14 Troubleshooting
Installation and operation manual
34
RWEYQ8~RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1A – 2017.04
Malfunction
Measure
The system operates
but cooling or heating
is insufficient.
▪ Check if air inlet or outlet of outdoor or
indoor unit is not blocked by obstacles.
Remove any obstacles and make sure
the air can flow freely.
▪ Check if the air filter is not clogged (refer
to "Maintenance" in the indoor unit
manual).
▪ Check the temperature setting.
▪ Check the fan speed setting on your user
interface.
▪ Check for open doors or windows. Close
doors and windows to prevent wind from
coming in.
▪ Check if there are too many occupants in
the room during cooling operation. Check
if the heat source of the room is
excessive.
▪ Check if direct sunlight enters the room.
Use curtains or blinds.
▪ Check if the air flow angle is proper.
If after checking all above items, it is impossible to fix the problem
yourself, contact your installer and state the symptoms, the complete
model name of the unit (with manufacturing number if possible) and
the installation date (possibly listed on the warranty card).
14.1
Error codes: Overview
In case a malfunction code appears on the indoor unit user interface
display, contact your installer and inform the malfunction code, the
unit type, and serial number (you can find this information on the
nameplate of the unit).
For your reference, a list with malfunction codes is provided. You
can, depending on the level of the malfunction code, reset the code
by pushing the ON/OFF button. If not, ask your installer for advice.
14.2
Symptoms that are NOT system
malfunctions
The following symptoms are NOT system malfunctions:
14.2.1
Symptom: The system does not operate
▪ The air conditioner does not start immediately after the ON/OFF
button on the user interface is pressed. If the operation lamp
lights, the system is in normal condition. To prevent overloading of
the compressor motor, the air conditioner starts 5 minutes after it
is turned ON again in case it was turned OFF just before. The
same starting delay occurs after the operation mode selector
button was used.
▪ If "Under Centralized Control" is displayed on the user interface,
pressing the operation button causes the display to blink for a few
seconds. The blinking display indicates that the user interface
cannot be used.
▪ The system does not start immediately after the power supply is
turned on. Wait one minute until the micro computer is prepared
for operation.
14.2.2
Symptom: Cool/Heat cannot be changed
over
▪ When the display shows
(change-over under centralized
control), it shows that this is a slave user interface.
▪ When the cool/heat changeover remote control switch is installed
and the display shows
(change-over under centralized
control), this is because cool/heat changeover is controlled by the
cool/ heat changeover remote control switch. Ask your dealer
where the remote control switch is installed.
14.2.3
Symptom: Fan operation is possible, but
cooling and heating do not work
Immediately after the power is turned on. The micro computer is
getting ready to operate and is performing a communication check
with all indoor units. Please wait 12 minutes maximally until this
process is finished.
14.2.4
Symptom: The fan strength does not
correspond to the setting
The fan speed does not change even if the fan speed adjustment
button is pressed. During heating operation, when the room
temperature reaches the set temperature, the outdoor unit goes off
and the indoor unit changes to whisper fan speed. This is to prevent
cold air blowing directly on occupants of the room. The fan speed
will not change even when another indoor unit is in heating
operation, if the button is pressed.
14.2.5
Symptom: The fan direction does not
correspond to the setting
The fan direction does not correspond with the user interface
display. The fan direction does not swing. This is because the unit is
being controlled by the micro computer.
14.2.6
Symptom: White mist comes out of a unit
(Indoor unit)
▪ When humidity is high during cooling operation. If the interior of an
indoor unit is extremely contaminated, the temperature distribution
inside a room becomes uneven. It is necessary to clean the
interior of the indoor unit. Ask your dealer for details on cleaning
the unit. This operation requires a qualified service person.
▪ Immediately after the cooling operation stops and if the room
temperature and humidity are low. This is because warm
refrigerant gas flows back into the indoor unit and generates
steam.
14.2.7
Symptom: White mist comes out of a unit
(Indoor unit, outdoor unit)
When the system is changed over to heating operation after defrost
operation. Moisture generated by defrost becomes steam and is
exhausted.
14.2.8
Symptom: The user interface display
reads "U4" or "U5" and stops, but then
restarts after a few minutes
This is because the user interface is intercepting noise from electric
appliances other than the air conditioner. The noise prevents
communication between the units, causing them to stop. Operation
automatically restarts when the noise ceases.
14.2.9
Symptom: Noise of air conditioners
(Indoor unit)
▪ A "zeen" sound is heard immediately after the power supply is
turned on. The electronic expansion valve inside an indoor unit
starts working and makes the noise. Its volume will reduce in
about one minute.
