Replacing a worn out or faulty toilet flapper is an easy DIY project that can save you money on plumbing bills. A failing flapper is the most common cause of a continuously running toilet, which can waste hundreds of gallons of water per day. Replacing the flapper takes less than 30 minutes and costs under $10 for the part. Follow this step-by-step guide to learn how to replace a toilet flapper correctly.
What is a Toilet Flapper and What Does it Do?
The toilet flapper, also called a flush valve, is a rubber seal at the bottom of the toilet tank that lifts up to allow water to flow into the toilet bowl when you flush. When the flush handle is pushed down, the chain connecting the handle to the flapper lifts the flapper valve and allows the water in the tank to empty into the bowl via the flush valve opening. Once the tank is empty, the flapper then seals the opening to allow the tank to refill for the next flush.
A properly functioning flapper should:
- Seal the flush valve opening completely when the tank is refilling after a flush
- Lift fully upright when the toilet is flushed to allow the tank to empty completely
- Close tightly over the flush valve once the tank is empty to stop any water from continuously leaking into the bowl
Signs that your flapper needs replacing include:
- Constantly running or leaking toilet
- Need to jiggle the flush handle to stop the running water
- Tank takes a long time to refill after flushing
- Reduced flushing power
Replacing the flapper is an easy fix that usually solves any of these common toilet problems.
Preparing for Flapper Replacement
Before you take the old flapper out and put a new one in, there are a few steps you should follow to prepare:
Turn Off the Water Supply
Locate the water supply valve behind or near the toilet and turn it clockwise fully to the right to shut off the water. This will prevent the tank from refilling while you work.
Flush the Toilet to Empty Tank
With the water supply turned off, press the flush handle to empty all water out of the tank before starting. Have a towel handy to sop up any leftover water in the bottom of the tank.
Check the New Flapper’s Compatibility
Make sure the replacement flapper matches the style you currently have. The most common are bell-shaped flappers with a slide clamp, and tower or canister flappers that use a traditional ballcock. Check sizing too. Measure the opening diameter the flapper covers to get the right size replacement.
Have Proper Tools on Hand
For this simple job you’ll only need:
- Adjustable pliers or channel lock pliers
- A screwdriver (usually Philips head)
- Teflon tape
- Rag or small towel
Removing the Old Toilet Flapper
Once you’ve gathered the necessary replacement part and tools, you’re ready to remove the old flapper:
Unhook the Flapper Chain
Reach into the tank and disconnect the chain that runs from the flush handle down to the flapper. Unhook it from the arm on the flapper.
Unscrew the Retaining Nut or Lift Off Seal
Depending on your flapper style, it is either held in place by a retaining nut or sits inside a seal ring. Use pliers or a screwdriver to remove the nut or lift the flapper out of the seal.
Clean Off Rust and Mineral Deposits
Examine the exposed area under the flapper and use a rag to remove any dirt, rust, or mineral deposits from the sealing surface. This allows the new flapper to create a tight seal.
Check the Flushing Channel
Peek inside the flushing channel leading from the tank to the bowl. Remove any obstructions like pebbles or toys that may have fallen in.
The old flapper can now be fully removed and discarded. Thoroughly clean off the flush valve seat to prepare for the new flapper installation.
Installing the New Toilet Flapper Correctly
Installation is just as easy as removal. Follow these tips for properly putting in a new toilet flapper:
Position the New Flapper
For slide clamp style, press the flapper into place over the flush valve seat.
For tower or ballcock style, lower the flapper into the tank seal ring. Make sure it is fully seated in place.
Reconnect the Flapper Chain
Attach the chain coming from the flush handle arm back onto the hook, clip or peg on the new flapper. Provide just enough slack so the flapper can seal when closed, but will pop all the way open when the handle is pushed.
Tighten the Retaining Nut or Seal
If present, tighten the retaining nut by hand or with pliers. Do not overtighten or you may crack the toilet tank.
Or if using a tower-style flapper, check that it aligns properly inside the seal ring and is held snugly in place.
Apply Thread Sealant to Refill Tube
Unscrew the refill tube from the tank fill valve. Apply a few turns of Teflon tape and reinstall until snug. This prevents leaks as the tank refills.
Turn the Water Supply Back On
Reopen the supply valve to allow water back into the tank and bowl.
Test Operation and Check for Leaks
Press down on the flush handle and make sure the new flapper rises fully to let the tank empty completely. Make sure it seals closed again once the bowl is flushed. Look for any drips or leaks as the tank refills to full. Adjust as needed.
Troubleshooting Common Flapper Replacement Problems
If you follow the steps correctly but are still having issues after replacing the flapper, here are some things to check:
Problem: Tank water level too high or low after flapper replacement.
Solution: Adjust the float cup height up or down to achieve the correct refill level. The tank should be about 1/2 to 3/4 full.
Problem: Flapper doesn’t quite seal and causes slow leak.
