Daikin VRV IV+ RXYTQ8U5/U7YF Installation And Operation Manual page 34

19 Troubleshooting
Main code
Master
Installation and operation manual
34
Sub code
Slave 1 Slave 2
Discharge temperature too high
(R21T/R22T):
▪ Stop valve closed
▪ Refrigerant shortage
Compressor casing temperature too
high (R8T/R9T):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Refrigerant overcharge
▪ Stop valve closed
Ambient temperature sensor
malfunction (R1T) - A1P (X18A)
Discharge temperature sensor
malfunction (R21T): open circuit - A1P
(X19A)
Discharge temperature sensor
malfunction (R21T): short circuit - A1P
(X19A)
Discharge temperature sensor
malfunction (R22T): open circuit - A1P
(X19A)
Discharge temperature sensor
malfunction (R22T): short circuit - A1P
(X19A)
Compressor casing temperature
sensor malfunction (R8T): open circuit
- A1P (X19A)
Compressor casing temperature
sensor malfunction (R8T): short circuit
- A1P (X19A)
Compressor casing temperature
sensor malfunction (R9T): open circuit
- A1P (X19A)
Compressor casing temperature
sensor malfunction (R9T): short circuit
- A1P (X19A)
Suction temperature sensor
malfunction (R3T) - A1P (X30A)
De-icing temperature sensor
malfunction (R7T) - A1P (X30A)
Liquid temperature sensor (after
subcool HE) malfunction (R5T) - A1P
(X30A)
Liquid temperature sensor (coil)
malfunction (R4T) - A1P (X30A)
Gas temperature sensor (after subcool
HE) malfunction (R6T) - A1P (X30A)
High pressure sensor malfunction
(S1NPH): open circuit - A1P (X32A)
High pressure sensor malfunction
(S1NPH): short circuit - A1P (X32A)
Low pressure sensor malfunction
(S1NPL): open circuit - A1P (X31A)
Low pressure sensor malfunction
(S1NPL): short circuit - A1P (X31A)
Cause
▪ Open stop valves.
▪ Check refrigerant amount+recharge
unit.
▪ Open stop valves.
▪ Check refrigerant amount+recharge
unit.
▪ Check refrigerant amount+recharge
unit.
▪ Open stop valves.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
VRV IV+ heat pump for high ambient temperatures
Solution
RXYTQ
4P546223-1C – 2021.11