Error 13; display may show very low or unrealistic temperature values.

Safety: Turn off power before handling internal wiring.

Steps:

• Check plug connection: Ensure the NTC sensor plug is fully seated on the PCB and at the sensor end.
• Inspect cable: Follow the cable from sensor to PCB, looking for breaks or damage. Repair or replace as needed.
• Test continuity: With the sensor disconnected, measure resistance across its terminals. Infinite resistance indicates an open sensor that must be replaced.

Tip: Label sensor wires before removal to avoid misconnection when refitting.