Error code
Remote control:
7-segment display:
LED
Green
Red
Indoor
Outdoor
Content
'14 • KX-SM-221
E28
–
Remote control
temperature thermistor anomaly (Thc)
Keeps flashing
Stays OFF
Keeps flashing
Stays OFF
1. Applicable model
5. Troubleshooting
All models
Diagnosis
Countermeasure
YES
Is
the connector of
thermistor connected
properly ?
Are
the characteristics
of thermistor OK?
Is the thermistor wire
OK *1
NO
NO
YES
*1 Check several times to prove any poor connection.
Temperature-resistance characteristics of remote
control temperature thermistor (Thc).
Regarding the characteristics of the thermistor,
see the following table.
Insert the connector
securely.
Replace thermistor
(Thc).
Replace indoor control
PCB.
2. Error detection method
Detection of anomalously low
temperature (resistance)
of Thc.
3. Condition of error displayed
• If -50ºC or lower is detected
for 5 seconds continuously,
compressor stops. After
3-minutes delay, the
compressor is restarted
automatically, but if this
anomaly occurs again within
60 minutes after the initial
detection.
4. Presumable cause
• Anomalous connection of
remote control temperature
thermistor
• Remote control temperature
thermistor anomaly
• Remote control PCB anomaly
Note:
After 10 seconds has elapsed since remote control temperature thermistor was switched from invalid to valid, E28 will not be displayed
even if the thermistor harness is disconnected or broken. However, in such case, the indoor return air temperature thermistor (Thi-A) will
be valid instantly instead of the remote control temperature thermistor (Thc).
Please note that even though the remote control temperature thermistor (Thc) is valid, the displayed return air temperature on the remote
control LCD shows the value detected by the indoor return air temperature thermistor (Thi-A), not by the remote control temperature
thermistor (Thc).
Temperature (°C) Resistance (k
Ω
) Temperature (°C) Resistance (k
Ω
) Temperature (°C) Resistance (k
Ω
) Temperature (°C) Resistance (k
Ω
)
0
65
14
33
30
16
46
8.5
1
62
16
30
32
15
48
7.8
2
59
18
27
34
14
50
7.3
4
53
20
25
36
13
52
6.7
6
48
22
23
38
12
54
6.3
8
44
24
21
40
11
56
5.8
10
40
26
19
42
9.9
58
5.4
12
36
28
18
44
9.2
60
5.0
-
93
-