Daikin VRV RXYQ72-384XAYCA Service Manual page 350

Troubleshooting by Error Code
343
Diagnosis Flowchart-3
UA-20
Error code Sub code
NO
Multi connection?
YES
Was the
outdoor unit NO
main PCB replaced with
a spare PCB?
YES
NO
Was proper setting
of spare PCB
made?
YES
Diagnosis Flowchart-4
UA-21
Error code Sub code
Are all
NO
indoor units for
VRV ? (no residential
indoor units)
YES
Replace the outdoor unit main
PCB (A1P).
A
NO
different model
Replace the outdoor unit main
of outdoor unit is
PCB (A1P).
connected.
YES
Check for the model of outdoor
unit.
Make setting again, and then
reset the power supply.
Replace the spare PCB.
Disconnect residential indoor units
from the system.
Replace the outdoor unit main PCB
(A1P).
SiUS342004EB
Part 6 Service Diagnosis