Troubleshooting Guide
- 89 -
Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
1. Wrong operation of 4way valve because of sludge
etc. inflow
2. No pressure difference because of compressor
fault
3. Wrong installation of In/outdoor common pipe
4. Defect of 4way valve
Error
No.
Error Type
Error Point
Main Reasons
Function error of 4way
(reversing valve) in Main or
Slave Compressor module
Function error of outdoor
4way (reversing valve)
1511
n
Error diagnosis and countermeasure flow chart
Is 4-Way valve connecter
connection are properly
connected?
No
Reconnect it
After reset, can we
check supply voltage at PCB
when starting heating
mode operation****
No
Is 4 way valve coil connected
to 4 way valve normally?**
ø
No
Is 4 Way valve coil
resistance normal?*
Change 4 Way valve coil
No
Yes
Refer to CH 51 & make measure
Yes
Is compressor working
normally?
No
Check and replace compressor,
Magnet switch, corresponding PCB
[refer electric component part]
Yes
Re-insert 4 way valve coil
Replace Compressor module PCB
Yes
Yes
No
Replace 4 way valve*****
After opposite
mode operation to present
mode, is the same error
occurred again?
If the same error is occurred in
near future replace 4way valve
Yes
Yes
No
In case of more than 2
units, does master Compressor
module recognize as more than 2
units? ***
