Indoor unit displays F6 and the unit may not reach set temperature or may cycle frequently.

Safety first: This is primarily a design/compatibility or control issue rather than a simple user-fixable fault.

• Step 1 – Confirm model pairing:
  • Check the model numbers of indoor and outdoor units and verify they are an approved pair in Hisense documentation.
• Step 2 – Check installation conditions:
  • Ensure the room size is appropriate for the unit capacity.
  • Verify that doors and windows are closed and that there are no major heat sources affecting operation.
• Step 3 – Power reset:
  • Turn off the breaker for 5–10 minutes and restart to clear temporary control errors.
• Step 4 – Technician evaluation: If F6 persists, a technician should check inverter operation, update firmware if applicable, and confirm correct system configuration.