Running Toilet: Causes, Fixes, and When to Call

A toilet that keeps running after you flush usually comes down to a problem with the tank—something is preventing the flapper from sealing, regulating the water level, or allowing water to drain properly. Because the issue can waste significant water over time, it’s worth diagnosing promptly.

Start by observing the behavior: does the toilet run constantly, run intermittently, or stop after a short delay? The pattern helps narrow the cause and determine whether you can fix it yourself or need professional help.