Daikin Air Conditioner Error Codes

Complete HVAC Troubleshooting & Diagnostic Guide

Indoor Unit Errors
A1
Indoor PCB Failure
  • Turn off power supply immediately.
  • Check indoor control board connections.
  • Inspect for burnt or damaged components.
  • Replace PCB if fault persists.
A3
Drain System Malfunction
  • Check drain hose for blockage.
  • Clean condensate pan and pipe.
  • Ensure proper water flow.
  • Clear debris from drainage path.
A6
Fan Motor Error
  • Inspect indoor fan motor for obstruction.
  • Check wiring and connectors.
  • Clean dust buildup from fan blades.
  • Replace motor if not operational.
Sensor & Mechanical Errors
C4
Heat Exchanger Sensor Fault
  • Check temperature sensor connection.
  • Inspect sensor for damage or corrosion.
  • Replace faulty thermistor if needed.
C7
Louver Motor Failure
  • Check louver movement for obstruction.
  • Inspect motor wiring and gears.
  • Reset system and test swing function.
Outdoor Unit Errors
E1
Outdoor PCB Failure
  • Turn off power supply before inspection.
  • Check outdoor control board connections.
  • Inspect for electrical damage.
  • Replace PCB if necessary.
E5
Compressor Overload
  • Allow compressor to cool down.
  • Check refrigerant levels.
  • Inspect condenser airflow.
  • Call technician if overload persists.
E6
Compressor Startup Failure
  • Check power supply stability.
  • Inspect capacitor and wiring.
  • Ensure compressor is not seized.
  • Service unit if startup fails repeatedly.
E7
Outdoor Fan Motor Fault
  • Check fan blades for obstruction.
  • Inspect motor wiring connections.
  • Clean dust and debris buildup.
  • Replace motor if defective.
E9
Electronic Expansion Valve Error
  • Check valve control wiring.
  • Inspect refrigerant flow system.
  • Reset system and retest operation.
  • Service valve if malfunction persists.
Important: HVAC electrical and refrigerant-related repairs should be handled by certified technicians for safety and compliance.