Fairly certain the fault lies with the valve seat letting bye as replaced washer and still leaking in to pan. Cistern is siliconed to wall but have resogned myself to taking the whole thing off. Interested to know what flush valves (drop not syphon) you guys would recommend. I have seen fluidmaster mentioned several times on other threads refering to replacing siamp valves are there any other candidates for the quality drop flush valve title. Still dont undersyand why we ever stopped using syphons they are far superior.