.
- A gas pipe has been hit: the gas emergency number too, day or night, even if no gas is escaping.
The emergency service may find a fault on the boiler. A Gas Safe registered engineer then needs to fix it and check it's safe. Ring us then, day or night: every engineer we send is Gas Safe registered.
Sources: Gas Safe Register, National Gas and the NHS.
Carbon monoxide: the signs from a boiler
Carbon monoxide is a poisonous gas you can't see, taste or smell. A gas appliance makes it when the gas doesn't burn properly. That happens when the appliance was badly fitted, badly repaired or poorly maintained, or its flue or vents are blocked.
The signs on the boiler and other gas appliances
A gas appliance may be making carbon monoxide if you see:
- a yellow or orange flame, where it should be crisp and blue
- dark, sooty marks on or around it
- a pilot light that keeps blowing out
- more condensation than usual inside the windows
Fuel-effect fires and flueless appliances are different: their flames are yellow or orange anyway.
Using a gas appliance you think is unsafe is against the law. Turn it off, and leave it off until a Gas Safe registered engineer has checked it. If it's the boiler, ring us for that check.
The symptoms
Carbon monoxide poisoning is easy to mistake for flu, food poisoning or tiredness. The six main symptoms are:
- headaches
- dizziness
- feeling sick
- breathlessness
- collapse
- loss of consciousness
These point to it too:
- symptoms that ease when you leave home
- others at home feeling the same at the same time
- pets behaving oddly
The symptoms may come and go. The NHS lists more, from feeling weak to chest and muscle pain: the NHS page on carbon monoxide poisoning.
If you suspect carbon monoxide, or the alarm sounds
Act straight away if you suspect carbon monoxide:
- Turn off the gas appliance, if it's safe to do so.
- Open the doors and windows.
- Leave, and go outside into fresh air.
- Ring the National Gas Emergency Service on 0800 111 999.
- Get medical advice as soon as you can. Ring NHS 111, or 999 for severe symptoms, such as trouble breathing, sudden confusion or passing out.
Don't go back inside. Wait for advice from the emergency services.
Carbon monoxide alarms, and the yearly check
Fit an audible carbon monoxide alarm in every room with a gas appliance, as its maker's instructions say.
- For a home, look for the Kitemark and BS EN 50291-1.
- Most alarms last 5 to 10 years. The maker's guidance says when to replace yours.
- Black spot detectors make no sound, so they aren't recommended.
An alarm is a second line of defence. The most important thing is a safety check of your gas appliances every year, by a Gas Safe registered engineer.
For a landlord in England, the yearly check is the law. So is a carbon monoxide alarm in each room with a gas boiler or gas fire. Landlord gas safety certificates, and what the check covers.
Sources: Gas Safe Register, the HSE, National Gas and the NHS.
Worth knowing
Fresh air alone won't treat carbon monoxide exposure. Get medical help, even if you feel better outside.
When the boiler smells of burning or fumes
Switch off a boiler that smells of fumes or burning. The boiler makers' user guides give these steps. For a smell of gas, use the steps at the top of this page.
- Fumes (flue gas): open all the doors and windows you can reach. Switch the boiler off, and contact a competent person.
- Burning or smoke from the boiler: turn the boiler off straight away, and switch off its electricity. Turn off the main gas valve. Open all the windows, then call for help, such as the gas emergency line.
The guides name no cause. Finding it is an engineer's job, so never open the boiler's case to look. Once the boiler is off and the room aired, ring us. We'll ask what you smelled and when, and a Gas Safe registered engineer comes to find the cause.
Sources: the user guides for Vaillant's ecoTEC plus and Ariston's E-Combi ONE, Clas ONE, Genus ONE+ and Alteas ONE+.
After a flood
Gas heating that has been in a flood needs checking before you use it again. Don't turn your gas on until your gas company or a qualified engineer has checked it's safe.
- During a flood: if you're told to leave, switch the gas off at the meter, if it's safe to do so. The lever is usually next to the meter. If you can't find it, ring the gas emergency line.
