Smell Gas? 6 Warning Signs of a Gas Leak and Exactly What to Do

Introduction

A gas leak isn’t a ‘deal with it tomorrow’ problem. It’s a same-hour, sometimes same-minute problem. Here are the six signs to know, and the exact safety steps to take if you suspect one — written by licensed Type A gasfitters.

The 6 warning signs

### 1. *The smell of rotten eggs*

Natural gas is odourless, so an additive (mercaptan) is added to make leaks detectable. If you smell sulphur or rotten eggs, treat it as a leak.

### 2. *A hissing or whistling sound near a gas line or appliance*

Audible escape near a meter, hot water unit, cooktop or heater is a serious indicator.

### 3. *Dead patches of grass or plants near a gas line*

Underground leaks displace oxygen in the soil and kill vegetation in defined patches.

### 4. *Higher than normal gas bills*

Sustained increases without a change in usage are a financial fingerprint of a slow leak.

### 5. *Physical symptoms*

Headaches, dizziness, nausea, fatigue or breathing difficulty that improves when you leave the house.

### 6. *A yellow or orange flame on your cooktop*

A healthy gas flame is blue. Yellow flames mean incomplete combustion — and potential carbon monoxide.

What to do RIGHT NOW if you suspect a leak

Safety first — in this exact order

1. Don’t flick switches, light matches or use phones inside.

2. Open all doors and windows.

3. Turn off the gas at the meter (handle perpendicular = OFF).

4. Get everyone outside.

5. From outside, call your gas distributor’s emergency line, then a licensed gasfitter.

6. Do not re-enter until the area is declared safe.

What licensed gas repair involves

• Pressure / pressure-decay testing of the line
• Electronic gas leak detection at joints and appliances
• Soap solution confirmation
• Repair or replacement of the affected section
• Compliance certificate issued on completion (legally required in Victoria)

Cost expectations (2026)

• Gas leak detection appointment: $250–$450
• Minor repair (single joint): $350–$650
• Section replacement: $700–$2,000
• Full line replacement: from $2,500

FAQ

Is it illegal to do my own gas work?

Yes. In Victoria, all gas work must be carried out by a licensed gasfitter and certified.

Will my appliances be tested too?

We test the line plus every connected appliance and issue a compliance certificate covering the work.

### Call-to-action

Smell gas? Ventilate, evacuate, and call a licensed gasfitter immediately. J.O. Plumbing offers priority response for suspected gas leaks.