• Plumbpedia™ - How Does A Toilet Work?

If you look in the toilet bowl before you flush you will obviously know that there is a small amount of water in the bottom of it. However, you may not know that the tank at the back of the toilet is also full of water. A device known as a flush valve plugs the tank so that water will not escape into the toilet bowl. This is important to understanding exactly how does a toilet work.

When you push the handle to flush the toilet a chain is pulled which lifts the flush valve so the water from the tank rushes into the toilet bowl in 2-3 seconds. The force of the running water combined with a siphoning effect causes nearly all of the water to rush into the sewerage drain. To see this in action simply get a bucket of water and tip it quickly into the toilet bowl and watch as almost all the water disappears down the drain. When the right amount of water has left the tank the flush valve again blocks the tank so that no more water will go into the toilet bowl. Now you know the most important step when discussing how does a toilet work, but now you need to consider how the toilet resets to its pre-flush state.

For water to in the tank and the toilet bowl to be refilled a device known as a filler valve must be switched on. It is turned on an off by a flotation device known as a filler float. When the water level in the tank drops, the filler float drops and switches the filler valve on. The filler valve sends water in two different directions; into the tank and into the toilet bowl via another tube known as the overflow tube. When the water level in the tank reaches a maximum, the filler float turns off the filler valve stopping any more water going into the tank or the toilet bowl. You might be asking why the water added to the toilet bowl doesn’t escape down the drain as it does when water from the tank is dumped into the bowl. The answer is quite simple. When the toilet bowl is refilled it is done very slowly so that there will be no siphon effect and, therefore, the water will not be sucked out of the bowl.