Plumbing and Piping - Help Please!!!! Banging water pipes in shower only!!!

We added a bathroom on our home about 2 years ago.. We had some problems with banging pipes in our shower...

When the single handle shower valve is in the six o-clock position (warm) the water pipes chatter loudly (loud banging sound), if the handle is moved slightly (hotter or colder) the noises stop.

The shower wall is tiled and it’s an American standard fixture set.

The plumber came out and installed a vent of some sort on the cold water line underneath the sink to help alleviate pressure. I thought it was odd that the plumber put it on the sink when the tub was the problem. Anyway, I think it worked fine because the noise stopped for a few weeks... But came back!

It got to the point that if we didn't pull out the handle all the way, it doesn't bang... It only bangs with the handle all the way out... So we lived with it...

Now, I need to fix it. A plumber came out today and said it is probably the cartridge and he doesn't think it's "water hammer"...

Do you think it's as simple as replacing the cartridge?

Any advice? I've noticed, if I have the sink on in the bathroom at the same time as the shower, it doesn't bang... I need help please!!!! :wall:

I should add that it only happens when I pull the handle all the way out (in the middle), if I pull it half-way, it's fine...

By the way, I also should add that I drained the plumbing system last night so the air chamber could be released (read it online) and it went away for the evening. This morning, I could feel it gradually coming back.

Thanks! :wall:

I'm not familiar with American Standard fixtures but that kind of machine-gun rattling is often caused by a loose washer in a valve somewhere. Do you have individual shut-off valves for servicing on this shower? That would be the first place I would look. It could be the cartridge in the shower valve itself as you were told.

So, what's the easiest way to diagnose the problem? It only happens in that bathroom room and their are ball valves on the outside? Could that be the problem? Would installing another air chamber on the hotwater side work as well?

Look forward to your replies! Thanks!

Air chambers are neither the problem nor the solution. You can try setting the valve so that you have the machine-gun stutter and then slowly closing the ball valves to see if this has any effect. If it does then you know it is a flow-related problem. Are you sure it has ball valves? Usually ball valves are not a source of trouble. My money is on the "guts" of the shower valve itself.

Thanks for the info...

Here is a picture of the ball valve I am referring to. I have these coming off existing pipes and going straight to the new bathroom: http://www.plumbingsupply.com/images/pvc-ball-valve.jpg

Any idea why resetting the water system helped? Here's a link the article that made me try it: Water Hammer - Hydraulic Shock - Description (http://homerepair.about.com/od/plumbingrepair/ss/pipe_noises_2.htm)

Looking forward to your feedback...

As I originally stated I am not familiar with the American Standard valve. If it is at all like its competitors it is a fairly easy and relatively inexpensive matter to change out the internal parts.

Sorry, but that's all I have to offer.

Thanks for the info...

Here is a picture of the ball valve I am referring to. I have these coming off existing pipes and going straight to the new bathroom: http://www.plumbingsupply.com/images/pvc-ball-valve.jpg

Any idea why resetting the water system helped? Here's a link the article that made me try it: Water Hammer - Hydraulic Shock - Description (http://homerepair.about.com/od/plumbingrepair/ss/pipe_noises_2.htm)

Looking forward to your feedback...

If the plumber put in a shock absorber and he is not living in the dark ages you don't have to recharge them, modern absorbers are sealed chambers with a bladder in them.

If the plumber said he though the cartridge was the prob. and this thead is leaning in the same direction, that should be the place to start, luck. :confused: