Daikin VRVII Manual page 295

Troubleshooting
Caution
Check the detailed error
status in the monitor
mode.
In
Confirmation
of error 4, LED
lamp indicates as
follows:?
YES
Check
if indoor
unit PCB or
outdoor unit
PCB has been
replaced. Or check if
indoor-outdoor, outdoor-
outdoor connecting
wires has been
modified.
NO
Do
all the
indoor remote
controllers within the
same refrigerant
circuit display
"U4"?
YES
A
290
Troubleshooting by Indication on the Remote Controller
Be sure to turn off the power switch before
connecting or disconnecting connectors, or parts
may be damaged.
NO
YES
NO
the indoor-
outdoor, outdoor-
outdoor connecting
wires normal?
Are
YES
NO
Go on to P.282.
LED lamp
(
display
Press the
RESET button on
the main PCB of
the master
outdoor unit.
Keep pressing
for 5 seconds or
more. (Operation
does not start for
a maximum 12
minutes.)
Replace the
indoor unit PCB.
Correct the
connecting wires.
)