When you turn off a tap, does it sound like someone is literally whacking your pipes with a hammer? It’s no surprise where the term ‘water hammer’ comes from – but understanding how to fix water hammer is a lot more difficult.

What causes water hammer?

Most common in areas of above-average water pressure or where the property’s water pipes are ageing, it’s an alarming sound for a very good reason – think of it like an actual alarm, alerting you to a problem. It’s actually not hard to understand the phenomenon, which is more technically referred to as ‘hydraulic shock, at all. Your water pipes also consist of valves, whose job is to suddenly stop the flow of water when you or an appliance requests it. Also common with today’s mixer taps, which can stop the flow in an instant flick of the lever, water hammer is simply the physics-based result of creating a sudden surge in water pressure that triggers a pressure wave – which we detect as a highly-concerning ‘hammering’ of your pipes.


And if you cringe when you hear that water hammering, your instincts are 100% correct – because it gradually chips away at your pipes and eventually leads to leaks and damage to the pipes, valves and fittings. In severe cases, water hammer that is bad enough can even trigger an instant pipe burst.

What else do you need to know about water hammer? We’ve got all the answers:

1. What are the dangers of water hammer?

Your pipes, joints, valves and other water pipe-related plumbing infrastructure are all at risk – but did you know it can even damage the appliances, fittings, seals and other equipment supplied by or connected to those pipes? Worse still, a devastating pipe explosion can even cause physical injury, or cause hazardous fluids to spill out.

2. What are the signs of water hammer?

The hammering is the obvious one! You’ll hear it either as a repetitive series of hammers in the worst cases, but the most damaging instances can actually be a single loud BANG, perhaps followed by less severe rattling. But in really serious cases, you could even notice connections that have rattled loose, or evidence of a water pipe leak.

3. How can water hammer be prevented?

Quite often, simply turning taps on and off more carefully, or opening all of the water valves in your plumbing system in a single session, can be enough to get rid of some of the air pockets that can cause simple water hammering. You can also consider simply turning off taps half-way, installing more or better wall insulation around the pipes, installing limiting valves to reduce your system’s overall water pressure, or replacing your taps for ones with more progressive valves.


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4. How to solve water hammer?

You may need to call a plumber! They may be able to do a variety of things that you cannot do yourself – especially considering that most plumbing work at home needs to be done by a fully-licensed plumber anyway. But it can take experience, skill and specialised equipment to:

  • Reduce water pressure below 500kPa (the Australian maximum) with limiting valves
  • Replace or reinforce pipes
  • Install more suitable valves
  • Install better air chambers
  • Install a water hammer arrestor
  • Check & remedy saddle supports, wooden joists & pipe straps
  • Repair leaks & inspect overall plumbing system
  • Update tapware or install improved washers.

Solve your water hammer problem with our help

Believe it or not, there are plenty of other ways in which Rapid Service Plumbing can diagnose, minimise or eradicate your water hammer problem, too – we’ll just need to check out the problem and then get straight to work! We can quickly dispatch an emergency plumber 24/7 for serious plumbing problems, all of our workmanship is fully guaranteed and we’ll always let you know the price before getting stuck in! Give the friendly and fully-licensed local Sydney plumbers at Rapid Service Plumbing a call today!