E8 Heating Overload Operation - Mitsubishi Electric FDT125VNVF Technical Manual

Error code
E8
Remote controller:
1. Applicable model
All models
2. Error detection method
Indoor heat exchanger
temperature thermistor (ThI-R1,
R2, R3)
3. Condition of Error displayed
When it is detected 5 times
within 60 minutes from initial
detection or when the overload
condition is detected for 6
minutes continuously.
4. Presumable cause
• Clogged air filter
• Defective indoor heat
exchanger temperature
thermistor connector
• Defective indoor heat
exchanger temperature
thermistor
• Anomalous refrigerant system
Note:
During heating operation; After starting compressor, compressor rotation speed is decreased by detecting indoor heat
exchanger temperature (ThI-R) in order to control high pressure.
LED Green Red
Keeps flashing 1 time flash
Indoor
Keeps flashing Stays OFF
Outdoor
5. Troubleshooting
Diagnosis
Is the air filter clogged?
NO
Is the
indoor heat exchanger
temperature thermistor
connection OK?
YES
(2)
Are the
characteristics of indoor
heat exchanger temperature
thermistor OK?
YES
Check the error data with the
remote controller.
Is the unit
operating in the state of
heating overload?
Note (1) Judge if it is in the state of overload or not as follows.
� Is there any short-circuit of air?
� Isn't there any fouling or clogging on the indoor heat exchanger?
� Is the outdoor fan control normal?
� Isn't the room and outdoor air temperature too high?
Note (2) For characteristics of indoor heat exchanger temperature thermistor,
see the error display E6.
Reset
56 63
Indoor heat exchanger temperature (°C)
378
-
Content
Heating overload operation
YES
NO
NO
NO
YES
Error stop
-
'12 • PAC-T-174
Countermeasure
Wash.
Defective indoor heat
exchanger temperature
thermistor connector ➞
Correct.
Defective indoor heat
exchanger temperature
thermistor.
Check refrigerant system.
Adjust