A toilet flush valve controls the flow of water from the tank into the toilet bowl. It is made of a valve body, a flapper, and a chain. When you flush, the chain lifts the flapper and water flows ...

This will open the flush valve at the bottom of the tank, emptying the water into the bowl and pushing your waste into the sewer. But that’s not the most elegant or sustainable solution.

For most toilets, the handle is attached to a chain that’s attached to the flapper—which is basically the lid on top of the flush valve. As soon as you press the handle down, the chain lifts ...