![background image](http://html.mh-extra.com/html/daikin/2amx40g2v1b/2amx40g2v1b_service-manual_501057193.webp)
SiBE12-933_A
Troubleshooting
Service Diagnosis
183
4.7
Freeze-up Protection Control
Remote
Controller
Display
A5
Method of
Malfunction
Detection
Indoor unit icing, during cooling operation, is detected by checking the temperatures sensed by
the indoor unit heat exchanger thermistor and room temperature thermistor that are located in a
shut-down room.
At another room (the indoor unit is normal), “
UH
” is displayed on the remote controller.
Malfunction
Decision
Conditions
In the cooling mode, the following conditions (A) and (B) are kept together for 5 minutes.
(A) Indoor unit heat exchanger temperature
≤
–1°C
(B) Indoor unit heat exchanger temperature
≤
Room temperature –10°C
If the freeze-up protection control is activated 4 times continuously, the system is shut down.
(The 4-time counter is reset if any of the following errors does not occur for 60 minutes.
: OL, radiation fin temperature rise, refrigerant shortage, and compressor lock.)
Supposed
Causes
Wrong wiring or piping
Electronic expansion valve malfunctioning in each room
Short-circuit
Indoor unit heat exchanger thermistor abnormality
Room temperature thermistor abnormality