How Does a Toilet Work?

How Does a Toilet Work?

10th Jun 2016

Toilets are a ceramic fixture in our lives that each of us spend ample time around, if not actively thinking about how they operate. This is how the basic model of toilet that exists in most residential bathrooms works. Other toilets tend to work on the same principles, but they may have different flushing mechanisms, move parts to different locations, or treat the waste material differently. Larger restrooms with multiple toilets frequently share their water tanks from a communal source, for example.

The Throne Awaits

A toilet is composed of three primary parts: the water tank that holds fluid for washing out the waste material, the basin or bowl in which the business is done, and the connections to the water and sewage line. When you walk into an average residential bathroom, you will typically find the toilet in the ready state with a tank containing water up to its fill line and the bowl filled with a low level of water. This sitting water doesn't have the force to push past the curved underbelly of the toilet and acts as a trapping seal for gasses in the sewage line.

As the Swirl Turns

After use, it's time to flush! The flushing lever is connected to a plug at the base of the water tank and lifts it when pressed, allowing the water held within to surge out using the force of gravity. Most toilet models will have a series of small holes around the inner rim that also allow water to seep through, washing the sides of the bowl free of waste. A water jet located below the bowl helps push through solids into the sewage line in some models.

Preparing for the Next Round

Releasing the lever will cause the plug to fall back down into the opening of the tank, sealing it shut. The basin is refilled with the trap seal of water, and the tank is refilled until a shutoff is initiated by a buoyant measuring device inside of it. In older tanks, a ridged plastic ball - called a ballcock -attached to a valve that controls the inlet from the water line serves the role, but newer tanks control the tank refilling using a design based on the FluidMaster 400A. Once the ball or tube (in the case of the FluidMaster) rise above the configurable fill level, the preparatory process is complete and you can once again use the toilet.