I'm not sure what you mean by "Turning the water on and off at the cut off valve, gets the water flowing again. " That is the purpose of the cut off valve. I think you should buy a new "fill valve", Louise. They are not expensive and come with a new hose. You must be fairly handy with tools to do-it-yourself. First, ask at your local hardware/home improvement store for a new fill valve. Shut the water at the cut off. Disconnect the water line that goes from the cut off to the bottom of the tank, at the bottom of the tank. Remove the nut from the bottom of the fill valve. Pull up and remove it. Read the directions thoroughly that come with the new valve. Then install it in the tank at the proper height, with the proper washers, and the float adjusted for the correct water fill. If you have a solid metal tube that connects your tank to the cut off, you may want to replace it with a flexible one. It makes installation so much easier, as they are hard to line up on an installation that differs from the old one. (Handyman, not a plumber.)