Overview of the Gas Leak Issue

At a property on Wallace Avenue in Murrumbeena VIC 3163, our team at Your Choice Plumbers was called out after the owners, who had two small children, noticed the smell of gas inside one of the bedrooms and understandably wanted the line checked immediately.

This is exactly the type of situation where homeowners start asking, “what should I do if I smell gas in my house?” or “can a plumber find a gas leak under the house?” In older suburbs like Murrumbeena, we often find aging gas installations with sections of old galvanised gas pipe still in service, particularly in older homes where parts of the original system have never been upgraded.

Because the smell of gas was being noticed inside the home, the priority was to determine whether the leak was on the consumer gas line, related to an appliance, or coming from older pipework concealed under the house.

Initial Gas Leak Testing Process

As part of our structured gas leak detection Melbourne approach, the first step was to disconnect the gas meter and connect our digital manometer to the consumer gas line.

We then pressure tested the installation at 1.1 kPa, which is the standard operating pressure for domestic gas appliances. With all appliances connected, we monitored the digital manometer over a 5-minute period to determine whether there was pressure loss across the property’s gas installation.

After the test period, the reading showed a pressure drop, confirming the presence of a gas leak on the property’s consumer line and a non-compliant installation under AS/NZS 5601.1:2022.

This is a critical stage in the process, because before any repairs are started, we need to establish whether the leak is on the fixed pipework, an appliance connection, or within an individual appliance itself.

Sectional Testing to Isolate the Leak

Once the leak had been confirmed, we proceeded by isolating the gas appliances individually.

The property had:

  • an outdoor gas hot water system
  • an internal freestanding stove
  • an external ducted heater

Each appliance had its own shut-off valve except the older freestanding stove. To bring that part of the system up to compliance, we installed a manual shut-off valve and flexible hose in accordance with:

  • AS/NZS 5601.1:2022 Clause 4.8.2 – manual shut-off valve requirements
  • AS/NZS 5601.1:2022 Clause 4.8.3 – hose assembly requirements

After isolating all three appliances, we re-tested the main consumer line only. This sectional testing process is extremely important because it tells us whether the leak is appliance-related or located on the fixed gas pipework itself.

The second test confirmed the pressure loss was still present, which told us the leak was on the main gas line rather than on an appliance.

Identifying the Source of the Gas Leak

We then inspected the gas consumer pipework more closely.

From the gas meter to the first appliance, the installation was copper. However, from the ducted heater onwards, the line ran under the house through the brick wall and then branched off in old galvanised pipe.

Once under the subfloor, the problem became obvious.

Sections of the old galvanised gas pipe were not clipped to the underside of the timber floor structure as they should have been. Instead, parts of the line were lying on the ground. Over time, age, moisture and corrosion had deteriorated the galvanised pipework, creating the gas leak the owners were smelling inside the house.

This is a very common issue we see as a plumber Murrumbeena, especially in older homes where ageing galvanised gas lines remain in service beneath damp subfloor areas

Repair and Upgrade of the Gas Installation

Without delaying the repair, we advised the owners that the installation was unsafe and that the affected section of underfloor galvanised gas pipe needed to be replaced.

We replaced the underfloor gas pipework using:

  • hard drawn copper pipe
  • gas-rated B-Press fittings

We also made new compliant connections to the shut-off valves serving the freestanding cooker and gas hot water system, in line with the requirements of AS/NZS 5601.1:2022 Section 5 relating to consumer piping installations.

Once the new gas pipework had been installed, we re-tested the line using our digital manometer and confirmed there were no leaks on the main gas run.

We then turned the isolating valves back on and carried out a second-stage test with the appliances connected, confirming there were no additional appliance-related gas leaks.

At that point, it was clear the owners had been smelling gas from the corroded galvanised pipework located under the house.Safe Recommissioning and Compliance

Once the repairs and testing were completed, we reconnected the gas meter to the consumer line and safely purged the installation in accordance with Appendix D – Purging of AS/NZS 5601.1:2022.

After purging, we recommissioned all gas appliances and made sure:

  • pilot lights were restored where required
  • the hot water system was operating correctly
  • the ducted heater was back online
  • the owners could safely resume normal use of the home

Upon completion, we issued the mandatory Certificate of Compliance and lodged it with the VBA, ensuring the work was formally recorded as compliant with the latest gas safety standards.

Outcome and Client Result

  • gas leak accurately identified and isolated
  • unsafe underfloor galvanised gas pipework replaced
  • freestanding stove connection brought into compliance
  • system re-tested with no further leaks detected
  • appliances safely recommissioned
  • Certificate of Compliance issued and lodged with VBA

The owners were extremely pleased with the speed and thoroughness of the work, especially given the safety concern involving two young children in the home.

They later left us a 5-star Google review praising the professionalism, fast response and the way the work was handled even when unexpected issues arose.

Compliance & Prevention Insight

This case highlights why older homes with original gas infrastructure should never ignore the smell of gas, even if the problem seems minor at first.

Many homeowners ask, “is a gas smell under the house dangerous?” The answer is yes — any suspected gas leak should be treated seriously and tested properly. Older galvanised gas lines are especially vulnerable to corrosion and can become unsafe over time, particularly when installed in damp subfloor areas.

It also shows the importance of sectional testing. Without isolating the appliances and testing the main line separately, it would have been much harder to confidently identify the true source of the leak.

Compliance with Australian Standards

All work carried out by Your Choice Plumbers is completed in accordance with AS/NZS 5601.1:2022, the governing standard for gas installations in Australia and New Zealand.

In simple terms, this means your gas installation is tested, repaired and recommissioned to strict safety standards — helping protect your home and family from gas leaks, unsafe appliance connections and compliance risks.

Our Home Plumbing Experts Approach

As part of our Home Plumbing Experts approach, we focus on both repair and prevention.

We offer a Complimentary Property Protection Audit as part of our service, assessing key areas like water pressure, hot water temperature, and flexible hoses — helping homeowners stay ahead of potential plumbing failures and avoid unexpected water damage.

👉 Find out more about our gas leak detection Melbourne services.