Indoor unit shows F1 and stops cooling; fan may still run.

Safety first: Turn off power before removing the indoor front panel.

Steps:

• Locate room sensor: The room sensor is usually near the air intake grille or behind the front panel, often in a small plastic holder.
• Check mounting: Ensure the sensor is not hanging loose inside the unit; it must be in the airflow path for accurate readings.
• Inspect connector: Trace the sensor wires to the PCB and verify the plug is secure.
• Measure resistance: Disconnect the sensor and measure its resistance at room temperature. Compare to Blaupunkt’s NTC chart. Replace with a Blaupunkt room temperature sensor if readings are out of range.
• Reassemble and test: After replacement, restore power and confirm that F1 clears and temperature control is normal.