1) Consult the owner's manual of your model of dishwasher to see if it has a food debris trap or an automatic solid waste disposer. Remove any trap filters and rinse out debris under running water. Wipe the vacated trap area with a dampened soft sponge before returning the filter.
2) Dip an old toothbrush in a small bowl filled with pure lemon juice. Press firmly as you brush the lemon juice onto the heating element and all the water jet nozzles in a circular motion. Apply a second coat of lemon juice and let it soak in for five minutes.
3) Check the temperature of the water being supplied to the nearest sink faucet by placing the kitchen thermometer into a tall glass and filling it with the hottest water from the tap. Turn up the hot water heater if the water is not at least 120 degrees.
4) Pour white vinegar into the dishwasher and secure the kitchen thermometer on the top rack. Check the manual to find out if your dishwasher model has a pre-heating cycle that can be turned on. Close the dishwasher door and set the dishwasher to run a wash cycle.
5) Stop the dishwasher after it has been in the wash cycle for five minutes and open the door to check the temperature of the thermometer. A working dishwasher should be capable of heating water to above 140 degrees to clean its load.
6) Load both racks with dirty dishes making sure that spray jets are not obstructed. Swing the arm of the sprayer to be certain that it rotates freely.
7) Add the soap and rinse agent dose prescribed by the manufacturer and run another wash cycle to determine the level improvement.
