Gas Leak? Signs & What to Do Immediately

If you smell gas, act immediately: don't use anything that could spark, open doors and windows, turn off the gas at the meter if it's safe to do so, get everyone outside, and call a licensed gas fitter from a safe distance. If the smell is strong or you feel unwell, leave the property first and call from outside. A gas leak is a genuine emergency — natural gas is explosive and can be harmful to breathe. This guide walks you through exactly what to do and, just as importantly, what not to do.

Signs of a gas leak

Natural gas (supplied in Perth by ATCO) is naturally odourless, so a rotten-egg or sulphur smell is added to help you detect it. Watch and listen for:

• A rotten-egg or sulphur smell — the most common sign
• A hissing or whistling sound near a gas appliance, pipe or meter
• A yellow or orange flame on a burner instead of a clean blue one
• Sooty black marks around an appliance
• Dead or dying plants near an underground gas line outside
• Physical symptoms — headaches, dizziness, nausea or tiredness that ease when you leave the house

What to do immediately

If you suspect a leak, follow these steps in order. Speed and calm both matter — panicking and doing the wrong thing (like flicking a light switch) is more dangerous than the leak itself in the first few seconds.

• 1. Don't create a spark or flame. No lighters, matches, cigarettes or naked flames.
• 2. Ventilate. Open doors and windows to let gas escape and fresh air in.
• 3. Turn off the gas. If you can reach the meter safely, turn the supply off at the isolation valve.
• 4. Get everyone out. Move all people and pets outside to fresh air, especially if the smell is strong.
• 5. Call for help from a safe distance. Once you're clear of the property, call a licensed gas fitter to attend. If it's a major leak or you feel unwell, treat it as an emergency and call emergency services.

What NOT to do

Some instincts are exactly wrong in a gas leak. Do not:

• Switch anything electrical on or off — lights, fans, appliances or the mains. A switch can spark and ignite the gas. Leave lights as they are.
• Use your phone inside the affected area. Make calls once you're outside.
• Light a match or lighter "to check" for the leak.
• Try to find or fix the leak yourself. Gas work is illegal for anyone but a licensed gas fitter in WA — and dangerous.
• Stay inside if the smell is strong. Get out first, worry about the source later.

Why only a licensed gas fitter can help

In Western Australia, all gas work must be carried out by a licensed gas fitter — it's the law, enforced by Building and Energy, and for good reason. Even a small mistake with gas can lead to fire, explosion or carbon monoxide poisoning. A licensed professional has the training and equipment to safely locate the leak, repair it, and confirm the system is sound before you use it again. This is exactly what our gas leak detection service is for.

The same rule applies to any gas installation or repair. If you're having a new appliance connected or gas lines run, that's a job for licensed gas plumbing and fitting — never a DIY project. You can read more about what legally requires a licensed plumber or gas fitter in WA if you're unsure.

What about carbon monoxide?

A gas leak isn't the only gas danger. When a gas appliance burns incompletely — often shown by a yellow or orange flame and sooty marks — it can produce carbon monoxide, a colourless, odourless gas that's dangerous to breathe. Because you can't smell or see it, the warning signs are physical: headaches, dizziness, nausea and tiredness that improve when you leave the house, especially if more than one person in the home feels it. If you suspect carbon monoxide, ventilate, get everyone outside, and have a licensed gas fitter inspect the appliance before using it again. A carbon monoxide alarm is a cheap and worthwhile safeguard.

Preventing gas leaks

You can lower your risk with a few simple habits:

• Have gas appliances serviced regularly by a licensed gas fitter
• Watch for yellow flames and sooty marks, which suggest poor combustion
• Never block the vents on gas appliances
• Consider a carbon monoxide alarm as an added safeguard
• Replace ageing appliances that are becoming unreliable rather than nursing them along

How gas fitters find and fix a leak

When a licensed gas fitter attends, they don't just guess. They use a combination of electronic gas detectors, a leak-detection solution applied to joints and fittings (bubbles reveal escaping gas), and a pressure test on the gas line to confirm the system holds pressure with no loss. Once they've pinpointed the source — a worn appliance connection, a corroded fitting, or a fault in the appliance itself — they repair it and re-test before signing off. Only then is it safe to use gas again, which is why you should never restore the supply yourself and "see how it goes".

After the emergency

Once a gas leak has been dealt with, don't turn the supply back on yourself. Let the licensed gas fitter confirm everything is safe and restore the supply. If a faulty appliance caused it — an old heater or a gas hot water system, for example — ask whether it needs repair or replacement so it doesn't happen again.

Smell gas right now? Get everyone outside, then call our licensed Canning Vale gas fitters from a safe distance.

Frequently asked questions

What should I do first if I smell gas?

Don't create any spark or flame, open doors and windows to ventilate, and avoid touching electrical switches. Turn off the gas at the meter if it's safe, get everyone outside, and call a licensed gas fitter from a safe distance.

Should I turn the lights off if I smell gas?

No. Operating any electrical switch — including light switches and the mains — can create a spark that ignites the gas. Leave lights as they are, ventilate the area, get out, and call a licensed gas fitter from outside.

Can I fix a gas leak myself?

No. In WA all gas work must be done by a licensed gas fitter — it's illegal and dangerous otherwise. A licensed professional has the tools and training to safely find the leak, repair it, and confirm the system is safe before use.

What does a gas leak smell like?

Natural gas is odourless, so a rotten-egg or sulphur smell is added to help you detect it. If you notice that smell, hear hissing near a gas line, or see a yellow flame instead of blue, treat it as a possible leak and act immediately.