Indoor unit displays F1; unit may run but with poor temperature control

Safety first: Turn off power before removing covers or disconnecting sensors.

Steps to check:

• 1. Locate T1 sensor: Open the indoor unit front panel. The T1 sensor is usually a small thermistor in a plastic sheath located near the air intake, often clipped to the evaporator or in the return air path.
• 2. Check connection: Trace the sensor wires to the indoor PCB. Ensure the connector is firmly seated and not corroded or burnt.
• 3. Inspect sensor: Ensure the sensor tip is not broken and is positioned in the airflow, not hanging outside the intake area.
• 4. Basic resistance check (if you have a multimeter): With power OFF and sensor disconnected, measure resistance across the sensor leads. Compare to Midea service data (typically 5–20 kΩ at room temperature). Infinite or near-zero resistance indicates a bad sensor.

When to call a technician: If you are not comfortable testing or replacing the sensor, or if a new sensor does not clear F1, the indoor PCB may be faulty and should be checked by a technician.