Specifications

Troubleshooting by Indication on the Remote Controller SiUS39-601
172 Troubleshooting
2.41
“UO” Outdoor Unit: Low Pressure Drop Due to Refrigerant
Shortage or Electronic Expansion Valve Failure
Remote
Controller
Display
U0
Applicable
Models
RXYQ72M, 96M
Method of
Malfunction
Detection
Short of gas malfunction is detected by discharge pipe temperature thermistor.
Malfunction
Decision
Conditions
Microcomputer judge and detect if the system is short of refrigerant.
★
Malfunction is not decided while the unit operation is continued.
Supposed
Causes

Out of gas or refrigerant system clogging (incorrect piping)

Defect of pressure sensor

Defect of outdoor unit PC board (A1P)

Defect of thermistor R2T or R4T