DIY May Be Possible Avg. cost: $175

Banging Pipes (Water Hammer): Causes, Fixes & When to Call a Plumber

Banging pipes (water hammer) occur when fast-closing valves create a pressure shockwave. Install water hammer arrestors at the problem fixtures, or have a plumber add an air chamber. Left unaddressed, water hammer can eventually loosen pipe joints.

What Causes Banging Pipes (Water Hammer)?

Fast-closing washing machine valves
Dishwasher solenoid valves closing quickly
High water pressure amplifying the effect
Loose pipes not adequately secured to framing
Worn or absent air chambers in the supply lines

How to Fix Banging Pipes: Step-by-Step

1

Verify water pressure is under 80 PSI using a gauge
2

Install washing machine water hammer arrestors ($10–$20 each)
3

Secure any loose pipes visible in the basement or crawlspace with pipe straps
4

Drain the system to recharge any existing air chambers: turn off main valve, open all faucets, then close faucets and restore water

When Should You Call a Plumber?

Call a plumber if the banging is very loud, affects the whole house, pressure reduction doesn't help, or you notice water damage near pipes — this can indicate pipe joints loosening.

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How Much Does Banging Pipes Repair Cost?

Average Cost $175

Typical Range $75 – $500

Costs vary by location, severity, and whether emergency service is needed. Prices shown are national averages. Get a free quote from a local plumber →

Frequently Asked Questions About Banging Pipes

Is water hammer dangerous?

Repeated water hammer stresses pipe joints, connections, and appliance valves over time, potentially causing leaks. It can also damage appliances. Addressing it is worthwhile, especially if your pipes are older.

What is a water hammer arrestor?

A water hammer arrestor is a small device with a sealed air chamber that absorbs the pressure spike when a valve closes. They install in minutes on washing machine and dishwasher supply lines and cost $10–$20 each.

Why do my pipes bang only when I flush the toilet?

Toilet fill valves close quickly after the tank refills. If banging occurs only then, install a water hammer arrestor on the toilet supply line or replace the fill valve with a slow-closing model.