HVAC Code Lookup

Daikin Mini-Split Operation Lamp Blinking

WarningShown as: Green OPERATION lamp on the indoor unit blinking continuously

The green OPERATION lamp on the face of the indoor unit blinks when the unit has detected a fault. Per the service manual it blinks in exactly two situations: a protection device in the indoor or outdoor unit has activated or a thermistor has malfunctioned, or a signal transmission error has occurred between the indoor and outdoor units. The lamp does not tell you which fault - you have to read the actual code from the remote using the service-check procedure.

Manual wording: “The operation lamp blinks when any of the following errors is detected. 1. When a protection device of the indoor or outdoor unit is activated, or when the thermistor malfunctions. 2. When a signal transmission error occurs between the indoor and outdoor units.”

Documented for: FTXS series and FDXS series indoor units; the same green OPERATION lamp behavior applies across Daikin residential ductless indoor units

Likely causes, most common first

  1. A protection device of the indoor or outdoor unit is activated
  2. A thermistor (temperature sensor) malfunction
  3. A signal transmission error between the indoor and outdoor units

What you can safely check yourself

  • Check and replace the indoor unit air filters
  • Make sure indoor airflow and the outdoor unit are not blocked
  • Check the breaker or disconnect for both the indoor and outdoor unit is fully on
  • Retrieve the actual error code: hold the remote's TIMER CANCEL button for 5 seconds, then press it repeatedly until you hear a long beep - the two characters shown are the code

When to call a technician

A blinking green lamp always has a stored code behind it. Read the code first, then call a technician with that code in hand.

A Daikin mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Other Daikin codes