I Can Smell Gas — What Do I Do Right Now?

Natural gas is odourless in its raw form, but suppliers add a distinctive sulphurous smell, often compared to rotten eggs, specifically so leaks can be detected. Any hint of this smell should be treated seriously.

Yes — 0800 111 999 is a free number available 24 hours a day, every day of the year, for reporting suspected gas leaks or smelling gas.

Yes — always err on the side of caution and call. It’s far better to report a false alarm than to ignore a genuine leak.

Follow the general emergency steps first (ventilate, don’t use switches, leave and call from outside) rather than approaching the boiler directly, since the source of the smell may not be confirmed until professionals attend.

A gas leak has a detectable smell; carbon monoxide has no smell, no colour and no taste, which is why CO alarms are essential and why the warning signs are physical symptoms rather than anything you can smell. See our separate Carbon Monoxide guide.

Yes — once the National Gas Emergency Service or a Gas Safe engineer has made the situation safe and identified the cause, reconnection and any repair needs to be carried out by a qualified professional before normal use resumes.

Yes — if it’s safe and quick to do so on your way out, letting immediate neighbours know is sensible, particularly in a shared building where gas supply or pipework may be connected. Prioritise your own safe evacuation first, and mention it to the National Gas Emergency Service when you call, since they can advise on wider building safety.

Treat an intermittent smell with the same seriousness as a constant one. A leak that only becomes noticeable occasionally — perhaps under certain conditions like wind direction or appliance use — is still a genuine leak and should be reported to 0800 111 999 rather than waiting to see if it becomes more persistent.