LG ARUN Series Service Manual page 130

Troubleshooting Guide
Error
Error Type
No.
151*
Master
Function error of outdoor
11¡511
4way (reversing valve)
Slave
12¡512
I Error diagnosis and countermeasure flow chart
Is 4-Way valve connecter
connection are properly
connected?
Yes
Is 4 Way valve coil
resistance normal?*
Yes
Is 4 way valve coil connected
to 4 way valve normally?**
Yes
In case of more than
2 units, does master outdoor
unit recognize as more
øπ
than 2 units? ***
Yes
After reset, can we
check supply voltage at PCB
when starting heating
mode operation****
Yes
Is compressor working
normally?
Yes
After opposite
mode operation to present
mode, is the same error
occurred again?
Yes
Replace 4 way valve*****
Copyright ©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Error Point
Function error of 4way
(reversing valve) in Main or
Slave outdoor units
No
Reconnect it
No
Change 4 Way valve coil
No
Re-insert 4 way valve coil
No
Refer to CH 51 & make measure
No
Replace outdoor unit PCB
Check and replace compressor,
No
Magnet switch, corresponding PCB
[refer electric component part]
No
If the same error is occurred in
near future replace 4way valve
- 130 -
Main Reasons
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
LGE Internal Use Only