Dishwasher displays F20; may not start or may stop with no clear mechanical symptom.

Safety: Turn off power at the breaker before accessing electronics.

• Hard reset: Leave the dishwasher powered off for at least 10 minutes. Restore power and attempt to start a basic cycle.
• Check model configuration: Some Asko models allow configuration of options via service mode. If the control was recently replaced, verify that the correct model configuration has been set (refer to service documentation).
• Inspect control board: Look for obvious damage, burned components, or signs of moisture.
• Surge protection: If F20 appeared after a storm or outage, consider installing surge protection on the circuit after repair.
• If F20 persists: The main control board is likely defective and should be replaced with the correct Asko part number. This is typically a professional-level repair.