Daikin Chiller

Daikin Chiller Error Code U0

Troubleshooting guide for the Daikin Chiller system fault U0.

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What It Means

Shortage of refrigeran.

Possible Causes

  • Refrigerant shortage and refrigerant clogging (wrong piping).
  • Defective thermistor.
  • Defective low pressure sensor.
  • Defective outdoor unit main 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.
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Full Diagnosis

Shortage of refrigeran

All Recorded Causes

Refrigerant shortage and refrigerant clogging (wrong piping) Defective thermistor Defective low pressure sensor Defective outdoor unit main 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 refrigerant shortage and refrigerant clogging (wrong piping).
  3. Look for restrictions, iced coils, or dirty heat-transfer surfaces that can mimic a charge problem, and separately confirm defective thermistor.
  4. After the correction, run the system long enough to confirm the chiller fault does not return under normal load.

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