The short answer
LG mini splits show a fault as a CH code on the display, or on many US heads as blinking lights, where one light counts the tens and the other counts the ones. The ones you’ll see most are CH05, the indoor and outdoor units not talking, CH38, low refrigerant, and CH07, two heads asking for different modes. A CH05 can clear after the breaker is off about 5 minutes. A CH38 means a leak, and that’s a repair, not a reset. Here’s the list, what to try for each, and when to call us in Northern Virginia.
How to read an LG code
If your head has a display, the code shows as CH and a number. If it doesn’t, the code blinks out on two lights. One light counts the tens digit and the other counts the ones, so three blinks on one and eight on the other is CH38. Your owner’s manual shows which light is which on your model. Watch the pattern twice before you write it down, and grab the model number off the label on the side of the head.
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Indoor unit codes
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| Code | What it means | What to do |
|---|---|---|
| CH01, CH02, CH06, CH12 | A temperature sensor in the head | A sensor or board repair |
| CH04 | The float switch tripped: the drain pan is full | Check the drain hose outside. More in mini split leaking water, and on a ceiling cassette, the condensate pump |
| CH05 | The indoor and outdoor units aren’t talking | Breaker off about 5 minutes. If it returns, the wiring between units or a board |
| CH07 | Heads on one outdoor unit are set to different modes | Set every head to the same mode |
| CH09 | The indoor board’s memory | A board repair |
| CH10 | The indoor fan | Turn it off and call |
Outdoor unit codes
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| Code | What it means | What to do |
|---|---|---|
| CH21 to CH29 | Inverter or compressor protection | Turn it off and call |
| CH32 | Compressor discharge running too hot | Call. Often tied to low refrigerant or a blocked coil |
| CH38 | Low refrigerant | Call. Low means a leak |
| CH40 to CH48 | An outdoor temperature sensor | A sensor repair |
| CH53 | A communication fault seen from the outdoor side | Same as CH05: one reset, then call |
| CH60 to CH67 | Outdoor board protections: CH61 is the outdoor coil too hot, CH67 is the outdoor fan locked | Clear leaves and debris from the outdoor unit. If it returns, call |
The three you’ll see most
CH05, communication. The head and the outdoor unit talk over the cable between them. A power blip, a loose wire or a failing board can break that conversation. LG’s first step is to switch the breaker off for about 5 minutes and back on. If CH05 comes right back, the wiring or a board needs testing.
CH38, low refrigerant. Refrigerant doesn’t get used up, so low means it leaked out somewhere. Finding and fixing the leak takes a tech licensed to handle refrigerant. Adding refrigerant without fixing the leak only buys time. Newer systems use R-454B, covered in the R-454B change.
CH07, mode conflict. On a multi zone system, every head shares one outdoor unit, and that unit can’t heat and cool at once. If one head is on cool and another on heat, you get CH07. Set them all to the same mode and it clears.
Normal LG behavior that isn’t a code
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| What you notice | Why it happens |
|---|---|
| Warm air stops in heat mode, and the outdoor unit steams | Defrost. It can take about 15 minutes |
| A click when it starts or stops | The reversing valve switching |
| Creaking | Plastic parts growing and shrinking with temperature |
| A sound like running water | Refrigerant moving through the lines |
| The fan keeps going after you turn it off | Auto clean drying the coil |
Sounds that aren’t on that list are covered in mini split making noise.
One reset, not ten. Turn the head off with the remote, switch the breaker off for about 5 minutes, then turn it back on. If the same code comes back, write it down with the model number from the label and call. Resetting a fault over and over can hide what it was protecting.
Brand by brand: Mitsubishi, Carrier, Daikin, Fujitsu, Samsung and MrCool, Pioneer, Gree and Senville. Every code family we’ve written up is on our error codes and warning lights page.
Book it
A mini split visit starts with our $99 diagnostic, and you get the repair price in writing before anything is opened. Call (703) 997-9757 or book a visit online and tell us the brand and the code or what you’re seeing. Rated 5.0 stars across 1,138 reviews on Google, Angi, Yelp, the BBB and Facebook, Virginia Class A license 2705192276.
Mitsubishi Electric, Carrier, Daikin, Fujitsu, LG, Samsung, MrCool, Pioneer, Gree and Senville are trademarks of their owners.
Questions people ask
What does CH05 mean on an LG mini split?
The indoor and outdoor units aren’t communicating. Turn the breaker off for about 5 minutes and back on. If it returns, the wiring or a board needs testing.
What does CH38 mean on an LG mini split?
Low refrigerant, which means a leak. A tech licensed to handle refrigerant has to find and fix the leak before the system is recharged.
What does CH07 mean on an LG mini split?
On a multi zone system, the heads are set to different modes. Set every head on that outdoor unit to the same mode.
Why are the lights blinking on my LG mini split?
Many US heads blink out the CH code instead of showing it. One light counts the tens and the other the ones, so three and eight is CH38.
Why does my LG mini split keep running after I turn it off?
Auto clean runs the fan for a while after shutoff to dry the coil. That’s normal.
