Is my fill valve or float to blame for a running toilet? The heart of your toilet’s functionality lies in the fill valve and the float. When either of these components isn’t doing its job ...

The float, the flapper, or the fill valve are the most likely causes of a toilet running continuously. You can perform easy tests like monitoring water movement to help identify the cause.

It’s known as the float valve, fill valve, ballcock, or fill cup, to list a few of its many names. When you flush, watch this valve. It’ll drop with the water level, then start floating back ...

If the tank isn’t refilling properly, or your toilet is constantly running, this valve could be the issue. To replace it, Sebestyen says you must make sure you’ve turned off the water supply.