"Aidan" wrote in message
oups.com...

Calvin wrote:
BG, bless 'em, have got a thing about non-barrier pipes.

It pains me to say that I think BG are probably right. It's probably
polybutylene tube (HEP2O?), but I don't know if it's a barrier type. If
it is not barrier pipe, there's probably existing corrosion of the
radiators and a lot of corrosion products in the primary side. The
plate heat exchangers on combis have narrow waterways and are liable
to get blocked with sludge. It may be some BG rule born of bitter
experience.

They don't take on non-barrier pipe CH systems. As long as the inhibitor is
changed every 4 years there is no problem. Very rarely is this done.

The early non-barrier tubes have caused big problems with some UFH
systems.


The trouble
is that because they are (erroneously) trusted people tend to think

Yes, I trusted them once. Huge mistake, that I'll never repeat.


Just to be clear for the OP, even if they are non-barrier there
shouldn't be an issue.

It will be an issue, but probably in some years.