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What Is Water Hammer?

Do you hear loud banging from your walls when you turn your taps on? A water hammer is the result of a pressure surge and is sometimes referred to as “hydraulic shock” which happens in your home’s plumbing system. More often it occurs in older pipes. What you’re hearing is the sound of the water creating a pressure wave. It sounds like a series of loud bangs.

It can happen when you switch a valve off or if you turn one on, increasing the water pressure in your water pipe. Anything above 80 psi should be considered extremely high pressure and, at this pressure, can damage appliances. If this continues unchecked, it may also impact any pumps, valves or other instruments included in your house’s plumbing system. This will eventually lead to expansion and gasket joints failing and will affect the integrity of pipes.

If you live in an old house, with an old plumbing system, it’s highly likely you’ve experienced this knocking sound coming from within your walls after you stop showering or using a tap of some kind including washing machines and dishwashers. Know that it’s actually really commonplace for old pipes in older homes to get worn out at some point. They absorb less shock from on/off changes in the water pressure when taps are open and closed to the water supply flowing through the pipes. For example, washing machines automatically control the flow of water from full-ball to nothing within seconds. So, this sudden stoppage causes water hammer or hydraulic shock with the result being your pipes banging against other fixtures. Over time this can lead to disastrous burst pipes and water leaks!

So, now you know how water hammer works, you gotta be wondering how to fix water hammer or prevent water hammer in your home! Your Pro Plumber might install water hammer arresters near your check valves or shutoff valve or we may choose to install air chambers that will reduce the pressure. In the meantime, here are a few things you can try before calling Pro Plumber…

1. Check For Loose Mounting Straps In Your Pipes

If you’ve been experiencing water hammer for a while, it can damage the pipes enough to loosen them from their straps or supports. Pro Plumber recommends the following check:

  1. Go to where your pipelines are installed
  2. Find the valve that gives water supply to your toilet or other fixtures
  3. Watch as you turn the valve on and off and
  4. Look for any movements in the pipes
  5. Secure the loosened pipes with a clamp.
  6. See if they still produce a hammering sound afterwards

If the noises keep up or you can’t see movement at the supply point, it might mean you have a more significant water hammer problem, so let’s try something else…

2. Drain The Water In The Pipers

Water hammer in pipes can be kept at bay by installing a water hammer arrestor or air chamber. Why replace the air chamber? An air chamber is made of copper pipe that absorbs water pressure by compressing it inside the chamber. The chamber loses air as water is switched on or off. Over time this makes it less shock-absorbent. Which, as we said earlier, causes that hammer sound.

So, how do you refill these air chambers with new air? Follow these steps.

  1. Locate the main valve of your water line and shut off the water line.
  2. Turn all your taps on. Every single one throughout the house, starting with the tap that’s up the highest (eg. Ensuite on the second floor) and ending with the lowest point (eg. garden tap).
  3. Remember to flush your toilet until it’s empty as well
  4. Keep them running until you drain all the water from all the open taps.
  5. Leave taps for an additional half an hour.
  6. Switch the main line back on and check that the water pressure is strong again.
  7. If successful, the water hammer should be gone.

If that doesn’t work and you still hear noises banging on your walls from the water pipes then there’s one last thing you can try before calling your Pro Plumber…

3. Reduce The Water Pressure

Try to reduce water flow to your house by adjusting the water pressure regulator. While not ideal, as it will lower the water pressure throughout your house, it will help the water pipes or air chambers absorb the shock wave to a level it can handle. If you don’t have a regulator and water pressure gauge to help absorb the shock wave, consider installing one, so you can adjust the pressure whenever necessary. Ensure that your water pressure range doesn’t go beyond 30-55 psi to avoid further damage to your pipes.

If All Else Fails, Call You PRO PLUMBER For Plumbing Assistance And Excellent Plumbing Services

If everything gets more technical than you expect, or if all else fails, contact your Pro Plumber immediately. It’s time to stop water hammer! Get water hammer solutions before it’s too late and irreparable damage is done. We’ll stop all your water hammer issues in your property. Get in contact with Pro Plumber.

Whether you’re trying to fix the problem on your own or hiring a PRO PLUMBER to do the job, regular maintenance on your plumbing system is the key to preventing water hammer or any other plumbing issues from happening in the future. Pro Plumber offers a free yearly check-up which will give you a detailed report on short-term and long-term issues. Get in contact with us now to get the ball rolling.