Service Manual

Troubleshooting by Error Codes SiUS281811E
232 Part 6 Service Diagnosis
Reference
4.35 Refrigerant Overcharged
Error Code F6
Applicable
Models
All outdoor units
Method of Error
Detection
Excessive charging of refrigerant is detected by using the outdoor air temperature, heat exchanger
deicer temperature and liquid pipe temperature during a check operation.
Error Decision
Conditions
During a check operation, the amount of refrigerant will be calculated based on the outdoor
temperature, the heat exchanger deicer temperature, and the liquid pipe temperature. If the
calculated amount exceeds the normal amount by 30%, too much refrigerant has been added.
(Adding only slightly more than the normal amount of refrigerant may also cause F6 to be
displayed)
Supposed
Causes
Refrigerant overcharge
Disconnection of outdoor air thermistor, heat exchanger deicer thermistor, liquid pipe thermistor
Defective outdoor air thermistor, heat exchanger deicer thermistor, liquid pipe thermistor
Troubleshooting
CHECK 11 Refer to page 270.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Are the above
thermistor installed on
pipes correctly?
Check the mounting condition of
the outdoor air temperature
thermistor, heat
exchanger
deicer thermistor and
liquid pipe
thermistor in the piping.
Remove the outdoor air
temperature thermistor, heat
exchanger deicer thermistor and
the liquid pipe thermistor from the
outdoor unit PCB and measure
resistance with a multimeter.
Rectify the overcharge of the
refrigerant.
YES
NO
NO
Replace the thermistor.
Install the thermistor correctly.
YES
Is the characteristic
of the above
thermistor normal?
CHECK 11