20 Troubleshooting
Installer and user reference guide
49
RXYSCQ4~6TMV1B
VRV IV-S system air conditioner
4P404224-1C – 2019.07
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).
20.1
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.
Main code
Contents
External protection device was activated
EEPROM failure (indoor)
Drain system malfunction (indoor)
Fan motor malfunction (indoor)
Swing flap motor malfunction (indoor)
Expansion valve malfunction (indoor)
Drain malfunction (indoor unit)
Filter dust chamber malfunction (indoor)
Capacity setting malfunction (indoor)
Transmission malfunction between main PCB and sub
PCB (indoor)
Heat exchanger thermistor malfunction (indoor; liquid)
Heat exchanger thermistor malfunction (indoor; gas)
Suction air thermistor malfunction (indoor)
Discharge air thermistor malfunction (indoor)
Movement detector or floor temperature sensor
malfunction (indoor)
User interface thermistor malfunction (indoor)
PCB malfunction (outdoor)
High pressure switch was activated
Low pressure malfunction (outdoor)
Compressor lock detection (outdoor)
Fan motor malfunction (outdoor)
Electronic expansion valve malfunction (outdoor)
Main code
Contents
Discharge temperature malfunction (outdoor)
Abnormal suction temperature (outdoor)
Refrigerant overcharge detection
High pressure switch malfunction
Low pressure switch malfunction
Fan motor trouble (outdoor)
Ambient temperature sensor malfunction (outdoor)
Pressure sensor malfunction
Current sensor malfunction
Discharge temperature sensor malfunction (outdoor)
Heat exchanger gas temperature sensor malfunction
(outdoor)
Suction temperature sensor malfunction (outdoor)
De-icing temperature sensor malfunction (outdoor)
Liquid temperature sensor (after subcool HE)
malfunction (outdoor)
Gas temperature sensor (after subcool HE)
malfunction (outdoor)
High pressure sensor malfunction (S1NPH)
Low pressure sensor malfunction (S1NPL)
INV PCB abnormal
Fin temperature abnormal
Inverter PCB faulty
Compressor over current detected
Compressor lock (startup)
Transmission outdoor unit - inverter: INV transmission
trouble
INV unbalanced power supply voltage
Fin thermistor malfunction
Capacity setting malfunction (outdoor)
Abnormal low pressure drop, faulty expansion valve
INV voltage power shortage
System test run not yet executed
Faulty wiring indoor/outdoor
Abnormal user interface - indoor communication
Faulty wiring to outdoor/outdoor
Abnormal main-sub user interface communication
System mismatch. Wrong type of indoor units
combined. Indoor unit malfunction.
Connection malfunction over indoor units or type
mismatch
Centralised address duplication
Malfunction in communication centralised control
device - indoor unit
Auto address malfunction (inconsistency)
Auto address malfunction (inconsistency)
20.2
Symptoms that are NOT system
malfunctions
The following symptoms are NOT system malfunctions:
20.2.1
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
