Fujitsu WATERSTAGE WS A050DD6 Series Maintenance Document page 14

Split system single phase type
Clear 8: Heat-exchange thermistor (outlet) error :
Hydraulic Unit LED: Green 7 flashes / Red 3 flashes
Outdoor Unit LED: flash
Probable causes:
•
Misconnection.
•
Sensor fault.
•
Main PCB failure.
Check:
1. Check the sensor connection:
See if the connector has been disconnected.
-
See if the connection is correct.
-
Check for any damage on the sensor cable.
-
After solving the misconnection problem, switch the heat pump back on.
2. Remove the sensor and check its resistance value :
- Check the resistancer value
-30
Temperature (°C)
95.6 50.3 27.8 21.0 16.1 12.4 9.63 5.98 3.84 2.5
Resistance (kΩ)
- If the thermistor is faulty, replace it.
3. Check the electronic board voltage:
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor (DC5.0V)
WO*A060LDC
EXP VALVE
PIPE
DISCHARGE PIPE
OUTDOOR TEMP
- If there is no voltage, replace Main PCB.
14
OK
-20 -10 -5 0
OK
WO*A080LDC
COMPRESSOR
TEMP
5 10 20 30 40
COMPRESSOR
TEMP
EXP VALVE
OUTDOOR
TEMP
DISCHARGE
PIPE
PIPE
50 60 70 80
1.7 1.2 0.8 0.6
WO*A100LDT
EXP VALVE
COMPRESSOR
TEMP
OUTDOOR
TEMP
PIPE
DISCHARGE
PIPE
Maintenance Document 1589-3