"Stretch" wrote in message
oups.com...
Might be Stress Corrosion Cracking. The insulation blowing agent used
in some rubber pipe insulations is corrosive to copper tubing when wet.
Usually just a problem with refrigeration piping, I never heard of it
on hot water lines. At any rate, your tubing in the wall needs
replaced.

Stretch


I didn't think of it until another poster brought up pinholes. In some
areas, the water is very corrosive to copper pipes. Perfect area to use PEX
if that is the case.