Gas Leak Detection Hawthorn VIC 3122 – Gas Leak Found After Meter Upgrade Shut-Off

Overview of the Gas Leak Issue

At a property on Smart Street in Hawthorn VIC 3122, our team at Your Choice Plumbers was called out after Multinet Gas Networks shut off the gas supply to the home while carrying out gas meter upgrades in the street.

The gas authority had knocked on the owner’s door, explained that a gas leak had been detected, and advised them to contact a licensed gas plumber to inspect, test and repair the installation before the gas could be safely reconnected.

This is exactly the kind of situation where homeowners ask, “why did the gas company turn my gas off?” or “do I need a licensed gas plumber if the gas authority shuts off my gas?” As an experienced plumber Hawthorn, we know that even very small gas leaks can go unnoticed by homeowners for years when the leak is external, minor, and located away from windows or doors.

In this case, the owner also confirmed they had never noticed the smell of gas either inside or outside the property, which can happen when the leak is very small and located in an exposed outdoor area.

Initial Inspection and Gas Installation Review

As part of our structured gas leak detection Melbourne process, we first inspected the client’s consumer gas installation.

We confirmed the visible consumer piping was copper and ran externally along the side wall of the property, serving:

• the ducted heater
• the continuous flow hot water system
• the internal gas cooktop

All appliances already had manual shut-off valves installed, which complied with AS/NZS 5601.1:2022 Clause 4.8.2 relating to shut-off valve requirements. This made the testing process more efficient because we were able to isolate the appliances properly without first altering the gas system.

Main Consumer Line Gas Tightness Test

We then carried out our standard gas leak testing procedure.

The gas meter was disconnected from the consumer line, and we removed the internal rubber safety plug that had been installed by the gas authority. This plug is fitted as a temporary safety measure after shut-off and is only visible once the gas meter is disconnected by a licensed gas plumber.

We connected our digital manometer and tested the consumer gas pipework at 2.0 kPa with the appliance shut-off valves turned off.

The test procedure was carried out in line with AS/NZS 5601.1:2022 Appendix E, specifically Appendix E.6 – Leakage test for existing installation. The process included:

• depressurising the gas line by disconnecting the meter
• ensuring appliances with pilot lights were turned off
• confirming all shut-off valves were off
• attaching the digital manometer
• pressurising the consumer piping to 2.0 kPa
• allowing at least 2 minutes for the temperature of the test medium in the pipework to stabilise
• measuring pressure loss over the required test period

For a standard residential property like this, the test period was 5 minutes. Larger properties with greater gas volume require longer testing periods in 5-minute increments.

This first test showed no pressure loss, confirming there was no leak on the main consumer line with the appliances isolated.

Secondary Testing with Appliances Connected

We then moved to the second stage of testing.

After turning the quarter-turn shut-off valves back on to reconnect the appliances, we repeated the pressure test. This time, the digital manometer showed a small pressure drop.

That result confirmed the leak was not on the main consumer line itself, but somewhere between a shut-off valve and an appliance connection — or potentially within an appliance.

Because the property had undergone a relatively recent extension and renovation at the rear, and the appliances were fairly modern, an appliance failure was considered possible but less likely. Even so, all possibilities still had to be tested properly.

Identifying the Source of the Leak

To locate the exact fault, we used an approved liquid gas leak detection solution known as Micro Leak Detector.

This product is a dense blue testing fluid specifically designed to reveal very small leaks by forming bubbles, making it much more reliable for micro leaks than ordinary soapy water.

We checked all visible joints and connections between the shut-off valves and the appliances. During this process, we identified small bubbles forming around a 20mm compression nut connecting the copper gas pipe to the ducted heater connection point.

That confirmed the leak source.

We tightened the compression nut using two spanners, reapplied the leak detection solution, and confirmed that the connection was now gas tight with no further bubble formation.

We then checked the remaining accessible joints and found no additional leaks.

Final Testing and Confirmation

Once the leaking connection had been rectified, we repeated the digital manometer testing procedure.

The line held pressure with no drop, confirming the installation was now gas tight.

This explained why the owner had never noticed the gas smell. The leak was:

• extremely small
• located externally
• positioned on the far side of the home
• away from openings such as doors and windows

In outdoor conditions like this, minor gas leaks can dissipate quickly into the air and be very difficult for homeowners to detect.

Root Cause and Compliance Insight

This case strongly suggested that the gas installation had not been fully pressure tested when the extension works were completed several years earlier.

There had been no recent appliance installation or gas fitting changes, which indicates the small leak may have been present for approximately 5 years before it was finally detected during the gas authority’s meter upgrade program.

This highlights why gas tightness testing is so important after renovations, extensions, or any gas installation work — even when there are no obvious warning signs.

Outcome and Client Result

• gas leak confirmed and isolated correctly
• main consumer line ruled out through sectional testing
• micro leak identified at ducted heater connection
• faulty compression connection tightened and re-tested
• installation confirmed gas tight
• owner able to proceed with gas reconnection safely

The owner was relieved that the leak was minor and that it had been found and resolved quickly, especially after having the gas shut off unexpectedly by the authority.

Compliance with Australian Standards

All procedures were carried out in accordance with AS/NZS 5601.1:2022, including Appendix E.6 – Leakage test for existing installation.

In simple terms, this means the gas installation was tested using the correct standards-based procedure to ensure the property was safe, compliant, and ready for reconnection.

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.