How It Works

Most dishwashers use sliding racks to hold your dishes while spray nozzles on rotating arms shoot powerful streams of hot water to get your dishes clean. The arms rotate with a connected drive motor and may move up and down to reach every tray. A heating element mounted on the lower portion of the bottom rack provides heat during the drying cycle, and many units are equipped with water heaters to increase the temperature of the wash water. Dishwasher Detergent is automatically released during the wash cycle. Controls are usually located on the front of the dishwasher.

What Can Go Wrong?

The most common issue with older units is deterioration of the bottom seal which results in leakage. Cost to replace a bottom seal may approach costs to replace the entire dishwasher. Many modern dishwashers have controls embedded in a circuit board. If these controls fail, they are not repairable and must be replaced as a unit. 

Automatic valves control the ratio of hot and cold water based on cycle settings. If these valves fail, the dishwasher will be unable to operate during the wash cycle. Motor breakdown sometimes makes the dishwasher inoperable. When possible, replacing a broken motor usually requires a complete removal of the dishwasher from its location.  

Environmental Impact

Consider the cycle settings you typically use: heating cycles have the largest impact on energy efficiency and cost. A typical dishwasher (1200 watts) might use 30 kilowatt-hours (kWh) of electricity per year (at 30 loads per month), while producing about 46 pounds of carbon dioxide (CO₂). This excludes energy consumption and CO₂ production from the home water heater that heats the water used by the dishwasher.