Daikin Fan Coil

Daikin Fan Coil Error Code U6

Troubleshooting guide for the Daikin Fan Coil system fault U6.

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What It Means

Malfunction of transmission between indoor units.

Possible Causes

  • Faulty wiring.
  • External factor (Noise etc.).
  • Defective indoor unit 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

Malfunction of transmission between indoor units

All Recorded Causes

Faulty wiring External factor (Noise etc.) Defective indoor unit PCB

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 faulty wiring.
  3. Measure airflow-related readings that match the symptom, such as temperature split or static pressure, and check whether external factor (Noise etc.).
  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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