Like many of the internal tank components, the flapper valve plays a crucial role in the transition of water from the tank to the bowl after the flush. This part is a round and rubber circular part that gets its name for its valve-like opening and closing. It is attached to the overflow tube by hooking arms that hold it in place on either side. When the toilet handle is pressed down to flush, the flapper valve opens up and allows the water stored inside the tank to go into the bowl, completing the flush cycle.

These valves are hardy parts that last for about five years before needing to be replaced. However, if the flapper valve is left unrepaired after it is torn or worn down, it can be one of the costliest repairs. There are four main reasons why a flapper valve is not operating correctly: debris around the seal, too loose of a connector chain, too tight of a connector chain, or disintegrating valve. The valve is easy to replace. First, shut the toilet water off. Then attach the new flapper valve and clip into the notches on either side.