LG Style Codes and Lookalikes
CH Error Code on Air Conditioners
A CH error code air conditioner display almost always belongs to one of two very different situations. On LG systems, CH is a prefix, and the number that follows names a specific fault. On some other brands, CH appears on its own as a reminder or general indicator. This page explains the LG system in detail, then compares how other makers use the same two letters.
Prefix or Message
Is CH a Fault Code or a Reminder?
The answer depends on whether a number comes with it. If your display shows CH followed by digits, such as CH05 or CH38, you almost certainly have an LG system reporting a fault. LG uses CH, short for check, as the start of nearly every split and ducted fault code.
If CH appears alone, with no number, the story changes. On Samsung units, a standalone CH is a status message rather than a fault, either a filter cleaning reminder or a short compressor warm up delay depending on the model. Our Daikin guide notes that some Daikin remotes can show CH as a general indicator, with the real code found through the check function.
So watch the display for a few seconds. LG units often alternate between CH and the number, which means you may see CH for a moment, then the digits. Write down everything that appears before deciding what it means.
How LG Numbers Its Codes
What Do the Numbers After CH Mean on an LG?
LG groups its codes by number range. Once you know the pattern, the number itself tells you roughly where to look. This grouping applies as a general guide to LG residential split and ducted systems, and a few numbers change meaning between generations.
Single digits and tens
- Single digits cover the indoor unit, such as room and coil sensors and indoor to outdoor communication
- CH04 relates to drainage on many indoor units
- The tens cover the indoor fan and inverter power, such as current spikes and compressor start
- Supply voltage that is too high or too low also sits in this range
Thirties to sixties
- The thirties and forties cover refrigerant protection and outdoor sensors
- CH38 is low refrigerant protection
- The fifties cover outdoor side communication
- The sixties cover condenser and heat sink overheating and the outdoor fan
As a rule of thumb, LG sensor codes are usually the least urgent. Inverter, compressor and refrigerant codes deserve prompt attention. Communication codes sit in between, because the cause can be simple or involved.
Common LG Codes
Which LG CH Codes Do Owners See Most?
These are the twelve LG codes we have written detailed pages for. Each meaning is described in general terms for residential LG split systems. Multi split, commercial and much older LG designs may differ, so a technician confirms the meaning against service data for your series.
Indoor sensors and communication
CH01 is the indoor room air sensor. CH02 is the indoor coil inlet pipe sensor. CH05 is lost communication between the indoor and outdoor units.
Fans and inverter
CH10 is the indoor fan motor locked or not turning properly. CH21 is a DC peak current trip in the outdoor inverter. CH26 means the inverter compressor failed to start or rotate.
LG also uses codes outside this list, including CH07 on some multi split systems when two indoor units ask for conflicting modes. If your code is not here, write it down and mention it when booking.
Other Brands
How Do Other Brands Use CH, If at All?
Here is what the documentation shows for the other brands on our list. Only two use CH in a way we could confirm, and neither matches the LG meaning.
Samsung, Confirmed on Some Models
Samsung uses a standalone CH as a status message, not a fault, but the meaning varies by model. Samsung’s own support material describes it on certain models as a filter cleaning reminder. On other models it relates to a compressor warm up delay before the system starts. Check your manual. See the Samsung code library.
Daikin, General Indicator on Some Remotes
On some Daikin remotes, CH acts as a general fault indicator rather than a code of its own. Use the remote check function or the wired controller to find the actual code behind it. See the Daikin code library.
Mitsubishi Electric, Not Confirmed
Mitsubishi Electric uses P, E and U letter groups. We could not confirm any CH meaning. Visit the Mitsubishi code library.
Mitsubishi Heavy Industries, Different Format
MHI codes almost always start with E and a number. There is no confirmed CH code for MHI.
Panasonic, Different Format
Panasonic uses H or F plus two digits. CH is not a Panasonic code we could confirm. Use the remote CHECK routine in the Panasonic code library.
Fujitsu, Different Format
Fujitsu codes are two characters, read from lamps or a wired controller. We could not confirm CH. See the Fujitsu code library.
Actron, Not Confirmed
Actron ducted controllers use E codes, and the WC-02 has its own letter and number set. There is no confirmed Actron CH. See the Actron code library.
Other Makers
Hitachi, Toshiba, Haier, Carrier and others have their own lists. We have not confirmed CH for them, so check the manual or call with the model number.
Reading an LG Display
How Do You Read the Code on an LG Unit?
How the code appears depends on the age and style of the system. Getting it right the first time saves a lot of back and forth.
Watch the indoor display
On units with a numeric display, the screen may alternate between CH and a number. Some show only the number. Watch for several cycles.Note leading zeros
Write the code exactly, such as CH05 rather than CH5. Some displays drop the zero, which is fine, but record what you see.Count flashing lights if there is no screen
Units without a numeric display blink indicator lights in a pattern. Film a full cycle on your phone so the technician can decode it.Check the wired controller
Ducted and cassette systems usually show the code on the wall controller, often with the indoor unit address.Photograph before resetting
A power reset can clear the display. Capture the code first.
Safe Steps
What Can You Safely Do When CH Appears?
The right first step depends on which situation you have. If it is a reminder, a quick clean may be all that is needed. If it is an LG fault code, a few safe checks come before booking.
For a standalone CH message
Give the unit a little time first, since a warm up delay clears on its own. Then switch off, lift the front panel and wash the filters in lukewarm water. Let them dry in the shade, refit them and reset any reminder as your manual describes.
For an LG CH fault code
Photograph the code, then switch off at the remote and the breaker for a few minutes. Clean the filters, clear around the outdoor unit and check the drain outlet. Restore power once only.
- Check the switchboard for a tripped breaker or safety switch, and note whether it trips again.
