Daikin VRV Error Code List

Error U4 means your indoor and outdoor units stopped communicating. The most frequently seen Daikin VRV fault, and usually one of the cheaper ones to put right.

Error U5 means an indoor unit has stopped talking to its remote controller. The unit usually still works — nobody can tell it what to do.

Error U9 is a transmission error between indoor and outdoor units within the same system. Related to U4 but not the same code — and it is diagnosed differently.

Error L5 is compressor instantaneous overcurrent — a sudden current spike that most often means a shorted or grounded compressor motor. Do not restart it.

Error L8 is sustained compressor overcurrent. Unlike L5, it often means the system is working too hard against an external condition.

Error L9 means the compressor failed to start. Often a drive, supply or wiring problem rather than a dead compressor — diagnose before quoting one.

Error E3 means the high pressure switch activated. The shutdown protected your compressor — but the condition that caused it damages compressors if left alone.

Error E4 means low pressure protection activated. On commercial VRV it often points at a failed expansion valve or a restriction rather than a simple leak.

Error U0 means refrigerant shortage. On a large commercial VRV system this is one of the most expensive faults there is, and it gets worse the longer it runs.

Error A6 is an indoor fan motor fault. It covers six distinct conditions — from a physically locked motor to simply low airflow — with very different repairs.

Error E7 is an outdoor fan motor fault. Extremely common on commercial rooftops, and it cascades into pressure and compressor problems if left running.

The J-series codes are thermistor faults. The sensors themselves cost very little — reaching them on a large commercial VRV unit is where the money goes.

Error JA is a high pressure sensor fault — the sensor itself rather than an actual pressure problem. But it removes protection the compressor depends on.

Error A3 is a drain level control fault. The system stopped an indoor unit to prevent condensate overflowing into the ceiling below — which is the real risk.

Error PJ is a field setting or PCB combination fault. It almost always follows a control board replacement where the settings were not carried across.