LG Multi V ARWM072CAS5 Service Manual page 144

Self-diagnosis function
Error
Error Type
No.
151*
Function error of outdoor
Master
4way (reversing valve)
1511
n 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
ø
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*****
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
- 144 -
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
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