Have you ever wondered what’s that thumping in the walls? In some homes the water pipes might make a loud “hammering” noise after a toilet is flushed or a faucet is running, this is a common problem that can be easily fixed. The noise is called water hammering or hydraulic shock and typically occurs when a water line’s valve is closed suddenly, sending a pressure or shock wave down the water line. The wave of pressure doesn’t just cause the noise, but can also cause pipes to collapse.
Many newer homes have devices called water hammer arresters (also known as an air chamber, air cushion, or water capacitor). The water hammer arresters are air-filled chambers connected to the plumbing that let the pressure wave dissipate harmlessly into a cushion of air. If your plumbing has been making the hammering noise for a long time, your home might not have any air chambers to alleviate the pressure.
The best solution to lessen the pressure is to contact a plumber and have a mechanical or engineered water hammer arrestor installed.