Service Manual

SiUS281811E Symptom-based Troubleshooting
Part 6 Service Diagnosis 171
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
ambient temperature and
humidity are low.
Hot gas (refrigerant) that has
flowed in the indoor unit results
to be vapor from the unit.
Normal operation.
Indoor and outdoor units
After the completion of
defrost operation, the
system is switched to
heating operation.
Defrosted moisture turns to be
vapor and comes out from the
units.
Normal operation.
11 The system
produces
sounds.
Indoor unit
Immediately after turning ON
the power supply, indoor unit
produces ringing sounds.
These are operating sounds of
the electronic expansion valve
of the indoor unit.
Normal operation.
This sound becomes low after a
lapse of approximately one
minute.
Indoor and outdoor units
Hissing sounds are
continuously produced while
in cooling or defrost
operation.
These sounds are produced
from gas (refrigerant) flowing
respectively through the indoor
and outdoor units.
Normal operation.
Indoor and outdoor units
Hissing sounds are
produced immediately after
the startup or stop of the
system, or the startup or
stop of defrost operation.
These sounds are produced
when the gas (refrigerant) stops
or changes flowing.
Normal operation.
Indoor unit
Faint sounds are
continuously produced while
in cooling operation or after
stopping the operation.
These sounds are produced
from the drain discharge device
in operation.
Normal operation.
Indoor unit
Creaking sounds are
produced while in heating
operation or after stopping
the operation.
These sounds are produced
from resin parts expanding and
contracting with temperature
changes.
Normal operation.
Outdoor unit
Pitch of operating sounds
changes.
The reason is that the
compressor changes the
operating frequency.
Normal operation.
12 Dust comes out
from the
system.
Dust comes out from the
system when it restarts after
the stop for an extended
period of time.
Dust, which has deposited on
the inside of indoor unit, is
blown out from the system.
Normal operation.
13 Odors come out
from the
system.
In operation Odors of room, cigarettes or
else adsorbed to the inside of
indoor unit are blown out.
The inside of the indoor unit
should be cleaned.
14 Outdoor fan
does not rotate.
In operation The reason is that fan
revolutions are controlled to put
the operation to the optimum
state.
Normal operation.
15 LCD display 88
appears on the
remote
controller.
Immediately after turning ON
the power supply
The reason is that the system is
checking to be sure the remote
controller is normal.
Normal operation.
This code is displayed for a
period of approximately one
minute at maximum.
16 The outdoor
unit compressor
or the outdoor
fan does not
stop.
After stopping operation It stops in order to prevent oil or
refrigerant from dwelling.
Normal operation.
It stops after a lapse of
approximately 5 to 10 minutes.
Symptom Supposed Cause Countermeasure