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.


  1. I bought and replaced the whole float valve unit, which solved the problem for about a week. Now, once again the water won’t quit running in the toiley. It actually submerses the float because it won’t shut off. You can manually push the float up and that still won’t shut off the water. There’s got to be a reason and solution because, like I said, it worked properly shutting off like it was supposed to for about a week when it was new.

    • May depend on the brand of toilet. American Standard (AS) has a different device than the standard flush valve. They use an “egg-shaped” flapper that comes apart in the middle and a large (about 3” across with opening in the middle soft gasket).
      Unscrew the top of the flush device, remove the gasket, make sure the top of the flush device is seated on the bottom half (with the seal in place) and twist back the locking device that attaches to the pull chain.
      If AS, go to their web site and / or let Youtube show you how to install. One of the important items for installing the American Standard “flapper” is to make sure the top part of the flush device is seated on the bottom half, with the soft gasket between the two pieces…..the top part must “click” into place or the top will not seat and the soft gasket will not shut off the water flow.
      Search Youtube for instructions for correcting a running toilet and you might find a hint that may solve your problem.
      Note, the AS gasket develops bubbles on the gasket and the bubbles prevent the gasket from sealing the flush device, that’s why water leaks from the tank and causes the fill device to add water to refill the tank.
      Call AS if their brand and talk to customer service, they were great and gave lots of help on how to solve my “phantom flush” toilet problem.
      Good luck…

      • Thanks for sharing your experience with the Today’s Homeowner community, Jim!
        TH community members helping other TH community members — we love it. 🙂

  2. I have been looking for an answer to this question, but after clicking on over 30 websites, no one addresses the kind of toilet that doesn’t have one of those ball fill valves. My fill valve does not have that big ball floater. Can anyone address how to adjust this other kind of fill valve?

  3. i have done all the things in the video, i still have to jingle the handle, i have even replaced the handle and the hardware inside the tank.
    does getting a new toilet solve this problem because that is what i am ready to do!! i never had this problem ever in the house i grew up in and they were built the same year, not that it matters but it is very frustrating. thank you

  4. when you put the lid on the back of the toilet on the water keeps running but when you take it off the water stops what can i do. Thank You very much.

  5. The floater floats on water. That creates a force closing the inflow. If the water pressure going in is too high that floater doesn’t have enough power.
    Most floaters are adjustable. Lowering the floater or extending it out generates more force.
    Inflow is usually also adjustable. Close the inflow valve by half a turn to reduce the water pressure coming in.

    So I’ve tried adjusting the water level and at times it appears to stop when it is supposed to but then hours later I can hear it running and it’s back to overflowing into the tube. If I turn the screw anymore it either doesn’t fill or fills painfully slow.
    I have also replaced the flapper and float and float arm. Should I be replacing the tower and overflow tube next?

  7. So, I figured out that the flapper needs to be replaced but I don’t have a chain. It’s all one piece. What do I look for when I go to the hardware store?

  8. While I was out of town, relatives sat for my house and dogs. They had a problem with one of the toilets and replaced parts. I do not have one of those balls and he said that they no longer use them. Now the bar that connects to the flush handle ends up on top of the overflow pipe. On the videos I don’t see this problem and I see that the tube sits inside the overflow. I am totally confused. Help!!!!

    • Hi, Debera!
      Anytime someone changes your toilet tank setup, issues can arise.
      To understand the problem with your system, we would need more information.
      We recommend submitting questions involving unique situations like yours to the Today’s Homeowner Radio Show.
      Please use this form to contact Danny Lipford, America’s Home Expert, directly:
      Take care!

  9. How do you adjust the chain so that I don’t have to hold the flushing lever till the water storage portion is empty ?


Please enter your comment!
Please enter your name here