MXS Service Manual

Troubleshooting for Outdoor Unit SiUS121736EA
185 Service Diagnosis
7.5 Anti-Icing Control for Indoor Unit
Error Code A5
Outdoor Unit LED
Display
A j 1 i 2 h 3 i 4 i 5 h
Method of Error
Detection
During cooling operation, indoor unit icing is detected by checking the temperatures sensed by the
indoor heat exchanger thermistor and room temperature thermistor that are located in a shut-down
room.
Error Decision
Conditions
 In cooling operation, the both conditions (A) and (B) are met for 5 minutes.
(A) Room temperature – Indoor heat exchanger temperature ≥ 10°C (18°F)
(B) Indoor heat exchanger temperature ≤ –1°C (30.2°F)
 If the error repeats, the system is shut down.
 Reset condition: 3-minute standby is over and the indoor heat exchanger temperature is above
0°C (32°F)
Supposed
Causes
 Wrong wiring or piping
 Defective electronic expansion valve
 Short-circuited air
 Defective indoor heat exchanger thermistor
 Defective room temperature thermistor