What is water hammering?

If you are hearing a knocking sound or a rattling sound then you may be experiencing a water hammer
problem that should be fixed immediately. There are a couple of different reasons this may be occurring.

One reason may be the hard pipe inside your wall may not be strapped down properly; water hammering can also be an indication that your home’s water pressure may be too high.

If a pipe is suddenly closed at the outlet (downstream), the mass of water before the closure is still moving forward with some velocity, building up high pressure and shock waves. In domestic plumbing, this is experienced as a loud bang resembling a hammering noise. Water hammer can cause pipelines to break if the pressure is high enough. When a valve in a pipe is closed, the water downstream of the valve will attempt to continue flowing, creating a vacuum that may cause the pipe to collapse or implode. This problem can be particularly acute if the pipe is on a downhill slope. To prevent this, air and vacuum relief valves, or water hammer arrestors, are installed just downstream of the valve to allow air to enter the line and prevent this vacuum from occurring.

If you think you may be experiencing a water hammer problem, we suggest you contact a local plumber so this problem does not cause a break in your water line. Please note that this problem is serious and should not be overlooked.