LG aircon CH49 error code
Use this LG CH49 error code guide to decide when to stop resetting, what to capture, and what to check before parts are quoted. Cross-check the exact model because the row is unofficial.
What does LG CH49 mean?
LG CH49 is listed as check power supply voltage to the outdoor unit is correct: 1Ph 220 Vac +/-10% or 3Ph 380 Vac +/-10% in the loaded residential diagnostic rows. The loaded row is unofficial, so do not approve parts from this code alone. Confirm the exact model, series, or signal row before accepting a parts quote.
Indoor or outdoor PCB fault recorded by the source table.
Power supply, connector, fuse, EEPROM, or board-input problem.
Water ingress, surge damage, or wiring issue that must be ruled out before board replacement.
What to do now
Use these steps before another reset or parts quote.
Stop using the unit if CH49 returns
If CH49 returns after one reset, stop repeated restarts and get the matching source row diagnosed.
Reset CH49 once
Capture the CH49 display first, then power-cycle once only and note whether the same fault returns.
Send these to us
CH49 error code, a clear display photo, LG model stickers, affected rooms, reset result, and exact model so the source can be cross-checked
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 | Check power supply voltage to the outdoor unit is correct: 1Ph 220 Vac +/-10% or 3Ph 380 Vac +/-10%. If OK check fuses; if fuses OK, replace outdoor main PCB. |
| Singapore / model note | Unattributed LG fault-code list; confirm against the installed model/service manual before applying. |
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 CH49, take a clear display photo. | Confirm which PCB or board input CH49 points to on the source row. |
| Capture the LG indoor and outdoor model stickers so the correct family row is used. | Check power supply, fuses, connectors, wiring, and board indicators. |
| Treat the code as a starting point and note the exact symptoms because this row is not brand-official yet. | Rule out water ingress, surge damage, and connected component faults before replacing the board. |
What changes the next step
These clues decide whether the first check is room-side, shared outdoor-side, refrigerant-side, source-table, or model-family confirmation.
| What you see | What it points to |
|---|---|
| Only one indoor unit shows CH49. | The affected room, indoor board path, wiring route, or local component should be checked first. |
| Several rooms or the outdoor unit show the same CH49 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 model family is different from the row you found online. | Use the model or series filter first; same-looking codes can still belong to different diagnostic tables. |
| The model belongs to the loaded residential diagnostic rows. | The loaded row is unofficial, so do not approve parts from this code alone. Use the matching source row before quoting parts. |
PCB repair or replacement decision
LG CH49 should not jump straight to board replacement. Confirm power, connectors, wiring, and connected parts before deciding whether PCB repair or replacement is justified.
Power, fuse, connector, and water-ingress checks should happen before board replacement.
Connected motors, sensors, or valves can damage or confuse a PCB diagnosis.
Board availability and system age decide whether replacement is sensible.
LG CH49 questions
What does the LG CH49 error mean?
Can I fix a LG CH49 error myself?
Is it safe to keep running the aircon with a CH49 error?
What causes a LG CH49 error?
Will a LG CH49 error need a repair or a full replacement?
What should I send a technician about a LG CH49 error?
Confirm the fault
Share the error code, model number and symptoms so we can assess the likely cause.
Not the right code?
Browse the full LG list or check a few codes in the same fault category.
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Read next
Use these if the quote mentions the parts, checks, or repair path this code points to.