Smell Gas Near Your Cooker or Hob? What To Do Right Now
The rest of this page explains each step, how to tell a genuine leak from a normal ignition smell, and what the real UK safety data says. Read it before you need it, not during.
What to do right now if you smell gas
- Open doors and windows to ventilate the room and let the gas disperse.
- Turn off the gas at the emergency control valve, usually next to the meter, unless the meter is in a cellar or basement. Turning it clockwise a quarter turn shuts it off.
- Do not smoke, strike a match, or use any naked flame.
- Do not touch electrical switches, on or off, including light switches and doorbells. A spark from a switch can ignite escaped gas.
- Get everyone out of the property and keep them out until it’s confirmed safe.
- Call the National Gas Emergency line on 0800 111 999 once you’re outside. It’s free and staffed 24 hours a day.
This exact sequence comes from Gas Safe Register’s official guidance on gas emergencies, the UK’s statutory register for gas engineers, and from National Gas’s own emergency contact guidance. If you’re calling from a mobile, step outside first: the advice against using electrical switches applies to phones too, in the room where the leak is suspected.
Is it normal to smell a little gas when my cooker or hob ignites?
A brief smell, lasting only a few seconds as the burner catches, is generally accepted as normal for gas cookers and hobs. It happens because a small amount of gas is released before the igniter sparks, and that residual gas burns off almost immediately once the flame catches properly.
What isn’t normal is a smell that lingers, one that’s strong or distinctly sulphurous (often described as a rotten egg smell), or one that returns every time you use the appliance without fading. If the smell doesn’t clear within a minute of the burner lighting, or if you notice a hissing sound alongside it, treat it as a possible leak rather than assuming it’s routine.
If your igniter is slow to spark, more gas can build up before it catches, which makes the smell more noticeable than it should be. That’s a sign the ignition system needs looking at by an engineer, even if it isn’t a safety emergency in itself.
Is my gas cooker or hob leaking carbon monoxide?
These are two different risks, and it’s worth being clear on the difference. Natural gas has a chemical called mercaptan added to it deliberately, specifically so it has a detectable smell and you notice a leak. Carbon monoxide, by contrast, is completely odourless: you cannot smell it, taste it, or see it, which is exactly why it’s dangerous and why “I can’t smell anything unusual” doesn’t rule it out.
Carbon monoxide is produced when gas doesn’t burn completely, which can happen with a poorly maintained or badly ventilated appliance. A gas cooker or hob in good working order and properly ventilated shouldn’t produce meaningful CO, but a fault in the appliance or a blocked flue on a connected system can change that. A working carbon monoxide alarm in the kitchen is the only reliable way to know CO levels are safe, since your senses genuinely cannot detect it.
What are the symptoms of carbon monoxide poisoning?
According to the NHS, the most common symptoms are headache, dizziness, nausea, tiredness and confusion, often described as flu-like. Because they overlap so closely with a cold, flu, or general tiredness, CO poisoning is easy to miss, especially at low levels over time.
Two signs are worth paying particular attention to: symptoms that ease or disappear when you leave the house, and other people or pets in the same room feeling unwell at the same time. Both point toward the building itself rather than an unrelated illness. The NHS advises calling 111 if you suspect CO poisoning, and 999 or going to A&E immediately for severe symptoms such as difficulty breathing, sudden confusion, or loss of consciousness.
How dangerous is this, really?
Different UK bodies publish different figures here, because they measure different things. Rather than picking the most alarming number, here’s what each actually covers.
| Source | Estimate | What it measures |
|---|---|---|
| HSE | ~7 deaths per year | CO poisoning specifically from gas appliances and flues that are poorly installed, maintained, or ventilated |
| CO-Gas Safety | ~8.5 deaths per year (last decade average); ~26.1 per year (longer-term average) | Unintentional CO poisoning from all fuel types, not gas appliances alone |
CO-Gas Safety, an independent UK charity that has tracked this data for decades, is explicit that these figures are likely an undercount: CO isn’t routinely tested for at death, even when the cause is unexplained, so cases can go unrecorded. Whichever figure you use, the direction is the same. This is a genuinely low-frequency but genuinely serious risk, which is exactly the profile that deserves a working alarm and a five-minute safety routine rather than either panic or complacency.
Who do I call: 999, or the gas emergency number?
For the gas leak or suspected CO emergency itself, call the National Gas Emergency line on 0800 111 999, not 999. It’s a dedicated, free, 24-hour line specifically for gas escapes and suspected carbon monoxide emissions, and the engineers who respond are equipped to make the property safe.
Call 999, or 111 for advice, if someone is actually showing symptoms of carbon monoxide poisoning, especially anything severe like difficulty breathing, confusion, or loss of consciousness. The two aren’t mutually exclusive: if there’s a leak and someone is unwell, both calls may be needed.
How do I check my engineer is Gas Safe registered?
Any gas work on a cooker or hob, whether it’s a repair, a service, or a new installation, must legally be carried out by a Gas Safe registered engineer. We’re not Gas Safe registered ourselves — we handle the electrical side of appliance faults (ignition, controls, elements), and for anything that needs Gas Safe certified work, we’ll put you in touch with a registered engineer we work with.
Beyond taking a company’s word for it, Gas Safe Register runs a free public checking tool where you can search any engineer or business by name, licence number, or postcode and confirm their registration is current, and see exactly which types of gas work they’re qualified for. It takes under a minute and it’s worth doing before anyone touches a gas appliance in your home, not just when something’s gone wrong.
If the fault turns out to be with the appliance itself rather than a leak, our oven and cooker repair service and hob repair service handle the electrical side directly, and we’ll refer you to a Gas Safe registered engineer for anything that needs one.
Frequently asked questions
Appliance fault sorted safely, every time.
If it turns out to be the appliance rather than an emergency, call and speak to us directly. We’ll diagnose the fault over the phone where we can, handle the electrical side ourselves, and point you to a Gas Safe registered engineer for anything that needs one.
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