- Check the water level in the tank to be sure that the water is not overflowing by way of the overflow pipe (the pipe in the middle of the tank with a small piece of tubing connected to it).
- If water is running into the overflow pipe, adjust the fill valve until the water stops approximately one inch below the top of the overflow tube (there may be a water level mark stamped on the side of the tank).
- Test the flush valve mechanism by putting a few drops of food coloring into the tank.
- Check the bowl after 15 minutes, if the water in the toilet bowl has changed color, the ball or flapper is leaking and needs to be replaced.