If your toilet keeps running or flushing on its own, it may be time to replace your flapper. Replacing the flapper can be an easy fix, especially if you have a hard plastic toilet flapper, and you won’t need to call the plumber. Follow our steps below to replace the flapper yourself.
Key Points
- Replace your toilet flapper as soon as you notice issues.
- Locate and identify the flapper in the toilet inside the tank.
- With the help of our guide, replacing a damaged flapper is quick and straightforward.
What Is A Toilet Flapper?
Located at the bottom of the toilet tank, the flapper creates a tight seal over the overflow tube to prevent water from leaking out of the tank. When you push the toilet handle down to flush, the flapper rises to allow water to flow into the bowl. Once all of the water has left the tank, the flapper should seal the hole again.
However, if the flapper is damaged, it won’t seal properly and water will continue to flow into the bowl. If this happens, the toilet won’t have a powerful flush and will keep leaking water. You should replace or repair your flapper as soon as you discover any issues.
Types of Flappers
To replace your flapper, you first need to know if it’s a tank ball, a seat disc, or a rubber flapper.
A tank ball flapper is a rubber ball that seals the overflow tube. It is attached to a chain that lifts the ball off the tube once the toilet is flushed. However, if the chain is the wrong length, the ball will not be lifted high enough or put back into place correctly to seal the tube.
A seat disc, on the other hand, doesn’t need a chain. Being an older model, it is much larger than other flappers and you may have difficulty finding a replacement. A seat disc is a circular plastic disc that covers a plastic tube. This plastic tube is connected to the overflow tube.. During a flush, the weight of the water moves the flapper to open the overflow tube. This allows the water to flow into the bowl. 
A rubber flapper is the most common model in newer toilets with the fewest parts, thus the easiest to replace. This flapper, which may be made out of plastic, is a simple cap that is attached to the top of the overflow tube. Similar to the tank ball flapper, a rubber flapper connects to a chain that must be the perfect length for the flapper to work.The chain pulls the cap off the tube when the toilet is flushed. If you think your flapper chain may be the incorrect length, keep reading to learn how to adjust the chain.
Adjusting the Flapper Chain
As mentioned above, your flapper may just need an adjustment to work properly again. Follow these steps to check your flapper:
- STEP 1: Turn off the water supply valve of your toilet. This valve is usually near the floor, close to the toilet. Simply rotate the knob counterclockwise and the water will stop flowing through the plumbing pipe into the toilet.
- STEP 2: Lift the toilet lid off the tank and place it in a safe location. Be careful as the lid is heavy and fragile. You should now have easy access to the inside of the tank.
- STEP 3: Find the chain that is attached to the flapper. This chain will be hooked onto the lever arm, which raises the chain when you flush the toilet.There should be a few extra links at the end of the chain. To adjust the length of the chain, detach the chain from the lever arm. Find the correct link to rehook the chain to create an appropriate length. Remember to allow for some slack.
- STEP 4: Turn the water valve back on and flush the toilet. If this didn’t resolve the issue, keep adjusting the chain until the flapper seals properly. However, if it looks like the chain is the correct length, you may need to replace the entire flapper.
Replacing a Flapper
Before you can replace your flapper, you will need to buy a new flapper. If you can’t find an exact model at the store, a similar model will work.
- STEP 1: Turn off the water valve and flush the toilet to empty the tank.
- STEP 2: If the flapper has a chain, detach the chain from the lever arm and then from the flapper itself. If the flapper is attached to pegs, either slide or snap the flapper off of them. Hard flappers will snap off the pegs, while rubber flappers will slide off. In some cases, the flapper will fall off on its own after a flush.
- STEP 3: Now attach the new flapper onto the overflow tube. Depending on the type of flapper, either snap it on the tube or align the flapper holes with the pegs.
- STEP 4: Get the chain that you set aside and attach it to both the new flapper and the lever arm. Remember to leave a bit of slack. Keep adjusting the chain until you get the perfect length.
- STEP 5: Turn the water back on and wait for the tank to refill completely. Make sure the water doesn’t stop below or over the water level mark. If it does, just turn the screw on the fill tube to adjust it.
- STEP 6: Flush the toilet and check that the flapper works properly without any leaks.
Read our DIY guide about replacing toilet flappers here.
Our Final Opinion
Using this guide, you will be able to replace your flapper without difficulty. If your new flapper has instructions on the packaging, follow along in case there are special steps included. In only a few steps, your toilet will be back to normal.