Service Manual

Troubleshooting by Error Codes SiUS281811E
244 Part 6 Service Diagnosis
4.47 Refrigerant Shortage
Error Code U0
Applicable
Models
All outdoor units
Method of Error
Detection
Refrigerant shortage check is conducted based on the discharge pipe thermistor temperature and
the low-pressure saturated temperature.
Error Decision
Conditions
Microcomputer is used to determine and check for system refrigerant shortage.
The unit can keep operating but there is an unconfirmed error.
Supposed
Causes
 Refrigerant shortage or refrigerant clogging (piping error)
 Defective suction pipe thermistor
 Defective pressure sensor
 Defective outdoor main PCB (A1P)