We recently bought our first house and it is great..except for the water hammering when running hot water. Most noticable in kitchen and bath sinks. Standard 3/4″ piping is buried in the walls with the valve protruding into the cabinet opening. 3/8″ flexible copper tubing runs from the valve to the sink. What options do I have to stop the water hammering? Will the commercial 3/4″ water hammer suppressors work if I splice into the 3/8″ line using couplers?
LASteve
Replies
The lousy plumber did not secure the waterlines in the wall. Also see if the water pressure too high.
There are several varieties (different connectors) of water hammer suppressors you can install. Best would be to "dismount" the current shutoff valve (I'm betting it's 1/2", not 3/4"), install a suppressor on a tee, then the valve. This gives full flow into the suppressor. Depending on how the valve is attached (generally either threaded to a soldered-on brass coupling or attached with ferrule and compression nut) you would need a different tee (suppressor with integrated tee).
Also, anchor any accessible parts of the problem pipes.
There is different kinds of water hammer.
If you have a single bang followed by several rattles when the water is shutoff the hammer arrestors will help. This is caused by the water suddenly being stopped and no place for the momentum of the water to go.
If you a continous series of bangs rattles, whistles, screaming, etc was long as the water is flowing it is a different problem. There is something loose that is causing this. The most common problem is with a loose washer and that is caused by a loose/missing screw or the wrong size washer. It can also be cause by something in the pipe moving or by worn stems.