Emptying the Tank

• A toilet's flush handle is connected by a chain to a rubber flapper covering the siphon hole in the bottom of the tank. When you flush, the flapper rises and water rushes through the hole into a passage built into the rim of the bowl. Precisely-sized holes allow the water to flow into the bowl. If the flow is fast enough, it creates a suction in the siphon hole that accelerates the flow. It's important for the tank to drain quickly, because the suction that empties the bowl depends on the quick release of a large volume of water through the bowl and into the waste line.