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Flashing Indicator Light

Daikin Air Conditioner

Severity:

Source: OnlyErrorCodes.com — Every error code. One place.

Daikin Air Conditioner Flashing Light — Meaning

What Does This Error Mean?

Daikin uses flashing light patterns to communicate error codes when no display screen is available. Count the number of times the Operation lamp flashes, pause, then count again — the two numbers form the error code (e.g. 3 flashes + 2 flashes = U3).

Affected Models

  • Daikin Cora Series
  • Daikin Alira X
  • Daikin US7
  • Daikin FTXM Series
  • Daikin Zena

Common Causes

  • Any system error — the specific flash pattern identifies the fault
  • Timer light flashing = scheduled timer is active (normal, not an error)
  • Operation light rapidly flashing = system fault detected

How to Fix It

  1. Identify which light is flashing.

    Daikin indoor units have two or three indicator lights: Operation (green), Timer (orange/yellow), and sometimes Economy. A slowly flashing Timer light simply means a schedule timer is set — this is normal, not an error. A rapidly flashing Operation light (or Operation + Timer together) indicates a system error.

  2. Count the flash pattern to identify the error code.

    Watch the flashing Operation light carefully. Count the rapid flashes, note the pause, then count the next sequence. For example: 3 rapid flashes — pause — 1 rapid flash = Error Code '31' on older models. Daikin also uses letter-based codes: U, E, A, etc. — the letter prefix is indicated by the number of flashes of the Timer lamp.

  3. Cross-reference with the error code list.

    Common Daikin error codes indicated by flash patterns: E1 = Indoor PCB fault E3 = Indoor fan fault E5 = Outdoor inverter overcurrent U0 = Refrigerant shortage U4 = Communication error (indoor to outdoor) A1 = Indoor PCB fault Consult your model's installation manual or the Daikin support website for the full list.

  4. Perform a power reset.

    Turn the AC off at the circuit breaker or isolator, wait 5 minutes, and restore power. Minor faults such as communication errors (U4) may clear after a reset. If the fault code returns immediately, the underlying issue needs professional repair.

  5. Record the code and call a technician.

    Write down the flash pattern before calling a technician. Providng the exact code speeds up diagnosis significantly. Most Daikin error codes beyond filter and power issues require a licensed refrigeration technician.

Frequently Asked Questions