Running noises occur when water leaks out of the tank and into the bowl, and then the tank re-fills with water. These noises should cease as soon as the tank is finished filling. Running noises when no one flushes could mean a variety of things: The valve in the tank allows water to escape into the bowl.
Additionally, how do I stop my toilet from making a running noise?
If you have a cylinder float, on the side you should notice an adjustable clip which can be squeezed to lower the float down until it stops the water from running. If you have a float ball, on top of the fill valve turn the screw counter clockwise until the water stops running fully.
In this manner, why is my toilet making a humming noise? It’s usually the result of an increase in pressure in the water line. That may be at night, if you’re on a municipal water system, or any time the pump cycles on, if you get your water from a well. If the fill valve in your toilet is old and made of metal, the pressure can make it vibrate with an audible humming sound.