LG R410A Service Manual page 181

Error
Error Contents
Code
Outdoor 4way
(reversing valve)
151
Switching Error
I Defect inspection method
1) Check whether the piping between the outdoor units is normal
(liquid pipe should be connected to liquid pipe, common pipe be connected to common pipe ) fi Pipe modifica-
tion
2) Check whether the Main/Sub outdoor compressor is damaged or not.(Refer to CH21)
3) Please confirm the Main PCB's 4way valve terminal voltage (220V±10%).
In case of abnormal voltage please replace the outdoor main PCB
4) Check the outdoor PCB's 4way valve connector connections and coil connections.
5) Measure the 4way valve's coil resistance at the connector
Normal resistance :
6) In case the error still persists even after the all above conditions are normal then replace the 4way valve .
Meaning
When the Main or the Sub
outdoor has one of them
having a 4way valve error
Main Causes
1. 4 way valve error due to the inlet of
sludge into the valve
2. Comp damage leading to pressure
change does not occur ,
3. Wrong installation of common pipe
between the outdoor units
4. 4way valve error
Troubleshooting Guide
Error display
position
Concerned
Remote
Controller
Outdoor unit
Service Manual 181