Gas Leak Signs Every Melbourne Homeowner Should Recognise (60-Second Response Guide)

Natural gas itself is odourless and colourless. The smell you associate with gas — that sharp, rotten-egg, slightly chemical bite — isn’t the gas. It’s an additive (mercaptan) put into the supply specifically so that humans can detect leaks. If you smell it, the warning system is working. The question is what to do in the next 60 seconds.

This guide is the response sequence I’d want my own family to follow. None of it is complicated; it just needs to be the right order and done quickly. I’m Alister at Prime Plumbing & Gasfitting. Type A gasfitter, Energy Safe Victoria endorsed. BPC Licence No. 103414.

The four signs

The gas leak signs Melbourne homes should look for fall into four categories — smell, sound, visual, and physiological. Each gets the same response sequence below.

1. Smell

The classic and most common indicator. Rotten egg, sulphur, or chemical. Even a faint persistent whiff in a room with a gas appliance should be treated as a possible leak until ruled out.

Where the smell is strongest matters. Right next to an appliance — probably a leak at the appliance connection. Across the room from any appliance — possibly a buried gas line leaking. Outside near the meter — possibly the meter or service pipe.

2. Sound

A pressurised gas line that develops a small hole will hiss. The sound is distinct from normal household noise — quiet, continuous, and obviously not mechanical. It’s loudest at the leak point.

If you can hear it but can’t smell it, you’re probably near a leak that hasn’t built up concentration yet. Move away from the area first, then act on the response sequence below.

3. Visible flame colour

A correctly burning gas appliance shows a clean blue flame, sometimes with a small yellow tip at the very top. A flame that’s mostly yellow, orange, or red is burning incompletely — which means the appliance is producing carbon monoxide instead of cleanly burning to water and CO₂.

This isn’t a leak in the “gas escaping the pipe” sense, but it’s arguably more dangerous. CO is colourless, odourless, and lethal at concentrations the body can’t detect. Yellow flames mean: stop using the appliance and book a service.

4. Health symptoms

This is where the gas-vs-CO distinction really matters. Symptoms of moderate carbon monoxide exposure: headache, dizziness, nausea, unusual tiredness, flu-like symptoms that improve when you leave the house and return when you go back. If anyone in the household is getting unexplained headaches that ease when they’re out and return when they’re home, treat that as a possible CO problem.

Severe symptoms: confusion, vomiting, loss of consciousness. At that level, call 000 and get everyone out of the house immediately.

The 60-second response (when you smell or hear gas)

Order matters here. Do these in sequence.

1. Don’t touch electrical switches. Any switch — light switch, exhaust fan, range hood, oven, even the doorbell. A switch can produce a small spark, and a small spark is enough to ignite a gas concentration. The rule: don’t change the state of any electrical device that’s already running or off.
2. Open windows and external doors. Get ventilation through the affected room. The goal is to dilute the gas concentration before anything else.
3. Turn off gas at the meter if it’s safe to reach. The meter is usually on the side of the house or in a meter box near the front. There’s a quarter-turn valve on the supply side — turn it perpendicular to the pipe to shut off. If the meter is in the affected room or you can’t reach it without going through the smell, skip this step and go to 4.
4. Leave the house. Take everyone with you. Don’t go back in for valuables.
5. Call your gas distributor’s emergency line from outside the house. The number is on your gas bill (look for “emergency” or “gas leak” — it’s a 24/7 number). The distributor sends a technician who locates and isolates the leak. There’s no call-out fee for a gas leak callout.
6. If anyone has CO symptoms (severe headache, confusion, vomiting), call 000. Ambulance, not just fire brigade. CO poisoning is treated with high-flow oxygen and the sooner that starts, the better.

Don’t use your phone inside the house if you can avoid it — mobile phones are technically capable of igniting gas in the right concentration, although the risk is low. Phone calls happen from outside.

Who fixes what — distributor vs licensed gasfitter

This trips most homeowners up. Two different parties handle gas leaks depending on where the leak is.

From the street main to the meter — gas distributor

The pipework that runs from the street main to your meter, and the meter itself, belongs to your gas distributor (AGN, AusNet, or the relevant carrier in your area). Leaks here are their responsibility to fix. Their callouts are free for the leak repair itself. They’ll typically isolate the supply at the meter while they investigate.

