The ‘ Smart Diagnosis ‘ functionality is an exciting feature of the latest LG inverter ACs. This feature enables the machine to self-detect errors in installation and usage. If there is a problem with the device, it flashes an error code on the indoor unit display or the remote control option. These codes can help you determine the error and allow the AC mechanic to arrive at the appropriate remedial measure.
We shall discuss some of the most commonly observed error codes in this article. First, however, we shall list all the error codes and their descriptions for your reference before that. Users should note that all LG AC models will not display all these errors.
Let us begin with the indoor unit
LG AC Indoor Unit Error Code List
| Error Code | Description |
| 1 | Indoor unit room temperature sensor error |
| 2 | Indoor unit inlet pipe sensor error |
| 3 | Wired remote control error |
| 4 | Float switch error |
| 5 | Communication errors between the indoor and outdoor units |
| 6 | Indoor unit outlet pipe sensor error |
| 9 | Indoor unit EEPROM error |
| 10 | Indoor unit BLDC fan motor lock |
| 12 | Indoor unit middle pipe sensor error |
LG AC Outdoor Unit Error Code List
| Error Code | Description |
| 21 | DC Peak (IPM) Fault – Compressor DC voltage is too high |
| 22 | CT2 (Max CT) – Alternating current input too high |
| 23 | DC Link Low Voltage |
| 25 | AC Low/High Voltage |
| 26 | DC Comp Position Error (not providing rotation – locking) |
| 27 | PSC Fault – Current to inverter compressor between AC and DC converter is too high |
| 28 | Inverter Compressor DC voltage is too high |
| 29 | Comp Phase Over-current – Inverter compressor amperage is too high |
| 31 | Current-to-current transformer (CT) thermistor is too low |
| 32 | Inverter Compressor Discharge pipe overheat |
| 34 | High-pressure sensor high |
| 35 | Low-pressure sensor low |
| 36/38 | Refrigerant Leak detection |
| 37 | Exceed the compression ration limit |
| 40 | CT sensor error – Thermistor is disconnected or shorted out |
| 41 | Discharge Pipe sensor error – INV is disconnected or shorted out |
| 42 | Low-Pressure sensor error |
| 43 | High-Pressure sensor error |
| 44 | Outdoor air sensor error – Disconnected or shorted out |
| 45 | Condenser middle pipe sensor error – Disconnected or shorted out |
| 46 | Suction pipe sensor error – Disconnected or shorted out |
| 48 | Outdoor unit coil outlet (liquid line) thermistor is disconnected or shorted out |
| 51 | Excess capacity – Mismatch between IDU and ODU |
| 53 | Communication error – between the IDU and ODU |
| 60 | Outdoor unit printed circuit board (PCB) EEPROM checksum error |
| 61 | Condenser coil temperature is too high |
| 62 | Heat sink sensor temperature – high |
| 63 | Condenser coil pipe thermistor temperature is low |
| 65 | Heat sink thermistor has disconnected or shorted out |
| 67 | BLDC motor fan lock |
| 72 | Detect 4-way valve transfer failure |
| 93 | Communication error |
Generally, the error codes flash as CH01, CH02, etc. As a user, you cannot do much about these error codes but note them down as they flash on the display unit or the remote. It will help the AC mechanic to arrive at the problem quickly and ensure appropriate repairs.
Besides these error codes, here are some commonly observed errors.
LG AC F1, F2, F3
It indicates that the AC is working in the FAN mode, and the number corresponds to the set fan speed. The situation is normal, and the AC does not have any other issues.
LG Air Conditioner P2 or FL Codes
This code indicates that the water collection tank is full. The solution is to empty the tank.
Now, let us discuss the most frequently searched error codes and their respective solutions.
P2 or FL – Water tank full error
Reason – Depending on your AC model, this error code flashes on display to indicate that the drain pan in the outdoor unit is full.
Generally, the drain pan does not need any emptying. The AC unit features a slinger fan mounted above the drain pan. The fan sucks the water and slings it on the condenser to discharge heat. So, the water accumulation usually does not occur.
However, you can take remedial action if you observe the following situations.
- P2 or FL code keeps recurring
You can remove the drain port cap and tilt the AC to allow the water to flow out of the drain outlet. If the AC unit is in COOL mode and the error code keeps recurring, it indicates that the humidity in the room is high. But, the unit is functioning correctly.
Setting the fan speed to ‘LOW’ ensures that you do not have to drain the unit frequently. It slows down air circulation and reduces the amount of moisture removed by the unit. However, you should create a controlled environment by shutting down all windows and doors.
If the unit is in the DRY mode, it indicates that it is primarily functioning to remove moisture from the air. So, you have to change the mode to COOL and reduce moisture removal.
- P2 or FL code without the water draining out
The unit requires repair service if the water does not drain out on tilting the AC. You can summon the AC mechanic to do the job.
- P2 or FL code does not clear after draining the water.
You need to reset the AC unit. First, unplug the AC and keep it unplugged for about ten seconds. Then, plug the unit again and start the AC. The unit should reset. If the P2 or FL code persists, it requires repair service.
- P2 or FL code displays, and the unit does not shut off.
The AC needs a repair service. You can contact the LG mechanic by raising a request.
LG AC CH 34 – Safety Issue
The CH 34 error code does not indicate any defect with the AC but is designed to protect the appliance from overheating. This code is displayed when the unit’s Safety Relay causes it to shut down because of abnormally high pressure in the sealed system.
