Daikin R71FUV1 Service Manual page 491

Si20-701_B
A
[In cooling]
High suction
air
temperature
of the
condenser
[In heating]
Degradation
in
condensing
capacity
Excessive refrigerant
charging
Improper model selection
Note:
∗1. In cooling, it is normal if the outdoor unit electronic
expansion valve (EVM) is fully open.
∗2. In heating, the indoor unit electronic expansion valve
is used for "subcooling degree control".
484
Troubleshooting by Remote Controller
Short circuit
High suction
air
temperature of
High outdoor
outdoor unit
air
temperature
Short circuit
High suction
air
temperature of
High room
indoor unit
temperature
Defective suction air
thermistor of indoor unit
High suction air
temperature of outdoor
unit
Defective outdoor air
temperature thermistor
of outdoor unit
Dirty condenser
Mixing of non-
condensable gas
Decreased
fan output
Decreased
airflow
rate
High
airflow
passage
resistance
[In heating]
← Is the suction air
temperature less than
43˚C?
← Is the outdoor temperature
less than 43˚C?
← Is the suction air
temperature less than
27˚C?
← Is the room temperature
less than 27˚C?
← Is the connector properly
connected?
Are the thermistor
resistance characteristics
normal?
← Is the outdoor air
temperature less than
16˚CWB?
← Is the connector properly
connected?
Are the thermistor
resistance characteristics
normal?
← Is the heat exchanger
clogged? (In cooling)
← Is air or else mixed in the
refrigerant system?
← Can the fan motor
Defective
fan motor
be rotated with
hands?
Are the motor coil
resistance and
insulation normal?
← If a spare PCB is
Defective
service
mounted, is the
monitor
capacity setting
PCB
properly made?
(Including
capacity
setting)
← Is the air filter
Dirty filter
clogged?
← Is there any
Obstacle
obstacle in the
airflow passage?
← Refer to error code "F6".
← Is the indoor unit too small
compared to the large-
sized outdoor unit?