Hi Everyone!
My parents house (built in 1960) recently started having pipe banging sounds on the cold water pipes. It happens from every faucet and toilet. The banging is in the basement and the pipes aren’t physically moving and banging.
I’ve tried draining the system but it comes back after a short period.
Last week I tried installing a home-made water hammer arrestor without any luck.
The water supply is 3/4″ copper. Before going to the first faucet its reduced to 1/2″ copper and remains 1/2″ for the whole house. In the 3/4″ section I installed a “T” with the third leg being a piece of 3/4″ x 9″ long capped pipe. The pipe is pointing straight up.
What do you think? Should I have placed it in the 1/2″ section? I can’t believe that after all these years I now need to install an arrestor at every fixture.
Thanks!
Replies
Try walking around in the basement and listening carefully while an assistant turns water on and off upstairs. See if the noise seems to come from a regulator or check valve or some other piece of equipment down there. Touch the pipes to feel if they might be vibrating, but not far enough to be visible.
-- J.S.
try a longer leg on the pipe. Better yet might be to put one in the basement next to the laundry tub cold water supply. You shouldn't need an arrestor at every fixture. Make it three feet long so it is more difficult fill with water, and has a larger air cushion.
Has your water supply pressure changed? This could explain the occurrence of the problem after so many years.
Since there is a basement, try this. Connect a water hose to a fawcett. Put a shut-off on the other end of the water hose, then turn on the water fawcett. Now see if the pipes still hammer using another fawcett somewhere. The hose will act as an air chamber.
If there is no more hammering, then somewhere in the house there should be riser pipes whose purpose is to control the hammering. They should be filled with air. These are usually located in the wall behind a hot water heater or behind a shower wall. Usually one on both the hot water and cold water pipes. If the riser pipes get filled with water, then there is no longer an air chamber to control the hammering.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
True water hammer is a single bang, maybe followed by a couple of ratles when the water is quickly shut off. Often seen on washers as the soleniod valve closes quickly. But I have seen it a little on newer "cartridge" faucets as the can be closed quicker.
It is made worse by higher water pressure and undersized lines (high flow rates) and pipes that are not secured (increase the rattle).
A sealed hammer arestor is the best thing to stop this. While the sealed pipe stub will work, it only works for a short period of time before the air is absorbed into the water.
However, there is a completely different problem.
It is caused by "something loose" in the water flow. It causes a continous noise as the water is flowing, but the pitch and amount can change by the flow rate.
It can vary from a high pitch squeal to a slow bang/bang to a machine gun sound.
If it is only at one location then often a loose/missing screw on the faucet washer.
If the noise is caused by flow in multiple locations then you need to look at something common to all of them. Might be the main shutoff, a pressure regular, water filter, etc.
Wow, thanks for all the info.- I can't feel any banging and don't see any valves in the area I hear it from.- I'll check the pressure. I don't think its changed. 15 years ago we put in a lawn sprinkler system and the pressure was 80 psig.- I don't see any existing riser pipes in the basement (except for the one I installed).- No continuous noise during flow, only at shutoff. The other day I had a faucet on the 2nd floor open. A toilet on the 1st floor shut off and it caused a quick surge from the open faucet!- I'll try the garden hose trick (great idea). If that works, I'll add a long riser pipe next to the washer. The pipe is only 1/2", so I'll step it up to 3/4 and run it all the way up to the ceiling.Probably won't get to the house till next month. I'll let you know what I find out!Thanks
Hey!I just noticed this computer's auto login to the forum has me as a different user! I better fix that!BigOtter alias Rx7Rob alias ....