When your LG dishwasher stops draining water out of the tub, there are some basic steps that you can perform to find out what is causing the problem, such as cleaning out the kitchen garbage disposer. In addition, other things can help prevent future drainage problems and maintain the dishwasher drainage system so that problems with water draining out of the dishwasher are a thing of the past.
Avoid pressing the "Power" button during a wash cycle if stopping the LG dishwasher temporarily is necessary. This will stop the cycle completely and leaves water in the tub. Open the door without pressing any buttons, then close the door within a few minutes and the cycle will resume automatically.
Remove the drain hose from the dishwasher and clear out the hose out to remove any obstructions. Reattach the drain hose firmly and straighten the hose out to prevent clogs caused by a bent hose.
Pull the bottom rack out of the dishwasher. Remove the lower spray arm and the spray arm support. Look inside for a device that looks like a blade and clean away any objects that might be blocking movement. This is the wash impeller, which is responsible for moving waste water into the drain port and can cause problems if obstructed.
Find the drain solenoid in the bottom of the tub and use a clean, damp cloth to loosen the solenoid if the device seems stuck in place. The solenoid opens and closes the drain valve.
Lift off the air gap lid if there is an air gap on the kitchen sink. Use a toothpick or running water to clear out the hoses. Reattach the hoses and set the lid back on top of the air gap, which is designed to prevent waste water from the kitchen sink and the dishwasher from merging together.
Turn on the water faucet in the kitchen sink and run the garbage disposal, if there is one, until the kitchen drain is clear. The drain between the kitchen sink and the dishwasher is interconnected, and clogs in the sink can create a clog in the dishwasher. Look under the sink at the tubes connecting the dishwasher and the garbage disposal to verify that the knockout plug between the two systems has been removed.