Gas Leak in Melbourne? Here's What to Do Before the Plumber Arrives

A gas leak is one of the few household emergencies where the wrong response in the first 30 seconds can be as dangerous as the leak itself. Most people know not to light a match. Fewer know that flicking a light switch, opening a fridge, or answering a mobile phone inside a gas-filled room carries the same risk. This guide covers what to do immediately, how to recognise a gas leak when there's no obvious smell, what causes them in Melbourne homes, and what happens when a licensed gasfitter arrives.

This article provides general safety guidance only. If you suspect a gas leak, prioritise evacuation and call emergency services. This is not a substitute for professional advice.

The 6 Steps to Take the Moment You Smell Gas

1. Stop what you're doing and don't touch anything electrical.
   Light switches, power points, doorbells, mobile phones, and even a torch can generate a small spark. In a gas-filled room, that's enough. Leave your phone where it is and move.

1. Don't touch any gas appliances.
   Do not turn the stove off. Do not turn the heater off. Do not turn anything on. If an appliance is already running, leave it. Interfering with a gas appliance during a suspected leak can make things significantly worse.

1. Open doors and windows as you leave, but only if they're on your direct path out.
   Ventilation helps dilute the gas, but don't go back into rooms you've already left to open additional windows. Get out.

1. Evacuate everyone, including pets.
   Get every person and animal outside and away from the building. Move to the street, not just the backyard; you want clear air and distance.

1. Call 000 if you believe the situation is immediately dangerous.
   If the smell is strong, if you hear hissing, or if anyone is feeling unwell, call 000 first. Gas emergencies are within their scope.

1. Call your gas network's 24-hour emergency line. 

In Melbourne, your gas distributor depends on your suburb (AusNet Services covers western metropolitan Melbourne and western Victoria, while Multinet Gas and Australian Gas Networks cover other areas). If you are in AusNet's network area, call 13 67 07. They can isolate the supply to your property from outside. Make this call from outside, away from the building.

Only contact a licensed gasfitter to locate and repair the leak once emergency services or the gas network has cleared the area.

How to Recognise a Gas Leak (Including When You Can't Smell It)

Natural gas is odourless in its raw form. The gas supplied to Melbourne homes has mercaptan added specifically so you can smell it; that distinctive rotten egg or sulphur odour. But not every gas leak produces a strong smell, particularly in larger or well-ventilated spaces, or with very small leaks in less-frequented areas of the home.

Signs of a gas leak with a smell:

• Rotten egg or sulphur odour near the stove, heater, meter, or any gas appliance
• The smell is stronger in enclosed spaces (under the house, inside cupboards near appliances)

Signs of a gas leak without an obvious smell:

• Hissing or whistling sound near a gas appliance, the meter, or underground lines; even faint hissing is significant
• Pilot lights that blow out repeatedly without an obvious draught cause
• Unexplained spike in your gas bill without a corresponding change in usage or weather
• Dead or dying vegetation in a line or patch above an underground gas service; gas displaces oxygen in the soil and kills plant roots
• Visible bubbling in standing water near a gas service underground (rare but definitive)

If you notice any of these signs without a smell, take the situation seriously. A slow leak that hasn't reached detectable concentration yet is still a leak.

What Causes Gas Leaks in Melbourne Homes

Understanding the cause matters for two reasons: it tells you how urgent the repair is, and it tells you what the gasfitter will likely need to do.

Corroded or cracked gas lines in older homes

Steel gas lines in homes built before the 1980s corrode from the outside in. Galvanised steel fittings and older copper connections can develop pinhole leaks that worsen slowly over years. In established Melbourne suburbs — Hawthorn, Kew, Box Hill, Camberwell — this is a common root cause for homes that have never had their gas infrastructure assessed.

Ground movement affecting underground services

The clay-heavy soils in growth corridors including Tarneit and Cranbourne East expand and contract with seasonal moisture changes. Underground gas services can shift, and poorly supported sections can develop stress fractures at joints. This can affect homes as young as seven to ten years old if the service wasn't properly bedded during installation.

