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www.climatecenter.co.uk
Daikin Trouble Shooting Guide
Past & Current Models
Daikin Fault Codes
System Fault Codes
Fault Code Definition
Supposed Causes
Split
Skyair
VRV
Package
HRV
U0
Shortage of refrigerant
Undercharged, EEV fault, faulty sensor
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•
•
•
U1
Reverse or missing phase
Reversed or missing phase
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•
•
•
U2
Power supply fault
Power supply fault, capacitor wiring error
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•
•
•
U3
Check operation not executed Check operation not carried out at
commissioning or after main PCB replaced
•
U4
Communication failure,
between indoor & outdoor
Wiring fault, defect of PCB, pump wired
across communication wiring
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•
•
•
•
U5
Communication failure,
between r/controller & PCB
Wiring fault, defect of Remote
controller & PCB
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•
•
•
•
U6
Communication failure
between indoor units
Wiring fault, defect of indoor PCB
•
U7
Communication failure,
between outdoor PCB’s
Defect of outdoor PCB,
wiring error between PCB’s
•
U7
Communication failure
between outdoor units
Wiring error between outdoor units,
defect of outdoor PCB
•
•
U8
Communication failure be-
tween remote controllers
Main/sub switch not set, wiring error,
defect of remote controller
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•
•
•
U9
System communication failed Fault with other indoor unit, no power, A9
•
UA
Improper combination
Incorrect field setting, wiring, defect of PCB
•
UA
Incorrect field setting
Wiring, defective PCB
Field setting incorrect (twin/triple), error in
•
UA
Improper combination of
Indoor/outdoor units
Excess of indoor units, incorrect PCB
Setting, defective PCB
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•
•
UC
Error in address setting
Duplicated central control address
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•
•
•
UE
Communication failure
between indoor central device
Wiring error between indoor unit & central
control, defect of indoor PCB, setting error
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•
•
•
UF
Wiring/piping mismatch
Wiring error indoor to outdoor, PCB defect
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•
•
UH
System malfunction
Unaddressed indoor unit
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•
UH
System malfunction
Mismatched indoor/outdoor, freeze protect
•
UJ
Communication failure
Defect of accessory device, wiring error
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M1
Central controller failed
Failure of central controller PCB
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•
•
•
•
M8
Communication failure
between central & options
Communication failed between central
controller & optional controllers
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•
•
•
•
MA
Improper combination of
optional controllers
Incorrect settings,
faulty central controller
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•
•
•
•
MC
Duplicated address
Duplicated central controller address
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•
•
•
•
60
Overall alarm
Open circuit across J1-JC
•
64
Failed return air sensor
Sensor open/short circuit
•
65
Failed ambient sensor
Sensor open/short circuit
•
6A
Failure of damper system
Defect of damper motor, limit switch, PCB
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