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Smell Gas? Immediate Safety Steps to Take Now

By The FixDelivered Team · Updated 2026-07-04 · 6 min read

Detecting the smell of gas in your home is a serious concern that demands immediate and decisive action. Natural gas, supplied to most UK homes, is naturally odourless. For safety, a distinctive ‘rotten egg’ or sulphuric smell is added to make leaks easily detectable. If you notice this odour, it's crucial not to panic but to follow a clear safety protocol to protect yourself, your household, and your property.

How to Identify a Gas Leak Beyond the Smell

While the distinct smell is the primary indicator, other signs can point to a gas leak:

• The Smell: A strong, unpleasant odour, often compared to rotten eggs or sulphur.
• Hissing Sound: A faint or loud hissing noise near a gas appliance or pipe indicates gas escaping.
• Visual Cues: A visible cloud of gas (rare indoors), dust or debris blowing from a hole in the ground, or bubbles in puddles of water over a gas line.
• Dying or Discoloured Plants: If indoor plants inexplicably wilt or die, especially near gas lines, it could be due to gas in the air.
• Physical Symptoms: For prolonged exposure, you might experience headaches, dizziness, nausea, fatigue, or breathing difficulties. These symptoms are more commonly associated with carbon monoxide poisoning, but a high concentration of natural gas can also displace oxygen, leading to similar effects.

Immediate Safety Actions: Your Step-by-Step Checklist

Your safety is paramount. Follow these steps without delay if you suspect a gas leak:

1. Ventilate Immediately: Open all windows and doors to allow fresh air to circulate and disperse the gas. Do this quickly but calmly.
2. Turn Off the Gas Supply (If Safe): If it's safe and easily accessible, turn off your main gas supply at the meter. The gas meter is usually located outside your property, under the stairs, or in a utility cupboard. The shut-off valve is typically a lever or a tap that you turn 90 degrees. Only do this if you can do so quickly and without fumbling or risking sparks.
3. Extinguish All Naked Flames: Put out any candles, cigarettes, or open fires immediately. Do not light anything.
4. Do NOT Operate Electrical Switches or Appliances: This is critical. Do not turn lights on or off, unplug appliances, use your phone indoors, or operate any electrical device. Even a tiny spark from a switch can ignite escaping gas.
5. Evacuate Everyone: Get everyone out of the house, including pets, as quickly and calmly as possible. Do not waste time gathering belongings.
6. Call the National Gas Emergency Service: Once you are safely outside and a good distance from the property, call the National Gas Emergency Service on 111. This is a free, 24-hour service. Provide them with your exact address and details of the smell.
7. Do NOT Re-enter: Do not go back inside your property until a Gas Safe registered engineer or the emergency services have confirmed it is safe to do so.

What NOT to Do When You Smell Gas

In a gas emergency, what you don't do can be just as important as what you do.

• Do NOT Use Matches or Lighters: Obvious, but worth reiterating. Even a tiny flame can be catastrophic.
• Do NOT Turn Electrical Appliances On or Off: This includes light switches, doorbells, garage door openers, and even your mobile phone inside the property. Electrical arcing can cause an explosion.
• Do NOT Try to Locate the Leak Yourself: Leave this to the professionals. Tampering with gas pipes or appliances without proper training and equipment is incredibly dangerous.
• Do NOT Delay: A gas leak is not something that will fix itself or can wait. Act immediately.

Understanding the Risks of a Gas Leak

Natural gas itself is non-toxic, but it is highly flammable and can be explosive when mixed with air in certain concentrations. The primary dangers are:

• Explosion: The most immediate and severe risk. A spark from an electrical switch, a static discharge, or a pilot light can ignite a build-up of gas, leading to a devastating explosion.
• Asphyxiation: In high concentrations, natural gas can displace oxygen, leading to suffocation. Symptoms include dizziness, fatigue, nausea, and loss of consciousness.
• Carbon Monoxide Poisoning (Indirectly): While natural gas doesn't contain carbon monoxide, faulty gas appliances can produce it when they don't burn fuel completely. A gas leak might indicate a wider issue with your gas system that could also lead to carbon monoxide production. Ensure you have working carbon monoxide detectors fitted.

