Daikin VRV

Daikin VRV Error Code H9

Troubleshooting guide for the Daikin VRV system fault H9.

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What It Means

Malfunction of outdoor air thermistor.

Possible Causes

  • Defective connection of thermistor.
  • Defective outdoor unit PCB.
  • Defective outdoor air thermistor.

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 outdoor air thermistor

All Recorded Causes

Defective connection of thermistor Defective outdoor unit PCB Defective outdoor air thermistor

Verify Before Replacing Parts

  1. Confirm the exact Daikin model family and vrv context before acting on a generic code description.
  2. Verify the sensor or thermistor reading against the expected range for the current operating condition, keeping in mind that defective connection of thermistor.
  3. Check the sensor harness and board connection before condemning the sensor itself; on Daikin units this is also where you'd confirm defective outdoor unit PCB.
  4. After the correction, run the system long enough to confirm the vrv fault does not return under normal load.

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