Error code
E: 74 Outdoor temperature sensor error
Applies to 6 models
ASUG09LZAS, ASUG12LZAS, ASUG15LZAS, AOUG09LZAH1, AOUG12LZAH1, AOUG15LZAH1
What this means
The outdoor-temperature thermistor is detected open or shorted at startup or while the compressor runs. Connector, thermistor, or main-PCB failure may be involved.
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.