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How does a Toilet Work - Toilet Basics 101

Novel Treasure is a do-it-yourselfer and prides herself on being able to make basic home repairs on her own.

Diagram of plumbing and parts of a toilet.

Diagram of plumbing and parts of a toilet.

What are the different parts of a toilet?

Ever wonder how a toilet actually works? Millions of people use one every day, several times a day, but probably without even giving a second thought to how this plumbing marvel works. We take for granted, the complexities of the inner workings of this modern day convenience.

The are many different brands and styles of toilets available today, but they all basically have the same three components: the tank, the bowl, and the plumbing attached.


Toilet Basics

The Tank

The big box-like thing on the back of the toilet, commonly known as the tank, houses the majority of the working parts of the toilet. The toilet tank generally consists of the handle, float ball, refill tube, overflow tube, fill valve (a.k.a. Ballcock), and the flapper.

Handle: the trip lever that begins the act of flushing the toilet.

Float Ball: located in the tank, it floats in the water that is in the tank. With each flush, it rises and falls with the level of the water.

Refill Tube: the tube connected to your water supply that fills the tank back up after each flush.

Overflow Tube: the tube that drains water from the tank if it gets to full.

Fill Valve (Ballcock): the valve that covers the refill tube

Flapper: covers the hole between the tank and the bowl.

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Basic Toilet Repair Kit: All-in-one

Common shapes of toilet bowls

Common shapes of toilet bowls

Toilet Bowls

The bowl is probably the most basic piece of the toilet, as it is generally, just two pieces: the bowl and the lid. Commonly made of porcelain, the toilet bowl is typically either round or oval, although there are some square ones out there. The lid (seat) is made of many different types of material; wood, porcelain, plastic, marble (yes, marble).

Bowl: the bowl refers to the whole piece connected to the tank. It includes the sitting area and the base of the toilet, as they are generally all one piece.

Lid: refers to the piece that covers the bowl, or sitting area of the toilet.

S Trap or S Shaped Plumbing

S Trap or S Shaped Plumbing

Wax Free Toilet Bowl Gasket

The Plumbing

One of the greatest inventions of all time, is that of the S-curve plumbing, which was invented by Alexander Cummings in 1775. The S-curve plumbing prevented sewage gases from flowing back up into your bathroom. Most people are not aware that the gases from sewage are quite flammable, not to mention foul smelling. The S-curve plumbing was later enhanced by Thomas Crapper in 1880, who introduced the U-bend plumbing which was less likely to jam and overflow.

The other piece of the plumbing for toilets is the water supply valve that is connected to the tank, that supplies the water to the filler valve to fill the tank. Without it, there would be no water supply to refill the tank to continue to flush.


How does a toilet work

Toilet bowl water level

Now that you know the basic parts of the toilet, let's explain how it all works together. First, water is supplied from the water supply valve to the refill tube. The water flows through the refill tube and fills up the tank. Once the float ball reaches a designated height it triggers the fill valve or ballcock to cover the refill tube so no more water fills the tank. If the fill valve is defective and continues to allow water in the tank, the excess water will flow out of the overflow valve and into the toilet bowl.

Once the tank is filled to the designated height, it is ready to be flushed. When the handle or button is pressed, this releases the flapper covering the inlet hole at the bottom of the tank. This allows the water from the tank to flush out of the tank and into the bowl. Some of the water goes down the refill tube to start refilling the tank, but the majority flushes into the bowl. The weight and amount of the water flushed into the bowl create a siphon effect and the water is sucked from the bowl through the S-curve plumbing and out through your sewage pipes.

While the water is rushing out of the tank, the float ball drops triggering the refill valve to open up and begin refilling the tank. Once the float ball reaches a certain level the refill valve shuts off and the toilet is ready to flush again.

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