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We get the story
What it's doing, when it started, how old the unit is. Half the diagnosis is knowing what changed.
CH05, CH04, CH34 and the rest. What each LG fault code means, which ones you can clear yourself, and the four displays that are not faults at all.
LG Error Codes Explained: A Sydney Technician's Guide
LG Fault Codes
Reading an LG Error Code
The same LG fault can show as C5, CH05 or plain 05 depending on where you read it. It is one code, not three.
LG shows fault codes a few different ways and that trips people up. Wall splits with a display show the code on the unit itself, and older splits shorten it to a C plus one digit, C1 through C9 and CA. Ducted systems, cassettes and multi head units show CH plus two digits on the wired wall controller. The outdoor unit's own circuit board shows just the bare number. So C5, CH05 and 05 are all the same fault.
Some LG wall units without a full display flash the code across two indicator lights instead, one light for the tens digit and one for the ones. Count carefully and write the number down.
Before you assume a fault, check the display is not just showing CL, Po, HL or Lo. Those are settings and modes, not faults. There is a table for them below.
LG's standard reset is worth one go. Switch off both breakers, indoor and outdoor, wait five minutes, then restore them together. A glitch clears. A real fault comes straight back.
We service LG splits, multis and ducted right across Sydney. If your code is not in the list, read it to us on (02) 9820 4500 and tell us what type of system you have, and we will tell you whether it is worth a callout.
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Most Common Codes
The LG Codes We See Most
Top four. The full list is below.
CH05 - units not talking
Indoor and outdoor have lost communication. LG's own advice is check the outdoor breaker, then switch both breakers off for five minutes and restore together. If it returns, the interconnect wiring needs testing.
CH04 - two different faults
On ducted and cassette systems it is the drain pump or float switch, so look for water and switch off if you find any. On older wall splits C4 is a heat sink sensor instead. The ducted version is the urgent one.
CH07 - check your modes first
On multi head systems this just means two rooms are set to different modes. Set every head to the same mode and it clears itself, no callout. On an older single split, C7 is compressor overcurrent, which IS a tech job.
CH34 - high pressure trip
The outdoor unit tripped on high pressure. Nearly always a filthy condenser coil or something crowding the unit. Clean the filters, clear the outdoor unit, restart once. If it comes back, book a tech.
The Full LG Error Code List
LG runs one set of underlying codes but shows them three ways. The table lists the CH form. If your unit shows C5 or a bare 05, read the row for CH05, same fault.
| Code | What it means | What causes it | What to do | Keep running it? |
|---|---|---|---|---|
| CH01 | Indoor air sensor fault | The sensor reading your room temperature is open or short circuit, so the unit cannot tell how warm the room is. | Power off at the breaker for 5 minutes and restart. If it returns, a tech swaps the sensor. | Turn it off |
| CH02 | Indoor coil inlet sensor fault | The pipe sensor on the indoor coil has failed, taking the freeze protection reference with it. | One power cycle. Tech if it returns. | Turn it off |
| CH03 | Wall controller not talking to the unit | The wired controller and indoor unit have lost contact. Cable damage or a failing controller. | Power cycle. Check the controller cable where you can see it. Tech if it returns. | Keep using |
| CH04 (ducted, cassette) | Drain pump or float switch | Condensate is not getting away. Blocked drain, dead pump or a stuck float. Real ceiling risk. | Look for water around the unit. Any water, switch off now and call. Not a DIY fix. | Urgent |
| C4 (older wall splits) | Heat sink sensor fault | Same digits, different fault. On old splits C4 is the sensor on the board's heat sink. | Tech required. | Turn it off |
| CH05 | Indoor and outdoor units not talking | Interconnect wiring damage, a tripped outdoor breaker or a board fault. | LG's own drill: both breakers off 5 minutes, restore together. If it returns, book a tech. | Turn it off |
| CH06 | Coil outlet sensor, or inverter overcurrent on older splits | Two documented meanings depending on the hardware generation. | One power cycle only. Either meaning is a tech job if it returns. | Turn it off |
| CH07 (multi head) | Rooms set to clashing modes | Not a hardware fault. Two heads are asking for different modes at once. | Set every room to the same mode and it clears itself. No callout needed. | Keep using |
