How to Fix a Leaky Toilet Flapper Valve in 6 Steps

Amy Pawlukiewicz
Written by Amy Pawlukiewicz
Updated January 17, 2022
Interior of stylish bathroom
Photo: New Africa / Adobe Stock

While fixtures that clean themselves might sound like a dream, a toilet that flushes itself usually means there’s a problem

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You’re home, by yourself, when you hear it—the toilet flushes. Is it a ghost? An intruder? Nope, it’s probably just a leaky toilet flapper valve. Worn-out flapper valves are something that happens to every toilet over time, and they’re an easy DIY fix. Here are the steps for how to fix a leaky toilet flapper valve.

1. Clean the Flapper

If the flapper is malfunctioning, it doesn’t necessarily need to be replaced. Sometimes, algae and minerals will build up around the flapper—since it lives underwater—and prevent it from sealing properly. If you see buildup on the flapper, clean it with a soft cloth and either a store-bought mineral-removing liquid or a solution of vinegar or lemon juice and water.

2. Turn Off the Water Supply

If cleaning the flapper doesn’t fix your issue, it’s probably time to replace the worn-out flapper. This can be a DIY project if you feel comfortable working with minor plumbing instructions like turning off the water supply.

You can turn off the water supply to the toilet at the valve in the back of the fixture, but if the valve looks damaged or corroded, it’s best to turn it off at the main water supply to your home. Once the water is off, flush the toilet to drain the standing water out of the tank. Since the water is turned off, the tank won’t refill.

3. Purchase a New Toilet Flapper

A white toilet bowl
Photo: gmstockstudio / Adobe Stock

Assuming you haven’t bought a new toilet flapper valve yet, you can ensure that you get the right one by taking the worn-out one to a home improvement store near you. Some flappers just snap off; some need to be unscrewed. 

Most toilet flappers cost less than $5, regardless of the brand you choose. When you compare the cost of a new toilet flapper to what a local professional plumbing company charges for tank component replacements, which averages between $80 and $120, that’s a pretty good deal.

4. Prep the New Flapper

Some of the new flappers available on the market have a ring attached to them. However, most toilets are configured so that the flapper attaches to pegs on the sides of the overflow pipe or flush valve tube. If your toilet valve attaches with pegs, you can simply cut the ring off.

5. Install the New Flapper

Install the new flapper by either hooking it onto or sliding it onto the overflow tube or flush valve. Next, be sure to reconnect the chain to the lever. The chain should be a little loose when the handle is in a resting position, and if the chain is too tight, the flapper won’t close. 

However, if there’s too much slack, the flapper won’t work properly. It’s a Goldilocks situation here—the tension has to be just right.

6. Turn on the Water

A hand flushing a toilet
Photo: Panuwat Dangsungnoen / iStock / Getty Images

Once you’ve got everything reassembled, you can go ahead and turn the water back on, either from the valve on the back of the toilet or at your home’s main water valve. Leave the lid to the tank off and flush the toilet a couple of times to ensure that the flapper valve is working. 

If the flapper is flipping up and down at the right times, then you’re done and you can replace the lid. If not, you may have a different problem and you may need to replace the toilet valve seal or troubleshoot other things. If you’re totally stumped and your toilet still won’t work properly, you should call in a plumber to help out.

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