Overview of the Problem – Noisy Pipes in the Wall

At a townhouse on Kalimna Street in Carrum VIC 3197, our team at Your Choice Plumbers was called out after the owner reported noisy pipes in the wall happening at all hours of the day and night.

What made this case unusual was that the client noticed the pipe noise even when she was not using any taps or appliances inside her own home.

This is exactly the type of issue where homeowners start asking, “why are my pipes making noise when no water is running?” or “why do I hear water pipes in the wall at night even when I’m not using anything?” As an experienced plumber Carrum, we often find that unusual pipe noise can point to a pressure issue or a shared supply layout rather than a fault inside the fixtures themselves.

The client lived in the first townhouse out of three on a shared driveway block, with one unit behind the other.

Why the Noisy Pipes Were Unusual

After speaking with the client in detail, it became clear that the timing of the noise did not match normal internal plumbing use.

The noise was happening:

  • during the day
  • during the night
  • even when the client was not using taps
  • even when no appliances like the dishwasher or washing machine were operating

That immediately told us this was not a straightforward tap, valve, or appliance-related pipe noise inside her own townhouse.

Investigating the Shared Water Supply Setup

We then inspected the water meter arrangement for the three townhouses.

What we found was very important:

  • the property had a shared 25mm common water meter
  • each townhouse also had its own individual 20mm water meter
  • the shared 25mm meter was located in the client’s front yard near the front fence
  • the client’s own 20mm meter was located closer to her unit

This was unusual.

In many townhouse developments like this, the shared main water line normally runs through the common driveway garden bed and branches off more evenly to each unit. But based on the meter position and the symptoms, we concluded that the main 25mm cold water service line was likely running through the client’s townhouse wall area before continuing to the two units behind.

That explained why she was hearing noisy pipes in the wall even when she was not using water herself.

In other words, when the owners in Units 2 and 3 used water, it was likely creating noise in the shared main line running through or alongside the first townhouse structure.

Testing the Fixtures and Ruling Out Internal Plumbing Faults

We tested the taps inside the townhouse to see whether any individual fixtures created obvious noise during operation.

Nothing unusual was found.

That was another critical clue, because it helped rule out common internal causes such as:

  • loose tap pipework
  • noisy appliance valves
  • faulty local fixture connections

At that stage, the shared supply line layout and water pressure became the main suspects.

Confirming the Real Cause – Extremely High Water Pressure

We then checked the water pressure using a pressure gauge connected to the common body corporate tap running directly off the main 25mm water service.

The reading was 860 kPa

That is far above the recommended 500 kPa limit under AS/NZS 3500.

At that pressure, water movement through the main supply line becomes much more aggressive and can create significant pipe noise, especially in townhouse developments where the shared main may pass through or close to internal wall spaces.

This was the moment the problem really made sense.

The client was not imagining the noise — she was hearing the shared high-pressure main line reacting whenever neighbouring units used water.

Why the Pressure Reducing Valve Needed to Be Installed on the Shared Main

We explained to the client that if the pressure regulating valve was installed only on her private 20mm meter, it would not solve the true issue.

That is because the noise was being generated on the shared 25mm common water service before the water reached her individual line.

To reduce the noise properly, the pressure had to be controlled at the common meter.

This is an important distinction in townhouse plumbing layouts, because the location of the pressure control device matters just as much as the pressure reading itself.

Pressure Regulation Upgrade and Same-Day Solution

The client agreed that the best solution was to install a pressure regulating valve on the common 25mm water meter.

Because she was the only owner being seriously affected by the noise and did not want to wait for body corporate approval, she chose to proceed with the installation immediately herself.

We sourced a right-angle 25mm Zurn pressure regulating valve from Reece Plumbing Chelsea Heights and installed it on the shared main water service the same day.

Final Result and Client Outcome

Because the original noise was mainly happening when the neighbouring units used water, we could not fully test the result on site at the time of installation.

However, the client called back the next day and confirmed the outcome clearly:

  • the pipe noise was gone
  • she had finally had a good night’s sleep

This confirmed that the excessive pressure on the shared main was the true cause of the noisy pipes in the wall.

Compliance & Prevention Insight

This case highlights why noisy pipes in the wall should never be dismissed as just an annoyance.

Sometimes the problem is not inside the home’s own fixtures at all — it can be caused by:

  • a shared main water line layout
  • excessive water pressure
  • neighbouring water use in townhouse developments

It also reinforces how important correct pressure control is. At 860 kPa, the water pressure was not just noisy — it was well above compliant levels and capable of contributing to long-term plumbing wear and failure.

Compliance with Australian Standards

All work carried out by Your Choice Plumbers is completed in accordance with the relevant plumbing standards, including the pressure requirements referenced under AS/NZS 3500.

In simple terms, this means your plumbing pressure is checked and controlled properly to help reduce noise, protect pipework, and prevent unnecessary wear on the system.

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 water hammer noisy pipes Melbourne services.