Daikin R407C PLUS - Malfunction of Transmission between Indoor and Outdoor Units in the same System

Si33-105 Troubleshooting
Troubleshooting R407C PLUS Series Heat Recovery System 187
3.31 Malfunction of Transmission Between Indoor and
Outdoor Units in the Same System
Remote
Controller
Display
U9
Supposed
Causes
!
Malfunction of transmission within or outside of other system
!
Malfunction of electronic expansion valve in indoor unit of other system
!
Defect of PC board of indoor unit in other system
!
Improper connection of transmission wiring between indoor and outdoor unit
Troubleshooting
(VF058)
The "U4"
display blinks on the
remote controllers of other
units within the same
refrigerant
system.
Refer to failure diagnosis for "U5"
malfunction code.
Re-diagnose by display after
passage of 2 minutes or more.
NO
NO
Refer to failure diagnosis for "U4"
malfunction code.
YES
YES
"U9"
has been displayed for 2
minutes or more.
NO
Turn on all indoor units.
Refer to failure diagnosis for "A1"
malfunction code.
NO
YES
The "A1"
display blinks on
the remote controllers of other
units within the same
refrigerant
system.
NO
Refer to failure diagnosis for "UA"
malfunction code.
YES
The "UA"
display blinks on the
remote controllers of other
units within the same
refrigerant
system.
Refer to failure diagnosis for "A9"
malfunction code.
NO
YES
The "A9"
display blinks on
the remote controllers of other
units within the same
refrigerant
system.
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.