Daikin FCQ18PVJU Service Manual page 76

Symptom-based Troubleshooting
Symptom
11 The system <Indoor unit>
produces Immediately after turning ON
sounds. the power supply, indoor unit
produces "ringing" sounds.
<Indoor and outdoor units>
"Hissing" sounds are
continuously produced while in
cooling or defrosting 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.
<Indoor unit>
Faint sounds are continuously
produced while in cooling
operation or after stopping the
operation.
<Indoor unit>
"Creaking" sounds are
produced while in heating
operation or after stopping the
operation.
<Indoor unit>
Sounds like "trickling" or the
like are produced from indoor
units in the stopped state.
<Outdoor unit>
Pitch of operating sounds
changes.
12 Dust emits from Dust emits from the system
the system. when it restarts after the stop
for an extended period of time.
13 Odors emits In operation
from the system.
14 Outdoor unit fan In operation
does not rotate.
15 LCD display "88" Immediately after turning ON
appears on the the power supply
remote
controller.
16 The outdoor unit After stopping operation
compressor or
the outdoor unit
fan does not
stop.
17 The outdoor gets While stopping operation
hot.
18 Hot air comes Hot air is felt while the system
out from the stops.
system even
though it stops.
19 The system does The system is in dry operation. The reason is that the dry
not cool air well.
69
Supposed Cause
These are operating sounds of
the electronic expansion valve of
the indoor unit.
These sounds are produced from
gas (refrigerant) flowing
respectively through the indoor
and outdoor units.
These sounds are produced
when the gas (refrigerant) stops
or changes flowing direction.
These sounds are produced from
the drain discharge device in
operation.
These sounds are produced from
resin parts expanding and
contracting with temperature
changes.
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.
The reason is that the compressor
changes the operating frequency.
Dust, which has deposited on the
inside of indoor unit, is blown out
from the system.
Odors of room, such as cigarette
smoke, are absorbed to the
inside of indoor unit and are then
blown out.
The reason is that fan revolutions
are controlled to put the operation
to the optimum state.
The reason is that the system is
checking to be sure the remote
controller is normal.
It stops in order to prevent oil or
refrigerant from dwelling.
The reason is that the compressor
is warmed up to provide smooth
startup of the system.
On VRV systems, small quantity
of refrigerant is fed to indoor units
in the stopped state when other
indoor units are in operation.
operation serves not to reduce
the room temperature where
possible.
SiUS28-902_a
Countermeasure
Normal operation.
This sound becomes low after a
lapse of approximately one
minute.
Normal operation.
Normal operation.
Normal operation.
Normal operation.
Normal operation.
Normal operation.
Normal operation.
The inside of the indoor unit
should be cleaned.
Normal operation.
Normal operation.
This code is displayed for a period
of approximately one minute at
maximum.
Normal operation.
It stops after a lapse of
approximately 5 to 10 minutes.
Normal operation.
Normal operation.
Change the system to cooling
operation.
Troubleshooting