- Clear leaves, plastic bags and garden growth from the outdoor coil and fan grille.
- Make sure the outside end of the drain hose is not blocked or sitting in a puddle.
- Replace the remote batteries if the display or remote behaves oddly.
If an LG fault code returns straight after a reset, leave the unit off. Repeated restarts can turn a minor electrical fault into a bigger one, particularly with inverter and compressor codes.
Urgency
Which LG CH Codes Need Prompt Attention?
Not every CH code carries the same weight. Here is a general way to prioritise, based on the code ranges described earlier.
Book promptly
Refrigerant codes such as CH38, inverter codes such as CH21 and CH26, and overheating codes such as CH61 and CH62. These can lead to further damage if ignored.
Book soon
Communication codes such as CH05 and fan codes such as CH10 and CH67. They stop the system but rarely cause further harm.
Less urgent
Sensor codes such as CH01, CH02, CH41 and CH44. They still need fixing, but usually do not damage anything else.
Any code accompanied by a burning smell, scorch marks, water near electrics or a repeatedly tripping breaker moves straight to the top of the list. Switch off at the breaker and call.
Licensed Work
Which CH Repairs Need a Licensed Technician?
Almost every LG fault code repair happens behind sealed covers. Inverter boards hold dangerous charge after power is off, and refrigerant work is legally restricted in Australia.
Sensor and wiring tests
Thermistors are measured against LG resistance data, and cables are tested for continuity. The technicians we send hold the electrical licences this work requires.
Refrigerant checks
A low refrigerant code such as CH38 means gauges, leak searching and possibly recharging. Only an ARCtick licensed technician may do this.
Inverter and fan diagnosis
Current trips, compressor start failures and fan locks need meters and an understanding of inverter drives. Boards are replaced only after testing confirms the fault.
Multi Split Homes
Why Might Only One LG Head Show a CH Code?
Many Australian homes have an LG multi split, with one outdoor unit serving two or more indoor heads. In that setup, which heads show the code tells you a lot. A fault on one head often points to that head’s own sensor, fan or wiring. A code on every head points to the outdoor unit or its supply.
LG also uses a mode conflict code on some multi and dual systems. CH07 can appear when one indoor unit is set to heat while another is set to cool, since a single outdoor unit cannot do both at once. Setting every head to the same mode often clears it.
One head affected
Note which room, what mode it was in, and whether the other heads kept running normally.
All heads affected
Check the outdoor isolator and the switchboard first, then note whether the outdoor unit makes any sound.
Open more detail
Wired controllers on ducted and cassette LG systems often show the indoor unit address beside the code. In a larger home or a small business with several units, that address saves the technician a lot of searching.
If your LG system is connected to a Wi-Fi app, the app may also show the code. A screenshot works just as well as a photo of the display.
Before the Visit
What Should You Prepare for an LG Repair?
A few minutes of preparation helps the visit go smoothly. It also lets the technician bring the right test gear and, where possible, the likely part.
- The full CH code, including any leading zero, and a photo of the display.
- The model numbers from the indoor and outdoor compliance labels.
- When the code first appeared and whether it has returned after a reset.
- Any storms, blackouts or electrical work in the days before.
- Clear, safe access to the outdoor unit, and roof access details for ducted systems.
With that information, we can brief the technician before they arrive. That often shortens the diagnosis, especially for intermittent faults.
Local Conditions
How Do Australian Conditions Affect LG Codes?
Long hot spells in Perth and Adelaide push outdoor units hard, which brings out condenser and heat sink overheating codes. A dusty or leaf choked coil makes that worse. Cleaning around the outdoor unit before summer is a simple way to reduce those codes.
Storm season in Brisbane and Sydney brings surges and outages, which can trigger communication and inverter current codes. Coastal homes from the Gold Coast to Fremantle also face salt corrosion on terminals and fins over time.
Meanwhile, Melbourne’s cold mornings put reverse cycle units into regular defrost. That is normal, but it can make owners watch the display more closely and notice codes they might otherwise miss.
Booking
How Do You Book a Technician for a CH Code?
Rapid Air Cooling is a booking service. We take your details, match the job to an independent licensed technician near you, and dispatch them. We are not affiliated with LG or any other maker, and we are not an authorised service agent for any brand.
See the repair page for your city: Sydney, Melbourne, Brisbane, Perth or Adelaide. You can also read about our air conditioning service Australia wide.
We arrange visits for LG wall splits, multi splits, cassettes and ducted systems, as well as most other major brands.
Have the full code, the model number and a photo ready when you call. For flashing light patterns, a short video is ideal.
Questions
Frequently Asked Questions
What does CH stand for on an LG?
CH stands for check. The number that follows identifies the specific fault, such as CH05 for indoor to outdoor communication.
My Samsung shows CH with no number. Is it broken?
Usually not. Depending on the model, a standalone CH is either a filter cleaning reminder or a short warm up delay before the compressor starts. Clean the filters, give the unit some time, and check your manual if it persists.
My Daikin remote shows CH. What now?
On some Daikin remotes, CH is a general indicator. Use the check function or wired controller to read the actual fault code.
Is CH5 the same as CH05 on an LG?
Yes. Some displays drop the leading zero. Both refer to the same communication fault.
Can I clear an LG CH code myself?
A single power reset is safe. If the code returns, the fault is real and needs a licensed technician.
Does CH38 mean I need a regas?
CH38 is low refrigerant protection. A technician must find and fix any leak before recharging, and only an ARCtick licensed technician can do that work.
Do LG portable units use CH codes?
LG notes that portable and window units often use different letter codes. Our pages cover split and ducted systems only.
Related Pages
Where Should You Go Next?
LG Code Still Showing?
Note the full CH number and the model, then call us. We will book a licensed technician in your area.
Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles