LG aircon CH49 error code
Use this LG CH49 error code guide to capture the fault correctly and see what should be checked before parts are quoted. Match the model first; some rows are unofficial or mean different things.
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%, master outdoor unit: Outdoor-unit IPM temperature sensor error, and slave 1 outdoor unit: Outdoor-unit IPM temperature sensor error in VRF, Cassette, Ducted rows such as LG Multi V 5 commercial VRF. The loaded rows include mixed source confidence, so the model family decides which row should carry the diagnosis. Do not collapse this code across model families; use the model, series, or system type to choose the right row. Confirm the exact model, series, or signal row before accepting a parts quote.
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 |
|---|---|---|
| CH49 | Check power supply voltage to the outdoor unit is correct: 1Ph 220 Vac +/-10% or 3Ph 380 Vac +/-10%. | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
| LG Multi V 5 commercial VRF — master outdoor unit: Outdoor-unit IPM temperature sensor error | master outdoor unit: Outdoor-unit IPM temperature sensor error | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
| LG Multi V 5 commercial VRF — slave 1 outdoor unit: Outdoor-unit IPM temperature sensor error | slave 1 outdoor unit: Outdoor-unit IPM temperature sensor error | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
| LG Multi V 5 commercial VRF — slave 2 outdoor unit: Outdoor-unit IPM temperature sensor error | slave 2 outdoor unit: Outdoor-unit IPM temperature sensor error | Match this row to the installed model or reporting unit, then use the source-specific checks below. |
What to do now
Use these steps before customer action, a sensor check, or PCB quote.
Stop using the unit if CH49 returns
If CH49 remains displayed or returns during operation, do not attempt an unsourced reset; get the matching source row diagnosed.
No manufacturer reset steps listed for CH49
Capture the complete CH49 display and model stickers first. The selected source row lists no customer reset procedure; do not treat a generic power-cycle as manufacturer guidance.
Send these to us
CH49 error code, a clear display photo, LG model stickers, affected rooms, operating state when the code appeared, when the fault appears, 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 |
|---|---|
| Diagnostic note | 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. |
| Diagnostic note | Record 491 and confirm that the master outdoor unit reported it. Have an authorised LG VRF technician check the named sensor, connector, harness, and service-manual readings before replacing a board. |
| Diagnostic note | Record 492 and confirm that the slave 1 outdoor unit reported it. Have an authorised LG VRF technician check the named sensor, connector, harness, and service-manual readings before replacing a board. |
| Singapore / model note | Unattributed LG fault-code list; confirm against the installed model/service manual before applying. |
| 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. Electrical limits vary by model and supply. Use the installed Singapore supply and model data rather than thresholds from another market. |
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 taking any system action on CH49, take a clear display photo. | Confirm which sensor CH49 maps to on the exact model table. |
| Capture the LG indoor and outdoor model stickers so the correct family row is used. | Measure the sensor value against the service-manual resistance or voltage range. |
| The selected source row lists no customer reset procedure. Note whether one room, several rooms, or the whole system is affected. | Check connector condition, harness continuity, and PCB input before replacing boards. |
Sensor or PCB decision
LG CH49 is usually repair-first if a sensor or harness reading is confirmed. Board replacement should wait until the sensor circuit is tested.
Sensor replacement is usually targeted when resistance or voltage readings are out of range.
Harness or connector damage can look like a sensor fault until continuity is checked.
PCB replacement is a later step if the sensor and wiring test correctly.
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?
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Use these if the quote mentions the parts, checks, or repair path this code points to.