Daikin | Chiller

Error Code U9

Troubleshooting guide for the Daikin Chiller system fault U9.

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.

System Diagnosis

Malfunction of transmission (other system)

Potential Causes & Solutions

  • Transmission error between other indoor and outdoor units Defective electronic expansion valve of other indoor unit Defective indoor unit PCB of other indoor unit.
  • Improper connection of transmission wiring between indoor and outdoor unit.

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