What It Means
Malfunction of electronic expansion valve.
Daikin Chiller
Daikin Chiller Error Code A9
Troubleshooting guide for the Daikin Chiller system fault A9.
ACLogics Standardize Chiller diagnostics See the commercial workflow → Standardize Chiller diagnostics
Possible Causes
- Defective electronic expansion valve coil.
- Defective indoor unit PCB.
- Defective relay cables.
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.
New to this code? Click to see why this happens
Full Diagnosis
Malfunction of electronic expansion valve
All Recorded Causes
Defective electronic expansion valve coil Defective indoor unit PCB Defective relay cables
Verify Before Replacing Parts
- Confirm the exact Daikin model family and chiller context before acting on a generic code description.
- Confirm filter condition, blower operation, and coil cleanliness before replacing any controls — start by ruling out whether defective electronic expansion valve coil.
- Measure airflow-related readings that match the symptom, such as temperature split or static pressure, and check whether defective indoor unit PCB.
- After the correction, run the system long enough to confirm the chiller fault does not return under normal load.
Diagnosing Chiller across a fleet?
ACLogics standardizes commercial Chiller diagnostics across your whole team — consistent steps, less guesswork on every call.