Often there is a simple solution for a dishwasher not turning on, such as a loose wire. Other causes can be diagnosed with a multimeter and easily fixed by replacing the part.
To order a replacement part, you will need to know your dishwasher model. Consult your manual, or sometimes you will find model information on the exterior sides of the dishwasher or inside the dishwasher door.
Pro Tip: If taking the dishwasher apart, wear gloves to protect yourself from cuts, as the metal can be sharp.
Remember to unplug your dishwasher or switch off its power from inside your electrical panel before checking electrical components.
Step 1: Check the Power Supply
Dishwasher plugs can become dislodged due to the vibrations of the dishwasher or other kitchen appliances. A fuse can also blow inside the plug.
- Check that it is plugged in properly.
- Check the power socket by plugging in another appliance and seeing if it has power.
Some dishwashers are wired directly from the wall to the wires in the junction box. You can check the power supply by accessing the junction box underneath the dishwasher. Make sure the power is turned off from inside your electrical panel before testing with a multimeter.
Step 2: Check Your Switches
Some models require an additional wall switch to the dishwasher power switch to be turned on. Often this switch is found next to the garbage disposal or kitchen light switches.
- Check that the dishwasher does not require an additional switch to be switched on.
Step 3: Check Your Electrical Panel
Once you have confirmed that the power connection is not at fault, check to see if a circuit breaker has been tripped.
- Check the electrical panel.
- If a circuit breaker has been tripped, reset it.
- If a fuse has blown, replace it.
Step 4: Check the Door Latch
Most dishwashers will not power up if the dishwasher door is not closed properly. If the door is not closing correctly, you may need to unscrew the panel around it to check the part.
- Check to see if the dishwasher door is closing properly.
- Depending on the model, you may be able to see a metal latch that is causing the problem. If it is bent, you may be able to use pliers to straighten out the latch and fix it. Make sure to disconnect the power first and be careful not to break it.
- If you cannot fix the latch, replace it.
Step 5: Check the Door Switch
If the latch is latching correctly, the door switch may have an electrical fault. The door switch allows power to the dishwasher only if the door is properly closed. Sometimes the door switch will come loose, or water can get in and damage it.
- Disconnect the dishwasher from its power source.
- On most models, the dishwasher switch can be accessed by unscrewing the control panel. On other models, the dishwasher front panel will need to be removed to access it.
- If the door switch was not connected, plugging it in should solve the power issue.
- To check if the door switch is faulty, disconnect it from the dishwasher and use a multimeter to check for continuity. If there is more than one wire connecting it, take note of where each wire goes.
- If it fails the multimeter test, replace the door switch.
Step 6: Check the Wiring Harness
The wiring or cable harness consists of various wires that connect to various parts of the dishwasher. On most models, the wiring harness can be found with the control panel. Excess heat sometimes damages the wiring harness, or wires can melt and attach to the dishwasher.
- Examine the wiring harness for any of the above issues.
- Replacing the wiring harness is difficult and should only be attempted by professionals. This is especially true if multiple wires need to be replaced. A mistake will likely be costly and dangerous.
- Replacing a couple of easily accessible wires is slightly easier, but it is still best repaired by a professional.
Step 7: Check the Electrical Control Board
Solving the dishwasher’s power problem could be as simple as examining the control board.
- Check that all the connections on the control board are connected, making sure they are plugged in tightly.
- Check the control board for any signs of corrosion, burn marks, or other damage to the board and wires.
- If you notice any damage, this may indicate what the problem is.
It is difficult to test the control board, so it is best checked by a professional. If you are unsure, it would be wise to check all the steps on this list before replacing the control board.
Step 8: Check the Touchpad or Buttons
A fault with your dishwasher controls is most commonly found when some buttons work but others don’t. Make sure the dishwasher is disconnected from the power before proceeding.
- The touch pad is usually part of the control panel. Check the connection between the touchpad and the control board.
- Look for any signs of corrosion and clean with a soft pencil eraser.
- Dishwashers with mechanical selector switches can be tested for continuity with a multimeter. Referring to the wiring diagram will help with this test.
Step 9: Check the Timer
Dishwashers with manual timers sometimes stop powering up because of a faulty timer.
- Make sure the dishwasher is disconnected from the power.
- Locate the dishwasher timer. The timer is usually a part of the control panel, but sometimes it can be found behind the lower kick plate.
- Test the timer with a multimeter. Refer to the wiring diagram to determine which wires to test.
- If it fails the multimeter test, replace the timer.
Step 10: Check the Thermal Fuse
The thermal fuse is a safety device that shuts off power to the control panel if the dishwasher overheats. On most models, the thermal fuse is in the control panel area. However, on other models, it may be located near the bottom of the tank.
- Make sure the power is disconnected.
- Locate the thermal fuse.
- Use a multimeter to test the thermal fuse for continuity.
- If it fails the multimeter test, replace the thermal fuse.