Daikin VRV IV+ RYYQ8U7Y1B Series Installer And User Manual page 156

23 | Troubleshooting
Main code
Master
Installer and user reference guide
156
Sub code
Slave 1 Slave 2
Cause
High pressure switch was
activated (S1PH, S2PH) - A1P
(X2A , X3A)
▪ Refrigerant overcharge
▪ Stop valve closed
Stop valve closed (liquid)
▪ Refrigerant overcharge
▪ Stop valve closed
Low pressure malfunction:
▪ Stop valve closed
▪ Refrigerant shortage
▪ Indoor unit malfunction
Electronic expansion valve
malfunction (main) (Y1E) - A1P
(X21A)
Electronic expansion valve
malfunction (liquid cooling)
(Y3E) - A1P (X23A)
Electronic expansion valve
malfunction (subcool) (Y2E) -
A1P (X22A)
Electronic expansion valve
malfunction (storage vessel)
(Y4E) - A1P (X25A)
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)
Solution
Check stop valve situation or
abnormalities in (field) piping
or airflow over air cooled coil.
▪ Check refrigerant amount
+recharge unit.
▪ Open stop valves
Open liquid stop valve.
▪ Check refrigerant amount
+recharge unit.
▪ Open stop valves.
▪ Open stop valves.
▪ Check refrigerant amount
+recharge unit.
▪ Check the user interface's
display or transmission
wiring between the outdoor
unit and the indoor unit.
Check connection on PCB or
actuator.
Check connection on PCB or
actuator.
Check connection on PCB or
actuator
Check connection on PCB or
actuator
▪ 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.
RYYQ+RYMQ+RXYQ
VRV IV+ heat pump
4P546228-1C – 2021.11