Daikin fault codes are a vital diagnostic tool for identifying system errors in Daikin air conditioning systems. These alphanumeric codes provide technicians with valuable information to pinpoint and rectify issues quickly, ensuring efficient and reliable operation of the equipment. Understanding these codes is crucial for effective maintenance and troubleshooting.
Simple Self-Diagnosis by Malfunction Code For Daikin Air Conditioning System
For fault and error codes beginning with U, see table below.
For error codes beginning with 6, 7, 8 or 9, find causes here
For error codes beginning with A or C, find causes here
For error codes beginning with E, F, H, J, L, M or P, find causes here
| System Error Codes and Contents | Supposed causes | Parts affected |
|---|---|---|
| U0 Shortage of refrigerant |
Refrigerant shortage and refrigerant clogging (wrong piping) Defective thermistor Defective low pressure sensor Defective outdoor unit main PCB |
RA, SkyAir, VRV, Package, Chiller |
| U1 Reverse phase, open phase |
Power supply reverse phase T phase open phase Defective outdoor unit PCB (A1P) |
RA, SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| U2 Malfunction of power supply or instantaneous power failure |
Abnormal power supply voltage Instantaneous power failure Defective main circuit wiring |
RA, SkyAir, VRV, Package, Chiller, Fan coil |
| U3 Check operation not executed or transmission error |
Check operation is not executed. | RA, SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| U4 Malfunction of transmission between indoor and outdoor unit |
Short circuit in indoor-outdoor or outdoor-outdoor transmission wiring (F1 / F2), or wrong wiring Outdoor unit power supply is OFF System address does not match Defective indoor unit PCB Defective outdoor unit PCB |
RA, SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| U6 Malfunction of transmission between indoor units |
Faulty wiring External factor (Noise etc.) Defective indoor unit PCB |
VRV, Package, Chiller, Fan coil |
| U7 Malfunction of transmission between outdoor units or outdoor storage unit |
Connection error of transmission wirings between outdoor unit and external control adaptor for outdoor unit Connection error of transmission wirings between outdoor units Defective outdoor unit PCB |
RA, VRV, Package, Chiller, Fan coil |
| U8 Malfunction of transmission between remote controllers |
Transmission error between main and sub remote controller Connection between sub remote controllers Defective remote controller PCB |
SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| U9 Malfunction of transmission (other system) |
Transmission error between other indoor and outdoor units 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 |
SkyAir, VRV, Package, Chiller, Fan coil |
| UA Defect of indoor/outdoor power supply |
Wrong model connections Improper power supply Wrong PCB connected Defective PCB |
RA |
| UA Improper combination of indoor and outdoor units |
Excess of connected indoor units Defective outdoor unit PCB Mismatch of the refrigerant type of indoor and outdoor unit Setting of outdoor unit PCB was not carried out after replacing to spare PCB |
SkyAir, VRV, Package, Chiller |
| UA Remote temperature setting wire disconnection |
Remote temperature setting wire disconnection Defective connector contact |
Heat reclaim ventilator |
| UC Malfunction of setting of centralized control equipment address |
Address duplication of centralized control equipment Defective indoor unit PCB |
SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| UE Malfunction of transmission between indoor unit and centralized control equipment |
Transmission error between optional controllers for centralized control equipment and indoor unit Connector for setting main controller is disconnected.(or disconnection of connector for independent / combined use changeover switch.) Defective PCB for central remote controller Defective indoor unit PCB |
SkyAir, VRV, Package, Heat reclaim ventilator, Chiller, Fan coil |
| UF System is not set yet |
Improper connection of transmission wiring between indoor-outdoor units and outdoor-outdoor units Failure to execute check operation Defective indoor unit PCB Stop valve is not opened |
SkyAir, VRV, Package, Heat reclaim ventilator |
| UH Malfunction of system |
Improper connection of transmission wiring between indoor-outdoor units and outdoor-outdoor units Defective indoor unit PCB Defective outdoor unit PCB |
RA, VRV, Package |
| UJ Malfunction of transmission (accessory device) |
Defect of accessory devices Faulty wiring |
RA, SkyAir, VRV, Package, Chiller |
