Thanks peteyboy for your response. I hesistated to do that because last year I replaced all the inards to the valve for both valves. But, the job is easy enough to do, so I will go ahead and replace, this time, the whole assembly rather than just the washers and O-rings. Thanks again.

I get a banging noise when I flush my toilets. The house is about 15 years old with copper plumbing. I thought it might be water hammer and tried to drain the system to clear out the air chambers but no luck. I also read that hammer only occurs when you turn off the water. Thanks for any help.

We have the same issue - FL repipe with CPVC. The pipes make noise after hot water is used in the mornings...it clicks, like a dripping sound for 10 minutes after the water has stopped. This is in the summer. We had the plumber come back out and they loosened some of the straps. This provided quite a bit of improvement as the issue is only in the mornings now and not throughout the day as it was before. The issue, I think, is because the pipes travel so far. We have a one story house and the pipes are in the attic. It is the strapping, I believe, that is causing the pipes to make the "dripping" sound. It is VERY annoying to me, but it does not bother my husband (he is the one showering in the mornings while I am sleeping). The sound wakes me up. I would have gone with PEX had I known about the sound issue. The concern I have is the stress on the pipes/straps causing damage on the joints/connectors.

So... If I had access to pipes (such as doing a remodel) I would just replace them. It's easy, and completely resets the clock. If you have some corrosive issue then use PEX instead of copper. The thing is that there is a lot of discussion about chemical leaching, long-term effects of chlorine, physical wear (from water moving over it) with regard to both copper and PEX. Those issues have been determined at this point for copper and PEX... I don't know about epoxy. I would also think that some of the long-term effects are really dependent on the installers: Was it mixed properly, was it cleaned properly, etc. I'm not sure how it could get NSF certification with the variables on each installation. Also, how are repairs/modifications handled? If it wasn't accessible (slab), I might be more willing to consider it... but would really try to go with what has a long history of use instead.