Oven displays E1 and does not heat or immediately stops the program.

Safety first: Disconnect the oven from mains power before removing any panels or touching internal wiring.

Steps to diagnose and fix:

• Locate the temperature sensor: In most OBH Nordica ovens, the cavity temperature sensor (NTC probe) is mounted on the rear wall inside the oven cavity, usually held by two screws and connected via a small harness.
• Visual inspection: Remove the rear cover (or top cover, depending on model) to access the sensor wiring. Check for broken wires, melted insulation, or a disconnected plug.
• Check connections: Reseat the sensor connector at both the sensor end and the main control board. Ensure it clicks firmly into place.
• Measure resistance: With the oven unplugged, disconnect the sensor and measure its resistance using a multimeter. A typical NTC sensor at room temperature is usually between 1 kΩ and 100 kΩ (consult the service sheet if available). If the meter shows infinite resistance (open circuit), the sensor is faulty.
• Replace the sensor: If open or out of specification, remove the mounting screws from inside the cavity, pull the sensor out gently, and install a new OBH Nordica-compatible oven temperature sensor. Route the wires as originally to avoid contact with hot surfaces.
• Test: Reassemble covers, restore power, and run a preheat cycle. Confirm that E1 no longer appears and that the oven heats normally.

Note: If the sensor tests good but E1 persists, the sensor input circuit on the main control board may be defective and the board may need replacement.