Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
I changed the fill valve with water sensor valve and the water is still running. The water does not exceed normal volume.
Why is this?
What @Tyson said, replace the flapper valve (the one that drains the water from the tank to the toilet bowl). Or check that the flapper is seating properly. It could have gotten stuck, warped, something is stuck under it or is just too old.