How Does a Dishwasher Work?


A dishwasher works by heating and pumping water and detergent over the dishes and then rinsing them with clean water. Dishwashers utilize a pump, heating element, and high-pressure water jets to clean and sanitize dishes.

Dishwashers take in water, either from a direct connection or a sink adapter, and heat it to a specific temperature range. This water is pumped into the spray arms, where it is forced through small ports, increasing its pressure as it exits. The hot water, mixed with detergent, is then circulated around by the action of the spray arms and collected as it falls to be recycled by the pump. Once the wash cycle is complete, the dirty water is drained and clean water is drawn in to rinse the dishes. Most modern dishwashers also have a drying cycle, where the heating element for the water is also used to warm the dishes and speed drying times.

Most dishwashers are computer-controlled, and some have spray arm assemblies on the top and bottom, spraying simultaneously for better cleaning. Other models have various cycles that allow users to choose the time and thoroughness of the cleaning, while others are equipped with sensors that detect the cleanliness of the water to determine when the dishes are clean.