Dishwashing Machine Diagnostic Guide

Use the diagnostic chart to find out what is causing the problem with your Dishwashing mechine. Look up the symptom, and then review some of the possible causes. Follow the links from the possible causes to facilitate to the tutorials on how to repair the problem.

Symptom

Click on underlined items for further course information

Dishwasher does not work - no sound, water or lights

Electric Shock can cause injury or death

warning-img.pngNever assume the electricity is off. Before servicing an electrical device, disconnect it from its electrical source either by unplugging the appliance, or turning off the power at the breaker fuse box. Mark the service panel with a note so that no one will restore power while you are working. After turning off the power to the circuit, test the circuit to be certain that there is no power before attempting service.

 

 

  • Check for a blown fuse or tripped circuit breaker
  • Check that the dishwasher is plugged in securely - usely a outlet under the sink
  • Inspect the wiring connection to the dishwasher for burns or breaks.
  • Check the door latch - See: if latch & dorr switch align
  • Test the door switch - for continuity(see:continuity test at the bottom*)
  • Test the timer control - if getting power out
  • Test the selector switch - for continuity(see:continuity test at the bottom*)
  • Test the motor start relay - for continuity(see:continuity test at the bottom*)
  • Test the motor - if getting power to

 *Learn To Use Multimeters

 

Dishwasher does not start but motor hums

 Dishwasher Repair Tutorials:

  • Unjam the motor - if getting power to(see below)
  • Unjam the pump - most newer machine pump & motor are the same assembly
  • Test the motor - continuity*  & power to
  • Test the motor start relay - for continuity(see:continuity test at the bottom*)
  • Check the drive belt - new DW do not have a belt

Dishwasher does not fill with water or it drains while filling

Dishwasher Repair Tutorials:

 

  • Check for adequate water level
  • Check the spray arms and spray tower
  • Check the water temperature
  • Check the detergent cup
  • Clean the fine particle filter
  • Check the inlet filter screens
  • Check the water pressure
  • Test the water inlet valve - for continuity(see:continuity test at the bottom*)
  • Check the drain valve - for continuity(see:continuity test at the bottom*)
  • Test the selector switch - for continuity(see:continuity test at the bottom*)
  • Test the timer control - for continuity(see:continuity test at the bottom*)
  • Test the heating element - for continuity(see:continuity test at the bottom*)
  • Test the bimetal terminal assembly

The walls, racks or tub are rust stained

  *Learn To Use Multimeters

multimeter.gif

*Continuity test is the checking of an electric circuit to see if current flows any electrial device, such as a switch, solanold, If contact is made inside the component its good.(that it is in fact making a complete circuit). A continuity test is performed by contenuity tester that can be used to perform the tests. See the multimeters in the picture to the left, which also measure voltage. Other continuity testers more basic devices which are cheaper, generally with a simple light bulb that lights up when current flows. SEE: Electrial Fundamentals Course 

When a bad motor winding cannot be found by a physical inspection, many times an ohmmeter may show that there is a defective winding. Read more: How to Test Electric Motor Windings Ohmmeter usages. While the ohmmeter may not show potential failures, it can be used to determine if the windings are good or bad.

 Learn To Use Multimeters