Odd noise from Moen M-Core 3 valve

[catbean]

My contractor recently installed a Moen M-core 3 with integrated transfer. When I turn the water off slowly there is no noises, however turning the water off fast I will hear a noise. Sometimes the noise is a dull "thud" and other times it sounds like a "pop" or "hiccup" coming out of the pipe. The noise is present on both hot and cold, on both the shower head and tub spout. Oddly, the handheld does not make this noise? Is this some manifestation of a water hammer? My plan is to swap the cartridge and see how it goes...

Link to a video of the noise.

 

[GReynolds929]

It's not the cartridge, it's the pipes in the wall. Probably had copper previously and was repiped with PEX. The PEX is moving when he water is shut off and hitting the studs. May not have been secured adequately.

 

[Sponsor]

 

[catbean]

It's not the cartridge, it's the pipes in the wall. Probably had copper previously and was repiped with PEX. The PEX is moving when he water is shut off and hitting the studs. May not have been secured adequately.

You are correct I believe they replaced copper with pex. Would adding hammer arresters before the valve be helpful, I'm not sure all the pex will be accessible to inspect/resecure as the tile/bathroom is finished.

 

[catbean]

Well I went ahead and added hammer arrestors to the supply lines and replaced the cartridge on a whim. The issue is exactly the same no resolution. I also used a camera to poke around in the walls confirming no major pipes movement and tested the house water pressure to be 60psi. I'm loosing my mind here, anything I'm overlooking?

 

[Tony3218]

I have this exact same issue. It is very aggressive water hammer when turning the diverter and turning the water on and off. New plumbing was done in copper. The mixer and integrated transfer valve are on the opposite side of the tub spout, shower head and handheld.

I have replaced transfer valve and cartridge and no change. Tried running the water with no shower head or tub spout and no change. Water is 65PSI.

I found using the flow restrictor in the shower head helped stop the hammering for that. I have tried to add a restrictor to the tub fill and that helped a little but still has the hammering. With the restrictor installed in the tub spout I am now at 5 gal per minute and still have the issue.

Did you ever figure out the issue?

I have air chambers on the hot and cold supply pipe to the mixer valve, but it seems they don't help because of the rubber check valves that are in the mixer.