Why would a toilet leak only at night?
— Russ H. Your toilet is not just running at night. What you hear is the water coming back into the tank at a very slow rate. Since it is so quiet at night, this is the only time you can hear the water running. Your problem is most likely a leaky flapper valve in the bottom of the tank. When the tank level drops an inch or so, the float drops enough to turn on the water just slightly until it is slowly filled again. Online: www.dulley.
