Went to the above boiler yesterday, have agreed to go back on Wednesday morning next week to repair it. When I got there was expanding over and emptying, emptied boiler blew out the Ex Vessel then recharged. Expansion problem now solved, boiler running ok at 1-1.5 bar. Still have water draining out of PRV, removed the screw in part of the PRV and cleaned up the rubber and the surface (done many times before) still leaking, now I've never removed one fully on the Heatline but it's xmas eve and looks like a ball5 up waiting to happen. Am tempted to buy it and just replace the top bit, and hope it works, what's the thoughts ??