A dishwasher is a mechanical device for cleaning dishes and eating utensils. Dishwashers can be found in restaurants and private homes. Unlike manual dishwashing, which relies largely on physical scrubbing to remove soiling, the mechanical dishwasher cleans by spraying hot water, typically between 55 and 75 °C (130 and 170 °F) at the dishes, with lower temperatures used for delicate items. A mix of water and detergent is circulated by a pump. Water is pumped to one or more rotating spray arms, which blast the dishes with the cleaning mixture. Once the wash is finished, the water is drained, more hot water is pumped in and a rinse cycle begins. After the rinse cycle finishes and the water is drained, a heating element in the bottom of the tub heats the air to dry the dishes. Sometimes a rinse aid is used to eliminate water spots for streak-free dishes.
Dishwasher fails to wash properly
Most dishwashers have rotating spray arms on upper and lower trays. If the trays are poorly loaded, they can foul the arms and prevent them turning.
Another common problem with most dishwashers; rice! Rice grains get into the spray arms and blocks the jets, this in turn prevents the arms from turning and properly washing the dishes. They can be cleaned by poking them through with a thin skewer or by blowing through with an air-line. Always rinse any rice laden utensils in the sink before placing in the dishwasher.