Fittings 3 Easy Solutions to Reduce Water Hammer

If you are a plumber, you have definitely heard of water hammer before, and you are probably not a fan (if you don't know what water hammer is, hang tight). When it happens, water hammer can cause significant damage to your pipes, not to mention the loud banging sound you will hear.

Are there ways to eliminate or at least help subdue water hammer? Let's take a look. 

Today, we will discuss what water hammer is and solutions you can try to minimize it. 

What is Water Hammer?

Considered an enemy in any plumbing system, water hammer happens when a valve closes too quickly. When the valve is closed quickly, a shockwave is sent back down the system and vibrations and stress are placed on the plumbing system. Toilet valves or valves commonly found on washing machines and dishwashers are frequent places where water hammer originates. 

Repeated abuse from the water hammer could cause leaks in the joint gaskets, damage to pressure gauges or damage to any other components associated with your pipe system. In severe cases, if the water hammer is bad enough, the pipes could explode causing urgent danger to someone in close proximity. 

Some check valves are more likely to cause water hammer at higher flow rates. Swing check valves commonly close very slowly as they do not include any assistants that have closing functions that would regulate the closing time. 


1. Use Appropriate PEX Materials SSPEX-T05_Top Right Angle

Water hammer can happen in any plumbing system including PEX systems. However, the flexibility that PEX systems have can drastically reduce the volume of pressure surges that would happen in metallic plumbing materials. By creating areas where your PEX tubing can expand and contract, the potential damage from water hammer is greatly reduced. However, you may still hear the noise of water hammer from time to time. 

2. Water Hammer Arrestors

Including a water hammer arrestor at locations where the noise is the main problem can drastically reduce any disruptions. Adding the water hammer arrestor at the closest fixture to the noise will help absorb the pressure surge caused by the water hammer. It also helps to reduce the noise, making it more bearable. You can find water hammer arrestors available in a variety of connection types and an important part of certain water supply stops. 

Although water hammer arrestors will reduce the noise caused by water hammer and using PEX materials will help eliminate damages, PEX piping that is free to expand and contract may occasionally hit something as it moves once the water flow has been stopped, causing some noise. Follow guidelines from your local building code or PEX manufacturer for best practices around securing PEX piping.

3. Turn your Water On and Off Slowly 

This one may seem tedious, but the easiest thing that anyone can do to reduce water hammer in your system is to turn on or shut off your water slowly. Abruptly shutting off the water at your taps or shut off valves will cause the pressure surge, ultimately causing water hammer. It may be a good habit to get into to slowly turn on or shut off your taps, hopefully then you will notice a noise reduction and begin eliminating the ability for any damages. 

Of course, this solution does not account for washing machines or other automatic appliances which, in our experience, tend to be the biggest culprits for water hammer. This is where the water hammer arrestors mentioned in #2 are going to provide the biggest benefit.

In Summary:

Home owner or plumber, both may run into damages and noises caused by water hammer from time to time. Thankfully, in most residential applications, it is an uncommon issue that is simple to fix.

Although there isn't always an easy and permanent solution to 100% eliminate water hammer, you can follow any of these 3 options to reduce any inconveniences caused by water hammer. 

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