11 Troubleshooting
Installer and user reference guide
44
RXYSQ8~12TMY1B
VRV IV-S system air conditioner
4P404225-1B – 2016.03
Main code
Cause
Solution
▪ The stop valve of an outdoor unit is left closed.
▪ The piping and wiring of the specified indoor unit are not
connected correctly to the outdoor unit.
▪ Open the stop valve on both the gas and liquid side.
▪ Confirm that the piping and wiring of the specified indoor
unit are connected correctly to the outdoor unit.
In case of 12:
Main code
Sub code
Cause
Solution
Earth leakage detector activated
Restart the unit. If problem reoccurs, contact your
dealer.
High pressure switch was activated (S1PH) - A1P
(X4A)
Check stop valve situation or abnormalities in
(field) piping or airflow over air cooled coil.
▪ Refrigerant overcharge
▪ Stop valve closed
▪ Check refrigerant recharge unit.
▪ Open stop valves
Stop valve closed (liquid)
Open liquid stop valve.
▪ Refrigerant overcharge
▪ Stop valve closed
▪ Check refrigerant recharge unit.
▪ Open stop valves.
Low pressure malfunction:
▪ Stop valve closed
▪ Refrigerant shortage
▪ Indoor unit malfunction
▪ Open stop valves.
▪ Check refrigerant recharge unit.
▪ Check
the
user
interface's
display
or
transmission wiring between the outdoor unit
and the indoor unit.
Electronic expansion valve malfunction (subcool)
(Y2E) - A1P (X21A)
Check connection on PCB or actuator.
Electronic expansion valve malfunction (main)
(Y1E) - A1P (X23A)
Check connection on PCB or actuator.
Discharge temperature too high (R21T):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Open stop valves.
▪ Check refrigerant recharge unit.
Compressor casing temperature too high (R8T):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Open stop valves.
▪ Check refrigerant recharge unit.
▪ Refrigerant overcharge
▪ Stop valve closed
▪ Check refrigerant recharge unit.
▪ Open stop valves.
Ambient temperature sensor malfunction (R1T) -
A1P (X18A)
Check connection on PCB or actuator.
Discharge temperature sensor malfunction (R21T):
open circuit - A1P (X29A)
Check connection on PCB or actuator.
Discharge temperature sensor malfunction (R21T):
short circuit - A1P (X29A)
Check connection on PCB or actuator.
Compressor casing temperature sensor
malfunction (R8T): open circuit - A1P (X29A)
Check connection on PCB or actuator.
Compressor casing temperature sensor
malfunction (R8T): short circuit - A1P (X29A)
Check connection on PCB or actuator.
Suction temperature sensor malfunction (R3T) -
A1P (X30A)
Check connection on PCB or actuator.
De-icing temperature sensor malfunction (R7T) -
A1P (X30A)
Check connection on PCB or actuator
Liquid temperature sensor (after subcool HE)
malfunction (R5T) - A1P (X30A)
Check connection on PCB or actuator.
Liquid temperature sensor (coil) malfunction (R4T)
- A1P (X30A)
Check connection on PCB or actuator.
Gas temperature sensor (after subcool HE)
malfunction (R6T) - A1P (X30A)
Check connection on PCB or actuator.
High pressure sensor malfunction (S1NPH): open
circuit - A1P (X32A)
Check connection on PCB or actuator.
High pressure sensor malfunction (S1NPH): short
circuit - A1P (X32A)
Check connection on PCB or actuator.
