How to Fix a Hammering Sound in a Water Pipe

Eliminating water hammer takes very little time.

The hammering sound, called a water hammer, in water pipes is due to the lack of an air cushion in the pipes causing a high level of water pressure. Unusually high water pressure damages faucets, fittings and pipes if left unfixed. Water hammer does not occur while water is running through the pipes, only when a faucet or valve shuts off. The easiest repair is to restore the air cushion to the pipes.

Instructions

1. Turn off the main water supply valve to your home.

2. Shut off all water valves in the house including dishwasher, washing machine, water heater and toilets.

3. Turn on the cold water at the faucet closest to the main supply valve and leave it turned to the open position to allow water to drain from the plumbing pipes.

4. Turn on the cold water at the faucet located farthest from the main valve and leave it turned to the open position to allow all water to drain from the interior plumbing.

5. Turn off the faucet closest to the main valve when the water stops flowing from the faucet, then the faucet farthest from the main valve.

6. Turn the main supply valve on.

7. Open the water supply valve on washing machines, refrigerators, water heaters and toilets; flush the toilets.

8. Turn on the hot and cold sides of the faucets beginning with the faucet nearest the main supply valve, leave it running, and continue to the next faucet or shower.

9. Allow the water to run for 10 minutes to force air out of the pipes.

10. Turn all faucets off beginning with the one located closest to the main supply valve to restore a water cushion.

Tips & Warnings

• Repeat this process to restore an air cushion as needed. This is a temporary, yet effective, fix.

• Expect pipe noise after restoring the water supply for the first five to 10 minutes.

References

• "Grandpa's 5001 Handyman Secrets"; Dr. Myles H. Bader; 2006