Hitachi RAS-5HVRNM1E Service Manual page 245

8 Troubleshooting
13
Alarm code
• The RUN LED flickers and "ALARM" is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section.
The unit number and the alarm code are displayed on the display of the outdoor unit PCB.
– This alarm code is displayed when the thermistor is short-circuited (less than 0.24 kΩ) or cut (greater than 840 kΩ)
during the cooling process or the heating process. The system is automatically restarted when the fault is removed.
Phenomenon
Faulty freeze protection thermistor
Faulty PCB
237
SMGB0060 rev. 1- 12/2010
Abnormal operation of the thermistor for the indoor unit heat exchanger liquid pipe
temperature (freeze protection thermistor)
Cause
Fault
Incorrect connection
Check item
(Turn OFF the main switch)
Check the resistance Replace the thermistor if faulty
Check the connection Repair the wiring and connections
Replace PCB and
check the operation
Action
Replace PCB if faulty
8