Daikin Fan Coil

Daikin Fan Coil Error Code A3

Troubleshooting guide for the Daikin Fan Coil system fault A3.

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What It Means

Drain Level Control System Abnormality.

Possible Causes

  • Drain clogging, upward slope, etc.
  • Defective drain pump.
  • Defective float switch or short circuit connector.

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

Drain Level Control System Abnormality

All Recorded Causes

Drain clogging, upward slope, etc. Defective drain pump Defective float switch or short circuit connector

Verify Before Replacing Parts

  1. Confirm the exact Daikin model family and fan coil context before acting on a generic code description.
  2. Confirm filter condition, blower operation, and coil cleanliness before replacing any controls — start by ruling out whether drain clogging, upward slope, etc.
  3. Measure airflow-related readings that match the symptom, such as temperature split or static pressure, and check whether defective drain pump.
  4. After the correction, run the system long enough to confirm the fan coil fault does not return under normal load.

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