Solution: Make sure you have the right size flapper. Adjust chain length so flapper sits flat on flush valve seat. Clean sealing surface again for a tight seal.
Problem: Toilet bowl refills slowly after flushing.
Solution: Clear any obstructions in the refill tube with a wire. Make sure the tube is properly connected to the fill valve.
Problem: Toilet does not flush properly.
Solution: Check for clogs. Adjust flapper chain length and float cup height. May need tank parts rebuilt or replaced.
Problem: Flapper chain disconnected or missing.
Solution: Reconnect chain or purchase replacement chain and install per flapper instructions.
If problems persist after trying the above solutions, the fill valve, flush valve seal, or other tank parts may need replacement.
FAQs about Replacing Toilet Flappers
Here are answers to some commonly asked questions about swapping out an old toilet flapper for a new one:
What are toilet flappers made of?
Most modern toilet flappers are made from rubber or a rubber-like elastomeric polymer. Older flappers were sometimes plastic or metal. Ensure your replacement is rubber for the best seal.
Where can I purchase replacement flappers?
Hardware stores, home improvement stores, and plumbing supply stores sell toilet flappers. They cost $2-$20 depending on style and material. Purchase in-person or online.
How often should the flapper be replaced?
Expect to replace a flapper every 3-7 years with regular use. Hard water causes minerals to build up and prevent a good seal over time.
Why does my flapper need to be replaced every few months?
If the flapper isn’t lasting, the chlorine in municipal water supplies can degrade the rubber. Consider switching to a chloramine-resistant flapper.
Can I just put any flapper on my toilet?
No, flappers are made in different styles, sizes, and materials. Match the new one to the old or bring the old one with you to purchase the right replacement.
What measurements do I need for finding the correct flapper?
You need to know your flapper style and measure the diameter of the flush valve opening it covers in the tank. This ensures fit.
How do I adjust a toilet flapper chain?
Use the sliding clasp to adjust length. Provide just enough slack so the flapper can close fully when seated, but will pop open fully when flushed.
Why does my toilet run intermittently after flapper replacement?
A small piece of debris or plumber’s putty may be stuck, preventing the flapper from sealing fully. Clean the seat and flapper thoroughly.
Can I fix a cracked flapper?
It’s not recommended. Even a small crack affects the seal. Cracked flappers should be replaced.
Replacing a faulty or leaking toilet flapper is an easy DIY bathroom fix that can conserve water and stop a running toilet. With the right replacement part, tools, and following these instructions, you can swap out the old flapper for a new one in under 30 minutes, saving on costly plumber service calls. Be sure to clean, adjust, and test for leaks during the installation process. Consider replacing flappers proactively every few years to prevent leaks and optimize toilet performance.
How to Know When You Need a New Toilet Flapper
It’s easy to overlook a worn-out toilet flapper valve as the cause of many common toilet troubles. But a deteriorating flapper is often the culprit behind a chronically running toilet, wasted water, higher utility bills, and other annoying toilet problems. Knowing when it’s time to replace this important part can save gallons of water and prevent the nuisance of a constantly cycling toilet.
Here are the signs that indicate your toilet needs a new flapper valve:
- Toilet frequently runs for long periods, even when no one has recently flushed. Water cycles from the tank into the bowl without being used.
- Toilet makes a sustained hissing, flowing or squeaking sound. Noisy running water indicates flapper leakage.
- Have to jiggle the flush handle, lift the flapper by hand, or take other measures to halt the running water.
- Water bill spikes for no apparent reason, especially if no one’s usage habits have changed. A leaky flapper can waste 200+ gallons daily.
- Notice reduced flushing power. A worn-out flapper may not lift fully, preventing a full flush.
- Tank water level drops without anyone flushing; refills slowly between flushes. The flapper isn’t sealing water in the tank properly.
- Mineral deposits crusted on flapper valve or seal ring. Hard water minerals prevent the flapper from sealing tightly.
- Flapper appears misshapen, warped, cracked or has stretched out sealing surface. Improper seal causes leakage.
- Toilet bowl refills sluggishly after flushing. A faulty flapper valve impedes proper refilling.
Any of these signs point to an aging, faulty flapper in need of replacement. Catching a malfunctioning flapper early keeps your toilet running smoothly and efficiently. Periodically inspect the flapper every year or two and replace proactively if you observe any deterioration or leaks.
When Should I Replace vs. Repair a Faulty Toilet Flapper?
Toilet flappers are inexpensive parts made of rubber materials that degrade over time. They’re designed to be replaced easily every few years with regular use. Attempts to repair a damaged flapper are usually temporary measures. The best solution is simply installing a new flapper valve.
However, here are a few instances when repair could be attempted:
- For cracks/tears – You may be able to temporarily patch or glue a small crack or tear in the flapper rubber as a temporary solution. This gains a bit more time before replacement is needed.
- To clean mineral buildup – Soaking a crusty flapper in vinegar or CLR can remove hard water mineral deposits and restore a better seal short-term.
