Gas Leak: What to Do if You Smell Gas in Your Home

Smell Gas? Act Immediately

Natural gas is odourless, but a chemical called mercaptan is added to give it that distinctive rotten-egg smell. If you can smell it, there's a leak — and you need to act fast.

Gas leaks are one of the few genuine emergencies where speed matters more than anything else. A buildup of gas in an enclosed space can cause an explosion. Even a small leak can cause carbon monoxide poisoning.

Here's exactly what to do, step by step.

Step-by-Step: What to Do

1. Don't Panic, but Move Quickly

Stay calm. You have time to act safely, but don't hang around.

2. Open Doors and Windows

Get fresh air flowing through the property immediately. Open as many windows and external doors as you can on your way out.

3. Turn Off the Gas at the Meter

If you can reach your gas meter safely:

• Turn the handle so it's at 90 degrees to the pipe (perpendicular = off)
• Your meter is usually outside in a meter box, under the stairs, or in a cupboard

If you can't reach the meter safely, don't worry about it — just get out.

4. Get Everyone Out

Get everyone out of the property — people and pets. Move to fresh air.

5. Call the National Gas Emergency Service

0800 111 999 — Free, 24 hours, 7 days a week.

Call from outside the property or from a neighbour's house. Do not use your phone inside the property.

They'll send a Gas Safe registered engineer to investigate. This service is free regardless of who your gas supplier is.

6. Wait Outside

Stay outside until the emergency engineer arrives and confirms it's safe to re-enter. This might take a couple of hours.

What About Carbon Monoxide?

Carbon monoxide (CO) is different from a gas leak but equally dangerous — and you can't smell it. CO is produced when gas (or any fuel) doesn't burn properly, usually due to faulty appliances or blocked flues.

Symptoms of Carbon Monoxide Poisoning

• Headache
• Dizziness
• Nausea
• Breathlessness
• Confusion
• Collapse

If multiple people in your household have these symptoms, especially if they improve when you leave the house, suspect CO.

What to Do

• Get everyone out and into fresh air
• Call 999 if anyone is unwell
• Call the National Gas Emergency Service on 0800 111 999
• Don't go back inside until it's confirmed safe
• Go to A&E — CO poisoning needs medical assessment even if you feel better

Preventing CO Poisoning

• Fit a CO alarm on every floor that has a gas appliance. They cost about £15 and save lives
• Get gas appliances serviced annually by a Gas Safe registered engineer
• Never block ventilation around gas appliances
• Check for warning signs: yellow or orange flames (should be blue), soot marks around appliances, pilot lights frequently going out

Common Causes of Gas Leaks

Understanding what causes leaks helps you stay vigilant:

• Old or damaged gas pipes — Corrosion, physical damage, or poor joints
• Faulty gas appliances — Boilers, cookers, gas fires that haven't been serviced
• DIY gone wrong — Never do your own gas work. It's illegal and deadly
• Building work — Accidental damage to gas pipes during renovations
• Flexible hose deterioration — The hoses connecting gas cookers can perish over time

How to Spot a Slow Leak

Not all gas leaks are dramatic. Slow leaks can go unnoticed for days or weeks. Watch for:

• A faint gas smell that comes and goes — particularly near appliances or pipe joints
• Higher-than-expected gas bills with no change in usage
• Dead or dying houseplants near gas appliances (gas displaces oxygen)
• Hissing sounds near gas pipes or appliances
• A pilot light that keeps going out

If you notice any of these, call the Gas Emergency Service. Don't wait to see if it gets worse.

Who Can Work on Gas?

Only Gas Safe registered engineers can legally work on gas installations in the UK. This covers:

• Boiler installation, repair, and servicing
• Gas cooker installation
• Gas fire installation and servicing
• Gas pipe work

Always check an engineer's Gas Safe ID card and verify it at gassaferegister.co.uk. The card shows which types of gas work they're qualified for.

Anyone doing gas work who isn't registered is breaking the law, and using them puts your household at risk.

Landlord Responsibilities

If you rent:

• Your landlord must arrange an annual gas safety check by a Gas Safe registered engineer
• They must give you a copy of the Gas Safety Certificate within 28 days of the check
• All gas appliances they provide must be safe and maintained
• If you suspect a gas issue and your landlord won't act, call the Gas Emergency Service directly and report the landlord to the Health and Safety Executive

Key Numbers

Prevention Checklist

• Annual gas safety check on all appliances
• CO alarm fitted on every floor with gas appliances
• CO alarm batteries tested monthly
• Everyone in the household knows where the gas meter is
• Everyone knows how to turn off the gas
• Emergency number (0800 111 999) written somewhere visible
• Gas appliance ventilation is never blocked
• Flexible gas hoses checked for wear

Gas leaks are rare but serious. Know the number, know what not to do, and get out fast. That's all there is to it.