Boiler Smells of Gas? Do This First
A gas smell from your boiler should always be treated as an emergency. Turn the gas off at the meter, open windows, avoid switches and naked flames, and call the National Gas Emergency Service on 0800 111 999. Then call Gas First on 07927 882561 for Gas Safe emergency help across East London.
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Upfront cost — no obligation If your boiler smells of gas, treat it as urgent. Natural gas has a distinctive ‘rotten egg’ odour added to it so leaks can be detected, and a genuine gas smell near a boiler can point to a loose connection, a failed seal or a combustion problem — any of which can risk fire, explosion or carbon monoxide. This page explains what to do straight away, what usually causes it, and how our Gas Safe registered engineers (587401) find and fix the source safely across East London.
What to do right now if your boiler smells of gas
Act quickly and safely. Open doors and windows to ventilate the room. Turn the gas off at the meter control valve if you can reach it safely. Do not turn any electrical switches on or off, do not use naked flames, and do not use your mobile phone inside the property — any of these can create a spark. Leave the property if the smell is strong, and call the National Gas Emergency Service on 0800 111 999 (free, 24 hours). Once the supply is made safe, call Gas First on 07927 882561 and a Gas Safe engineer will locate and repair the fault.
Act quickly and safely. Open doors and windows to ventilate the room.
Why does a boiler smell of gas?
Common causes include a loose or worn gas connection at the boiler, a failed seal or gasket, a faulty gas valve, or incomplete combustion caused by a blocked flue or dirty burner. A pilot light that has gone out on an older boiler can also let a small amount of unburnt gas escape. Because it is impossible to tell the cause — or how serious it is — without proper testing, a gas smell should never be ignored or ‘aired out’ and left.
Common causes include a loose or worn gas connection at the boiler, a failed seal or gasket, a faulty gas valve, or incomplete combustion caused by a…
Is it a gas smell, or the 'hot' smell from a new or unused boiler?
A brand-new boiler, or one fired up for the first time after summer, can give off a faint burning or dusty smell for a short while as dust burns off the heat exchanger — this usually clears within a few minutes. That is different from the sharp, sulphur/rotten-egg smell of gas. If you are ever unsure, treat it as gas: ventilate, turn off the supply, and call 0800 111 999. It is always better to be cautious with gas.
A brand-new boiler, or one fired up for the first time after summer, can give off a faint burning or dusty smell for a short while as dust burns off the…
How Gas First finds and fixes it
Our Gas Safe registered engineers carry out a tightness test to confirm whether gas is escaping, then trace the leak to its exact source using detection equipment, inspect the gas valve, connections, seals and flue, and repair the fault. We re-test to confirm the system is safe before we leave, and issue advice or a certificate where appropriate. We work from local bases in Bow (E3) and Dagenham (RM10), so we can attend emergencies across East London quickly.
Our Gas Safe registered engineers carry out a tightness test to confirm whether gas is escaping, then trace the leak to its exact source using detection…
Frequently Asked Questions
Is a boiler that smells of gas dangerous?
Yes. A genuine gas smell risks fire, explosion and carbon monoxide exposure, so it must be treated as an emergency and handled only by a Gas Safe registered engineer.
Should I turn my boiler off if it smells of gas?
Turn the gas off at the meter control valve if you can do so safely, ventilate the room, avoid switches and flames, and call 0800 111 999. Do not keep using the boiler.
Can I use my phone to call you if I smell gas?
Not from inside the property — a phone can create a spark. Leave the building first, then call from outside or a safe distance away.
My new boiler smells a bit when it first fires up — is that a gas leak?
A faint burning/dusty smell from a new or long-unused boiler is usually dust burning off and clears quickly. A sharp rotten-egg smell is different — if unsure, treat it as gas and call 0800 111 999.
How fast can you attend a gas smell in East London?
With bases in Bow and Dagenham we treat gas smells as priority emergencies and aim to attend the same day across East London. Make the property safe and call 0800 111 999 first, then call us on 07927 882561.
What Our Customers Say
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