21 Troubleshooting
Installation and operation manual
50
REMA5+REYA8~20A7Y1B
VRV 5 heat recovery
4P684060-1 – 2022.02
Main
code
Sub code
Cause
Solution
SVEO
(a)
SVS
(b)
Master
Slave 1
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
(upper heat exchanger) (Y1E) – main PCB
(X21A)
Check connection on PCB or actuator.
Electronic expansion valve malfunction
(inverter cooling) (Y5E) – main PCB (X23A)
Check connection on PCB or actuator.
Electronic expansion valve malfunction
(lower heat exchanger) (Y3E) – main PCB
(X22A)
Check connection on PCB or actuator
Electronic expansion valve malfunction
(receiver gas) (Y4E) – main PCB (X25A)
Check connection on PCB or actuator.
Electronic expansion valve malfunction
(subcool heat exchanger) (Y2E) – main PCB
(X26A)
Check connection on PCB or actuator.
Discharge temperature too high (R21T) –
main PCB (X33A):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Open stop valves.
▪ Check refrigerant recharge unit.
Compressor casing temperature too high
(R15T) – main PCB (X33A):
▪ 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) – main PCB (X18A)
Check connection on PCB or actuator.
Discharge temperature sensor malfunction
(R21T): open circuit – main PCB (X33A)
Check connection on PCB or actuator.
Discharge temperature sensor malfunction
(R21T): short circuit - main PCB (X33A)
Check connection on PCB or actuator.
Compressor casing temperature sensor
malfunction (R15T): open circuit - main PCB
(X33A)
Check connection on PCB or actuator.
Compressor casing temperature sensor
malfunction (R15T): short circuit - main PCB
(X33A)
Check connection on PCB or actuator.
Suction compressor temperature sensor
(R12T) – sub PCB (X35A)
Check connection on PCB or actuator.
Suction temperature sensor (R10T) – main
PCB (X29A)
Check connection on PCB or actuator.
Heat exchanger deicer temperature sensor
(R11T) – sub PCB (X35A)
Check connection on PCB or actuator
Upper heat exchanger – gas - temperature
sensor (R8T) – main PCB (X29A)
Check connection on PCB or actuator.
Lower heat exchanger – gas - temperature
sensor (R9T) main PCB (X29A)
Check connection on PCB or actuator.
Liquid main - temperature sensor (R3T) –
main PCB (X30A)
Check connection on PCB or actuator.
Subcool heat exchanger – liquid -
temperature sensor (R7T) - main PCB
(X30A)
Check connection on PCB or actuator.
Subcool heat exchanger – liquid -
temperature sensor (R16T) - main PCB
(X35A)
Check connection on PCB or actuator.