Geberit dual flush valve leak

[Pish]

I've just replaced a bubbling valve seal, but the toilet is still constantly filling.

Any suggestions?

 

[Pish]

Are you sure it's not that the cistern is filling too high and overflowing into the pan?

Failing that you could be suffering from a loss of joint seal between the flush valve and the bottom of the cistern

How do I know its filling too high, and how do I stop it?

 

[xtaffa]

Same issue for ages, finally investigated - this thread wasmassively useful. We're in a hardwater area; flush seal was crusted with limescale - one bubble too, but cleaning limescale off worked fine...Did the same for all the easy to reach mechanisms/seals at the same time.