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How Does a Dishwasher Work?

Kelly Townsend

The dishwasher is a common home appliance that saves countless hours of time compared to washing dishes by hand. Hand-powered versions were initially introduced in the 1880s, with electric-powered dishwashers following in the 1940s. Research has shown that dishwashers are much more efficient than hand washing, using less water, less energy and less soap.

19th-Century Invention

How Does a Dishwasher Work?

Push of a Button

How dishwashers work is not very complex for the user as you simply load the dishes, place the soap into the proper area, press a button and the dishwasher does the rest. However, the internal mechanics are much more complex.

Appropriate Settings

Before starting the dishwasher, you fill it with dishes, pots and pans, silverware and other kitchen utensils. You then select a particular cycle by pushing a button and start the machine. The available options correspond to the types of dishes, along with the duration and/or intensity of the cycle.

Soap, Water Mix

The fundamental concept behind dishwashers is that they combine hot water with detergent, making a sanitizing mixture that is then sprayed on the dishes. When you put the soap into the machine and turn on the dishwasher, the detergent mixes with the water in the first few minutes. Sensors within the unit make sure that the water does not overflow, a situation that would cause damage for both the dishwasher and the surrounding area of the kitchen.

Dishes Jet Sprayed

The motor forces the water up through jets in the dishwasher, causing it to spray the dishes with the water and detergent. The force of the water removes the food particles and grime from the dishes while the soap sanitizes them. After the wash cycle, more water is sprayed on the dishes to rinse them, then the water drains from the bottom of the unit back through the plumbing. Depending on the dishwasher, the dishes are either air dried using a fan to circulate the air or heated through the use of an electric heating element. A thermostat inside the dishwasher makes sure that the dishwasher does not overheat.

Automatic Turnoff

Once a dishwasher has finished its cycle, the machine will turn off. The result will be, in a properly working machine, a dishwasher full of spotless items.

Improved Efficiency

Dishwashers have evolved in size and use throughout the decades. Today's versions are bigger, use less energy and are safer to use. Some dishwashers are outfitted with soil sensors that monitor the dirtiness of the water, advancing to the next sensor cycle once the water is sufficiently clean. This helps ensure that the items will be thoroughly cleaned. The time it takes for a dishwasher to run has also decreased, as many modern day versions can clean a rack of dishes in 15 minutes or less.