About Water Hammers

Einstein was a brilliant man. Perhaps one of his most famous quotes is, "For every action, there is an equal and opposite reaction." A water hammer is just that. While some may consider it nothing more than an annoying noise in their pipes, it is the culprit of some very devastating plumbing problems. Recognizing a water hammer and repairing it before it destroys your pipes will not only save you money, but many unnecessary headaches as well.

Function

Water hammers are symptoms to an underlying plumbing problem. They present themselves as a loud knocking or hammering noise in your pipes and are considered to be the equivalent to an explosive shock wave. They occur when a large amount of water pressure has accumulated from water flowing in one direction. Once the source of the flow has been shut off, the water movement stops suddenly and begins to move backward, while the remaining water in the pipes continues to move forward. This causes a collision, resulting in a shaking or vibration of the water pipes. Water hammers commonly occur with washing machines, dish washers, toilets and sprinkler systems.

Causes

There are many reasons why water hammers occur; they include pipes that are handling a large amount of water pressure without a gauge to regulate its force, piping that is too small to handle the speed of the water flow, the piping system being improperly connected to the structure, and pipes that lack a dampening system.

Considerations

A water pressure setting of 40 psi (pounds per square inch), will allow sufficient pressure to flow through the pipes, while possibly eliminating the chances of a water hammer occurring. If you do not have a water pressure regulator on your piping system, and your psi is 60 or greater, you may want to have a plumber install one to ensure your psi is regulated to a normal level.

Prevention/Solution

Once you begin to hear water hammers in your pipes, locate the specific area such as the washer or the toilet, and install a water arrestor on that joint. The water arrestor will absorb the water pressure so that it doesn't shake and damage your pipes. You will also want to attempt to reduce the velocity of the water as it moves through the pipes by installing a low flow fixture at the problem site.

Warning

Leaving a water hammer untreated can cause more serious plumbing problems in the future. They rupture pipes, cause connections to weaken, resulting in water leaks, damage water valves, rupture water tanks, and rupture joints and pipes without warning. Not only will these problems cause damage to the rest of your home, they will also be more expensive to repair than the water hammer itself would have been.