Replies

1. 
   DanH | Jun 05, 2010 05:16pm | #1

   Cartridge makes a little bit of difference, based on how quickly the water is cut off.  But since all the units are acting the same I'd say it's unrelated to the cartridge.

   I had a similar problem where the pipes would bang whenever the water was shut off in the upstairs bath.  Tried several things, including installing a water hammer device at the sink.  Nothing helped until I happened to be downstairs when my wife operated the faucet.  I then could clearly see/hear where a pipe was banging against the main return air duct for the furnace.

   Added an extra pipe clamp to hold the pipe away from the duct and everything was hunky-dorey.

   You may have disturbed something when you changed out the cartridge, possibly when you cut off the water.  Look in the area of the water cutoff to see if the pipe's obviously hitting something.  Shake the pipe around a little to see if it moves and what it might be hitting.

2. 
   Matt | Jun 05, 2010 05:44pm | #2

   .

3. 
   barmil | Jun 13, 2010 04:07pm | #3

   Water Hammer

   I think you're describing water hammer. This is especially prevalent with a fast closing valve, like on a clothes washer. You could pretty much resolve this throughout your house by installing water hammer arrestors between the clothes washer water inlet and the washer hose, available at all big box or hardware stores. They'll probably last about ten years.

4. 
   JohnSprungX | Jun 14, 2010 04:06pm | #4

   It's definitely water hammer.

   Are you sure that there are water hammer arrestors in that bathroom?  If not, install a pair where it's most convenient, probably under the sink.  The flow will still stop abruptly for anything downstream of the arrestors, but only for the distance to the arrestors. 

   Modern arrestors have a flexible diaphragm to protect the air they contain.  Draining the system helps with the old dry risers, which do fill up with water because the air dissolves into the water over time.  Somebody else will probably know better, but I think dry risers went out of style like about 30+ years ago. 

   Even with hammer arrestors, the water still has to come to a stop.  It's just that it's more like falling onto a set of box springs instead of a concrete floor.  The peak impact is just spread out a little over time.  So, your pipes still have to be properly secured.  What seems tight enough when you wiggle it by hand might not be.  Have somebody turn the faucet on and off while you look around and listen for the source of the noise. 

   -- J.S.

5. 
   NDMatt | Jun 17, 2010 05:17pm | #5

   Well I learned my lesson on this one.  I looked everywhere for a pipe that I might have loosened.  They were all tight.

   I also drained the whole plumbing system to make sure any hammer arrestors had air in them.  That didn't do anything either.

   So I looked around on the web a bit and found that others (read: real plumbers) thought the knockoffs from HD aren't any good. Finally I got sick of the knocking and went to a real plumbing supply store and bought a Moen cartridge.  Put that one in and the knocking stopped immediately.  So it must have been the cheap Danco cartridge that was causing it.

   I guess I'll put that one in the knowledge bank: BUY QUALITY!

   Thanks for the advice everyone.

1. 
   calvin | Jun 18, 2010 06:21am | #6

   Here's another to add to the bank

   Moen would probably have supplied you with the cartridge replacement for free.  At least it's worth the call.  Most of these quality plumbing fixture suppliers carry a much longer warranty (than a yr)  on simple parts like that.