my grohe air concealed cistern overflows contiualy
i have fitted a new filling valve, but the problem seems to be on the flush. can you please give me a brake down of how this works so i can fix this problem.

H.johnson, May 2011

there is a small screw/nut, on the end of the ballcock arm, were the water comes out to fill up the cistern, you need to turn the screw/nut, clockwise,to make a new cut off point"were the water will stop filling just before the overflow outlet,turn the screw /nut 3 or4 times clockwise.then flush it to test it, if your happy with the new level, put the lit back on......

m, May 2011

its not the flush its the adjustment on the valve,

mm, May 2011