How To Deal With Water Hammer

f you have banging or thumping pipes, you may have an issue called Water Hammer – read on to find out what damage this can cause, and how to stop the problem…


The term water hammer refers to the noises and pressure surges associated with movement of water through the plumbing system when the flowing water comes to a sudden and complete stop.

When a valve or tap is shut off, the water is stopped abruptly – the momentum in the water then turns into a pressure increase within the pipe, due to the fact that water cannot be compressed. This pressure wave results in the banging noise that characterises water hammer.


Aside from the annoyance of having thumps, bangs and crashes occuring in your pipes, water hammer can cause actual damage too.

  • Valves – pressure from the shock waves caused by uncontrolled water hammer can pop, loosen or even crack valves within the system. Safety Relief Valves and Pressure Reducing Valves can be particularly affected, and reduce the safety of your plumbing.
  • Water heaters – although not the main cause of tank failure, the repetitive shock waves and pressure can reduce the lifespan of your water heater and exacerbate any failure.
  • Fittings and joints – welded fittings and joints are especially vulnerable to damage caused by water hammer. Internal pressure can exceed the system’s rating, while pipe movement can create external pressure on different parts of the system.
  • Hangers and brackets – due to the way water hammer moves pipes, they are the biggest cause of loose pipe hangers and failed supports. This can even cause additional noises, with the noise of rattling pipes added to the water hammer sounds.


To avoid the irritation and potential damage caused by a water hammer, there is a simple solution. The most effective way to control a water hammer is to install a Water Hammer Arrester.

Arresters use a compressible cushion of air or gas, which is separated from the water. When a valve closes, the moving column of water travels into the arrester and compresses the gas/air, reducing the momentum of the water and preventing the water hammer occurring.

Unlike having a simple air chamber or simple capped pipe, a water hammer arrester doesn’t become waterlogged over time – the fact that the gas or air is kept permanently separate means that it doesn’t get absorbed by the water, a risk that can leave air chambers and capped pipes ineffective.


Masefield Beta offer a range of Sioux Chief Water Hammer Arresters – all of which are guaranteed to control water hammer for the lifetime of the plumbing system.

  • Lifetime guarantee
  • Ultimate protection against water hammer damage
  • Can be installed at any angle
  • Easy to install
  • Mini resters with a male 1/2″ thread are simply fitted with female 1/2″ x 15mm iron tee
  • Mini resters with a hose tee connection install directly on washing machine supply valves, or directly onto washing machines or dishwashers.

Find out more about our water hammer arresters, or contact us if you have more questions.