How to Stop Water Hammer (and Make Your Laundry Room a Whole Lot Quieter)

A simple device can put an end to all that clanging and banging

person with fingers in ears to block noise from washing machine behind them Photo Illustration: Consumer Reports, Getty Images

Some washing machines are noisy, and you learn to live with it. We find there’s a huge range in the machines we evaluate in the lab, but even the noisiest machines might not bother you if your laundry room is located in the basement or otherwise far enough away from your living spaces.

But when the pipes connected to your washer shake and rattle, it’s a disturbance you can’t easily tune out—no matter where your machine is located. That rattling sound is called water hammer, and Consumer Reports has a fix.

Fast-closing washer valves cause water hammer. And when water hammer gets bad, it can actually damage your washing machine’s pipes or the fixtures attached to the pipes.

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Not all washing machines create water hammer, says Bernie Deitrick, a Consumer Reports engineer. But if your washer does shake the plumbing, first try an inline water hammer arrester with hose fittings. The Sioux Chief Mini-Rester 660-HB Water Hammer Arrester, $16, (shown below) solved the problem in our tests.

If an arrester doesn’t eliminate the water hammer, reduce peak flow by partially closing the water-supply valves. The washer will fill more slowly but it will still fill to the right water level.

If that doesn’t work, consider a larger arrester or pressure reducing valves. (Hire a plumber to install those.)

Sioux Chief Mini-Rester 660-HB Water Hammer Arrester

Photo: Sioux Chief Photo: Sioux Chief

If you’re shopping for a new washing machine, start with our washing machine buying guide, or look for the best machine that fits your needs, starting with our round-up of the best washing machines from our extensive lab tests.