LG Troubleshooting Guide
LG Air Conditioner Not Cooling
An LG air conditioner not cooling on a hot afternoon is frustrating, but the cause is often simple. This guide walks through what the symptom looks like, the reasons behind it from the easy fixes to the serious faults, and the checks you can safely make before calling anyone. It applies to LG Dualcool, Artcool and ducted systems in homes right across Australia.
Spotting the Symptom
What Does Poor Cooling Look Like on an LG Unit?
Weak cooling rarely arrives all at once. More often, an LG split system slowly loses its edge over a few weeks. The room takes longer to settle, the unit runs for hours without pausing, and the air from the louvres feels cool rather than cold.
Sometimes the change is sudden instead. The fan keeps blowing, yet the air is the same temperature as the room. In other cases, the indoor unit shows a CH code and stops altogether. Each pattern points to a different group of causes, so it helps to note exactly what you are seeing.
Air Is Cool but Not Cold
The system works, but it struggles to reach the set temperature. This usually suggests restricted airflow, a dirty coil or a gradual loss of refrigerant.
Fan Runs With Room Air Only
The indoor fan spins while the outdoor unit stays silent. In that case, the compressor is not starting, which points to power, communication or protection faults.
Unit Stops and Shows a Code
LG indoor displays show CH followed by a number when a sensor or protection trips. That code is the most useful clue you have, so write it down.
Before going further, confirm the remote is in cool mode, shown by a snowflake symbol on most LG remotes. A unit left in fan, dry or auto mode can feel like it has stopped cooling when nothing is actually wrong.
Causes, Simple to Serious
Why Is My LG Air Conditioner Not Cooling Properly?
We have ranked the common causes from the easiest to fix to the most involved. Start at the top, because most cooling complaints are solved in the first few items. If you reach the lower half of the list, it is time for a licensed technician.
1. Settings, Timers and Modes
A low battery remote, a sleep timer or a ThinQ app schedule can quietly change settings. Energy saving features on some LG models also cap compressor output. Check the mode, the set point and any active timers first.
2. Clogged Filters
LG wall splits pull air through mesh filters behind the front panel. When those filters fill with dust and lint, airflow drops sharply. As a result, the coil cannot pass heat to the air efficiently and cooling suffers.
3. Blocked or Overheated Outdoor Unit
The outdoor unit must shed the heat removed from your home. Overgrown plants, stored boxes or a unit sitting in full afternoon sun all reduce its ability to do that. Consequently, the system protects itself by slowing down.
4. Dirty Indoor Coil or Fan Barrel
Even with clean filters, fine dust and mould build up on the evaporator fins and the barrel shaped fan. This layer insulates the coil and restricts airflow. A deep clean is the only real fix.
5. Faulty Sensors
LG units rely on thermistors to read room and coil temperatures. If one drifts or fails, the board may think the room is already cold and throttle back. Sensor faults often trigger CH01 or CH02.
6. Low Refrigerant From a Leak
Refrigerant does not wear out. Therefore, a low charge means a leak somewhere, often at a flare joint or a corroded coil. LG systems may report this as CH38, and ice can form on the pipes.
7. Fan Motor, Board or Compressor Failure
The most serious causes involve the outdoor fan motor, the inverter board or the dual inverter compressor itself. These need professional diagnosis, and they usually come with a specific CH code.
Owner Checks
What Can I Safely Check Before Calling a Technician?
These checks need no tools and carry no risk. Work through them in order, and give the system time to respond between each one. For a broader walkthrough, our guide on resetting common faults yourself covers the basics in more depth.
Confirm the Mode and Set Point
Choose cool mode and set the temperature a few degrees below the room. Switch off Jet Cool, energy control and sleep features while you test.Replace the Remote Batteries
Weak batteries cause missed commands. Fresh batteries also rule out a remote that only half sends its signal.Power Cycle the System
Turn the unit off, then switch off its circuit breaker for a few minutes. Restore power and wait at least three minutes, because LG compressors use a restart delay.Wash the Filters
Lift the front panel, slide out the filters and rinse them in lukewarm water. Let them dry completely in the shade before refitting.Clear Around the Outdoor Unit
Remove leaves, plants and stored items from around the outdoor unit. Aim for open space on all sides, and never cover the top.Listen and Look at the Outdoor Unit
With cooling running, check whether the outdoor fan spins and the compressor hums. Do not open any panels or touch the pipes.
