William Keogh
Robin, Check and amke sure the inlet valve is operating correctly, by checking that it stops water comong in if lifted. If it does not then this will need to be replaced has continually filling cistern and then overflowing. Then once above done, then if all the seals on the Siphon are in order the water should stop running, if it does not then you a new Siphon. All the parts will have instructions on how to change them. Bill Pipe Dreams Plumbing Services, Bournemouth, Dorset
