F0 error and the unit may not start or may shut down shortly after starting.

Safety first: Isolate power before removing covers.

Steps:

• Locate room sensor: On Bosch wall-mounted units, the room sensor is usually behind the front grille near the air intake. Remove the front panel and locate the small NTC probe.
• Check connection: Ensure the sensor plug is firmly seated on the indoor PCB. Inspect the cable for cuts or damage.
• Basic test: If you have a multimeter and the Bosch service manual, you can measure sensor resistance at room temperature and compare to the specified value. A reading of 0 Ω (short) or infinite (open) indicates a bad sensor.

Resolution: Replace the indoor ambient temperature sensor with the correct Bosch part number. This is usually a simple plug-in replacement.