LG CH01, CH02, CH06 and CH12: the codes LG calls a sensor problem
LG groups CH01, CH02, CH06, CH12 and the CH41 to CH48 range as a sensor problem. See what that grouping does and does not tell you about your unit.
What this means
LG's own help-library article does not give these codes one meaning each. It places CH01, CH02, CH06, CH12, the CH41 to CH48 range, E1 to E3, E7, E8, F2 and F3 in a single category described as a problem with a sensor. The practical consequence is that the code identifies which sensing input is unhappy, while LG's published customer guidance stops at the category.
Equipment and model context
LG residential air conditioners covered by the United States help-library article that groups these codes as sensor problems
- LG single-split wall units
- LG multi-split indoor units
- LG art cool wall units
The grouping quoted here is LG's United States help-library guidance for residential air conditioners. LG multi-split and commercial equipment publish fuller per-code tables in their service literature, and LG documentation varies by region and by generation, so a code on a commercial LG system is read from that system's own manual.
What you may notice
- The indoor display alternates a two-character code with the set temperature, and cooling or heating has stopped or become unreliable.
- The displayed room temperature disagrees with the room, or it no longer tracks changes in conditions.
- One indoor unit on a multi-split system carries the code while the other rooms behave normally.
Likely causes
- A sensing element can fail open or short, which puts the resistance it returns outside the range the control will act on.
- A connector at the indoor board can work loose over time, or after panel access, and present the same electrical picture as a failed element.
- Moisture, corrosion, or insect ingress across sensor terminals changes the resistance without any element failing.
Diagnostic paths
One power interruption clears it and it does not return
Following LG's stated step of removing power for about five minutes, the unit restarts and operates normally over the following days with no code.
Note the date and treat it as a recorded event. LG's guidance allows this single interruption, and an isolated occurrence that does not repeat needs no further action beyond watching for it.
The same code returns after the reset
The code reappears within minutes, hours, or on the next cycle after the power interruption LG describes has been carried out once.
Stop using the unit and request service. LG's own instruction is to stop using the product and request service when the same code appears again after a reset.
The fault moves between codes in the same group
Different codes from the sensor group appear on different days rather than one code repeating consistently.
Write down each code with its date. A wandering fault within one group points at something shared, such as a harness or a board, rather than at one element.
LG splits its codes into two categories for the home customer, and the split is the useful part. One group is sensing, the other is the outdoor compressor or circuit board, and the reset advice is the same for both.
- Sensor groupCH01, CH02, CH06, CH12 and others
- Compressor groupCH21, CH23, CH26, CH29 and E9
- One resetAbout five minutes without power
- Same ruleIf it returns, stop and request service
| Question | LG's published answer | Where the rest lives |
|---|---|---|
| Is it a sensor? | Yes, for this group of codes | Stated in the help-library article |
| Which sensor? | Not stated for the home customer | Model service literature |
| Can I reset it? | One interruption of about five minutes | Stated in the help-library article |
| What if it returns? | Stop using it and request service | Stated in the help-library article |
Why a manufacturer would publish a category rather than a list
It looks unhelpful at first. A reader with CH02 on the display wants to know which sensor, and LG answers with a category. There is a defensible reason for it. A per-code component list published to homeowners invites two behaviours the manufacturer would rather avoid: ordering parts from a code, and opening an indoor unit to reach them. Neither is safe and neither is reliable, because the same code can be raised by a connector, a harness, or an element.
That said, the category is not empty. Knowing the fault is on the sensing side rather than the compressor side tells you the outdoor unit is probably not in trouble, that the repair is likely to be in the indoor casing, and that the fault will not resolve by running the system harder. That is genuine information, and it is more than many code charts on the open web can honestly claim.
Use the reset once, then use your eyes
LG's published step is specific: remove power at the plug or the breaker, wait about five minutes, restore it, and see whether the code has cleared. That is a legitimate test because a transient can leave a latched code behind. LG then draws the line just as plainly, instructing the owner to stop using the product if the same code appears again, which is an unusually direct statement from a manufacturer and worth following.
Between the reset and the service visit, the useful work is observation. Which code, on which date, on which indoor unit, and whether the displayed room temperature had been drifting beforehand. The thermistor definition explains what a sensing element does and why its resistance matters, and the mini-split reset guide covers how to interrupt power safely.
What to give the technician
Provide the indoor and outdoor model numbers, the exact code characters, the dates each code appeared, whether one reset cleared it, and the displayed against measured room temperature.
Safe homeowner checks
- Write the code down exactly as shown, since a zero and a letter O are easy to confuse on a small indoor display.
- Carry out the single power interruption LG describes, at the plug or the breaker, and wait about five minutes before restoring supply.
- Compare the displayed room temperature with a separate thermometer and record both figures before the reset.
Is a reset appropriate?
LG permits exactly one interruption of about five minutes at the plug or the breaker. Repeating it after the code returns is contrary to LG's own published instruction to stop using the product.
When to call a technician
- LG instructs the owner not to disassemble the air conditioner or replace internal parts, and warns that doing so may cause fire, electric shock, or serious injury.
- If the same code appears again after one reset, LG's stated instruction is to stop using the product and request service to prevent further damage.
Questions people ask about this
Which sensor does LG CH02 refer to?
LG's home-customer article does not name a component for each code in this group. It states that the codes indicate a problem with a sensor, and the component-level detail sits in the service literature for the specific model.
How long should I leave an LG air conditioner unplugged?
LG's stated step is to remove power at the plug or the breaker, wait about five minutes, and then restore it. That interval is what the published guidance gives, and it is intended as a single attempt.
Is CH01 more serious than CH21?
LG places them in different groups: CH01 among the sensor codes and CH21 among the outdoor compressor and circuit board codes. The reset advice is the same, but the second group concerns the outdoor unit rather than sensing.
Evidence recordHow this page was checked
official manufacturer support article · checked 2026-09-15
Every technical claim above was written from primary documentation held in the HVAC Bench evidence record: LG Electronics technical literature. Where a source limits a definition to certain models, test conditions, or product classes, that limit is repeated here rather than generalised.
- Documentation class
- official manufacturer support article
- Scope of the definition
- LG residential air conditioners covered by the United States help-library article that groups these codes as sensor problems
- Last checked
- 2026-09-15