Aging appliance fittings and flexible connections

The flexible connectors behind stoves, dryers, and heaters have a limited service life. They're not designed to last indefinitely, and in practice many are never inspected or replaced. A cracked or perished flexible connector is one of the most common causes of minor household gas leaks.

DIY gas work

In Victoria, all work on gas appliances and gas lines must be done by a licensed gasfitter. Homeowners who attempt to connect or disconnect appliances, replace regulators, or modify gas lines themselves create a risk that often isn't discovered until something goes wrong and sometimes years later. DIY gas work also voids appliance warranties and home insurance coverage for any resulting damage.

Appliance faults

A faulty regulator, a cracked burner, or a failed valve inside an appliance can leak gas even when the supply line is intact. This is why a gas safety check inspects the appliance, not just the line.

Are Your Gas Appliances Overdue for a Safety Check?

Most Melbourne homeowners have never had their gas appliances formally inspected. Unlike a smoke alarm battery or a car service, there's no recurring reminder and unless something fails visibly, it tends not to get done.

For owner-occupiers:

There is no legal requirement to arrange a periodic gas safety check (unlike Victorian rental properties). But the absence of a legal obligation isn't the same as the absence of risk. Energy Safe Victoria recommends servicing all gas heaters at least every two years by a licensed gasfitter, and staying vigilant for unusual burner flames, soot buildup, or changes in appliance performance.

For landlords:

The requirement is different and mandatory. If your rental agreement was entered into or renewed since 29 March 2021, you are legally required to arrange a gas safety check every two years by a licensed gasfitter with a Type A appliance servicing endorsement. Records must be kept and produced within the required timeframe if a renter requests them. 

For the full breakdown of what this obligation involves, see our Victorian Landlord Plumbing Obligations guide.

What a gas safety check involves:

• Inspection of all Type A gas appliances in the property (cooktop, oven, heater, hot water system)
• Pressure testing of the gas line from the meter through to the appliances
• Inspection of flexible connectors and fittings
• Check of ventilation requirements for each appliance
• Written record of the inspection, signed by the licensed gasfitter

A gasfitter who completes this work will issue an inspection record. If any appliance or fitting fails the inspection, they will advise on the repair required before issuing a Certificate of Compliance for that work. 

For clarity on the difference between a licensed plumber and a licensed gasfitter and who does which work, see our guide: Plumber vs Gas Fitter: What's the Difference (and Why It Matters in Victoria).

What a Gasfitter Does to Find and Fix a Leak

Once the area is safe and you've called a licensed gasfitter, here's what to expect:

• Pressure testing the gas line. The gasfitter isolates sections of the gas system and applies pressure to identify where pressure is dropping, which indicates where gas is escaping. This is the primary diagnostic tool for leaks in the line itself.

• Electronic leak detection. For suspected appliance or fitting leaks, electronic gas detectors identify the precise location of a leak faster and more accurately than any other method including smell. This is particularly useful when a leak is too small to be obvious but large enough to register on the instrument.

• Inspection of flexible connectors and fittings. Every accessible flexible connector and threaded fitting is checked, both visually and with detection equipment. Connectors are a common failure point that's missed when only the appliance is serviced.

• Repair and Certificate of Compliance. Once the leak is located and repaired, the gasfitter pressure-tests the system again to confirm it's holding. They then issue a Certificate of Compliance confirming the work meets the relevant Victorian standard. Keep this document; it's what your insurer needs if there's been any associated damage, and it's proof that the work was done by a licensed tradesperson.

What You Cannot Do Yourself

Under Victorian law, all gas work must be performed by a licensed gasfitter. This includes:

• Connecting or disconnecting any gas appliance
• Replacing a flexible connector behind a stove or dryer
• Adjusting a regulator
• Any modification to a gas line
• Capping off a gas point

It is not a matter of difficulty or competence; it is a legal requirement. Unlicensed gas work also voids your home insurance for any related damage, which means that if a DIY repair fails and causes a fire or explosion, you bear the full liability.

To verify that a gasfitter is licensed before they start work, use the VBA licence lookup at vba.vic.gov.au. A licensed gasfitter will have no hesitation providing their licence number when asked.