On the covered LG air conditioner, CH 05, E0, CH 53 means a communication error between the indoor and outdoor units of inverter air conditioners — LG's own wording. First, note whether the error started shortly after installation or relocation.
Try in this order
0 of 8 completedWhat to do first
ReversibleNote whether the error started shortly after installation or relocation.
Correct only the documented fault domain
ReversiblePower-cycle the unit; If the code appeared shortly after installation or relocation, LG directs you to the installing technician rather than to general service..
Reset both breakers together
ReversibleTurn off the indoor unit's breaker as well as the outdoor one for 5 minutes, then switch both back on at once.
Check the connecting wires
ReversibleThe most common cause is a loose, damaged or mismatched communication wire between the units. A tripped breaker, a blown fuse or a bad socket on the outdoor unit gives the same code.
Reset both breakers together
ReversibleTurn off the indoor and outdoor breakers for five minutes and turn them on at the same time so both boards start together.
Check the outdoor unit's supply
ReversibleA tripped breaker, a blown fuse or a loose socket at the outdoor unit gives the same code, so check the supply before suspecting the wiring.
Think about recent storms or work
ReversibleIf the code began after a storm, a power cut or work on the building, mention that to the technician, since it points to a tripped supply or a disturbed wire.
Book the installer
ReversibleIf the code stays after a clean restart, the communication wire or a board needs checking.
Evidence ledger
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Exact questions
Common questions about “LG air conditioner code CH 05, E0, CH 53”
What does CH 05, E0, CH 53 mean on a LG air conditioner?+
a communication error between the indoor and outdoor units of inverter air conditioners — LG's own wording.
How long before LG shows CH05?+
The code shows when the indoor board has received no signal from the outdoor board for about two minutes.
Why does my LG mini-split show CH05 after a storm?+
A tripped outdoor breaker or blown fuse after a storm leaves the indoor unit without a signal; reset both breakers together first.
Is CH05 the same as E0 on LG?+
They are the same communication alert, shown as CH05 or E0 depending on the model.
How is CH05 different from CH93 on an LG air conditioner?+
Both describe a communication fault between indoor and outdoor units, but LG lists them for different model families, so read the code against your model and use the page that matches it.
Should I keep restarting the system if CH05 returns?+
No. One restart of both breakers is reasonable, and a code that returns means a wire, a fuse or a board needs checking, which is the installer's job.
What if CH05 or E0 appears after the air conditioner has been moved?+
Moving the unit can disturb the communication wire or its connections. Tell the installer, because the line needs to be checked and re-fixed properly.
Can I run an LG split system while it shows CH05?+
The units cannot coordinate, so the system will not run normally. Turn it off and have it checked rather than restarting it repeatedly.