Thanks, Stoney - I'm a bit thick on the detail, sorry: all I know is that this is a syphon type and the new-style see-through disc has been replaced. Dave
Apologies if this has been covered before: despite the syphon in our toilet cistern having been serviced a number of times by qualified plumbers (replacement of outlet valve seal and clip, etc), water continues to run down the back of the inside of our toilet bowl, as evidenced by the 'toilet tissue...
