Troubleshooting by Error Code
5.55 Other Indoor Units and Outdoor Unit Abnormality
Applicable
All indoor unit models
Models
All outdoor unit models
U9
Error Code
Method of Error
Detect the error signal for the other indoor unit within the circuit by outdoor unit main PCB.
Detection
Error Decision
The error decision is made on any other indoor units within the system concerned.
Conditions
Supposed
Transmission error between other indoors and outdoor units
Causes
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
Troubleshooting
276
Be sure to turn off the power switch before connecting or disconnecting
Caution
connectors, or parts may be damaged.
Turn ON all indoor units.
NO
All the units are
display U9.
YES
U9 has
NO
been displayed for 2
minutes or more.
YES
SiAF341904E
Continue the operation.
Re-diagnose by display after
passage of 2 minutes or more.
The outdoor unit PCB indicated
by the error code U9 is normal.
Check for the indoor unit of other
system, and then conduct
troubleshooting by diagnosis
according to the Error Code
Flowchart.
Part 6 Service Diagnosis