How to Stop Water Continuously Trickling into the Toilet Pan
If you have a push button operated cistern, there's a few different possible causes.
The most likely being what is known as a base sealing washer. Over time this small rubber washer will deteriorate and often warp, resulting in an adequate seal no longer being made once the flush valve closes. We stock many different makes an models of flush valve, as such the base sealing washers are not universal or interchangeable. It is also often worth cleaning this washer if it doesn't look excessively warped / deteriorated, this has been known to fix the issue.
Another possible cause is the flush valve is getting stuck open. This can be a problem with the internal mechanism which lifts the flush valve, or a fault with the cable or button attached to the valve.
It is also possible that there may be an issue with your inlet valve. Many flush valves have what is known as an internal overflow - whereby if the cistern doesn't stop filling; the water will spill over into the overflow assembly on the flush valve and into the toilet pan. This is unlikely as typically this won't just be a small trickle, there would be quite a large flow of water constantly in the toilet pan.
Most push button operated flush valves feature a 2-part design, allowing you to replace the complete assembly or the base sealing washer without having to remove the cistern.