How to Replace a Toilet Flapper

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  • 01 of 05

    Diagnosing a Flapper Problem

    Replacement toilet flapper
    Aaron Stickley

    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. That's 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. Eventually, the tank level gets low enough that the fill valve kicks on to top up the tank. This happens with flappers because the rubber hardens over time and fails to seal the valve. The solution? Replace the flapper with a matching new part. It takes about five minutes. 

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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. 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 it along with 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

    Set up the flapper based on your toilet's design:

    • The most common toilet configuration has the flapper attached to the 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 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 on the flapper and prevent it from dropping down.
    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.