Daikin R71FUV1 Service Manual page 493

Si20-701_B
A
[In cooling]
Low suction
air
temperature
of the
evaporator
[In heating]
Less
circulation
quantity of
refrigerant
Degradation
in
condensing
capacity
486
Troubleshooting by Remote Controller
Short circuit
Low suction
air
temperature of
Low room
indoor unit
temperature
Defective suction air
thermistor of indoor unit
Low suction air
temperature of outdoor
unit
Defective outdoor air
temperature thermistor
of outdoor unit
Abnormal
piping length
Bent or
crashed pipe
High pipe
Clogging of
resistance
foreign
materials
Stop valve
closed
Inadequate refrigerant
quantity
Moisture choke
Dirty evaporator
Decreased
fan output
Decreased
airflow
rate
High
airflow
passage
resistance
← Is the suction air
temperature more than
14˚C?
← Is the room temperature
less than 14˚C?
← Is the connector properly
connected?
Are the thermistor
resistance characteristics
normal?
← Is the outdoor air
temperature more than
-20˚C?
← Is the connector properly
connected?
Are the thermistor
resistance characteristics
normal?
← Does the piping length fall
in the permissible range?
← Conduct visual checks for
pipe conditions.
← Is there any temperature
difference caused before
and after the filter or
branch pipe?
← Refer to error code "U1".
← Eliminate moisture by
vacuum operation.
← Is the heat exchanger
clogged?
← 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?