Error code
U2 Power-supply voltage fault
Applies to 15 models
FTXJ20A2V1BW, FTXJ25A2V1BW, FTXJ35A2V1BW, FTXJ42A2V1BW, FTXJ50A2V1BW, FTXJ20A2V1BS, FTXJ25A2V1BS, FTXJ35A2V1BS, FTXJ42A2V1BS, FTXJ50A2V1BS, FTXJ20A2V1BB, FTXJ25A2V1BB, FTXJ35A2V1BB, FTXJ42A2V1BB, FTXJ50A2V1BB
What this means
The outdoor unit detects defective or abnormal power-supply voltage.
When to call a technician
This fault involves refrigerant, pressure, or electrical work that must be handled by a certified technician under EU F-gas rules. Do not attempt to open the refrigerant circuit, access mains wiring, or adjust pressure components yourself. Contact a qualified installer or servicer for this one.