Modern toilet cistern leaks into the bowl

[robob]

Hi, my toilet cistern constantly leaks into the bowl causing the toilet to keep refilling itself. It's coming from the valve at the bottom of the tank the releases the water for the flush, not from the over flow.

Is it a new valve or can I adjust it?
Thanks

 

[oilman]

Probably a nev valve or repair kit. These flap valves are not a fail safe like the siphons, and are not good to have if you have a water meter. They leak!

 

[chrishutt]

Are you sure it's not an internal overflow? If there is not an external overflow pipe, any overflow would discharge as you describe.