My parents had the same problem. They had the whole house replumbed in
CPVC approx 20 years ago. I would not have used CPVC, but this was
before PEX, and for some reason the guy that did it didnt want to use
copper. I live about 250 miles away so it would not have been feasable
for me to have done it for them. Anyway, my mother lucked out and found
someone just starting a plumbing business and he bid the job for some
rediculously low price-- $500 as I recall. When they got through, she
told them that they were way too cheap and gave them more than they had
asked for. FWIW- the house was built in 1957(we moved there in 1961) 2
bathroom, slab on grade, pipes in the attic. Very tip of South Texas, so
not too much danger of freezing.Anyhow, that solved the problem, and
they have not had a bit of trouble with the new plumbing since.
Larry