If cooling returns after these steps, keep an eye on it for a few days. However, if the same problem comes back quickly, there is likely an underlying fault that needs a technician.
LG Features
Could an LG Feature Be Making It Seem Like a Fault?
LG builds several comfort and efficiency features into its split systems. They are useful, yet they occasionally make a healthy unit look like it is failing. Knowing how they behave can save you an unnecessary call out.
Dual Inverter Ramping
LG’s dual inverter compressor speeds up and slows down rather than switching hard on and off. Once the room nears the set point, output drops to a gentle hum. That quieter phase is normal, not a loss of cooling.
Auto Clean Drying
Many LG models run the indoor fan for a while after you switch off, drying the coil to limit mould. Air from the unit during this time is not cold, because the compressor has already stopped.
Energy Control Settings
Some LG remotes and the ThinQ app offer an energy control option that limits power draw. With it active, the system cools more slowly on very hot days. Turn it off to see if performance improves.
App Schedules and Smart Modes
A schedule set months ago in the ThinQ app can still switch modes or temperatures. Similarly, a family member may have adjusted settings remotely. Review the app before assuming a fault.
LG also offers a Smart Diagnosis feature on many models, either through the ThinQ app or by holding a phone near the unit. It can help identify issues, although a technician will still need to confirm any repair.
Climate and Season
Does the Australian Climate Make LG Cooling Problems Worse?
Yes, quite often. Most LG cooling complaints arrive during the first heatwave of summer, when units that sat idle all winter suddenly run flat out. Each of our major cities adds its own pressure on top of that.
Heat and Humidity
- Brisbane’s long, sticky summers keep coils wet and encourage mould growth
- Sydney’s humid nights make units work hard to remove moisture as well as heat
- Perth’s dry heat pushes outdoor units close to their protection limits on scorching afternoons
- Adelaide’s run of extreme days in summer stresses older compressors and fan motors
Salt, Dust and Storms
- Salt air near the coast corrodes outdoor coil fins and joints over time
- Red dust and pollen clog outdoor coils in drier suburbs
- Summer storms can cause power surges that upset inverter boards
- Bushfire smoke loads filters quickly, cutting airflow within days
Melbourne has its own pattern. Hot northerly days arrive suddenly, so a unit can go from idle to maximum output overnight. A service in late spring catches dirty coils and slow leaks before that first hot spell.
Error Codes
Which LG Error Codes Are Linked to Weak Cooling?
When an LG unit stops cooling and shows a code, that code narrows the search considerably. Our LG error codes hub explains how the CH system works. The codes below are the ones most often tied to cooling complaints.
CH38 Low Refrigerant
The system detects a low charge and stops to protect the compressor. A leak search is usually needed.
CH61 High Temperature
The condenser runs too hot, often from a blocked or dirty outdoor coil on a hot day.
CH67 Outdoor Fan
The outdoor fan is locked or not reporting its speed, so heat cannot be rejected.
CH01 Room Sensor
The indoor unit cannot read room temperature, so it may cool erratically or not at all.
CH02 Coil Sensor
A coil inlet sensor fault stops the unit, since it cannot guard the coil against freezing.
CH26 Compressor Start
The inverter tried to start the compressor but could not confirm it was turning.
Other codes can also appear alongside poor cooling. For instance, CH44 relates to the outdoor air sensor, and CH62 flags an overheating inverter heat sink. Code meanings can vary slightly between models, so treat these as a guide.
The Visit
What Does a Licensed Technician Check on an LG That Will Not Cool?
A proper diagnosis follows a logical path. The technician confirms the symptom, reads any codes, and then measures how the system is actually performing. Here is what that usually involves.
- Reading stored CH codes and confirming the model and serial details
- Measuring supply and return air temperatures at the indoor unit
- Inspecting filters, the evaporator coil and the indoor fan barrel
- Checking outdoor coil condition, fan operation and airflow clearance
- Testing room and coil thermistors against expected resistance values
- Measuring operating pressures and temperatures with gauges
- Leak testing flare joints and coils if the charge looks low
- Checking supply voltage and communication between indoor and outdoor units
- Assessing compressor and inverter behaviour under load
Refrigerant work in Australia must be done by an ARCtick licensed technician. The technicians we send hold the licences their work requires, and they will explain what they find before any repair begins.
