Service manual

Symptom-based Troubleshooting SiUS28-902_a
69 Troubleshooting
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 defrosting 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 defrosting
operation.
These sounds are produced
when the gas (refrigerant) stops
or changes flowing direction.
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.
<Indoor unit>
Sounds like "trickling" or the
like are produced from indoor
units in the stopped state.
On VRV systems, these sounds
are produced when other indoor
units in operation. The reason is
that the system runs in order to
prevent oil or refrigerant from
dwelling.
Normal operation.
<Outdoor unit>
Pitch of operating sounds
changes.
The reason is that the compressor
changes the operating frequency.
Normal operation.
12 Dust emits from
the system.
Dust emits 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 emits
from the system.
In operation Odors of room, such as cigarette
smoke, are absorbed to the
inside of indoor unit and are then
blown out.
The inside of the indoor unit
should be cleaned.
14 Outdoor unit 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 unit
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.
17 The outdoor gets
hot.
While stopping operation The reason is that the compressor
is warmed up to provide smooth
startup of the system.
Normal operation.
18 Hot air comes
out from the
system even
though it stops.
Hot air is felt while the system
stops.
On VRV systems, small quantity
of refrigerant is fed to indoor units
in the stopped state when other
indoor units are in operation.
Normal operation.
19 The system does
not cool air well.
The system is in dry operation. The reason is that the dry
operation serves not to reduce
the room temperature where
possible.
Change the system to cooling
operation.
Symptom Supposed Cause Countermeasure