LG Multi V 5 commercial VRF aircon CH105 error code
Use this LG Multi V 5 commercial VRF CH105 error code guide to decide when to stop resetting, what to capture, and what to check before parts are quoted. Read the final display digit: 1 identifies the master, 2 slave 1, and 3 slave 2.
What does LG CH105 mean?
LG Multi V 5 commercial VRF CH105 is listed as master outdoor unit: Communication error between the fan PCB and inverter-compressor PCB, slave 1 outdoor unit: Communication error between the fan PCB and inverter-compressor PCB, and slave 2 outdoor unit: Communication error between the fan PCB and inverter-compressor PCB in VRF, Cassette, Ducted rows such as LG Multi V 5 commercial VRF. The loaded row is source-backed by official diagnostic material. Use the complete display code and its final digit - 1 for master, 2 for slave 1, or 3 for slave 2 - to choose the reporting outdoor frame before parts are quoted. Confirm the complete display code and whether its final digit identifies the master, slave 1, or slave 2 outdoor frame before accepting a parts quote.
Loose, corroded, crossed, or damaged indoor-outdoor signal wiring.
Terminal block, connector, or junction fault on the indoor or outdoor side.
Indoor or outdoor PCB communication circuit fault after wiring is proven sound.
Choose the matching source row
The same visible code has more than one source-backed meaning. Match the model family, system type, or reporting unit before approving parts.
| Code | What it means | What to check first |
|---|---|---|
| 1051 | master outdoor unit: Communication error between the fan PCB and inverter-compressor PCB | Use the complete 1051 display for the master outdoor unit source row. |
| 1052 | slave 1 outdoor unit: Communication error between the fan PCB and inverter-compressor PCB | Use the complete 1052 display for the slave 1 outdoor unit source row. |
| 1053 | slave 2 outdoor unit: Communication error between the fan PCB and inverter-compressor PCB | Use the complete 1053 display for the slave 2 outdoor unit source row. |
What to do now
Use these steps before another reset, signal-wire check, or PCB quote.
Treat it as a fault signal
If CH105 returns or cooling is still abnormal, stop treating it as a simple reset issue.
Reset CH105 once
Capture the CH105 display first, then power-cycle once only and note whether the same fault returns.
Send these to us
CH105 error code, a clear display photo, LG Multi V 5 commercial VRF model stickers, affected rooms, reset result, and whether one room or every room failed
Source-specific guidance
These diagnostic-reference notes help match the code to the exact model. Electrical, refrigerant, wiring, resistance, and component checks are technician work, not DIY steps.
| Source detail | What it says |
|---|---|
| Source repair action | Record 1051 and confirm that the master outdoor unit reported it. Have the technician trace the applicable communication wiring, plugs, addressing, and board communication path before replacing PCBs. |
| Source repair action | Record 1052 and confirm that the slave 1 outdoor unit reported it. Have the technician trace the applicable communication wiring, plugs, addressing, and board communication path before replacing PCBs. |
| Source repair action | Record 1053 and confirm that the slave 2 outdoor unit reported it. Have the technician trace the applicable communication wiring, plugs, addressing, and board communication path before replacing PCBs. |
| Singapore / model note | LG Singapore lists Multi V 5, but the installed unit nameplate and matching service manual control. Do not apply this row to Multi V i or another LG family. Public guidance intentionally omits market-specific electrical thresholds; use the installed Singapore supply and model data. |
What to check before repair
Use this split to separate safe evidence capture from the tests a technician should prove before quoting parts.
| You can check | Technician should confirm |
|---|---|
| Before resetting CH105, take a clear display photo. | Match CH105 against the exact model-family source row before quoting parts. |
| Capture the LG Multi V 5 commercial VRF indoor and outdoor model stickers so the correct family row is used. | Test communication terminals, cable continuity, polarity, and outdoor power. |
| Note whether one room, several rooms, or the whole system is affected, plus whether it returns after one reset. | Read indoor and outdoor PCB indicators only after the signal path is proven sound. |
What changes the next step
These clues decide whether the first check belongs to the master, slave 1, or slave 2 outdoor frame identified by the final display digit.
| What you see | What it points to |
|---|---|
| Only one indoor unit shows CH105. | The affected room, indoor board path, wiring route, or local component should be checked first. |
| Several rooms or the outdoor unit show the same CH105 fault. | The shared outdoor side, power path, communication trunk, or refrigerant circuit needs priority checking. |
| The fault returns immediately after one reset. | Start with the source-row diagnostic branch before approving parts. |
| The final display digit identifies the master, slave 1, or slave 2 outdoor frame. | Match 1 to master, 2 to slave 1, or 3 to slave 2 before checking the shared fault path. |
| The model belongs to VRF, Cassette, Ducted rows such as LG Multi V 5 commercial VRF. | The loaded row is source-backed by official diagnostic material. Use the matching source row before quoting parts. |
Wiring or PCB decision
LG Multi V 5 commercial VRF CH105 should start with terminal, signal-cable, and power checks. PCB replacement only makes sense after the communication path is proven sound.
A loose terminal or bad junction is a targeted repair once the path is confirmed.
Signal-wire replacement depends mostly on access through trunking, ceiling, or concealed routes.
PCB cost should be weighed against age only after wiring and power checks pass.
LG CH105 questions
What does the LG CH105 error mean?
Can I fix a LG CH105 error myself?
Is it safe to keep running the aircon with a CH105 error?
What causes a LG CH105 error?
Will a LG CH105 error need a repair or a full replacement?
What should I send a technician about a LG CH105 error?
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