what is water hammer

What is Water Hammer & What Causes it?

If you’ve been hearing strange noises coming from your pipes every time you shut off a tap or when your water-using appliances are in use, you might be wondering what’s going on. Don’t worry; there are no goblins in your plumbing system making all that racket. In fact, the explanation is much simpler and far less bizarre: it’s just the annoying water hammer that most people are all too familiar with. 

Water hammer is one of the most common plumbing issues home owners have to deal with. The bad news is it can be very irritating to hear that loud banging noise in your pipes every now and then, and it can sound quite creepy in the middle of the night. The good news is that fixing it isn’t exactly rocket science. 

What exactly is water hammer?

To put it simply, water hammer can happen in any plumbing system that uses valves to control the water flow. Although most people call it water hammer, the technical terms are hydraulic shock or hydraulic surge. But no matter which term you prefer, they all describe the same thing: a loud rattle sound resembling a hammering noise coming from the plumbing system when the water is forced to change direction or stop abruptly. 

Water hammer usually occurs when the pipes in the plumbing system are made of metal, but it’s not uncommon to experience this problem if you have plastic water supply pipes. The only difference is the banging noise won’t be as loud. Whatever the case might be, water hammer has to be stopped if you want to avoid more serious issues further down the line. 

Water hammer causes 

The explanation behind this common plumbing problem is rather simple. When an open valve closes suddenly, the water that was flowing freely slams into it making a loud noise. Similarly, when a pump suddenly stops, the water that was running changes direction abruptly causing a rattling sound. Since the water supply has nowhere to go, it slams against the closed valves sending a shockwave through the pipes. If the pipes are not secured in place, they can move and bang against other pipes or against the wall framing and thus you hear that familiar hammering noise. 

How to fix water hammer 

Now that we’ve unravelled the mystery of water hammer, what’s there to be done? There are a few methods one can use to address water hammer and get rid of it for good. Here’s what you can do.

Securing loose pipes 

If you’re dealing with a mild case of water hammer, you can fix that easily by securing loose pipes, so they don’t move around when water slams against them. Check your pipes and tighten any loose straps that you encounter or add extra straps where needed and you’re good to go. As a side note, remember not to mix different materials when choosing straps or pipe hangers because that can lead to corrosion. You can also use foam pipe insulation that acts like a cushion to solve the problem. However, if the water hammer is severe, you might want to try a different method to fix it. 

Installing an air chamber

Another simple yet effective solution to solve water hammer problems is to install an air chamber. It might sound complicated, but there’s really not much to it. The method implies installing a short segment of pipe with an air filled chamber next to the valves that are responsible for creating the water hammer. The air chamber will provide a cushion for the water, absorbing the shock when the valve closes and preventing the water from slamming against the side of the pipes. If you already have an air chamber installed, it might have become waterlogged and thus you have to drain the plumbing system. Simply shut off the main water valve, open the highest tap in the house, then open the lowest water tap, and you’ve solved the problem. 

Using a water pressure regulator 

High water pressure can also be responsible for causing water hammer. If you’ve tested your water pressure and found out it is higher than it should be, you need to bring it back to normal parameters. You can do that by installing a water pressure regulator in your home.

If water hammer is causing you trouble, the best thing you could do is to contact a reliable local plumber ASAP and bid all your plumbing issues goodbye. 

Contact Off Tap Plumbing

Off Tap Plumbing Pty Ltd
Jesse Sorensen
[email protected]
(02) 9053 8797
Randwick NSW 2031

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