Owners often mistake pauses or lulls in the dishwasher cycle as an indication that the dishwasher has finished. They then open the dishwasher door and discover that water has not drained from the tub and think that a drainage problem is afoot. However, the cycle may have simply been interrupted. Shut the dishwasher door, and press "Start/Resume" to continue the cycle. A green or blue light will illuminate on the dishwasher control panel to indicate that the cycle has fully completed.
Dishwashers are usually installed under a counter and pushed up against a wall, which can result in the drain hose getting bent, trapped or kinked. Any obstructions or bends in the hose can cause a drainage problem with the dishwasher, so pull the dishwasher out and straighten out the drain hose. If the problem persists, disconnect and clean out the drain hose to remove debris that could cause a blockage.
Other possible reasons for a dishwasher to stop draining are the air gap and the garbage disposal, both of which are typically connected to the dishwasher. If you have an air gap on the sink, pull off the cap and remove the hoses within. Rinse the hoses by flushing them with water, and then reconnect them. If there is a garbage disposal, run the disposal and water in the sink to clear out the drain. Look at the knockout plug, located at the disposal inlet under the sink to ensure it was removed when the dishwasher or disposal was installed.
Check the bottom of the dishwasher tub for utensils or small objects that may have fallen from the racks and are blocking the drain or the pump. Inspect the filter on the bottom of the dishwasher for large items that were not ground up properly as this can block the filter and create a problem. Turn the upper filter assembly one-quarter turn in a counterclockwise motion, lift it out and then grab the lower filter and pull it forward and out to remove. Rinse the filter under running water, but don't use a wire scouring pad or brush as this may damage the filter. Reinstall the filter in place.