Water hammer in the shower

[dallasl]

I remodeled the bathroom and put a single handle avalon price pfister faucet in. I also put in a eljer titan toilet. When I flushed the toilet I would get three loud rattles behind the shower valve. I cut holes in the wall, everything was secured down well. I put a water hammer arrestor in the cold line which changed nothing. I have isolated the sound to the shower valve itself. I changed the cartridge and the sound changed form a loud rattle to a less loud thump. Anything else I can do or is the cartridge in the valve to blame. Would a water hammer arrestor on the hot line have any impact? Any other thoughts.

[jadnashua]

Where did you put the arrestor? To work, it needs to be near the valve that is causing the problem - near the toilet. An easier solution might be to replace the fill vavle in the toilet with one that doesn't turn off as fast. One other thing you can try is to turn the water shutoff for the toilet down a little...less water, less hammer.

Also, check your water pressure. Depending on how high it is, dropping it down with a pressure reduction valve (PRV) may be called for. You can buy a screw-on valve that will fit on your hose bib or washing machine supply an check it fairly easily ($about10).

[dallasl]

The arrestor in right near the toilet valve. I tried turning the toilet valve to near closed and flushing but got the same rattle. Would i need the pressure reducing valve if I never had a problem before this remodel?

Open the shutoff at the wall all the way. There may be a bad washer in the shutoff that is vibrating.
Terry