AC Error Codes: What They Mean and How to Fix Them

Decode common air conditioner error codes from major brands and learn which ones you can fix yourself versus when to call a technician.

When your air conditioner displays an error code, it's trying to tell you something. Understanding these codes can help you diagnose problems quickly and decide whether to DIY or call a professional.

Common Error Code Categories

Communication Errors (E1, E2, E3)

These indicate problems between the indoor and outdoor units. Common causes:

  • Loose wiring connections
  • Damaged communication cables
  • Control board issues

DIY potential: Check connections; call tech if persists

Sensor Errors (E4, E5, E6)

Temperature sensor malfunctions:

  • E4: Room temperature sensor
  • E5: Evaporator sensor
  • E6: Outdoor temperature sensor

DIY potential: Can replace sensors yourself for 200-500 THB

Refrigerant Errors (E7, E8)

Low refrigerant or pressure problems. Signs include:

  • Ice forming on pipes
  • Weak cooling
  • Compressor cycling frequently

DIY potential: No—requires licensed technician

Motor/Fan Errors (E9, F1)

Fan motor problems in indoor or outdoor unit:

  • Fan not spinning
  • Unusual noises
  • Overheating

DIY potential: Check for debris; motor replacement needs tech

Brand-Specific Codes

Different brands use different code systems. Our tool covers Daikin, Mitsubishi, LG, Samsung, Panasonic, Carrier, and more.

Look Up Your Error Code

Use our Error Code Lookup Tool to find your specific code. For repair guidance, check our DIY Repair Guide.