What Happens After You Call 111?

When you call 111, the National Gas Emergency Service will dispatch a Gas Safe registered engineer to your location immediately. Their priority is to make the situation safe. They will:

• Investigate the source of the smell.
• Locate and isolate the leak.
• Turn off your gas supply if it hasn't already been done.
• Advise you on what needs to happen next, which may include repairs by a private Gas Safe engineer.

Getting Your Gas Appliances Checked and Repaired

Once the immediate danger has been neutralised by the emergency service, you will likely need to arrange for a Gas Safe registered engineer to carry out repairs to your gas pipework or appliances. This is not a task for a DIY enthusiast or an unregistered tradesperson. Only a Gas Safe registered engineer has the legal authority and expertise to work on gas installations in the UK.

They will:

• Diagnose the exact cause of the leak.
• Carry out necessary repairs to pipes, fittings, or appliances.
• Test the integrity of your gas system to ensure it is safe to use.
• Relight your appliances and issue appropriate safety certificates if required.

Finding a reliable and vetted Gas Safe engineer quickly can be stressful, especially after an emergency. This is where services like FixDelivered can help. We connect you with vetted local emergency plumbers and gas engineers who can respond promptly. Our booking process is straightforward, and the plumber's callout fee is agreed upfront.

Prevention is Key: Regular Maintenance

While emergencies happen, regular maintenance significantly reduces the risk of gas leaks:

• Annual Gas Safety Checks: Have all your gas appliances and pipework checked annually by a Gas Safe registered engineer. This is a legal requirement for landlords.
• Install Carbon Monoxide Detectors: Fit audible carbon monoxide alarms in rooms with gas appliances and in sleeping areas.
• Know Your Gas Meter: Familiarise yourself with the location of your gas meter and how to turn off the main supply in an emergency.

When to Call a Professional: Always for Gas Leaks

Unlike a dripping tap or a blocked drain, a gas leak is never a DIY job. Even if you think the leak is minor, or you've managed to turn off the supply, you absolutely must call a Gas Safe registered professional. The risks are too high to take chances.

Stay Safe, Act Fast

Smelling gas is a clear warning sign that should never be ignored. By acting quickly, calmly, and following the safety steps outlined above, you can protect yourself and those around you. Once the immediate danger has been handled by the National Gas Emergency Service, remember that professional repair by a Gas Safe registered engineer is essential to restore your gas supply safely. For fast, reliable access to vetted local Gas Safe engineers, consider using FixDelivered to get your home safe and sound again.

Frequently asked questions

What does a gas leak smell like?

Natural gas is odourless, but a chemical called mercaptan is added to give it a distinctive, strong smell often compared to rotten eggs or sulphur. This makes leaks easily detectable.

Can I fix a gas leak myself?

Absolutely not. A gas leak is an extremely dangerous situation that requires immediate attention from a qualified professional. Attempting to fix it yourself can lead to severe injury, explosion, or even death. Always call the National Gas Emergency Service on 111 first, and then a Gas Safe registered engineer for repairs.

Who should I call if I smell gas?

First, get everyone out of the property to a safe distance. Then, from a safe location, immediately call the National Gas Emergency Service on 111. They will send a Gas Safe registered engineer to make the situation safe. For repairs after the emergency is contained, you'll need to contact a private Gas Safe registered engineer.

How much does it cost to fix a gas leak?

The cost to fix a gas leak can vary significantly depending on the complexity of the leak, its location, and the parts required. Emergency services from 111 are free to make the situation safe. Repairs by a private Gas Safe engineer could range from approximately £150 for a simple fitting replacement up to several hundred pounds for more extensive pipework or appliance repairs. You should always get an upfront quote from your chosen engineer.

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

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