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Moen Solutions

Replacing a worn toilet flapper


If you happen to hear your toilet running or filling its tank on its own, there's a good chance the flapper needs to be replaced. After some time, toilet flappers will not seal properly. Without a proper seal, water will trickle down and cause the toilet fill valve to activate and refill the tank. In some cases, the valve could be filling constantly, resulting in thousands of gallons of water being wasted, in just one day.

Luckily, replacing the toilet flapper is a simple "do-it-yourself" task.

Note: Before performing any plumbing related tasks in your home, know where your main water shut off valve is, leading into your home. In case of an emergency, you can use this shut off to turn off all water leading into your home.

Step 1: Purchase the right part:

Acquire the correct flapper. Your local hardware store will carry universal flappers that will work with most toilets and generally carry a variety of brand specific flappers for unique designs. If you're unsure which flapper you need, open the fill tank lid and take a photo of the existing flapper. Also make a note of the brand and model of your toilet. If you're unsure of the model, snap a photo of the toilet. Use these pictures to help find the right flapper, or use them as visual aids when asking a store employee.

Step 2: Shutting off the water:

Begin by turning off the water going to the toilet using the angle stop near the floor. Take causing when turning multi-turn angle stops to not over-tighten as this may break the stem. If you’re angle stop is wet or corroded, consider having it replaced.

Note: For installation of non-universal flappers, please refer to specific installation notes provided with flapper package.

Step 3: Removal of old flapper:

With the toilet’s water shut off, flush to toilet to drain the fill tank. It's normal for some water to remain at the bottom of the tank.

Remove the old flapper by disconnecting or un-looping a piece of the chain from the flapper.

Remove the old flapper from the valve tube. Plastic flappers will snap off at their ears, and rubber flappers will slid off from the valve tube.

Step 4: Installation of new flapper (For universal flappers)

Note: Depending on the style or design of the new flapper, you may have to snap off a piece of the rubber or plastic that the flapper came with. This will typically be a piece that holding the flapper ears together. Test fit your flapper before snapping off any pieces or use the old flapper as a visual guide to how your replacement flapper should look.

Install the new flapper by attaching the flapper’s ears to the pegs on the flush valve.

Re-install the chain and ensure it is long enough to allow the flapper to sit flush around the ring but not too long so that it doesn't get tangled beneath the flapper while it’s open.

Test your chain length and connection by pulling the flush lever several times.

Step 5: Verify installation

With the flapper installed, slowly turn the water back on from the angler stop. The toilet tank should begin filling. Test your installation by flushing the toilet several times to make sure the flapper and chain are firmly attached and no water is trickling through.

If your toilet is still allowing water to trickle through, adjust the chain length or remove the flapper and re-install it, in case the ears were not properly snapped around the pegs.

If you continue to experience issues, contact Flo support or call 844-Meet-Flo, or your local plumber for further assistance.

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