HVAC Code Lookup

Daikin fault codes

58 documented codes for Daikin mini-splits, each cited to the manufacturer's own manual. Daikin uses one alphanumeric error-code set across its residential ductless line. The same table appears in the FTXS-L / FDXS-L pair service manual, the H-Series (FTXS/RKS-HVJU) pair manual, the FTXM-W/V (Atmosphera) manual, and the RMXS multi-split manual, so an A5 or U4 on a 2015 FTXS wall-mount means the same thing as on a current Atmosphera. Multi-zone systems (MXS / RMXS with Branch Provider units) add transmission and address codes (U9, UF, UH, UC, UE) that pair systems never show, and a few codes are re-used with a different meaning on multi-zone hardware (E5 and F6 in particular). Codes are read on the wireless remote's temperature display using the unit's service-check / code-retrieval mode, not on the indoor unit itself..

Mini-Split codes

CodeMeaningSeverity
00NormalStatus
A1Indoor unit PCB abnormalityHard lockout
A3Drain level control system abnormalitySoft lockout
A5Freeze-up protection control or heating peak-cut controlWarning
A6Indoor fan motor or related abnormalitySoft lockout
C4Indoor heat exchanger thermistor or related abnormalityWarning
C5Indoor heat exchanger thermistor 2 or related abnormalityWarning
C7Front panel open/close faultWarning
C9Room temperature thermistor or related abnormalityWarning
CCHumidity sensor abnormalityWarning
CEPresence sensor or floor sensor abnormalityWarning
CJRemote controller thermistor abnormalityWarning
E1Outdoor unit PCB abnormalityHard lockout
E3Actuation of high pressure switchSoft lockout
E4Actuation of low pressure sensorSoft lockout
E5On pairSoft lockout
E6Compressor lockHard lockout
E7DC fan lockSoft lockout
E8Input overcurrent detectionSoft lockout
E9Moving part of electronic expansion valveSoft lockout
EAFour way valve abnormalitySoft lockout
F3Discharge pipe temperature controlSoft lockout
F6On pair systems, high pressure control in cooling - the outdoor coil sensor went above about 140-149F so the unit cut back or haltedWarning
F8System shutdown due to compressor internal temperature abnormalityHard lockout
H0Compressor system sensor abnormalitySoft lockout
H6Position sensor abnormality - the compressor failed to startSoft lockout
H8DC voltage or current sensor abnormality on 09/12 class units, or CTSoft lockout
H9Outdoor temperature thermistor or related abnormalityWarning
J3Discharge pipe thermistor or related abnormalityWarning
J5Suction pipe thermistorWarning
J6Outdoor heat exchanger thermistor or related abnormalityWarning
J7Outdoor liquid pipe thermistorWarning
J8Liquid pipe thermistor or related abnormalityWarning
J9Subcooling heat exchanger gas pipe thermistorWarning
JAHigh pressure sensor abnormalityWarning
JCLow pressure sensor abnormalityWarning
L1Outdoor unit PCB abnormality on the inverter sideHard lockout
L3Electrical box temperature riseSoft lockout
L4Radiation fin temperature riseSoft lockout
L5Output overcurrent detectionHard lockout
L8Inverter current abnormalitySoft lockout
L9Compressor start-up errorSoft lockout
P1High voltage of capacitor in main inverter circuitSoft lockout
P4Radiation fin thermistor or related abnormalityWarning
U0Refrigerant shortageWarning
U2Low-voltage detection or over-voltage detectionWarning
U3Check operation is not conductedWarning
U4Signal transmission error between the indoor unit and the outdoor unitSoft lockout
U5Signal transmission error between the indoor unit and the remote controllerWarning
U7Signal transmission error on the outdoor unit PCBSoft lockout
U8Signal transmission error between the MAIN remote controller and the SUB remote controllerWarning
U9Signal transmission error between an indoor unit and the outdoor unit within the same multi-zone systemSoft lockout
UAOn pair systems, unspecified voltage between indoor and outdoor unit - a pair-type and a multi-type unit have been connected togetherSoft lockout
UCAddress duplication of central remote controllerWarning
UETransmission error between the centralized remote controller and an indoor unitWarning
UFSystem is not set yetSoft lockout
UHSystem abnormality, refrigerant system address undefinedSoft lockout
Operation lamp blinkingGreen OPERATION lamp on the indoor unit blinking continuouslyThe green OPERATION lamp on the face of the indoor unit blinks when the unit has detected a faultWarning

Manuals used for this page