Certain dishwashers will flash various status indicator lights if a problem has occurred with the dishwasher, such as a water fill error or temperature problem. If the "Lock" light is on and the dishwasher won't perform any operations, there are a few reasons why this might be happening. Figuring out what is causing the "Lock" error and resolving the issue may take a few steps.
Certain dishwashers offer a control lock that prevents use of the dishwasher by unauthorized individuals, such as children. Release the control lock by pressing and holding the "Control Lock," "Heated Dry" or "No Heat Dry" key pad for three seconds. The control lock light or icon should go out. Repeat the process to set the control lock again.
Touch Pad Console
Another potential reason for the "Lock" light to flash or stay lit on a dishwasher is a stuck key on the console. Clean off the console if there's residue or food debris on the key pad that is making the pads sticky. Use a clean, damp cloth to wipe off the touch pad and then wipe the touch pad dry with a towel.
If the control lock feature isn't engaged and the "Lock" light continues to stay lit or flash, try to perform a power reset. Disconnect power to the dishwasher for 30 seconds and then restore power. Open and close the dishwasher door and select a new wash cycle then select or press "Start." If the dishwasher resumes normal operation, no further action is necessary.
After all troubleshooting and reset methods have been tried and if the lock light continues to stay on or flash and the dishwasher won't work, the key pad console will need to be replaced. This is a task best left to professionals, so contact the dishwasher manufacturer or a service technician for assistance.