Symptom-based Troubleshooting
SiUS281117
Service Diagnosis
97
6
COOL-HEAT
selection is
disabled.
The remote controller displays
"UNDER CENTRALIZED
CONTROL".
This remote controller has no
option to select cooling operation.
Use a remote controller with
option to select cooling operation.
The remote controller displays
"UNDER CENTRALIZED
CONTROL", and the COOL-
HEAT selection remote
controller is provided.
COOL-HEAT selection is made
using the COOL-HEAT selection
remote controller.
Use the COOL-HEAT selection
remote controller to select cool or
heat.
7
The system
conducts fan
operation but not
cooling or
heating
operation.
This symptom occurs
immediately after turning ON
the power supply.
The system is in preparation
mode of operation.
Wait for a period of approximately
10 minutes.
8
The airflow rate
is not
reproduced
according to the
setting.
Even pressing the AIRFLOW
RATE SET button makes no
changes in the airflow rate.
In heating operation, when the
room temperature reaches the set
degree, the outdoor unit will stop
while the indoor unit is brought to
fan LL operation so that no one
gets cold air.
(The fan LL operation is also
enabled while in oil return mode in
cooling operation.)
Normal operation.
9
The airflow
direction is not
reproduced
according to the
setting.
The airflow direction is not
corresponding to that
displayed on the remote
controller.
The flap does not swing.
Automatic control
Normal operation.
10 A white mist
comes out from
the system.
<Indoor unit>
In cooling operation, the
ambient humidity is high.
(This indoor unit is installed in
a place with much oil or dust.)
Uneven temperature distribution
due to heavy stain of the inside of
the indoor unit
Clean the inside of the indoor unit.
<Indoor unit>
Immediately after cooling
operation stopping, the
outdoor air temperature and
humidity are low.
Hot gas (refrigerant) flown in the
indoor unit results to be vapor
from the unit.
Normal operation.
<Indoor and outdoor units>
After the completion of
defrosting operation, the
system is switched to heating
operation.
Defrosted moisture turns to be
vapor and comes out from the
units.
Normal operation.
Symptom
Supposed Cause
Countermeasure
