E13 is displayed and the refrigerator may not defrost or may show erratic temperature readings.

Safety first: Unplug the refrigerator before working on the control board or defrost wiring.

Steps to address E13:

• 1. Manual defrost: Turn off and defrost the unit fully to restore airflow and cooling temporarily.
• 2. Force defrost test (for advanced users): Some models allow entering a service mode to force a defrost cycle. Refer to service documentation; if the heater does not energize, suspect control or heater circuit.
• 3. Inspect control board: Check for signs of overheating around the defrost relay area on the PCB.
• 4. Verify heater and thermostat: Before condemning the board, ensure the defrost heater and thermostat are functional (see E4 procedure).
• 5. Replace control board if necessary: If the heater circuit is good but the board never supplies power, replace the main PCB.