Indoor unit shows F1, unit may run but with poor temperature control.

Safety first: Disconnect power before accessing the indoor PCB.

• Step 1 – Locate room sensor: On most Royal Clima wall splits, the room sensor is near the air intake behind the front grille, usually encased in a small plastic holder.
• Step 2 – Check connection: Ensure the sensor plug is firmly connected to the indoor PCB and the wires are not cut or pinched.
• Step 3 – Inspect sensor: If the sensor body is cracked or corroded, it should be replaced with a compatible Royal Clima sensor.
• Step 4 – Reset: After reseating the connector, restore power and test. If F1 remains, the sensor is likely defective.

When to call a technician: If replacing the sensor does not clear F1, the indoor PCB analog input may be faulty and will need professional replacement.