I never really understood why they called it a "Joker" valve, now I think I know: it is a joke, it doesn't work!

I've replaced this valve in both heads twice now and the bowls still slowly fill with backflow from the pipe to the holding tank.

Does anyone have any ideas on how to stop this, or have i just got a bad batch of valves ?

Cheers

Alan

Elyse SM437 

Noumea