The part(s) or condition(s) listed below for the symptom Dishwasher won't start are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The thermal fuse shuts off power to the dishwasher if it overheats. If the thermal fuse blows, it will prevent the dishwasher from starting. To determine if the thermal fuse is defective, use a multimeter to test the fuse for continuity. If the thermal fuse does not have continuity, replace it.
Dishwasher thermal fuse (or bi-metal fuse) assembly. The thermal fuse opens to cut off power to the dishwasher if the dishwasher overheats. If the thermal fuse fails, the dishwasher will not start. If the thermal fuse has failed, first investigate what caused the dishwasher to overheat.
The door switch prevents the dishwasher from running while the door is open. If the door switch is defective, the switch will prevent the dishwasher from running even when the door is closed. To determine if the door switch is at fault, use a multimeter to test the switch for continuity. If the switch does not have continuity, replace it.
The door latch ensures that the dishwasher door latches shut. If the door does not latch properly, the door switch might prevent the dishwasher from running. If the door latch is broken, replace it.
The main control board provides power to nearly every component of the dishwasher. If there is a problem with the main control board, it might not send voltage to the dishwasher, causing the dishwasher not to start. Control boards are often misdiagnosed—make sure you check more commonly defective parts before replacing the main control board.
To determine if the touchpad is at fault, try pressing various buttons on the touchpad. If some of the buttons don’t respond, the touchpad might be defective. (Some manufacturers sell the touchpad separately from the control panel. Other manufacturers require that you purchase the touchpad and control panel together. If you cannot replace the touchpad individually, replace the touchpad and control panel.)