In article ,
Phil Richards writes:
Perhaps not too clear from the photo I took, there are screw on connections
on both pipes on the RHS. I can see now how easy the job will probably be.
What I don't understand is why they effectively got sealed off presumably
after the boiler and radiator system were installed making it difficult to
top it up after, say what I did, by draining out one radiator.

The filling loop must be disconnected when not being used.
This is to prevent any remote chance of the radiator water
getting back into the fresh water supply. I can't see clearly
in the photo, but the supply end should have a tap and the
heating end should have a one-way valve to prevent water
coming back out.

--
Andrew Gabriel