What Is a Toilet Flapper? How to Find It, Get It Working, and More

The key to the perfect flush

Luxury white and minimal bathroom
Photo: Thapakorn Rujipak / iStock / Getty Images Plus / Getty Images
Luxury white and minimal bathroom
Photo: Thapakorn Rujipak / iStock / Getty Images Plus / Getty Images
Mizuki Hisaka
Written by Mizuki Hisaka
Contributing Writer
Updated September 19, 2024

Highlights

  • The toilet flapper is the round rubber piece on the bottom of your toilet tank.

  • When you flush the toilet, the flapper lifts and allows water to flow into the bowl.

  • A damaged or poorly adjusted flapper causes problems with flushing or makes a toilet run continuously. 

  • Replacing a toilet flapper is a DIYable project or you can call a plumber.

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A constantly running toilet or weak or short flushes can slow you down during your busy day and cause high water bills. Before distressing, check to see if it’s a simple problem with your toilet flapper. Read on to find out what a toilet flapper is and how to figure out if it’s the culprit behind your plumbing woes.

What Is a Toilet Flapper?

The toilet flapper is a circular rubber piece that seals the flush valve opening, making it an essential part of the toilet. The flush valve is at the bottom of the tank and allows water to flow between the tank and the bowl. A properly working flapper ensures water stays in the tank until you flush the toilet.

Toilet Flapper Types

The standard and most common flapper size is 2 inches, although there are 3-inch flappers. To determine the right flapper size for your toilet, measure the diameter of your flush valve opening.

Rubber toilet bowl flappers are the most common, either adjustable or nonadjustable. Adjustable flappers, which sometimes come with a float, allow you to change how much water is flushed. These types of toilet flappers are available for toilets that use 1.28 to 3.5 gallons per flush (GPF). 

Nonadjustable flappers are for older toilets manufactured before 1994. For these toilets, you also have the choice of vinyl flappers, which are bacteria- and chemical-resistant and have a longer life span. 

You can also find options in plastic, silicone, metal, and Acrylonitrile Butadiene Styrene (ABS), a type of thermoplastic. These flappers are manufactured for specific toilet brands and models. A toilet repair pro can steer you in the right direction and help you choose the right flapper for your toilet. 

How Does a Toilet Flapper Work?

6 toilet parts illustrated, including the tank lever, chain, and flapper

The toilet flapper connects to your tank lever via a chain. When you press down on your toilet handle to flush it, the tank lever lifts along with the chain. This also causes the flapper to lift, allowing the water to flow from the tank into the bowl. Once the tank empties, the toilet flapper closes, and the fill valve refills the tank.

Common Problems With Toilet Flappers

Man flushing toilet
Photo: boonchai wedmakawand / Moment / Getty Images

You’ll likely have two problems with toilet flappers: constantly running toilets and flushing issues.

Here are some possible reasons why your toilet is constantly running. For one, you might have a worn-out, cracked, or damaged flapper that no longer creates a tight seal. Or, you might have a problem with the chain. It could be adjusted too tightly, so your flapper can’t shut all the way. The same issue can happen if the chain gets twisted. Additionally, you might have sediment or rust buildup on your flush valve opening.

If you’re having flushing issues, here are a few things to look for. A common issue is a short flush, which requires you to hold down the lever longer than usual to get a complete flush. The problem happens when the chain has too much slack, so the flapper doesn’t fully open when you flush the toilet. You might also have a weak flush. This can happen if your flapper has a float that needs readjusting. 

When Should I Replace a Toilet Flapper?

A visual inspection of your toilet flapper will help determine if you need a new one. If your flapper is worn out, cracked, or damaged, replace it immediately to avoid an excessively high water bill. Your flapper material can deteriorate due to mold, mildew, or bacteria growth. Using harsh chemical cleaners in your toilet bowl can also break down your flapper over time. 

Another instance when you should replace your flapper is if it’s been over four to five years since you installed a new one. That’s about how long a toilet flapper lasts, so changing it out regularly will help you prevent problems.

Whether there’s an issue with your flapper or it’s nearing the end of its life span, hire a toilet repair service near you to help out. A pro will inspect your toilet and fix your flapper or install a replacement. It’s advantageous to have a pro take a look at what’s going on just in case you have other issues with your toilet. For example, a constantly running toilet is sometimes caused by a broken fill valve.

On the other hand, if you’d like to put your DIY skills to use, you could learn how to fix a leaky toilet flapper or how to adjust the chain tension. These are beginner DIY projects, as long as you have some time and are willing to learn a thing or two.

How to Replace a Leaky Toilet Flapper 

A leaky toilet flapper can cause your toilet to run constantly, so your next water bill could be unusually high. Luckily, learning how to replace a flapper is fairly simple.

First, turn off the water valve and remove the toilet tank lid. Flush the toilet once or twice to empty the water from the tank. Next, remove the old flapper by unclipping the arms and removing the chain.

Installing the new flapper requires aligning it with the small pegs and sliding it into place over the flush valve. Connect the new chain to the flush handle lever, and attach the arms. Once you’re done, turn your water back on and do a test flush to make sure everything was done correctly.

Frequently Asked Questions

You can DIY your toilet flapper replacement if you’re up for a small plumbing project. Turn off the water to the toilet, open the tank lid, remove the chain from the lever, and unhook the flapper. For a new, adjustable flapper, adjust it to the right setting according to your toilet's gallons per flush rating. Hook the flapper in place and install the chain with 1/2 inch of slack.

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Learn more about our contributor
Mizuki Hisaka
Written by Mizuki Hisaka
Contributing Writer
Mizuki Hisaka is a freelance writer with 6+ years of experience. She's written for various companies, websites, and publications, including The Knot, Pottery Barn, Williams-Sonoma, The Inquisitr, and more.
Mizuki Hisaka is a freelance writer with 6+ years of experience. She's written for various companies, websites, and publications, including The Knot, Pottery Barn, Williams-Sonoma, The Inquisitr, and more.
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