E20 error with the dishwasher failing to drain completely or intermittently.

Safety first: Turn off power before working under the dishwasher or sink.

• Check for standing water: After a cycle, open the door and inspect the sump. A small amount of clean water is normal; more than 1/2 inch indicates poor draining.
• Clean air gap and disposer inlet: If you have an air gap, remove the cap and clean out debris. Ensure the disposer knockout plug was removed when the dishwasher was installed.
• Inspect drain hose routing: Verify the hose has a high loop under the counter and is not kinked or sagging excessively.
• Test drain pump: Access the Viking drain pump, check the impeller for looseness or wear, and test motor resistance. Replace if weak or intermittent.
• Secure wiring: Ensure the pump connector is tight and free of corrosion.