AC Error Codes · LG
LG AC Error Codes (CH Codes): What They Mean & What to Do
Find your code, understand what it means, then run a guided diagnosis.
Error Code Finder
Look a code up against sourced manufacturer records. Codes we cannot source are not listed — a guessed meaning is worse than no meaning.
LG uses "CH" (check) codes on indoor displays and wired controllers across its split lines. The number range indicates the fault location, which makes even an unfamiliar code partially readable. LG's Multi V (VRF) systems use a separate, purely numeric code architecture — the two must not be mixed up.
How do LG CH error codes work?
LG CH codes are grouped by number range: CH01–CH12 are indoor-side faults, CH21–CH33 are compressor and inverter faults, CH40–CH48 are outdoor sensor faults, and CH51 upward are system and communication faults. The exact meaning of a few codes (CH03, CH04, CH06, CH10) varies between model years and product lines, so the model should be confirmed before acting on those.
Product families covered
-
Residential split / Dual Inverter
CH-prefixed codes on the indoor display or wired controller.
-
Multi V (VRF)
Purely numeric codes; outdoor codes carry a unit-position suffix digit.
Where the code is displayed — and why it matters
The same fault can be labelled differently depending on which display you read it from, so identify the display before looking the code up.
- Indoor unit display
- Residential splits flash the CH code on the front panel display.
- Wired wall controller
- Shows the CH code, and on multi-unit installations often the affected zone.
- Multi V outdoor 7-segment display
- Shows a plain 2–3 digit number — never a CH code. The final digit of a 3-digit reading is the unit position, not part of the fault.
LG CH code number ranges
The range tells you roughly where the fault is before you know the exact code:
- CH01–12
- Indoor-side faults
- CH21–33
- Compressor / inverter faults
- CH40–48
- Outdoor sensor faults
- CH51+
- System / communication faults
How the families differ
- A CH-prefixed code on a wall unit is a split-system code. A plain number on a large outdoor unit is Multi V — the two systems share almost no code meanings.
- Multi V outdoor codes append a position digit: 1 = master, 2 = slave 1, 3 = slave 2, 4 = slave 3. Code 211 is fault 21 on the master unit, not fault 211.
- Multi V codes numbered 200+ belong to the heat-recovery branch controller and centralized-management domain — a different fault category again.
Documented LG split-system codes
LG's CH-code documentation in our research database comes from LG regional support material plus independent technical compilations rather than a single official service PDF — meanings should be verified against your model's service manual before repair decisions. Codes marked as conflicting are also reported on Multi V lines, which is precisely why no single meaning is published.
| Code | What it reports | Applies to | Severity | Source |
|---|---|---|---|---|
| CH01 | Is reported to indicate indoor air temperature sensor fault (short or open circuit) | Split / Dual Inverter | Moderate | C |
| CH03 | Meaning varies by model — no single verified meaning published Reported meanings for CH03 differ between LG residential split, Dual Inverter and Multi V lines and across model years. Our sources disagree, so we publish no single meaning — the unit's model-specific service documentation is the only reliable resolution. | Split / Dual Inverter · Multi V | — | X |
| CH04 | Meaning varies by model — no single verified meaning published CH04 meanings differ across LG product lines and model years in our sources — model-level verification required. | Split / Dual Inverter · Multi V | — | X |
| CH06 | Meaning varies by model — no single verified meaning published CH06 is reported differently across LG lines; LG regional documentation and independent compilations do not agree. | Split / Dual Inverter · Multi V | — | X |
| CH10 | Meaning varies by model — no single verified meaning published CH10 meanings diverge between residential and Multi V documentation in our sources. | Split / Dual Inverter · Multi V | — | X |
LG Multi V (VRF) outdoor base codes
Multi V outdoor displays append a position digit to the base fault number: 1 = master, 2 = slave 1, 3 = slave 2, 4 = slave 3. Example: 211 means fault 21 (high pressure) on the master unit; 213 is the same fault on slave 2.
| Code | What it reports | Applies to | Severity | Source |
|---|---|---|---|---|
| 21 | Indicates high pressure fault | Multi V outdoor | High | B |
| 22 | Indicates low pressure fault | Multi V outdoor | High | B |
| 23 | Indicates compressor overcurrent | Multi V outdoor | High | B |
| 52 | Indicates outdoor-to-outdoor unit communication fault | Multi V outdoor | Moderate | B |
| 53 | Indicates outdoor-to-indoor unit communication fault | Multi V outdoor | Moderate | B |
| 60 | Indicates eEPROM error | Multi V outdoor | Moderate | B |
Before you act on a code
- CH03, CH04, CH06 and CH10 have documented meaning differences between residential split, Dual Inverter and Multi V lines — never act on these codes without confirming the model. We publish the conflict instead of choosing a meaning.
- Multi V codes numbered 200+ belong to the heat-recovery branch controller and centralized-management domain — a different fault category from simple indoor/outdoor faults.
- The remaining CH code table is in technical review against official LG service documentation before publication.
Secondary source only
How to identify your system
- Note the code and whether it shows on the indoor unit display, a wired wall controller, or an outdoor unit 7-segment display.
- A CH-prefixed code on a wall unit is a split-system code; a plain 2–3 digit number on a large outdoor unit is Multi V.
- Photograph the indoor unit's model label — it settles the ambiguous CH codes.
No code showing? Start from the symptom
LG error codes — common questions
What does an LG CH code mean?
CH is LG's 'check' prefix. The number identifies the fault, and its range identifies the area: 01–12 indoor, 21–33 compressor/inverter, 40–48 outdoor sensors, 51+ communication. The unit usually stops or restricts operation while a code is active.
Why do different websites give different meanings for my LG code?
Because a few CH codes genuinely changed meaning between model years and product lines. CH03, CH04, CH06 and CH10 are documented examples. The only reliable resolution is your specific model's service documentation — which is also why we publish no meaning for them rather than guessing.
What does the last digit of an LG Multi V code mean?
On Multi V outdoor displays the trailing digit is the unit position, not part of the fault: 1 = master, 2 = slave 1, 3 = slave 2, 4 = slave 3. Code 211 is high pressure (fault 21) on the master unit.
Need this looked at properly?
Call or send a photo on WhatsApp and we will tell you whether it needs an inspection, and what the work involves, before anyone travels.
Sources consulted
- LG regional support documentation (CH01/CH02/CH06/CH12 on split systems)
- LG Multi V error-code guide, cross-validated against an independent LG VRF compilation
- Multiple independent CH-code technical compilations (flagged: requires model-level verification)