Fault Code U7

Fault: 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
 

For Daikin split and multi-split air conditioning systems included wall-mounted, duct-connected, floor-standing, multi-flow, stylish, european, ururu sarara & cassette-type units.
If molded case circuit breakers or earth leakage circuit breakers have tripped, do not reset the breaker immediately without first checking for any problems with insulation of equipment.
Resetting breakers without a check of insulation may cause damage to equipment.