| C7 (older single splits) | Compressor overcurrent | Same digits again, very different story. The compressor is drawing too much current. | One restart. If it returns, stop and book a tech. | Turn it off |
| CH08 | Indoor fan not rotating | Jammed fan barrel, choked filters or a failed fan motor. | Power off, check nothing is jammed, wash the filters, restart. | Turn it off |
| CH09 | Outdoor fan (older splits) or board memory error (ducted) | Two documented meanings. On old splits the outdoor fan is stuck, on ducted it is the PCB. | Clear debris off the outdoor fan, power cycle. Tech if it returns. | Turn it off |
| CH10 | Indoor fan motor locked | The indoor fan cannot turn at all. | Power off, check for obstruction, clean filters, restart once. | Turn it off |
| CH21 | Inverter overcurrent | The inverter power module has tripped, often heat or a compressor problem. | Check the outdoor unit can breathe, one restart. Tech if it returns. | Turn it off |
| CH24 | Pressure switch trip | High or low pressure switch has opened. Gas or airflow trouble. | Clean filters and the outdoor coil, restart once. Reading pressures is licensed work. | Turn it off |
| CH25 | Supply voltage out of range | Power to the unit is too low or too high. Sometimes the street supply, sometimes a connection. | Restart once. Note whether lights dim or other appliances play up too. | Turn it off |
| CH26 | Compressor start failure | The inverter cannot get the compressor turning. Can mean a seized compressor. | One restart only, then stop running it. | Turn it off |
| CH32 | Compressor running too hot | Discharge temperature past its limit. Often low gas from a leak, or a smothered outdoor coil. | Clear the outdoor unit, wash filters, restart once. If it returns, book a leak check. | Turn it off |
| CH34 | High pressure trip | Dirty condenser coil, blocked airflow, occasionally an overcharge. | Clean and clear the outdoor unit, restart. Tech if it returns. | Turn it off |
| CH38 (newer models) | Refrigerant shortage | The system thinks it is low on gas, which usually means a leak. LG also lists unstable power as a trigger. | One restart. If it returns, it needs a licensed leak find and regas, not a top up. | Turn it off |
| CH44 | Outdoor air sensor fault | The ambient sensor is open or short circuit. | Power cycle. Tech if it returns. | Keep using |
| CH53 | Comms fault, seen from the outdoor side | Same family as CH05, reported by the outdoor unit. | Same drill as CH05. Both breakers off 5 minutes, restore together. | Turn it off |
| CH54 (three phase) | Missing or reversed phase | A phase problem on three phase ducted supply, common after electrical work. | If it appeared after an electrician visited, call them back. Not DIY territory. | Turn it off |
| CH61 | Outdoor coil overheating | Condenser coil past 65 degrees. Nearly always dirt, leaves or blocked airflow. | Clean filters, clear the outdoor unit, gently hose the fins with the power off. | Turn it off |
| CH62 | Inverter heat sink overheating | The electronics are cooking, usually an airflow problem around the outdoor unit. | Clear around the outdoor unit, restart once. Tech if it returns. | Turn it off |
| CH67 | Outdoor fan locked | Something is stopping the outdoor fan from turning. | Power off, remove debris you can see. Do not reach in. Restart. | Turn it off |
LG displays that are not faults
These four cause a good share of the LG calls we get, and none of them is a breakdown.
| Display | What it actually is | How to clear it |
|---|---|---|
| CL | Child lock is on. The remote and panel are locked, nothing is broken. | Hold the Timer button combination for a few seconds, it varies by model, check your manual. |
| Po | Jet Cool or Power Cooling mode running flat out. It switches itself back after a burst. | Press the Jet Cool or Turbo button again to come out of it. |
| HL | Usually Hard Lock, the unit is being run by a central controller. But on some ducted models HL is the condensate float alarm. | In a centrally controlled building it is normal. If you have no central control, or you can see any water, treat it as a drain alarm and call. |
| Lo | Test or commissioning mode. | It clears when the test run ends. If it sticks around, power cycle and ring your installer. |
A few numbers carry two meanings because LG reused them across generations, CH04, CH06, CH07 and CH09 being the traps. That is why we ask whether you have a wall split, a multi or ducted before we quote anything over the phone.
Safe DIY Checks
What You Can Safely Try First
LG's own troubleshooting starts with the same moves ours does. Work through these before you book anyone. If the code comes back after all four, the table above tells you how urgent it is.
Power both breakers off
Switch off the indoor and outdoor breakers, wait five full minutes, then restore them together. That is LG’s own reset. A one off glitch clears, a real fault comes straight back.
