Every few months our 24 year old slimline concealed cistern does not properly stop flushing. It continues flowing at a fast dribble. How can it do this when the volume of water flowing surely is insufficient to maintain a siphon? I suppose it means that the suction of the column of water exiting the siphon is greater than the head of the water entering the siphon, and that no air has entered the columns (why not?) to break the siphon.
I can stop it by unscrewing the joint by my finger to let some air in.
Failing someone offering a solution here, am wondering about drilling a small (say 1-2mm) hole by my finger in the picture. This maybe would be small enough to not impede the main flush, but large enough to let in enough air to break the siphon
We have 2 other identical cisterns and they do not give the same problem. Have replaced the plastic diaphragm on some.
I can stop it by unscrewing the joint by my finger to let some air in.
Failing someone offering a solution here, am wondering about drilling a small (say 1-2mm) hole by my finger in the picture. This maybe would be small enough to not impede the main flush, but large enough to let in enough air to break the siphon
We have 2 other identical cisterns and they do not give the same problem. Have replaced the plastic diaphragm on some.