The Sounds Of Water Knock

wopachop

Hoping you pros have the ear and experience that i dont. there is a water knock that developed after installing a new shower valve. the old valve was very poory attached.

this house was remodeled before homeowner bought it. if you stand in the shower and face the shower valve the pipes actually exit the exterior wall to my right, travel up the exterior wall attached to the stucco, then re enter the 2nd story where a bath was added years ago.

i was hearing the knock down and to my right so i thought the pipes were shaking there. the wall is freshly tiled i fully secured every pipe i had access to when the wall was open...now tiled...now we hear this knock

the guy at the plumbing supply suggested that since the old shower valve was just floating it kind of took some impact. now that the new one is solid its causeing other pipes to move more than they used to.

sorry post is so long....we installed size aa arresters on each valve...now the noise has changed pitch and comes from a different location. it seems to come from my left where pipes run to a toilet and sink in a bathroom that shares the wall with the bath im working in.

well the noise almost osilates now its not a thud like before, sounds more high pitched and pingy, and sometimes there a multiple quick vibration sounds...could i be hearing the hammer arresters springs absorbing the blow and that sound resinating through the pipes? its weird maybe i can get video so you guys can hear it...nobody will be here till 530 though.

thanks for reading

JamesNLA

Since Ron said he was going to help anyone that came in here...I guess I will too!!!hehe

First, shut the angle stop on the toilet to eliminate the possibility that the ball cock is causing an issue.
Now, most times water hammer (not knock) is due to poorly strapped piping. Not always the case....washing machine for example, anyhow from what you said, I gather that this is a constant noise as the shower is running?

If that is the case a few things. A of course make sure ALL pipe is strapped correctly. If you do not know how to strap pipe properly, call a plumber who does. Next, remove the cartridge again. I say again because a good plumber will remove the shower valve cartridge when sweating the new one on. A somewhat common occurance of the noises you are talking about is caused from debris that got to the cartridge. The debris can get into a position to cause as resonance or humming. I have heard these in high pitch as well as low too. Pull the cartridge and flush the valve body. (that means turn the water on briefly with the cartridge removed. Inspect the cartridge....hell just replace it to eliminate that being the issue. Most real supply houses will just swap you a new one. If you do all that and the problem still exist than you missed something so start over and do it again. Strapping pipe is alot more important than people think. You should not need arrestors for a shower valve, so if you get relief by using the arrestors...your just covering up the main issue with a cheap bandaid. Good luck and don't take on jobs that are above you. Yes...yes..I know it hurts the ego to tell a home owner that you can't do something however it will make you a better person. If you feel the need to do plumbing work may I suggest you hire on with a plumbing contractor to learn...who knows maybe you will one day want to graduate from being a handy person to a real contractor. And when that day comes, you too may look down upon handy people who have not invested the time effort or energy...or money to become licensed. Handy people are great for changing that back gate latch or changing the knobs on the cabinet faces.....installing a new shower valve may sound simple but actually requires a good amount of experience and supervision.


Holy Jesus you're in San Diego.....you know damn well you are not alowed to cut into or sweat pipe.......you can do jobs that do not require a permit and where the total job does not exceed $500. Play by the rules, they are there for good reason...

__________________
"....And then we all switch places when I ring the bell"
-Adrock

Ron The Plumber

Knocking sounds come by via loose washer, pipes, parts. Have to tested the pressure on the house, excess pressure can be a cause at least high pitched sounds, does it happen no matter what is used in on the valve, cold or hot usage?