How-To Videos

How to Repair a Running Toilet

By: Danny Lipford

A constantly running toilet is not only annoying but it’s also a big waste of water. (DepositPhotos)

There are two common reasons a toilet won’t stop running, both of which are easy to fix. Here’s how to go about repairing a toilet to keep it from running.

Replace 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.

To replace a defective flapper:

  1. Turn off the 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. Turn the water back on.

Fluidmaster’s 502 PerforMAX Water-Saving, Adjustable Flapper offers a customized flush. You just have to turn the dial left for more water per flush, or right for less, depending on your needs.

Adjust 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. To adjust the water level in the tank:

  1. Turn the screw on top of the fill valve* to adjust the float in the tank so the toilet stops filling approximately 1” below the top of the overflow tube.
  2. 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 find out how.

Further Information

Video Transcript

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

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.
Snap on a new flapper and reconnect the chain before turning back on the water.

If water is constantly running down the overflow tube, the fill valve needs to be adjusted.
Turning the adjustment screw on the valve in one direction raises the water level and the other direction lowers it.

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


Please Leave a Comment

17 Comments on “How to Repair a Running Toilet”

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  • Official Comment:

    Thomas Boni Says:
    February 4th, 2019 at 9:47 am

    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!

  • Debera Hoffman Says:
    February 3rd, 2019 at 12:50 am

    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!!!!

  • Official Comment:

    Thomas Boni Says:
    January 19th, 2019 at 4:47 pm

    Hi, Diane!
    We recommend installing a Fluidmaster repair kit, as seen here:
    Good luck. 🙂

  • Diane Ogren Says:
    January 19th, 2019 at 4:23 pm

    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?

  • Official Comment:

    Thomas Boni Says:
    November 14th, 2018 at 4:25 pm

    Hi, Carri!
    Sounds like your toilet has a mind of its own!
    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!

  • Carri Says:
    November 11th, 2018 at 9:34 am
    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?

  • Official Comment:

    Thomas Boni Says:
    November 2nd, 2018 at 1:46 pm

    Glad to hear we could help, Jo Ann. Take care!

  • Jo Ann Says:
    November 2nd, 2018 at 12:30 pm

    Thank you! One twist with the screw driver solved the problem and saved me calling a plumber!!!!

  • Official Comment:

    Thomas Boni Says:
    July 31st, 2018 at 8:41 am

    Hi, Olivia,
    A toilet not flushing properly is a common problem.
    Fortunately, we have some information!

    We recommend checking out this video:

    Thanks for your question!

  • Olivia Says:
    July 31st, 2018 at 5:14 am

    I need some help to fix my toile it. Is not flushing right

  • Joe Says:
    June 8th, 2018 at 11:54 pm

    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.

  • Kim Says:
    December 8th, 2017 at 1:16 pm

    Lizard and Theo,
    Could it be the spring in the arm of the float?

  • Mark King Says:
    September 3rd, 2017 at 7:59 am

    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.

  • sue hamel Says:
    July 8th, 2017 at 10:47 am

    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

  • Mark Says:
    August 29th, 2016 at 7:37 pm

    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?

  • Theo Says:
    July 6th, 2016 at 9:02 pm

    I am having the same issue as Lizard: full tank, float won’t stop water filling and is submersed

  • Lizard Says:
    March 18th, 2016 at 7:27 am

    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.

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How to Repair a Running Toilet