Hi all need some help in fixing the above problem, I have a cistern with an internal overflow, however it’s running water into the pan 24 /7 not a lot just a trickle. The valve releases and tops up the loss about every 1-2 hours. I have adjusted the water level in the cistern and I do not feel this is the problem it just feels like the syphon is leaking could it be and if so what do I do, changing it looks like a nightmare job.