Often you will hear much more hammering and knocking noises when the household water pressure is too high. Test the water pressure with a gauge that can screw onto an exterior hose bib or behind the washing machine. If the pressure is above 75 pounds per square inch (psi), you may need to have a pressure regulator installed or, if you have a regulator, it may have gone bad and should be replaced.

Water hammer arresters are simple devices that are installed within the water line to a specific fixture or appliance. Arresters absorb the shock wave created by a sudden stoppage of the water flow. Installing a water arrester on each line supplying the offending fixture (or fixtures) usually solves the problem. However, if the problem seems to be widespread, you may want to start by testing your home's water pressure to make sure it's not too high.

NitroRegulator

Aaron Stickley is a licensed plumber with 15 years of experience in commercial, new residential plumbing, and residential service and repair. He started his own residential service and repair plumbing business. Aaron's articles about plumbing on The Spruce span four years.

High PressureRegulator

Most water hammer arresters are installed on the washing machine valves, but the instructions may recommend connecting them directly to the back of the washing machine to protect the washer hoses. The issue with installing them here is that it can make the washing machine sit farther away from the wall. If space is too tight, then connecting the arresters to the valves may be the only option.

If the washing machine water supply is the culprit, then install water hammer arresters on both the hot and cold water supply lines. The easiest type to install is simple screw-on devices that fit onto the faucet spigots where the washing machine hoses are connected. There are similar devices for other types of appliances and water supplies.

High Pressure nitrogen regulators

Sometimes, you might find that the best place to install a water hammer arrester is somewhere that doesn't provide easy access to shut-off valves or threaded connectors. In this case, you will need to purchase and install a T-shaped fitting into which your water hammer arrester can be attached. You'll need to cut into the pipe, install the fitting, and connect the arrester to the threaded outlet on the side of the fitting. Again, using plumber's tape before screwing in the arrester will help prevent leakage.

Shut off the valves on the washing machine hoses tightly, then disconnect the hoses from the valves. Take care that you do not lose the washers at the end of the hoses.

Harris OxygenRegulator

Progress. Together: Our partners share our focus of providing the highest-quality water products and solutions customers need today, while innovating for future needs.

If you find that your water hammer is originating when you flush a particular toilet, you'll want to install your arrester on the water fill line, To install one there, first turn off the water by turning the football-shaped knob in the clockwise direction. Then, unscrew the line from the toilet tank, screw the water hammer arrester onto the threads at the bottom of the tank, and attach the water line to the other side of the arrester. Plumber's tape on the threads will help secure the installation.

Observe to determine what appliance or fixture seems to be causing the banging in your pipes. The most common culprits include washing machines, dishwashers, toilets, and refrigerator ice makers or water dispensers. All of these appliances have solenoid valves that shut off the water instantly, unlike a faucet, which reduces the water flow until it is shut off completely.

Connect the washer hoses to the water hammer arresters, taking care to make sure that you match up the hot water hose to the hot water supply. Tighten each connection carefully with the pliers.

If you hear banging, rattling, and other odd sounds coming from inside your walls or floors, and the noises seem to coincide with flushing the toilet or running the washing machine, chances are you've got a water hammer. Water hammer occurs in water supply piping and is caused by the sudden stop or change in direction of water flow, such as when a washing machine or toilet stops filling from a quick closing valve. Usually, a water hammer does not cause any damage to plumbing, but in extreme cases, it can lead to failure in fittings or pipes.

We are committed to providing value-added design and maintenance resources through world-class support and continuing education opportunities both in-person and online. Here is everything you need to be the smartest person in the room.

Where areRegulatorboats made

Turn the water back on and check for leaks. If any joints are leaking, tighten them just a bit more, using the pliers. The arresters will work at any angle, so position them however they best they work for your situation.

What fish is onRegulatorLogo

If a water hammer arrestor doesn't fix the banging noises, there are a few other things you can try. First, make sure the pipes are secure with enough straps to prevent pipes from moving. To absorb any shock, try wrapping the pipes with foam insulation. Lastly, try turning on the taps, which can help release any existing air pockets in the pipes. If you still hear banging after this, call a plumber to ensure there is not a deeper problem at play.

Harris Regulators

When everything looks good, turn the water back on, check for leaks, and give the toilet a flush to make sure the hammering is eliminated.

High water pressure and if your pipes are copper are other reasons you might be hearing banging noises if your water hammer isn't to blame.

You can easily find the source of the banging/water hammer by checking any visible pipes and air chambers in the plumbing. Banging is caused by a change in water flow, so you'll be able to gauge the source of the noise from the pipes.

Thread a water hammer arrester onto each water supply valve, making it hand-tight. Then, snug it up a bit more with tongue-and-groove pliers, but be careful not to overtighten.

Regulatorlogin

Our family of brands has grown substantially over the years. What does that mean for you? Only the highest-quality solutions to get the job done reliably and efficiently. We have everything you need for plumbing & flow control, water quality & rainwater harvesting, drainage, and HVAC & hot water systems.

Be Our Greatest Resource: Bring your professional skills and goals to a global leader designing and manufacturing water technology solutions that are protecting our planet's future.