- To adjust flapper chain – A chain that’s too tight or too loose can affect proper sealing. Adjust the chain first in case that’s the cause.
- To remove debris – Something stuck under the flapper seat preventing full closure can sometimes be removed to prolong flapper lifespan slightly before swapping out.
But for more significant flapper valve damage or leakage, replacement is the recommended and longer-lasting solution. The cost of a new flapper is minimal, making replacement the best value when repairs will only be temporary on an already failing part.
Signs It’s Time to Replace Other Toilet Tank Parts
While a faulty flapper valve is the most common culprit behind a poorly functioning toilet, other tank components can also cause problems if deteriorated. Be on the lookout for these signs that indicate additional toilet parts may need replacing:
- Fill valve – Turns on/off very slowly; needs multiple flapper flushes to fully refill tank; makes loud noises when refilling
- Float ball – Water in tank doesn’t rise to normal 1” below overflow tube level; float ball cracked or waterlogged
- Flush handle – Loose or disconnected; broken or missing components; no longer lifts flapper fully
- Overflow tube – Allows water to rise too high in tank; cracked or detached from tank
- Refill tube – Poor or sluggish bowl refill after flush; leaks from connection
- Gaskets – Tank leaks at fittings; dried out or cracked tank gaskets
- Flush valve seal – Doesn’t fully seal around flapper; cracked or bent out of shape
Catching malfunctioning toilet components early provides the chance to replace parts before major leaks or damage occur. Know how to spot the signs that your toilet needs new parts for smooth sailing flushes.
Frequently Asked Questions About Replacing a Toilet’s Flapper
- What are some common signs my toilet flapper needs to be replaced?
Some common signs include the toilet continuously running, reduced flushing power, having to jiggle the handle to stop running water, the tank not fully refilling, increased water usage, and minerals deposited on the flapper valve.
- How often should the toilet flapper be replaced?
Expect to replace a flapper every 3-7 years with regular use. Hard water can cause mineral deposits that degrade the flapper more quickly.
- Is it easy to replace the flapper myself?
Yes, flapper replacement is typically an easy, straightforward DIY project taking less than 30 minutes. Make sure you get the correct replacement part for your toilet.
- What measurements do I need when shopping for a new flapper?
You’ll need to know the diameter of the flush valve opening that the flapper covers, along with the style (slide clamp or tower). Bring your old flapper to purchase the right replacement.
- Anything special I need to do when installing the new flapper?
Make sure the flapper chain has the right amount of slack, allow enough time for leaks to appear, and test flush several times. Inspect fill levels and make any float adjustments after install.
- How do I stop my flapper from leaking after replacing it?
Carefully clean sealing surfaces of any debris. Make sure you have the precise size replacement flapper. Adjust the chain length. Replace again if leaks persist.
- Why does my new flapper keep cracking?
Using low-quality or plastic flappers can lead to cracks. Also ensure you aren’t overtightening the retaining nut. Buy a better grade rubber flapper.
- Can I just patch or glue a cracked flapper?
Attempting to patch or glue cracks is just a very temporary fix. Any deformation prevents a good seal. Replace cracked flappers for a reliable solution.
- How do I choose the correct flapper for my toilet?
Match your existing flapper style and measure the flush valve opening diameter it covers. Bring the old flapper to the store to buy the identical replacement.
- Why is my water bill suddenly spiking?
A major cause of unexpectedly high water bills is a leaking toilet flapper valve. Replacing a faulty flapper can solve this common issue and save water.
How a Toilet Flapper Works
The flapper, sometimes called a flush valve seal, is a critical working part located at the bottom of a toilet’s tank. Understanding how a toilet flapper functions provides a better grasp of common toilet troubleshooting when flushing problems arise.
Here’s a look at how a toilet flapper works each time you flush the toilet:
1. Flapper seals water into the tank
The flapper acts as a seal, covering the flush valve opening at the bottom of the tank to retain water in the toilet tank between flushes. The flapper should completely seal the opening to prevent leakage.
2. Pushing flush handle lifts flapper
When the toilet handle is pushed down, the connected chain pulls up on the flapper, lifting it vertically to open the flush valve.
3. Open flush valve releases water
With the flapper raised, the pressurized water in the full tank is allowed to escape rapidly into the toilet bowl via gravity. This provides a siphon flushing action.
4. Tank empties into bowl
The unsealed flush valve opening allows continuous water flow from the tank to the bowl until the tank is nearly empty, providing sufficient water volume for flushing waste through the trapway.
5. Flapper seals again when tank empty
As the water drains out, the now unsupported flapper floats back down into the seated, closed position over the flush valve. This reseals the opening between the tank and bowl.
6. Float valve refills tank
With the flapper valve closed again, a float-operated fill valve refills the tank with a new volume of water. This prepares the correct tank level for the next flush.
7. Flapper holds water in tank
The sealed flapper retains the refilled water in the tank until the next flush. The cycle then repeats each time the toilet is flushed