LG Aircon CH23 Error Code & Blinking Light
Capture the LG CH23 fault correctly, then see what should be checked before parts are quoted. Match the model first; same-looking signals can point to different rows.
What does LG CH23 mean?
LG CH23 is listed as DC link low voltage, DC link voltage too low, and master outdoor unit: Inverter-compressor DC-link low-voltage fault in Wall-Mounted Split, VRF, Cassette rows such as HSV4 / HSV5 single-zone wall-mounted systems, LS091HSV / LS121HSV wall-mounted single-zone. This meaning comes from the manufacturer's own diagnostic material. 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 listing that matches your unit
The same code has more than one listed meaning. Match the model family, the system type and the unit that shows the code before approving parts.
| Code | What it means | What to check first |
|---|---|---|
| HSV4 / HSV5 single-zone wall-mounted systems | DC link low voltage | Match this meaning to your installed model and the unit that shows the code, then use the checks below. |
| LS091HSV / LS121HSV wall-mounted single-zone | DC link voltage too low | Match this meaning to your installed model and the unit that shows the code, then use the checks below. |
| LG Multi V 5 commercial VRF — master outdoor unit: Inverter-compressor DC-link low-voltage fault | master outdoor unit: Inverter-compressor DC-link low-voltage fault | Match this meaning to your installed model and the unit that shows the code, then use the checks below. |
| LG Multi V 5 commercial VRF — slave 1 outdoor unit: Inverter-compressor DC-link low-voltage fault | slave 1 outdoor unit: Inverter-compressor DC-link low-voltage fault | Match this meaning to your installed model and the unit that shows the code, then use the checks below. |
| LG Multi V 5 commercial VRF — slave 2 outdoor unit: Inverter-compressor DC-link low-voltage fault | slave 2 outdoor unit: Inverter-compressor DC-link low-voltage fault | Match this meaning to your installed model and the unit that shows the code, then use the checks below. |
- Code
- HSV4 / HSV5 single-zone wall-mounted systems
- What it means
- DC link low voltage
- What to check first
- Match this meaning to your installed model and the unit that shows the code, then use the checks below.
- Code
- LS091HSV / LS121HSV wall-mounted single-zone
- What it means
- DC link voltage too low
- What to check first
- Match this meaning to your installed model and the unit that shows the code, then use the checks below.
- Code
- LG Multi V 5 commercial VRF — master outdoor unit: Inverter-compressor DC-link low-voltage fault
- What it means
- master outdoor unit: Inverter-compressor DC-link low-voltage fault
- What to check first
- Match this meaning to your installed model and the unit that shows the code, then use the checks below.
- Code
- LG Multi V 5 commercial VRF — slave 1 outdoor unit: Inverter-compressor DC-link low-voltage fault
- What it means
- slave 1 outdoor unit: Inverter-compressor DC-link low-voltage fault
- What to check first
- Match this meaning to your installed model and the unit that shows the code, then use the checks below.
- Code
- LG Multi V 5 commercial VRF — slave 2 outdoor unit: Inverter-compressor DC-link low-voltage fault
- What it means
- slave 2 outdoor unit: Inverter-compressor DC-link low-voltage fault
- What to check first
- Match this meaning to your installed model and the unit that shows the code, then use the checks below.
What to do now
Use these steps before customer action or a parts quote.
Stop using the unit if CH23 returns
If CH23 remains displayed or returns during operation, do not attempt a reset the manufacturer does not list; arrange diagnosis.
No manufacturer reset steps listed for CH23
Capture the complete CH23 pattern and model stickers first. The manufacturer lists no customer reset procedure; do not treat a generic power-cycle as manufacturer guidance.
Send these to us
CH23 error code and blinking light, a clear display photo and blinking-light video if the unit shows one, LG model stickers, affected rooms, and operating state when the code appeared
Guidance for your model
Notes that match the code to your exact model. Electrical, refrigerant, wiring, resistance and component checks are for a technician.
| Detail | What it says |
|---|---|
| Diagnostic note | Check power stability and arrange outdoor inverter PCB diagnosis if CH23 returns after reset. |
| Diagnostic note | Record the exact code and LED blink pattern before booking diagnosis. For LS091HSV / LS121HSV systems, this pattern points to: DC link voltage too low |
| Diagnostic note | Record 231 and confirm that the master outdoor unit reported it. Isolate the system through a qualified technician and verify the relevant supply, wiring, inverter, PCB, and compressor path against the installed model manual. |
| Singapore / model note | Official LG HVAC HSV4 / HSV5 wall-mounted self-diagnosis table. Use this row only for matching single-zone wall-mounted systems. |
| Singapore / model note | Use this LS091HSV / LS121HSV LED table only when the installed model or service manual matches this standard wall-mounted single-zone family. |
| 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. |
- Detail
- Diagnostic note
- What it says
- Check power stability and arrange outdoor inverter PCB diagnosis if CH23 returns after reset.
- Detail
- Diagnostic note
- What it says
- Record the exact code and LED blink pattern before booking diagnosis. For LS091HSV / LS121HSV systems, this pattern points to: DC link voltage too low
- Detail
- Diagnostic note
- What it says
- Record 231 and confirm that the master outdoor unit reported it. Isolate the system through a qualified technician and verify the relevant supply, wiring, inverter, PCB, and compressor path against the installed model manual.
- Detail
- Singapore / model note
- What it says
- Official LG HVAC HSV4 / HSV5 wall-mounted self-diagnosis table. Use this row only for matching single-zone wall-mounted systems.
- Detail
- Singapore / model note
- What it says
- Use this LS091HSV / LS121HSV LED table only when the installed model or service manual matches this standard wall-mounted single-zone family.
- Detail
- Singapore / model note
- What it says
- 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 CH23, take a clear display photo and blinking-light video if the unit shows one. | Confirm which PCB or board input CH23 points to for your model. |
| Capture the LG indoor and outdoor model stickers so the correct family row is used. | Check power supply, fuses, connectors, wiring, and board indicators. |
| The manufacturer lists no customer reset procedure for this code. Note whether one room, several rooms, or the whole system is affected. | Rule out water ingress, surge damage, and connected component faults before replacing the board. |
- You can check
- Before taking any system action on CH23, take a clear display photo and blinking-light video if the unit shows one.
- Technician should confirm
- Confirm which PCB or board input CH23 points to for your model.
- You can check
- Capture the LG indoor and outdoor model stickers so the correct family row is used.
- Technician should confirm
- Check power supply, fuses, connectors, wiring, and board indicators.
- You can check
- The manufacturer lists no customer reset procedure for this code. Note whether one room, several rooms, or the whole system is affected.
- Technician should confirm
- Rule out water ingress, surge damage, and connected component faults before replacing the board.
PCB repair or replacement decision
LG CH23 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 CH23 questions
What does the LG CH23 error mean?
Can I fix a LG CH23 error myself?
Is it safe to keep running the aircon with a CH23 error?
What causes a LG CH23 error?
Will a LG CH23 error need a repair or a full replacement?
What should I send a technician about a LG CH23 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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Use these if the quote mentions the parts, checks, or repair path this code points to.