Alarm code
25
Abnormal operation of the thermistor for the outdoor unit heat exchanger gas pipe (Tg/Tbg).
•
The RUN indicator flashes and the ALARM indication is displayed on the remote control switch.
•
The unit no., the alarm code and the unit code are alternatively displayed in the temperature setting section and the unit
no. and alarm code are displayed on the outdoor unit's PCB1 display.
If an anomaly is detected in the thermistor, check the thermistors as follows:
* This alarm is indicated when the thermistor is short-circuited (less than 0.2 kΩ) or cut (greater than 840 kΩ) for eight
minutes during operation.
* These thermistors are installed as shown in the following figure.
If this thermistor is faulty, this alarm is indicated.
Thermistor Holder
Butyl Sheet
Butyl Sheet
Plastic Sheet
Tg Thermistor (THM11),
Tbg Thermistor (THM23)
< Details for Thermistor >
Tbg Thermistor
(THM23)
Tg Thermistor
(THM11)
Yes
Yes
Connect it.
No
Faulty Thermistor
Faulty PCB1
No
Are thermistors connected to
THM11 (Tg) or THM23 (Tbg)
on PCB1?
Is resistance of the
thermistor between
0.2kΩ and 500kΩ?
Refer to "Alarm Code 11"
for thermistor resistance.
Tg: Thermistor for Outdoor Gas Pipe
Tbg: Thermistor for Super Cooling Bypass Line
PCB1: Control PCB in Outdoor Unit
Cause
Check Item
Action
(Turn OFF Main Switch)
Phenomenon
Faulty
Outdoor Unit
Gas Pipe
Thermistor
Check resistance.
Replace thermistor
if faulty.
Fault
Check wiring to PCB1.
Repair wiring and
connections.
Incorrect Connection
Replace PCB1 and
check operation.
Replace PCB1 if faulty.
Faulty PCB1
8 Troubleshooting
204
SMGB0065 rev. 1 - 12/2010