ErrorCodeDoctor
Daikin · Air Conditioner

Daikin Air Conditioner L9 error code

Difficulty: Medium · Cost: $0–$500 · Duration: 5m

The L9 error means your Daikin air conditioner's inverter compressor failed to start. A common installation-related cause is a closed stop valve on the refrigerant piping. Check that all refrigerant stop valves on the outdoor unit are fully open. If they are open contact a qualified technician.

Common causes

  • Stop valve on the refrigerant piping is not open
  • Compressor is defective
  • Wiring connections to the compressor are incorrect
  • High differential pressure prevented compressor startup
  • Inverter PCB has a fault

How to fix it

  1. 1

    Check that all refrigerant stop valves on the outdoor unit are fully open — this is especially relevant for newly installed systems

  2. 2

    If stop valves are fully open and the error persists contact a qualified technician to inspect the compressor and inverter PCB

Related Daikin Air Conditioner error codes

1

A0

An external protection device connected to the indoor unit has been activated

hard
2

A1

A fault was detected in the indoor unit PCB (control board)

hard
3

A3

The drain level control system has detected an abnormality — drain may be clogged

medium
4

A5

Freeze-up protection (cooling) or high pressure control (heating) has activated — check the air filter

easy