2. Install a water hammer arrestor. When a valve shuts off, these air-fill cylinders absorb the jolt resulting from sudden water pressure increase.

Q: Every time I turn off the water faucet in my laundry room, it sounds like someone is banging on the wall. Is my house possessed by evil spirits? Please help; the noise is frightening my kids.

If your water pressure is over 80psi, your plumber may suggest several solutions. Usually, he can install a pressure-reducing valve to lower the water pressure, and install a water-hammer-arrester ...