Finally threw out the didn't-flush-properly toilet and replaced it with a B urlington Close Coupled WC. This has the most complicated internals of any WC I've ever seen, not that I've seen many, and has two different volumes a nd two different flush controls. Resetting these will require a strong drin k and a long study of the instructions.
Anyway the question is should the cistern empty completeley after a full fl ush ?
Also has anyone any experience of these ?