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How to Test if a Dishwasher Thermostat Works

A malfunctioning dishwasher thermostat will cause the dishwasher to not work properly and leave your dishes less than clean. In addition, a damaged thermostat will prevent the dishwasher from completing a full cycle. Before you consider replacing the thermostat, try a few tests to determine whether the problem really is with the thermostat and not some other malfunctioning part. For best results, consult your specific dishwasher’s owner’s manual for thermostat troubleshooting.

Things You'll Need

  • Water thermometer
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Instructions

    • 1

      Check the kitchen hot water with a water thermometer 30 seconds before beginning the dishwasher. If the water temperature is not hot enough, it will not clean the dishes properly. Consider turning the temperature on your hot water tank up a few degrees.

    • 2

      Run the dishwasher diagnostic test. Many new models will have a series of buttons that you press to run a diagnostic test. This test will inform you of any malfunctioning parts including a damaged thermostat. Since each brand and model has its own method to start the diagnostic test, consult your dishwasher owner’s manual for the specific series of buttons to push.

    • 3

      Set the dishwasher on the highest temperature setting at the shortest cycle. Close the dishwasher door and press the start button. If the dishwasher does not complete the full cycle, the thermostat is malfunctioning and will require replacing.