In this video, This Old House plumbing and heating expert Richard Trethewey quiets a tap that's making a hammering sound.
1. To determine which water-supply line is creating the hammering noise, start by turning the faucet's hot water to the fully on position. Then turn off the hot water and turn on the cold water. Listen for which line is causing the noise.
2. Once you've isolated the problem, reach under the sink and open the shut-off valve all the way. A partially closed valve will often produce noise.
3. If opening the valve doesn't silence the noise, replace the existing valve with a new valve.
4. Hammering, vibrating noises in plumbing fittings, including toilet fill valves, are often caused by worn or damaged rubber washers.
5. Ball valves don't contain rubber washers, so they're less likely to produce noise.
6. If your home's water pressure is too high, install a pressure-reducing valve at the water main. Adjust the valve to maintain the desired amount of water pressure.