Diagnose a Running Toilet in 3 Easy Steps

  • 01 of 05

    Start by Removing the Tank Lid

    Start by opening the toilet tank.
    Start by opening the toilet tank. Aaron Stickley

    Is your toilet running? This is a very common and annoying plumbing problem that can quickly cost you money. Luckily a running toilet is also easy to fix on your own.


    Before you run to the hardware store to buy parts follow these steps to find the source of the problem.


    Continue to 2 of 5 below.
  • 02 of 05

    Step 1: Check the Overflow Valve

    Check the toilet overflow tube for running water.
    Check the toilet overflow tube for running water. Aaron Stickley

    Check the overflow tube. If you can see water going into the overflow when the tank is full then, you know that the fill valve is not shutting off all the way and needs to be replaced.


     



     


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  • 03 of 05

    Step 2: Check the Flapper Chain

    Look inside toilet tank to see if the flapper chain is causing the toilet to run.
    See if the flapper chain is causing the running water. Aaron Stickley

    If the overflow is not the problem, you’ll want to check the flapper chain next. If the flapper chain is too long or too short it could be the source of the problem. If the chain is too short, the flapper can’t go down completely to seal the opening of the tank. A chain that is too long could get caught under the flapper and hold it up, again preventing a good seal. A simple adjustment will fix the problem.


     



     


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  • 04 of 05

    Step 3: Check the Flapper Seal

    Adding food coloring to toilet tank as a way to check the flapper's seal.
    Check the flapper's seal by adding food coloring to the toilet tank. Aaron Stickley

    The third possibility is the flapper itself. As the flapper gets old it could get hard or warped which could prevent a good seal. Even a slight imperfection could be causing the toilet to run. A few drops of food coloring can let you know if this is the problem.


    Add the food coloring to the toilet tank and give it a few minutes.



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  • 05 of 05

    What's the Cause?

    Colored water in toilet bowl.
    Food coloring from the toilet tank runs into the bowl if the flapper doesn't seal. Aaron Stickley
    Any coloring in the toilet bowl will let you know that the flapper is not sealing and needs to be replaced.