From the meter into the house — licensed gasfitter

Everything from the meter onwards — the buried line into the house, the lines through walls and ceilings, the appliance connections, the appliances themselves — is the homeowner’s responsibility. Repair work needs a Type A licensed gasfitter (regulated by Energy Safe Victoria). Once repaired, the gasfitter issues a BPC Compliance Certificate and the supply can be turned back on.

Both parties on the same callout

The common sequence: distributor attends first, locates the leak, identifies it’s on the homeowner side, isolates the supply at the meter and locks it off. The homeowner then calls a licensed gasfitter (us, or any Type A endorsed business) to do the actual repair and certify the work. Distributor returns to re-commission the supply once the certificate is lodged.

Carbon monoxide is different — here’s how

Gas leaks and carbon monoxide are often discussed in the same breath but they’re different problems with different responses.

The dangerous case is a gas heater (often older, sometimes 30+ years old) with a cracked heat exchanger or a blocked flue. The gas burns normally so there’s no smell of unburnt gas, but the combustion products leak into the room instead of venting outside. The CO concentration builds slowly. Symptoms creep up over hours.

Carbon monoxide testing is part of a proper annual gas heater service. We do CO testing as part of every heater service. If you have a gas heater that’s 15+ years old and hasn’t been serviced in the last 2 years, that’s the appliance most worth booking in. Details on our CO testing service.

Detectors are cheap insurance

A retail-grade CO detector is $40–$80 and lasts 5–7 years. Mount one in any room with a gas appliance, especially bedrooms with shared walls to a heater or hot water unit. Replace the batteries annually (most have a 9V backup) and replace the whole unit at end-of-life.

A combination smoke + CO detector is similar money and covers both. Worth installing in the main bedroom corridor and the living area.

Detectors are not a substitute for annual servicing — they’re a last-line safety net for the times servicing missed something. Both matter.

FAQs

I smell gas faintly — should I really evacuate, or am I overreacting?

Treat any persistent gas smell as a real possibility until proven otherwise. The response sequence (don’t use switches, ventilate, isolate, leave, call) is the same whether the leak turns out to be a major one or a slow seep at an appliance fitting. The cost of overreacting is a free distributor visit and 30 minutes of inconvenience. The cost of under-reacting is everything else.

What if the smell is only when the oven is running?

Most likely an appliance issue rather than a supply leak. Could be a worn gas connection at the oven, a failed seal, or (more commonly with older ovens) a partially-blocked burner producing incomplete combustion. Don’t use the oven, book a gasfitter service.

Can I check for a gas leak myself with soapy water?

That’s the traditional bubble test that gasfitters use on accessible fittings. It’s safe (you’re looking for bubbles, not making sparks) and it works on fittings you can see and reach. It doesn’t help you find a leak in a wall, in a slab, or in a flue. For anything beyond a visible fitting, you need a licensed gasfitter with the right equipment.

How often should gas appliances be serviced?

Every 2 years is the practical standard for gas heaters, hot water units, ovens, and cooktops. Energy Safe Victoria recommends gas heaters specifically be serviced and CO-tested every 2 years. Older appliances (15+ years) benefit from annual servicing because failures become more likely as components age.

The distributor said the leak is on my side of the meter. What now?

Call a Type A licensed gasfitter. The distributor will have locked off the supply at the meter. The gasfitter locates and repairs the leak, issues a Compliance Certificate, and arranges for the distributor to re-energise the supply. Most jobs done same-day if the access is good.

If you need a gasfitter

For gas leaks on the property side of the meter, gas appliance issues, or annual servicing: ring 0475 407 670 or contact Prime Plumbing & Gasfitting. We’re Type A gasfitters with Energy Safe Victoria endorsement and we issue BPC Compliance Certificates with every gas job.

For the leak itself — especially if you’ve already smelled or heard it — call your distributor first. Their number is on your gas bill, marked as the emergency or leak line.

— Alister Williams, Prime Plumbing & Gasfitting
BPC Licence No. 103414 · ABN 12 721 359 467 · Serving Melbourne since 2014

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• How often should gas appliances be checked in Victoria?
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