How to Replace a Toilet Flapper

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  • 01 of 05

    Diagnosing a Flapper Problem

    Replacement toilet flapper
    Aaron Stickley

    When a toilet continues to run after you flush it, there are several possible causes, but a good place to start is by simple observation. If you take the cover off the tank of your toilet and peer inside, you will see an unusual component down in the bottom: a kind of hinged flap valve made of plastic and soft rubber (usually black or red) that is connected to the chain hanging down from the flush handle lever. This component is known as the flapper.

    If you then flush the toilet, you'll see that the chain lifts up the flapper, allowing the water to rush down into the toilet bowl. This initiates the flush cycle. As the water empties from the tank, the flapper drops back down like a trap door, closing the valve so the tank can refill for the next flush. 

    When a toilet continues to run after a flush cycle, it's usually because the flapper fails to seat itself properly back over the flush valve opening. This allows water to trickle down into the toilet bowl. If the tank level remains low enough, the fill valve will remain open as it continues its attempt to refill the tank. While sometimes there are adjustments you can make to the flapper, in other instances it happens because the rubber of the flapper hardens over time and can no longer seal the valve. The solution? Replace the flapper with a matching new part.

    It takes about five minutes. All you will need is a new flapper, available at any home center or hardware store.

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  • 02 of 05

    Turn Off the Water

    Turning off the water to the toilet
    Aaron Stickley

    Turn off the water to the toilet by closing the shutoff valve located on the water supply line leading to the toilet; turn the handle on the valve clockwise until it stops. Drain the toilet tank by flushing the toilet. If necessary, hold the flush handle down until most the water is out of the tank. 

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  • 03 of 05

    Remove the Old Flapper

    Removing old toilet flapper
    Aaron Stickley

    Disconnect the flapper chain from the flush handle lever. This lever is a horizontal bar that runs from the flush handle to a position just above the flapper. There is usually a small clip on the top end of the chain that hooks into one of the holes on the handle lever. Undo the clip and let the chain drop; you will replace this chain as you install the new flapper.  

    Slip the side ears of the flapper off of the pegs extending from the sides of the flush valve tube. On flappers made of hard plastic, these ears will snap loose; on flappers made of soft rubber, the ears simply slide off the pegs.

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  • 04 of 05

    Prepare the New Flapper

    New toilet flapper with ring cut off
    Aaron Stickley

    How you set up the flapper will vary depending on your toilet's design:

    • The most common toilet configuration has the flapper attached to pegs on the sides of the flush valve tube. In this case, cut off the ring (if there is one) on the back of the new flapper—it won't be needed.
    • If your flush valve doesn’t have the side pegs for the flapper, use the ring provided with the new flapper to slide the flapper into place over the overflow tube.
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  • 05 of 05

    Install the New Flapper

    New toilet flapper
    Aaron Stickley
    1. Put the new flapper into place and hook each ear of the flapper onto one of the pegs on the sides of the flush valve.
    2. Connect the flapper chain onto the handle lever, adjusting the chain length as needed. When the handle lever is in the resting position, the chain should be relaxed, with a little bit of slack. If the chain is too tight, the flapper may not close completely. If the chain has too much slack, it can get caught under the flapper and prevent it from fully seating in the flush valve opening.
    3. Turn the water back on by turning the shutoff valve counterclockwise all the way.
    4. Test the new flapper and the chain length by flushing a couple of times and watching the flapper go up and down.