A loud bang or thud when you turn off a tap — or when the washing machine or dishwasher stops filling — is called water hammer. It’s common in Melbourne homes and is more than just an annoyance: over time, water hammer can stress pipe joints and connections, potentially causing leaks.
What Causes Water Hammer?
Water hammer is caused by the sudden stoppage of fast-moving water. When a tap is closed quickly, or when an appliance solenoid valve shuts, the momentum of the water column has nowhere to go and creates a pressure wave that reverberates through the pipe — the bang you hear. It is more pronounced in: homes with high water pressure (above 500 kPa), long straight pipe runs, rigidly mounted pipes, and homes with quarter-turn ball taps (which close much faster than old washer taps).
Solutions for Water Hammer in Melbourne Homes
The most effective solutions depend on the cause:
- Pressure reducing valve (PRV): If water pressure is above 500 kPa (test with a gauge on an outdoor tap), installing a PRV to reduce pressure to 300-400 kPa is often the single most effective fix. It also protects flexi hoses and appliances from excess pressure.
- Hammer arrestors: Fittings installed on the supply lines to washing machines and dishwashers that absorb the pressure spike. Very effective for appliance-related water hammer.
- Air chambers: Short vertical pipe sections that trap air and act as a cushion. May already be present in older Melbourne homes — can become waterlogged over time and need draining to restore effectiveness.
- Pipe securing: Pipes that bang against framing or in the wall can be secured with additional pipe clips to reduce noise transmission.
Sedcon Plumbing — Water Hammer Solutions Across Melbourne
We diagnose and fix water hammer in Melbourne homes. A pressure test and inspection usually identifies the cause in one visit. Call 0468 013 012 to book.