Check
SiMX042215E
90
Part 6 Service Diagnosis
Note
5. Check
5.1 Thermistor Resistance Check
Check No.01
Measure the resistance of each thermistor using multimeter.
The resistance values are defined by below table.
If the measured resistance value does not match the listed value, the thermistor must be
replaced.
Disconnect the connector of thermistor ASSY from the PCB to measure the resistance
between the pins using multimeter.
To check the thermistor soldered on a PCB, disconnect the PCB from other PCB/parts, and
measure the resistance between the both ends of soldered thermistor.
R6000664
When replacing the defective thermistor(s), replace the thermistor as ASSY.
Thermistor
Resistance Type
B value
R(25°C)
Indoor
Unit
R1T
Room temperature thermistor
B
3435 K
10 kΩ
R2T
Indoor heat exchanger thermistor
A
3950 K
20 kΩ
Outdoor
Unit
R1T
Outdoor temperature thermistor
A
3950 K
20 kΩ
R2T
Outdoor heat exchanger thermistor
A
3950 K
20 kΩ
R3T
Discharge pipe thermistor
A
3950 K
20 kΩ
Thermistor
temperature (°C)
R(25°C) = 20 k
:
B = 3950 K
R(25°C) = 10 k
:
B = 3435 K
Type B
Type A
73.4
197.8
–20
57.0
148.2
–15
44.7
112.1
–10
35.3
85.60
–5
28.2
65.93
0
22.6
51.14
5
18.3
39.99
10
14.8
31.52
15
12.1
25.02
20
10.0
20.00
25
8.2
16.10
30
6.9
13.04
35
5.8
10.62
40
4.9
8.707
45
4.1
7.176
50
Multimeter
Resistance range
Thermistor ASSY
Soldered thermistor
Multimeter
R(25°C) = 10 k
:
, B = 3435 K
(°C)
50
25
0
–15
0
15
30
45
(k
:
)
R(25°C) = 20 k
:
, B = 3950 K
(°C)
(k
:
)
–15
0
15
30
45
150
100
50
