Smell Gas? Urgent UK Safety Steps to Take Now

By The FixDelivered Team · Updated 2026-09-06 · 4 min read

Detecting the smell of gas in your home or on your property is a serious matter that demands immediate and correct action. Natural gas is odourless, so a strong, rotten egg smell is added to it specifically to alert you to a potential leak. Knowing exactly what to do can prevent injury, protect your home, and ensure everyone's safety.

Recognising the Signs of a Gas Leak

While the most obvious sign is the distinctive 'rotten egg' smell, other indicators can also point to a gas leak:

The Smell: A strong, unpleasant sulphur or rotten egg odour.
Hissing Sound: A hissing, whistling, or roaring sound near a gas line or appliance.
Visual Cues: A white mist or cloud near a gas line, dead or dying plants in or around your home (if the leak is underground), or bubbles in a puddle of water over a gas line.
Physical Symptoms: If you or others experience dizziness, nausea, fatigue, headaches, or breathing difficulties, especially when these symptoms improve when you leave the property, it could be due to carbon monoxide from an incomplete combustion of gas, or the gas itself.

Immediate Safety Steps if You Smell Gas

Your swift and calm response is vital. Follow these steps without delay:

Do NOT Turn On or Off Any Electrical Switches: This includes lights, fans, appliances, doorbells, or even your mobile phone inside the property. A spark could ignite the gas.
Extinguish All Naked Flames: Put out candles, cigarettes, and anything else that could cause a spark.
Open Windows and Doors: If it's safe to do so, quickly open all windows and doors to ventilate the area and disperse the gas. Do this without causing any sparks.
Turn Off the Gas Supply (If Safe and Accessible): If you know where your main gas shut-off valve is (usually near your gas meter) and it's easily and safely accessible without walking through a strong gas smell, turn it off. Turn the handle a quarter turn so it's at a right angle to the pipe.
Evacuate Immediately: Get everyone, including pets, out of the building and to a safe distance. Do not re-enter for any reason.
Call the National Gas Emergency Service: Once you are outside and at a safe distance, call the National Gas Emergency Service free of charge on 0800 111999. Do not call from inside your property.
Wait for Professional Help: Stay away from the property until the emergency service personnel confirm it is safe to return. They are trained to handle gas leaks and will assess the situation thoroughly.

What NOT to Do During a Gas Leak

Equally important as knowing what to do is knowing what to avoid:

Do NOT use your mobile phone or landline inside the property.
Do NOT operate light switches, doorbells, or any electrical appliances.
Do NOT light matches or use lighters.
Do NOT start your car if it's parked near the building.
Do NOT re-enter the property until advised it's safe by the National Gas Emergency Service.
Do NOT attempt to find or fix the leak yourself. Gas leaks are extremely dangerous and must only be handled by qualified professionals.

After the Emergency

Once the National Gas Emergency Service has attended and deemed your property safe, they will advise you on any necessary next steps. This might include checking your gas appliances. Remember, any work on gas appliances, boilers, or pipework must only be carried out by a Gas Safe registered plumber. Never attempt to service or repair gas appliances yourself.

For any non-gas related plumbing emergencies, such as a burst pipe or a serious leak, you can always tell us your emergency and we can help you find a qualified local plumber fast. You can also browse emergency plumbers near you for other urgent issues.

Prevention and Awareness

While gas leaks are rare, prevention and preparedness are key:

Regular Servicing: Ensure all your gas appliances, including your boiler, are serviced annually by a Gas Safe registered plumber.
Carbon Monoxide Detectors: Install audible carbon monoxide detectors near all sleeping areas and heat sources. Carbon monoxide is a silent killer, and these detectors provide an essential early warning.
Know Your Shut-Off Valve: Make sure everyone in your household knows where the main gas shut-off valve is and how to operate it safely.
Educate Your Household: Ensure all adults and older children understand the signs of a gas leak and the emergency steps to take.

Your safety is paramount. By understanding the risks and following these critical steps, you can react effectively and protect everyone around you should you ever smell gas. For further advice on various home issues, explore our plumbing emergency guides.

Frequently asked questions

What should I do first if I smell gas?

Immediately open all windows and doors if safe to do so, extinguish any naked flames, do not operate any electrical switches, and evacuate everyone from the property to a safe distance.

Who should I call if I smell gas?

Once you are safely outside and at a distance from the property, call the National Gas Emergency Service on 0800 111999. Do NOT call from inside the building.

Can I try to find or fix the gas leak myself?

Absolutely not. Gas leaks are extremely dangerous and must only be handled by qualified professionals from the National Gas Emergency Service or a Gas Safe registered engineer for appliance-related issues after the immediate danger is cleared.

What should I avoid doing if I smell gas?

Do not turn on or off any electrical switches, use mobile phones inside, light matches, or start a car near the property. Do not re-enter until advised it's safe by professionals.

How can I prevent gas leaks?

Ensure all gas appliances are serviced annually by a Gas Safe registered plumber, install audible carbon monoxide detectors, and know the location of your main gas shut-off valve.

Need a plumber now? Tell us your emergency and FixDelivered will find and confirm an available local plumber near you, usually within the hour.

Written by the FixDelivered Team. Reviewed by Rupert Lowe, Editor. Last updated 2026-09-06.