If you hear water running in your toilet tank for extended periods after a flush, then your toilet is leaking. The problem just may be your flush valve assembly, sometimes the problem is a worn out flapper valve too. You need to have the inside of your toilet tank rebuilt. If you have more than one toilet that leaks, you could be wasting up to 200 gallons of water per day, which adds up to one high water bill.
To stop the water from running until a professional plumber comes over, turn off the water to the toilet from the shut off valve that is normally located just below your toilet.
CA. Lic: 931807