- Afterwards: contact your gas supplier. They can tell you how things stand in your area.
- Before the gas goes back on: a Gas Safe registered engineer makes sure no water has got into the pipework. Then they check the appliances are safe.
- The electrics: don't switch on a gas appliance's electricity until it has been checked. A boiler that wasn't under water may still have condensation inside it, which could cause a fault.
- Pumps and generators: follow their makers' instructions. Make sure there's enough fresh air, so their exhaust can't expose anyone to carbon monoxide.
A flooded boiler can sometimes be used again after a full safety check, depending on the damage. Once the water has gone, ring us. A Gas Safe registered engineer checks the boiler before it runs again, and we'll tell you when one can come.
Sources: GOV.UK and Gas Safe Register.
When the gas can go back on
The gas goes back on once a Gas Safe registered engineer has checked it. Don't turn it on again yourself before then.
After the emergency service's visit
Follow the emergency operative's advice first. If they can't confirm a gas appliance is safe, they may fit a "Danger Do Not Use" label to it. They may also leave a warning notice.
The appliance stays off until a Gas Safe registered engineer has checked it, and the homeowner arranges that check. For a boiler, ring us. We'll ask what the label and the notice say.
A "Danger Do Not Use" label
A "Danger Do Not Use" label on a boiler means a gas engineer or the emergency service found it unsafe. The gas industry has two unsafe categories: "immediately dangerous" and "at risk".
Using a gas appliance you know or think is dangerous is against the law. So the boiler stays off until it has been repaired.
Ring us to have it repaired. The rate is agreed on the call, before an engineer comes, and no work is done until you say yes. How our rates work.
Check the engineer's Gas Safe ID card
Every Gas Safe registered engineer carries a Gas Safe ID card. It may be a physical card, or a digital one on their phone, and you can ask to see it. Check that:
- the photo matches the person at your door
- the business is the one you contacted
- the card is in date
- the work it lists covers the job, such as natural gas and domestic boilers. It's on the back, or further down a digital card.
- a physical card has the Gas Safe hologram, and a digital card a QR code you can scan
You can also check an engineer or a business on the Gas Safe Register. If someone can't show a valid card, don't let them work on your gas. Every engineer we send is Gas Safe registered, so ask to see the card.
Do you cover my part of London?
Yes: we repair boilers all over Greater London, day and night, once the gas is safe. Pick your side of the river to see the areas.
North of the river
Every borough north of the Thames: Barnet and Enfield at the top, Hillingdon in the west, Havering in the east, and central London in between.
South of the river
Every borough south of the Thames: Richmond and Kingston in the west, Bexley in the east, and down through Croydon to Sutton and Bromley.
Questions about gas safety at home
Is the gas emergency line free to ring?
The gas emergency line, 0800 111 999, is free to ring, 24 hours a day, 7 days a week. British Sign Language users can reach it free through SignLive.
Should I turn the gas off at the meter?
Turning the gas off at the meter is one of the steps for a smell of gas, if it's safe to do so. The lever is usually next to the meter. Turn it off if you know where it is, unless the meter is in a basement or cellar, or at an LPG tank.
What does a carbon monoxide alarm sound like?
A carbon monoxide alarm that sounds non-stop may mean there is carbon monoxide in the air. Turn off the gas, open the windows and doors, leave, and ring 0800 111 999. A beep or a flashing light can also mean a low battery or a fault in the alarm. The alarm's own instructions say which.
Who checks the boiler afterwards?
A Gas Safe registered engineer checks the boiler before it is used again, once the emergency service has made the gas safe. We do that day or night. How we handle a boiler breakdown.
Don't know what has failed? You don't have to.Ring and say what you can see or hear. Finding the fault is our job.
Calls answered 24 hours a day
A real person answers and gives you the rate on the call. No work starts until you say yes, and repairs are guaranteed for 12 months: parts, labour and any return visit.