Safety
Is It Safe to Keep Running an LG That Is Not Cooling?
It depends on the cause. If the problem is a dirty filter or a blocked outdoor unit, fixing that is enough and the system can carry on. By contrast, if the unit keeps running without cooling, it may be doing harm.
A unit low on refrigerant can overheat its compressor, and ice on the coil can lead to water leaks inside. Repeated CH codes also suggest the system is protecting itself for good reason. In those cases, switch it off and arrange a check rather than resetting it again and again.
Open more detail
Ice on the pipes. Frost on the outdoor pipes or indoor coil usually means low refrigerant or very poor airflow. Turn the unit off and let it thaw. Our guide to an air conditioner that has frozen up explains why this happens.
Burning smells or tripping breakers. These are electrical warning signs. Leave the system off at the breaker and do not try to reset it repeatedly.
Outdoor unit silent. If the indoor fan runs but the outdoor unit never starts, read about an outdoor unit that is not running before booking.
General cooling issues. For non LG specific advice, see our article on an air conditioner not cooling.
Prevention
How Do I Stop My LG Losing Its Cooling Again?
Most of the slow decline in cooling comes from dirt and neglect rather than broken parts. A little regular care keeps your LG closer to the performance it had when new. It also means small faults get noticed while they are still cheap to sort out.
- Rinse the indoor filters every few weeks during the cooling season
- Keep at least a clear gap around the outdoor unit and trim nearby shrubs
- Hose loose leaves off the outdoor coil gently, never with high pressure
- Use the auto clean or drying function if your model offers it
- Book a professional clean before summer, especially for coastal or dusty sites
- Note any new noises, smells or codes and mention them at the next visit
In addition, run the system briefly in cool mode during spring. That simple test reveals problems weeks before the first heatwave, when technicians are far easier to book.
Where We Help
Where Can I Get an LG Cooling Fault Fixed?
We book LG repairs in five capital cities and dispatch them to licensed local technicians. Choose your city for repair information, or browse our troubleshooting hub for other symptoms. Our main LG air conditioning page covers Melbourne servicing.
Sydney Repairs
Help for humid coastal and hot western suburbs alike.
Melbourne Repairs
Fault finding for sudden heatwaves and cold winters.
Brisbane Repairs
Repairs for systems working hard through long, sticky summers.
Perth Repairs
Support for outdoor units baking in dry, intense heat.
Adelaide Repairs
Diagnosis for units pushed by runs of extreme summer days.
Each city also has a dedicated LG page: LG in Sydney, LG in Brisbane, LG in Perth and LG in Adelaide. To learn how our booking model works, visit our air conditioning service Australia homepage.
Keep Reading
Related LG and Troubleshooting Guides
If cooling is not your only concern, these guides cover other common LG symptoms and general fault advice. You can also get in touch with any questions.
Questions
Frequently Asked Questions
Why is my LG blowing air but not cooling?
Usually the compressor is not running. Check the mode, power cycle the unit and wait three minutes. If the outdoor unit still stays silent, a technician should check power, communication and the inverter board.
Can a dirty filter really stop an LG from cooling?
Yes. A heavily blocked filter starves the coil of airflow. In severe cases, the coil can even freeze, which blocks airflow further and causes dripping later.
Does my LG need a regas if it is not cooling?
Only if testing confirms a low charge. Even then, the leak should be found and repaired first. Topping up without fixing the leak simply delays the same problem.
How long should an LG take to cool a room?
It varies with room size, insulation and the outside temperature. A correctly sized unit should feel noticeably cooler within a short while. If it runs for hours without progress, something needs attention.
Is the CH38 code always a refrigerant leak?
It most often points to low refrigerant, which usually means a leak. However, sensor or installation issues can occasionally contribute, so a technician confirms it with proper testing.
Why does my LG cool well in the morning but not the afternoon?
Afternoon heat pushes the outdoor unit hardest. A dirty outdoor coil, poor clearance or direct sun can tip it into protection mode, reducing output exactly when you need it most.
Can I reset my LG to fix a cooling problem?
A power cycle at the breaker clears temporary glitches. If the problem returns, the reset is only masking a fault. Repeated resets with a code showing are not recommended.
LG Still Not Cooling After Your Checks?
Call with your model number and any CH code on the display. We will book a licensed technician to find the cause.
Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles