How To Fix Water Hammer In Plumbing Pipes

Your home is your haven and it is the ideal place for peace and relaxation. Is there anything worse than a sudden and alarming sound from your plumbing to ruin that peace?  Have you ever heard what sounds like hammering or banging after you shut off your tap? That sound, which often comes with a strange and disturbing vibration, is known as a “water hammer”. It is also called, rather dramatically and even more accurately, “hydraulic shock” or “hydraulic surge”.

What Is Water Hammer?

Water hammer refers to the sound that comes from the water in your pipes when water gets backed up in a pipe. It is a specific sound, not just any plumbing knock. It is a very clear knocking, banging, or hammering sound. It can happen when a dishwasher or washing machine abruptly stops drawing water, or from turning off the water at any tap in the house. 

What Causes Water Hammer?

It occurs because when you suddenly cut off the water, the water that is rushing through the pipes is also stopped quickly as well. This creates a shock wave and the hammer sound is a result of the pipes hitting against each other, or against wooden supports around them. This effect can be so strong that it can loosen joints in the plumbing or even break pipes.

Properly installed plumbing uses air cushions, also known as air chambers, that prevent the hammer effect by absorbing the effect when the air is compressed. When those chambers fail, or if they aren’t present for some reason, you have the shock sound. 

How To Fix Water Hammer

So, what do you do if you are experiencing a water hammer in your house? Here are some things you can try. You will need to shut off and drain the water from your pipes before doing some of this work so make sure you feel comfortable working in this area before you start. And, if you’re lucky, that is the easiest fix of all because sometimes that solves the problem right there! If not, check out the ideas below:

  • Support and cushion the pipes. If the affected pipes are visible, you can tighten any straps that have loosened or cover the pipes in a layer of foam pipe insulation. This could resolve a minor water hammer. ( A word of caution: consult your hardware department or trusted plumber if you have metal pipes since mixing metals can cause dangerous corrosion)
  • Is there an air chamber? If there isn’t one, they are easily found at your local hardware store. It is basically just a segment of empty pipe that provides an air pocket for water to escape into when it is stopped or needs to change direction quickly. If it *is* present, you will want to check if water has filled the chamber, or if debris or minerals have blocked it. 
  • You can also install mechanized arrestors. These are placed directly into faucets and washing machine valves but are most often used in commercial buildings or where the water pressure is unusually high. They work by using a simple bladder and spring system.
  • Install a water pressure regulator. The high water pressure causes water hammer and with one installed you can protect appliances and plumbing fixtures against high water pressure *and* prevent water hammer from harming the pipes. 

Quiet Your Water Hammer Noise

So, if your plumbing has started making that annoying and sometimes scary water hammer noise, try a few of these solutions first. If that isn’t your thing or if you aren’t successful, you may need the help of high quality, reputable plumber like us here at Phend Plumbing.  We are trained in handling every kind of plumbing issue and our skilled, qualified plumbers are ready to assist. You can find us at and you can give us a call at 480-388-6093 to schedule an appointment to handle your plumbing issue, no matter how simple or complex.