Hi,
I have a problem with water overflowing into the overflow pipe and into the toilet bowl on a siamp. Due to a separate problem where the cistern was filling slowly, I changed the black washer (the old one was split) on the shut off valve. That solved the slow filling cistern problem. But then, this new problem occurred very shortly afterwards. I have noticed that the float connected to the grey threaded rod stays submerged when the cistern fills and I am assuming this is the problem. It rises a bit when the cistern fills but is totally underwater. If this is the problem, how is it solved? Do I need a new inlet valve unit?