You can reduce the risk of the ODU overheating by doing the following.
- Protect the ODU from direct sunlight by installing an awning over the unit. It can also prevent the ODU from adverse weather conditions.
- Cleaning the condenser coils regularly helps maintain proper airflow.
- You need not shut off the AC when away from home. A better option is to raise the temperature to a higher setting to allow the AC to maintain better humidity control and cooling. In addition, it lessens the strain on the unit when you set a lower temperature for cooling.
E1 or CH02 – Auto Stop Protection Error
Reason – A short or open circuit in the indoor pipe sensor results in an Auto-Stop Protection Error.
Solution – Note the error and summon the LG AC mechanic to repair the AC.
E2 or CH01 – Auto Stop Protection Error
Reason – It is similar to the E1 or CH02 error.
Solution – Your AC requires repair service. Note the error code and call the LG AC service personnel.
E3 or CH03 – No refrigerant
Reason – If the AC unit does not detect any refrigerant, it displays the E3 or CH03 error code.
Solution – You have to summon the LG AC service person to get the AC repaired.
E4 – Defrost Mode
E4 is not an error code but an indication that your AC unit has entered the Defrost mode. When the AC unit detects ice on the evaporator located behind the grille, it can happen. The AC resumes normal operations after it completes defrosting.
E5 – Water tank Full
E5 indicates a full water collection tank. Next, you can remove the drain cap and automatically allow the water to drain away. Once the water drains off, you can fix the cap and restart the AC.
HI or LO – Temperature indication
If your unit displays HI or LO, there is no need to panic. It is not a product error. HI, or LO indicates indoor temperature. If the indoor temperature is 36 degrees Celsius or more, it indicates HI. If the temperature is 10 degrees Celsius or below, it shows LO. You can reduce or increase the set temperature accordingly.
SP/CP/PO Codes – Function Codes
Reasons – These codes can appear on the AC display or the remote when you set it to ‘Power Cooling.’ The names can change depending on the model. For example, some models call it Super Cool Power, Ice Cool Power, Turbo-Z, etc.
Solution – The Power Cooling function discharges colder air than the normal cooling mode to cool the room quicker. This mode can be used in the Cooling Mode alone, not the Dry or Air Purification Mode. In addition, the unit sets the wind speed and temperature automatically. So when you encounter such codes on your LG AC unit or remote, you need not worry.
ON – Function Code
Reason – When you set the Air Purification Mode in sole operation on the AC, it displays the ON code on the screen and the dust and air freshness levels.
Solution – The LG unit features a diffuser to produce ions and remove cigarette smoke and fine dust. The ACs also feature PM1.0 dust sensors to detect dust particles. When the Air Purification mode is in sole operation, it displays the ON code, a color indicator, and the size/level of dust particles.
The Blue color indicates good air purification levels, and the diffuser does not need to function. Green indicates that the air purification is satisfactory, and there is no need for the diffuser. Yellow and Red indicate bad/very-bad pollution levels, and the diffuser switches on.
You can clean the PM1.0 sensor by opening the sensor cover and using a wet earbud to wipe the lens. Finally, use a dry earbud to remove the moisture. Close the sensor cover.
CH05 or CH53 – Communication Error Code
Reason – The lack of communication between the IDU and ODU results in flashing the CH05 or CH53 error codes. The reasons could be disconnection of the communication cable, short circuits, circuit faults in the IDU or ODU, T-phase line disconnection, auto addressing is not done, and insufficient distance between the power and communication cable.
Solution – You cannot resolve this issue by yourself. You have to book an AC service request and summon the LG service personnel.
CA or CH10 – Faulty discharge thermistor error
Reason – When the discharge temperature is more than 130 degrees Celsius, your AC flashes this CA code.
Solution – You should call the AC service personnel to remediate the problem.
CH38 – Low Refrigerant Detection
Reason – Your AC flashes the CH38 error code if it detects low levels of refrigerant. The objective is to protect the appliance.
Solution – If the appliance flashes this code immediately after installing/re-installing the device, the technician should ensure that the refrigerant levels are sufficient. If the code flashes after using the appliance for a sufficiently long period, the reason could also be electrical instability. Under such circumstances, you can unplug the device and turn it on after five minutes. If the error persists, the refrigeration levels can be low. The solution is to refill the refrigerant. You need a qualified technician to perform this operation.
CO – Communication Error
Reason – A communication error between the control board and the display causes the CO error to flash on the remote.
Solution – You will need the help of a qualified AC technician to resolve this error.
CH12 – Indoor Pipe Temperature sensor error
Reason – Your LG AC displays a CH12 error code when the indoor pipe temperature measures a temperature out of range. It is a protective measure.
Solution – A qualified AC technician, can handle this matter. You can note down the code and switch off the AC.
CH32 – High discharge temperature
Reason – A high discharge temperature can trigger the CH32 error code on your AC. The reason could also be that the AC is low on refrigerant.
Solution – Call the AC mechanic to investigate the problem.
CH44 – Sensor Error
Reason – If the outdoor unit sensor gets disconnected or shorted, the AC can display a CH44 error code.
Solution – You have to summon the AC service personnel to resolve the issue.
Final Thoughts
We have listed all the LG AC error codes and the solutions to the commonly observed error codes. Generally, you cannot address the problem yourself. The correct option is to book an AC service request and call the LG AC mechanic to deal with the issue.