Daikin Chiller

Daikin Chiller Error Code 77

Troubleshooting guide for the Daikin Chiller system fault 77.

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What It Means

System No.

Possible Causes

  • Defective relay contact.
  • Broken wire.

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

System No. 1 Malfunction of fan inter lock

All Recorded Causes

Defective relay contact Broken wire

Verify Before Replacing Parts

  1. Confirm the exact Daikin model family and chiller context before acting on a generic code description.
  2. Start with line voltage, low voltage, and board output checks in sequence so the fault is isolated cleanly — the data plate flags defective relay contact.
  3. Inspect connectors, relay outputs, and any recently replaced electrical parts for mismatch or loose fit, and verify broken wire.
  4. After the correction, run the system long enough to confirm the chiller fault does not return under normal load.

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