John wrote:
My 1988 house has the C/H pipes behind the plasterboard. I have a concern
that one radiator is not getting hot and have discovered a restricted flow
from one of the pipes. (8mm)

If I need a pipe replacing when I have a new boiler how easy is it to have a
strip of PB removed and then replaced over one of the drops from the
ceiling? Somehow it doesn't seem right just to cover with plaster.

The simple answer is that in principle it'd straightforward enough to
do; from the wording of your query it doesn't sound like you'd be
diy'ing it?

Dependinf what needs replacing and exactly where it is, you might get
well away with removing and repairing patches, rather than a whole
'strip', ie poking the new pipe through as required.

However, are you sure this is actually necessary? Why do you think the
flow in this pipe is 'restricted'? Even if it is, unblocking it is
probably the way forward.

David