can anybody help me i have a titan tank in loft mains fet no header tank . last year water kept leeking out of overflow pipe so had plumber round and he said diaphram had split in expansion vessel so a new vessel was replaced and a few months later its dripping again from overflow pipe . there has to be a reason why its splitting and filling with water . i dont even know if they have diiaphrams in them or just fed a load of tosh