How to Fix a Running Toilet

Usually, a toilet won’t stop running for two reasons. Fortunately, both of them are easy to repair. Here’s how to fix a running toilet.

Replace a Running Toilet’s Tank Flapper

If the rubber flapper at the bottom of the toilet tank is warped or damaged, water will seep out around it, causing the toilet to continue to run.

Here how to replace a defective flapper, and ultimately, fix a running toilet.

  1. Turn off water to the toilet.
  2. Flush the toilet.
  3. Disconnect the chain from the flapper.
  4. Remove the flapper.
  5. Replace the flapper.
  6. Reconnect and adjust the chain to the flapper.
  7. Finally, turn the water back on.
    Tip: There are many products out there that make flapper replacement easy. For instance, Fluidmaster’s 502 PerforMAX Water-Saving, Adjustable Flapper offers a customized flush. To use it, you just have to turn the dial left for more water per flush, or right for less, depending on your needs.

Adjust a Running Toilet’s Tank Water Level

If water is constantly running into the overflow tube in the toilet tank, the fill valve in the tank needs to be adjusted.

Here’s how to adjust the water level in the tank, and ultimately, fix a running toilet:

  • Turn the screw on top of the fill valve* to adjust the float in the tank so the toilet stops filling approximately 1 inch below the top of the overflow tube.
  • Finally, flush the toilet and check to see that the fill level is correct.

*Note: Some tanks have other methods of adjusting the height of the float.

Watch this video to learn more.

Further Information

A constantly running toilet means that the flapper isn’t sealing correctly or the fill valve is improperly adjusted.

So, if the flapper is warped or damaged, turn off the water supply and empty the tank, then disconnect the flapper from the flush chain and unsnap it from the flush tower.

Finally, snap on a new flapper and reconnect the chain before turning back on the water. If you’re wondering how to fix a running toilet and that didn’t do the trick, that’s just one way.

If water is constantly running down the overflow tube, the fill valve needs to be adjusted.

So, just turn the adjustment screw on the valve in one direction to raise the water level and the other direction to lower it.

The ideal level for a toilet tank is about an inch below the top of the overflow tube.

Keep in mind some toilets have other ways to adjust their water levels, but this is the latest method for how to fix a running toilet.