4-20
Trouble shooting
4-3. Appropriate Measures for Different Symptoms
4-3-1. Fan coil unit ROOM sensor error (OPEN/SHORT)
1. How to check
Yes
Did the indoor room temperature sensor
connector
break away from the PCB?
Did the resistance value significantly
stray from the following temperature table?
After separating the indoor room temperature sensor
connector from the PCB, measure the resistance value
between the two terminals.
Restart operation after replacing the PCB.
Restart operation after connecting the
connector to the PCB.
Replace indoor room temperature sensor
as it is defective.
Yes
No
No
Temp.(°C)
70
60
50
40
30
20
10
0
‑10
Resistance(KΩ)
2.2
3.0
4.2
5.8
8.3
12.1
18.0
27.3
43.0
EX) ROOM TEMPERATURE 26℃
‑ RESISTANCE 09.26KΩ
Error number
Fan coil unit
display
Duct, cassette (1‑Way/2‑Way/
Mini 4‑Way)
4‑Way cassette type
Wall mount type
Circular cassette type
LED Indication
or
or
r u n /
stop
Defrost Timer
Clean
Filter
18°C
21°C
Timer
24°C
27°C
Ice
Blue
Yellow
Green
Blue
Red
1‑Way
blue
Yellow
green
2‑Way
Green
Red
×
×
◑
×
×
×
◑
×
×
×
×
◑
×
×
×
×
×
◑
Criteria
∙ Refer to the judgment method below
Cause of
problem
∙ Faulty OPEN/SHORT of number xxx fan coil unit indoor temperature sensor