Give me the old fashioned crappers any day , a 1/2” ball valve contains 1 washer , 1 orifice low or high pressure and the rest is all brass ,, syphon units that lasted forever but might need a new diaphragm every 5 or 10 years compared to nice fancy loos and cisterns that forever seem to demand our attention.Dunnit! It was the little washer in the lever arm. Wouldn't have known it was there - more of a plug than a washer. Prised it out, turned it round, seems to work! I can **** again!
Design too clever by half. Seems to be a valve working another valve, but gives near silent fill and precise float height adjustment, when working as is supposed to.