‘ Water hammer’ is a very specific plumbing noise, it’s a pressure surge or shock wave that is created when water moving through a pipe is force to either stop or change direction suddenly. For example, a ninety-degree pipe bend or union would cause this. Water hammer often occurs when a dishwasher, washing machine, toilet, or faucet shuts off water flow suddenly. This produces a loud bang or banging sound. The shock waves of the bang(ing) travel faster than the speed of sound and can create a great deal of pressures. Over time, water hammer effect can damage pipes, valves and even weaken pipe joints.

A solution to the water hammer problem, in more modern homes, is to install devices called air chambers. The chambers or cushions are filled with air, they absorb the shockwaves. The problem is that over time these devices often become partly or completely filled with water. This happens because the air, over time, is absorbed by the water, and water takes the lost air’s place.

The damage water hammer causes can lead to a pipe breaking or bursting, which can lead to property damage or even injury. A professional evaluation is recommended, both to determine the extent of the problem and to get an estimate of what repairs or replacement will cost.

Even though water hammer generally isn’t very threatening, it has caused accidents and fatalities. Usually the most damage done is the breaking or busting of a pipe from the inside. It’s important to have a professional evaluate your problem and see how extensive the problem is and what it will take to repair it.

If the air chamber is lower than the height of the valve, more work may be needed. The main water supply lines might need to be drained too. Sometimes air chambers won’t drain completely; it may be because of build-up of mineral or chemical deposits. If the chamber can’t be cleaned out it will need to be replaced.

If the home’s plumbing system doesn’t have air chambers built into it, reducing the water pressure may be a solution, this could be accomplished with the installation of valves that reduce the pressure of the lines coming into the house. But this might not work if it leads to such low pressure that faucets and valves on upper-floors only have a trickle of water coming out of them. If pressure reduction doesn’t work, it may be necessary to install air chambers into the current plumbing system. Many of the chamber devices currently on the market have a built-in valve for letting air refill.