Daikin Chiller

Daikin Chiller Error Code UA

Troubleshooting guide for the Daikin Chiller system fault UA.

ACLogics Standardize Chiller diagnostics See the commercial workflow → Standardize Chiller diagnostics

What It Means

Improper combination of indoor and outdoor units.

Possible Causes

  • Excess of connected indoor units.
  • Defective outdoor unit PCB.
  • Mismatch of the refrigerant type of indoor and outdoor unit Setting of outdoor unit PCB was not carried out after replacing to spare PCB.

Not sure which one it is — or if it's none of these? Try ACLogics today.

Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
New to this code? Click to see why this happens

Full Diagnosis

Improper combination of indoor and outdoor units

All Recorded Causes

Excess of connected indoor units Defective outdoor unit PCB Mismatch of the refrigerant type of indoor and outdoor unit Setting of outdoor unit PCB was not carried out after replacing to spare PCB

Verify Before Replacing Parts

  1. Confirm the exact Daikin model family and chiller context before acting on a generic code description.
  2. Verify airflow first, then confirm operating pressures and temperature relationship before adjusting charge, since excess of connected indoor units.
  3. Look for restrictions, iced coils, or dirty heat-transfer surfaces that can mimic a charge problem, and separately confirm defective outdoor unit PCB.
  4. After the correction, run the system long enough to confirm the chiller fault does not return under normal load.

Diagnosing Chiller across a fleet?

ACLogics standardizes commercial Chiller diagnostics across your whole team — consistent steps, less guesswork on every call.

See the commercial workflow →