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Why Toilet Flapper Won’t Close [5 Reasons & Solutions]

The classic toilet flapper may be on its way out as canister-style flushing valves become more widespread. 

Though, it is unlikely to occur anytime soon.

Manufacturers continue to use flappers because they are cheap and easy to fix.

But sometimes the toilet flapper won’t close. But why?

Flappers sometimes fail to close because of a faulty flapper chain. A buildup on the flapper seal or the hinge could also be the cause. Sometimes while rechaining the flapper chain gets hooked in the wrong opening, making it harder to close. The lightweight flapper can also cause this.

Do you want more information about this and how to fix the issue? I got you covered. 

We will take a detailed look at how you can identify the proper reason and solve it.

Why Your Toilet Flapper Won’t Close

A flapper is a low-cost piece of a toilet that gets its name from how it works. When it’s not in use, it covers up the syphon tube in the tank’s bottom. 

The flush handle opens the flapper as you push it from the outside button. This allows water to drain. When the toilet bowl is filled with enough water the flapper closes down. 

Flappers normally work well for years. But it does occasionally become stuck in both closed and open positions. The former causes flush to be incomplete, while the latter wastes water.

But, there could be a handful of other reasons. We will have a look now-

Reason 1: Short Flapper Chain

Many flushing issues are caused by the chain that connects the flapper to the toilet flush handle. Sometimes the flapper chain is too short. As a result, when you flush the flapper gets raised too high.

It makes it harder to close and all the water gets drained down to the bowl. At the same time, the chain may just slide off the handle. This also makes the flush malfunction.


Before making any chain adjustments, switch off the water supply to the toilet. A chain connects the flapper to the flush handle. You can easily detach this chain and make adjustments so that your flapper closes properly.

You need to extend the chain length by one or two links. This will make the flapper close after a complete flush cycle. And you can use pliers to tighten the hook if it slips off the handle armature.

Reason 2: Buildup on the Flapper Seal

Residue can easily build up in a toilet flapper if it has been in use for a long time. Mineral deposits or Hard water are frequently the sources of these residues.

The gunk build ups are usually found on the flapper’s bottom or the part it seals. As a result, the flapper does not close properly and water continues to drain into the bowl.


Turn off the water supply valve to the toilet. Then flush the toilet until there is no more water in the tank. 

Lift the flapper and use a sponge to clean the bottom. You can clean the residue using vinegar. These residues are comparatively easier to remove than hard water stains from stainless steel.

If that doesn’t work, you can try bleach-based cleaners. Following are a few of  the most effective cleaners for cleaning mineral residues:

Product 1
Product 2

You should also clean the ring’s buildup. You can clean the tank while the water is still in it. But, cleaning is easier with an empty tank.

After the cleaning is done, replace the flapper in its original position. To test whether the flapper closes properly, turn the water supply back on. And now flush the toilet to see if the flapper closes.

Reason 3: Buildup on Flapper Hinge

When working properly, the hinged flapper controls water flow by moving up and down. Like the seal, the hinged portion of the flapper is vulnerable to buildup.

Over time,  a layer of residue forms on the interior of the tank. This can quickly stick to the hinges, making closing the flapper more difficult. This is particularly true if your water is hard or has mineral deposits.


Similar to buildup on the seal, you have to clean this with vinegar. Simply soak a sponge with some vinegar and clean up the hinge. This procedure is as simple as getting film of shower doors made of glass.

Reason 4: Flapper Chained in the Wrong Hole 

The flapper is usually linked to the flush via the tank lever. The tank lever has three holes in it. The flapper and the flush are connected through one of these holes.

If the chain came loose recently, you might just have reattached it with a guess. And While re-chaining you could have picked the wrong opening. This made the chain short to set back after the flush.


In order to check the flapper length, try to put the flapper back into the seal. The flapper is attached to the lever by the chain.

If the flapper doesn’t go all the way down, you need to remove the chain. Attach the chain to the nearby hole and see if the flapper goes down.

This may take a couple of tries. But once the chain is attached to the right hole the flapper should go down properly.

Reason 5: The Lightweight Flapper 

Toilet flapper is usually very lightweight. This is another reason for the toilet flapper’s failure to close. As there isn’t enough sufficient force to push it down to close.


By placing some weight on top, it will close down as soon as you release the handle. But, before using this method, I would recommend that you clear the mineral buildup first.

Weights aren’t necessary because toilet flappers are meant to shut on their own. But if you still want to add some weight, metal washers are the answer.

Remove the flapper chain from the lever. Take a couple of metal washers and drop them on top of the flapper through the chain.2-3 metal washers should be enough to create enough weight to shut it down.

Replace the chain and check if the flapper closes or not. But these metal washers need to be changed. Every six months you will be required to change the washers.

If you’ve checked all of the possible causes and still don’t know what’s wrong. Then it’s most likely the result of a worn-out flapper. In such cases, the flapper needs to be replaced.

When to Replace the Toilet Flapper

It’s natural for the flapper to wear out if the toilet has been in use for a long time. In such cases, the flapper must be replaced.

The flapper is one of the most inexpensive parts of a toilet tank. It’s available at any home improvement or hardware store in a range of 5 to 10 dollars.

How Can You Replace the Flapper

Before beginning any replacement, turn off all the water supply. Then proceed to drain the toilet tank. The old flapper can usually be removed by hand. Attach the new flapper with the chain and see if it closes properly.

If it’s in the right hole of the lever it will close down completely. But there’s a possibility the ring under the flapper won’t form a perfect seal. Over time, the shape of the old flapper and ring adjusted to one another.

If this is the case, you will have to buy a new assembly kit. This kit will include all of the pieces needed to repair every flush-related item inside the toilet tank.

It is preferable to replace the flapper as soon as possible to avoid much larger problems. Because of a faulty flapper, your toilet will run every 5 minutes. And you will soon run out of water in your home.


What can you do instead of holding down the handle for adjusting the toilet? 

You only need to know how to adjust the toilet flapper to fix this problem. Reduce the chain length to leave only around 12 inches of the gap. If the leftover chain falls down too far and clashes with any portion, cut it.

Why do I need to flush the toilet three times?

Flappers wear out over time, allowing water to drain continuously. As a result, not enough flushing pressure is released to thoroughly empty your toilet bowl. You can easily resolve this issue by changing the flapper. Any regular flapper from a hardware shop will do.

When it comes to the flapper chain, how tight should it be?

The flapper shouldn’t be so tight that it can not move. It should have a slight slack for it to function properly. But the flapper might not even lift if there is too much gap. It might need a couple of tries before you can find the perfect length.

How can I know whether my toilet needs flapper number 2 or number 3?

Check the bottom of your tank for the drain opening of  the flush valve. A number 2 flapper is recommended if the opening is as big as an orange. But if the opening is the size of grapefruit then flapper 3 is recommended.

End Words

That’s the end of the discussion about toilet flapper won’t close. You are now aware of the reasons and their solutions. Doesn’t that seem like a simple task?

I believe you can pull it off by yourself. All you need to do now is gather the tools and start working. 

Good luck, everyone! I hope it goes well.