Thanks for your help guys. I couldn't see what was wrong with it either but I suffer from cronic ingrained caution. I contracted this some years ago after a long stint working as a MechEng in Aerospace. If it don't feel right......
Coming to the end of a long and problematic plumbing refit. The house is old, extended at least 4 times, has been flats, even a rooming house. It is 3 story but with 9 different floor levels which has made pipe routing a nightmare. One last prob is to get a 15mm cold (main) feed to a particular spot...