How to Replace a Toilet Flapper

Knowing you have the right flapper for the job is the most important step, as certain toilet flush valve models can require a specific fit. Universal toilet flappers are the best choice when choosing a flapper, but knowing what size you need before proceeding is crucial. Try reading our guide about determining flapper size for more guidance. If you are still unsure, try using our Toilet Genius Assistant® to find a compatible Korky flapper for your toilet.

To start, turn off the water supply by turning the handle clockwise until the valve is fully closed.

Next, flush the toilet as you normally would, and mark where the water level drops inside the tank with a pencil. This step will be important later.

Once completed, remove the rest of the water by holding the flush handle down until the water is drained.

Removing the old flapper is simple, all you have to do is unhook both flapper ears from the flush valve arms and unhook the chain from the flush lever.

Installing a new toilet flapper is easy. Start by cleaning the flush valve and ensuring there is no sediment or debris. This extra step will make sure your new flapper seals properly while preventing slow leaks after a new install.

Next, take the new flapper and place it in the flush valve opening, hooking each ear onto the arms located on the side of the flush valve base.

Once the new flapper is installed, connect the flapper chain to the tank lever arm. Be sure only to leave one to two chain links in slack. 

If the chain is too loose, the flapper will not open all the way, resulting in a slow flushing toilet. The chain is too tight, your flush valve will not seal properly, causing your toilet to continue running.

After the flapper chain is connected to the lever arm, turn the water supply back on by turning the valve counterclockwise.

Some Korky flappers can be adjusted to match your original toilet's settings. Don't worry, this is not difficult to do! If you do not have an adjustable flapper, your installation is completed and you do not have to proceed to the next steps.

Turn your water supply back off, then flush. If the water level falls at or below one-half inch of the pencil mark inside of the tank, your installation is complete!

If the water level is above the pencil mark, turn the red or white band to the next highest number. This will close off the holes and allow the flapper to float longer, resulting in a longer flush. 

Repeat this process until your water drops within a half inch of the pencil mark.