Indoor unit displays F9 and the unit may not respond correctly to temperature settings.

Safety first: Disconnect power before accessing the sensor and PCB.

• Step 1 – Compare temperatures:
  • Use a reliable room thermometer placed near the indoor unit.
  • Compare the displayed temperature on the remote or unit to the actual room temperature.
• Step 2 – Inspect sensor location:
  • Ensure the room sensor is in the correct holder and exposed to return air, not pressed against the coil or casing.
• Step 3 – Dry and clean sensor:
  • If condensation is present, allow the unit to dry and gently clean the sensor.
• Step 4 – Replace sensor if needed:
  • If readings remain inaccurate, replace the room sensor with a Hisense-compatible part.
• Step 5 – PCB replacement: If a new sensor does not correct the offset, the indoor PCB may require replacement by a technician.