Display shows E20; unit indicates defrost or de-ice failure in models with automatic defrost.

Safety first: Unplug the unit before accessing the evaporator and electrical components.

Steps:

• 1. Access evaporator: Remove the internal panel to expose the evaporator coil and defrost heater assembly.
• 2. Inspect for heavy ice: If the coil is encased in ice, manually defrost with warm air and towels.
• 3. Test heater: Disconnect heater leads and measure resistance. An open circuit indicates a failed heater that must be replaced.
• 4. Check defrost thermostat: Test continuity of the thermostat or thermal fuse when cold. Replace if open when it should be closed.
• 5. Verify wiring and relay: Inspect wiring for burns or breaks. If heater and thermostat are good, the defrost relay on the PCB may be faulty and require board replacement.