LG Error Codes & Diagnostics
Complete diagnostic directory for official LG fault codes. Verify root causes, safe troubleshooting steps, and replacement part numbers before calling a technician.
LG CH01, CH02, CH06 and CH12: the codes LG calls a sensor problem
LG's own help-library article does not give these codes one meaning each. It places CH01, CH02, CH06, CH12, the CH41 to CH48 range, E1 to E3, E7, E8, F2 and F3 in a single category described as a problem with a sensor. The practical consequence is that the code identifies which sensing input is unhappy, while LG's published customer guidance stops at the category. Applies to: LG residential air conditioners covered by the United States help-library article that groups these codes as sensor problems The grouping quoted here is LG's United States help-library guidance for residential air conditioners. LG multi-split and commercial equipment publish fuller per-code tables in their service literature, and LG documentation varies by region and by generation, so a code on a commercial LG system is read from that system's own manual. Owner-safe checks: Write the code down exactly as shown, since a zero and a letter O are easy to confuse on a small indoor display. | Carry out the single power interruption LG describes, at the plug or the breaker, and wait about five minutes before restoring supply. | Compare the displayed room temperature with a separate thermometer and record both figures before the reset. Qualified technician: LG instructs the owner not to disassemble the air conditioner or replace internal parts, and warns that doing so may cause fire, electric shock, or serious injury. | If the same code appears again after one reset, LG's stated instruction is to stop using the product and request service to prevent further damage.
LG CH04: float switch error, or a missing jumper
CH04 reports the float switch circuit rather than a measured water level. On an indoor unit fitted with a float switch it points at drainage or the switch; on a model built without one it follows a short key missing from the float switch connector on the indoor board. Applies to: LG single-zone systems in general service manual MFL41161610 Whether your indoor unit has a float switch at all decides which half of this code applies, and that depends on the cabinet style and the exact model. Establishing it is the first thing document MFL41161610 asks a technician to do, which is why the characters alone cannot answer CH04 on any single-zone LG system. Owner-safe checks: Note whether water has appeared at or under the indoor unit, and whether the outside drain discharges during cooling. | Record the indoor model number, since whether a float switch is fitted at all depends on it. | Note any recent work at the indoor unit, particularly a board replacement or a service visit that opened the electrical cover. Qualified technician: The float switch connector, the short key, and the indoor board sit inside the electrical compartment and are technician work with the supply isolated. | Ask for the short key test described in the manual before an indoor board is quoted, because the manual conditions that replacement on it.
LG CH05 error code: indoor-outdoor communication error
LG's documented CH05 code indicates an indoor-to-outdoor communication error; the same service table groups related CH53 and CH93 communication conditions by system context. Applies to: LG single-zone systems in MFL41161610 This page follows the LG general service manual for single-zone ductless systems. LG multi-zone and ducted ranges maintain their own code tables, and a CH number read from a different manual is not interchangeable, so confirm the model against the manual before relying on this definition. Owner-safe checks: Record the complete code, model numbers, and whether either unit shows signs of power. | Note whether the code followed an outage, installation, or other electrical work without opening a panel. Qualified technician: Terminal, grounding, resistance, motor, and PCB checks in the service manual require a qualified technician. | Wait-time and stored-energy warnings in the service literature must be followed before electrical access.
LG CH07 error code: indoor units set to conflicting modes
LG shows CH07 on a multi-split when the indoor units connected to one outdoor unit are set to modes that cannot run at the same time, such as one head in heating and another in cooling or dehumidification. It is a setting conflict, not a hardware fault, and it clears when every head is set to a compatible mode. Applies to: LG multi-split systems where several indoor units share one outdoor unit This applies to LG multi-split systems where more than one indoor unit shares a single outdoor unit. A single-split system with one indoor and one outdoor unit does not produce CH07 for this reason, so confirm the system is a multi-split first. Owner-safe checks: Check the mode shown on every indoor remote for units sharing the outdoor unit, and set them all to heating or all to cooling. | After the modes match, turn the affected heads off and on again and confirm CH07 has cleared. Qualified technician: If CH07 stays after every head is confirmed on the same mode, a wired controller or communication fault may be reporting a mode incorrectly, which needs an LG technician.
LG CH21, CH23, CH26 and CH29: the outdoor compressor and board group
LG's help-library article assigns CH21, CH23, CH26, CH29 and E9 to a single category: a problem with the outdoor unit compressor or circuit board. That is a narrower statement than it appears, because it moves the fault out of the indoor unit and out of the sensing group and places it in the inverter drive and compressor side of the system. Applies to: LG residential air conditioners covered by the United States help-library article grouping these codes as outdoor compressor or circuit board problems What is quoted below is the category LG gives home customers in its United States help library, and nothing finer. LG service literature publishes fuller definitions for each of these codes, and the meaning of a CH number on LG commercial or variable refrigerant flow equipment is taken from that product's own manual rather than from this article. Owner-safe checks: Make one start attempt after LG's five-minute power interruption, and count how many seconds the outdoor unit runs before it stops. | Observe whether the outdoor fan turns at all during the attempt, from a safe distance and without touching the guard. | See whether a breaker or fuse serving the outdoor unit has tripped, and whether anything else in the property is misbehaving at the same time. Qualified technician: LG instructs the owner not to disassemble the unit or replace internal parts, warning of fire, electric shock, serious injury, or death. | Measuring compressor windings, inverter output, and supply voltage under load are energised tasks inside the outdoor enclosure and belong to a qualified engineer.
LG multi-split: one outdoor unit cannot heat and cool at once
LG states that on a multi-product system every indoor unit connected to one outdoor unit has to run in cooling only or in heating only. Cooling and dehumidification cannot run at the same time as heating, while air purification and fan modes are unrestricted, so one room set the wrong way stops another from getting what it asked for. Applies to: LG multi-split systems where several indoor units share a single outdoor unit, as described in LG help-library guidance This applies to LG multi-split arrangements where several indoor units share one outdoor unit. Heat recovery systems, which are a different architecture, can serve simultaneous heating and cooling, and single-split installations have no conflict to resolve. Confirm how many indoor units your outdoor unit serves. Owner-safe checks: Walk through every room with an indoor unit and note which mode each one is set to, including any that are switched on but unused. | Switch off indoor units in rooms nobody is using rather than leaving them running in a conflicting mode. | Set every remaining unit explicitly to the same mode rather than relying on automatic selection. Qualified technician: A conflict that persists after every indoor unit is set to the same mode is no longer a mode conflict and needs the system examined. | Changing how a multi-split is configured, including adding or reassigning indoor units, is installer work rather than a settings change.
LG Washer OE Error Code: Drain Malfunction
Water level frequency does not decrease during the drain sequence.