What is Water Hammer & What causes it

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. 

How to Stop Water Hammer & Noisy Pipes in Sydney Homes

Have you ever had a peaceful moment ruined by a loud clatter coming from your pipes? You are not alone. Sydney households are no strangers to these sounds, as a lot of people deal with this very annoying plumbing issue, and it even has a name – it’s called water hammer. While some might get used to the noise and eventually ignore it, you must know that water hammer can do more than irritate sensitive ears. It can cause serious damage to your water supply system, such as failure of fittings or burst pipes, so it’s not a problem that you should overlook. 

Water hammer can happen for various reasons. The most common culprits are high water pressure or loose mounting straps. Left unattended, these problems can lead to costly repairs over time. The good news is you can get rid of water hammer yourself and stop noisy pipes from ever bothering you again. Here’s what you should do. 

Troubleshoot air chambers 

First thing first, if you want to fix water hammer, you must find out where it comes from exactly. This is no rocket science – you simply have to follow the sound and it will lead you to the source of the problem. Now that you know the location, you can get down to business. 

It’s time to learn a little about air chambers. They’re vertical pipes, usually located near a water valve in your home. When the water travels through the pipes and hits a closed valve, it can cause a loud clamor that can be heard throughout the house. That’s when air chambers come into play, acting like a cushion that absorbs the shock and stops the water from crashing against the pipes. The problem occurs when the air chamber gets waterlogged and you have to refill it with air. In order to do that, you must drain the plumbing system in a few simple steps:

  • shut off the main water valve
  • open the highest tap on the property
  • leave the lowest tap in your home open
  • once the water is drained from the system, turn off the lowest tap and switch on the main water supply valve 

NOTE: If you don’t have an air chamber in your house, you might want to contact a qualified plumber to have one installed. 

Secure loose pipes

Pipes are normally fixed to a building structure with pipe-mounting straps or fixtures. Plumbers use these straps to attach water lines to framing, so when the water runs through them, they won’t move. However, in time the straps or fixtures can loosen or break, causing the pipes to bang against the framing when the water is turned on and off, creating that familiar noise. 

This issue has an easy fix. You have to check the pipes and make sure that the straps are tight enough to hold them in place. You can tighten them with a screwdriver, replace broken ones or add additional straps for extra safety. You can find both metal and plastic stripes, but if you want to quiet your pipes and reduce vibration sounds, it’s best to use padded straps. Another thing you should pay attention to is the type of straps and fixtures you use on copper pipes. In this case you should never use galvanized or steel straps, as these materials don’t work well together and can lead to leaks in the plumbing system. 

Reduce water pressure 

As mentioned earlier, high water pressure can also be responsible for causing water hammer. It’s an issue not only for your plumbing system, but also for the environment, as you’re wasting precious resources. Besides, you must also take into consideration the damages it can cause to your appliances if they don’t have pressure reducing valves installed. Dish-washers, washing machines and other home appliances that rely on water supply can be seriously affected by high water pressure.

The obvious solution is to reduce water pressure in your home by using a water pressure regulator. A pressure reducing valve can also be of help. If you don’t have a water-reducing valve on your property yet, installing one can save you a lot of trouble.

Alternatively, you can contact the water department in your region and ask them to conduct a check. In most areas, they’ll conduct water pressure tests for free. If the pressure is too high, they’ll have it reduced and your water hammer problem will become a thing of the past.

Need some assistance with your Sydney plumbing issues? Call Off Tap Plumbing Pty Ltd Today on (02) 9053 8797 

Quick Links: 

Off Tap Plumbing Pty Ltd
Randwick NSW 2031
(02) 9053 8797
Monday – Friday: 7am – 5pm
Saturday: 7am -12pm
Jesse Sorensen

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