Indoor unit displays F2 and may stop cooling or heating.

Safety first: Disconnect power at the breaker.

Steps:

• Locate T2 sensor: The evaporator coil sensor is typically clipped directly to the indoor coil tubing.
• Check mounting: Ensure the sensor is firmly clipped to the coil and has good contact with the copper tube.
• Verify connection: Trace the sensor wires back to the PCB and confirm the plug is secure.

Repair: If F2 remains, replace the T2 evaporator temperature sensor. This is usually a straightforward plug-and-play part.