The toilet is a simple machine that we all take for granted. In fact history shows that over 5000 years ago there were primitive toilets using river water to flush wash away waste. So how does this simple machine work. It really only has four parts, the water tank,the bowl, the flush mechanism and the refill mechanism. The water tank is filled with water waiting to be needed. When you pull the flush handle a valve opens in the bottom of the tank allowing water to enter the bowl, wish with the use of gravity forces the waste and water out to the drain. The the tank must refill but not overflow, to be waiting for the next flush. Inside the tank there is a float which will cut of the water when the tank is full. At the drain there is an S shaped pipe that keeps some of the water in the bowl at all times. This water keeps the sewer smells from coming back into your bathroom.