On a slightly different matter here, is the syphon a 'two-part' type? This means, when the thin plastic washer fails in the bit that lifts on flushing, it can be replaced without dismantling cistern from pan, etc. My B & Q syphon was one-piece, so fitted two-piece instead. I cannot recall the brand now, but I know I had to go to plumbers merrchant, B & Q didnt have one.