Wash the filters
Choked filters starve the airflow and help throw CH08, CH10 and the pressure codes. Pull them out, rinse, dry properly, refit. Every three months in a Sydney summer.
Clear the outdoor unit
CH34, CH61 and CH62 are mostly a hot, smothered outdoor unit. Clear leaves and rubbish, give it 300mm of breathing room, and hose the fins gently with the power off.
Check it is not a setting
CL is the child lock, Po is jet cool mode, Lo is a test mode. Nothing is broken. The child lock clears by holding the Timer button combo, check your manual for the exact one.
When to Call a Technician
Call a tech when a code comes back after LG's five minute reset and a clean, when it points to refrigerant (CH38), pressure (CH24, CH34), the inverter (CH21, CH26, CH62) or three phase power (CH54), or when there is any water around a ducted unit showing CH04. Refrigerant and inverter work is licensed territory, do not keep resetting through it. We quote before we start, our pricing and costs page shows how that works.
Diagnosis Process
LG Repairs, Done Properly
We do not swap parts on a guess, and with LG reusing code numbers across generations, guessing fits the wrong part. We confirm what system you have, read the fault against the right table, gauge the system if it is gas related, then quote before we start. Servicing every brand across Sydney since 1991. 4.8 stars from 280+ reviews. Call (02) 9820 4500.
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Gauges on, pressures read
Refrigerant pressures tell us straight away if it's a gas problem or something else.
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Electricals and capacitor tested
We check the capacitor, test the fan motors and go over the electricals for anything on the way out.
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Coils and filters checked
Covers come off so we can see the state of the coils and filters, not guess at them.
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Fixed quote before we fix
Once we know the fault, we quote the repair before we start. You decide. Most jobs get done same visit.
Real Jobs
Code Not Listed?
LG runs slightly different code tables across wall splits, multi head and ducted, and the same number can mean different things on different hardware, CH04 and CH07 being the classic traps. Read us the exact display and tell us whether it is a split, multi or ducted on (02) 9820 4500 and we will place the code properly.
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NSW licence 273312C, ARCtick AU13058, $20M public liability, our own techs not subbies. We repair every brand and install Daikin, Panasonic and Actron. Family run since 1991.
FAQ's
LG Error Codes - Common Questions
Look at the indoor unit display or the wired wall controller. Older splits show C plus a digit, newer units and controllers show CH plus two digits, and the outdoor board shows a bare number. All three are the same code. No display at all? Two indicator lights flash the tens and the ones digits.
The indoor and outdoor units have stopped communicating. Check the outdoor breaker has not tripped, then switch both breakers off for five minutes and restore them together. If CH05 comes back it needs the interconnect wiring tested. Do not keep resetting it.
Depends on your system. On ducted and cassette it is the condensate drain pump or float switch, so check for water and switch off if you find any. On older wall splits C4 is a heat sink sensor fault instead. Either way, a code that repeats needs a tech.
No. CL is the child lock and Po is jet cool mode running flat out. HL and Lo are control modes too, though HL on some ducted models can be the drain alarm, so check for water. Hold the timer buttons to release the child lock, or press the jet cool button to come out of Po.
Depends what failed. A sensor is a quick visit, a fan motor or an inverter board is more. We quote the fix before we start, every time. Our pricing and costs page shows what drives the cost.
We do. Jay’s Air Conditioning has serviced every major brand including LG since 1991. NSW licence 273312C, ARCtick AU13058, 4.8 stars from 280+ reviews. Every repair carries 12 months on parts plus our lifetime workmanship guarantee. Ring (02) 9820 4500.
If the unit’s under about 10 years and it’s a capacitor, a fan motor or gas, repair it every time. If it’s 12 years plus, running old R22 gas, and the compressor or board’s gone, a new system’s usually the smarter spend. We’ll give you the honest call, not the dearest one. If you’re weighing up a new system, our sizing guide tells you what you actually need.
Yeah, the lot. Daikin, Mitsubishi, Panasonic, Fujitsu, Actron, LG and the rest. Ducted and split, homes and businesses. We do split system repairs and ducted repairs right across Sydney.
Jay’s Air. Family run since 1991, our own blokes not subbies, fixed pricing and no surprises. Licensed (NSW 273312C), ARCtick certified (AU13058), 4.8 stars from 280+ reviews. Give us a bell on (02) 9820 4500 and we’ll get it sorted.