Technician examining the fault code on an air conditioner control panel

Air conditioner and VRF fault codes

The meaning, likely cause and what you can do for 204 error codes across 8 brands. Search for the code, choose the brand.

Important: The same code can mean different things on different model series. For an exact diagnosis, send us the code together with the unit's brand and model label. Only an qualified technician should work on the refrigerant circuit and the electrical panel.

LG fault codes

Scope: LG wall-mounted split, multi split, cassette/duct indoor units and Multi V VRF systems. The numbering of CH codes is largely shared between split and Multi V; on Multi V, the last digit of the 7-segment display on the outdoor unit board shows the unit number.
How to read the code: When a fault occurs, the indoor unit's indicator lamp blinks at about 2-second intervals or the display shows 'CH' followed by a number (on some models short codes such as E0, F4, EF). On systems with a wired controller the code also appears on the controller display. On Multi V the code appears on the 7-segment LED of the outdoor unit control board; the first three digits are the error number and the fourth digit is the unit number (1: Master, 2: Slave 1...). If there are several errors at once, the lower-numbered code is shown first.

Code	Meaning	Likely cause	What can you do?
CH01	Indoor unit room (air intake) temperature sensor fault	Sensor open/short circuit, loose connector or indoor unit board fault	Do a safe reset (breaker off for ~5 min). If the code returns, service is needed.
CH02	Indoor unit pipe inlet temperature sensor fault	Sensor open/short circuit or connection problem	Do a safe reset. If the code returns, service is needed.
CH03	Communication error between the wired controller and the indoor unit	Indoor unit board is not receiving the controller signal; controller cable or board problem	Do a safe reset. If it continues, service is needed.
CH04	Drain (condensate discharge) error	Drain pump/float problem or blocked discharge on ceiling-type units; full water tank on portable/window types. On some models it appears as FL.	On portable/window types, empty the water through the drain plug described by the manufacturer. On ceiling/cassette types do a reset; if it continues, service is needed.
CH05 / CH53 / E0	Communication error between the indoor and outdoor unit	Faulty/loose communication cable connection, wiring error after installation or relocation, mains fluctuation, board fault. On some models 'E0' may appear on the display while kW Manager is running (this is not a fault).	Do a safe reset. If the error appeared after a new installation or relocation, contact the installer; if it continues, service is needed.
CH06	Indoor unit pipe outlet temperature sensor fault	Sensor open/short circuit or connection problem	Do a safe reset. If the code returns, service is needed.
CH07	Indoor units are in different operating modes (mode conflict)	In multi split / 2-in-1 systems one unit is heating while the other is cooling or dehumidifying	Set all indoor units to the same mode (all heating, or all cooling/dehumidifying). Fan and air-purifying modes can be used without restriction.
CH09	Indoor unit EEPROM (memory) error	Faulty memory data on the indoor unit board or board fault	Service required
CH10 / E6	Indoor unit fan motor fault	Fan motor connector came off, motor is locked, or there is an obstruction in front of the fan	Without opening the unit, remove any visible obstruction at the indoor unit air inlet/outlet and do a reset. If it continues, service is needed.
CH12	Sensor-related error (listed among the sensor group codes in LG's official source)	Faulty/loose sensor, board error or temporary electrical problem. Which sensor it is can vary by series.	Do a safe reset. If the code returns, service is needed.
CH21	Inverter compressor driver (IPM/IGBT) error – DC peak	Power module protection tripped; compressor, driver board or sudden voltage problem	Do a safe reset. If the code returns, service is needed.
CH22	Inverter board input overcurrent (Max CT)	Outdoor unit inverter board input current exceeded the limit	Service required
CH23	Compressor DC link low voltage error	DC voltage is not produced after the outdoor unit starts; supply or board problem	Do a safe reset. If it continues, service is needed.
CH24	Outdoor unit high pressure switch tripped (Multi V)	High pressure, dirty condenser or insufficient air/water flow	Remove any items around the outdoor unit that block airflow. Service is required.
CH25	Outdoor unit input voltage too high or too low	Mains voltage is outside limits	Watch whether there are voltage fluctuations across the building, and do a reset. If it continues, service is needed.
CH26	Inverter compressor initial start error	Compressor or driver circuit fault (some sources list it as a compressor position detection error)	Do a safe reset. If it continues, service is needed.
CH29	Inverter compressor overcurrent error	Compressor or power element (IGBT) fault, phase problem	Do a safe reset. If it continues, service is needed.
CH32	Excessive rise in inverter compressor discharge temperature	Insufficient refrigerant, flow problem or sensor problem	Service required
CH34	Excessive rise in high pressure	Dirty condenser, insufficient outdoor unit ventilation, overcharge of gas. On some models it is also shown for overheating in heating mode.	Clear the area around the outdoor unit and clean the indoor unit filter. If it continues, service is needed.
CH38 / F4	Refrigerant (gas) shortage protection	Gas leak, insufficient charge or pipe connection problem	If it appeared after installation/relocation, contact the installer. If it appeared during normal use, do one reset; if it repeats, service is needed.
CH41–CH48	Outdoor unit sensor errors (discharge, pressure, outdoor air, condenser, suction line, etc.)	Sensor fault/loose connection or board error. Which number is which sensor can vary by series.	Do a safe reset. If the code returns, service is needed.
CH54	Reverse phase / phase sequence error	Usually the phase sequence of the three-phase supply changing after a power outage or electrical work	Switch the air conditioner's breaker off and on. If it appeared after electrical work, tell the electrician it is a 'reverse phase' error; if it continues, service is needed.
CH61	Outdoor unit overheating in cooling / indoor unit overheating in heating	Hot air building up around the outdoor unit (closed balcony, closed louver, stacked items) or a dirty/blocked filter in heating. On some models it appears as P4, P6, P7, P8 or CH34.	Clear the front and surroundings of the outdoor unit, keep the ventilation window/louver open and clean the indoor unit filter. The code does not clear by itself; do a reset. If it continues, service is needed.
CH66	Communication line or pipe connection problem between indoor and outdoor unit	Usually a wrong cable/pipe connection during installation; sometimes a temporary electrical fluctuation	If it appeared after a new installation, contact the installer; otherwise do a reset. If it continues, service is needed.
CH67 / EF	Outdoor unit fan motor error (fan lock)	Obstruction in front of the outdoor fan, snow/ice buildup or fan motor fault	From the outside, clear obstructions such as leaves, bags or snow around the outdoor unit. If it continues, service is needed.
CH90 / CH91	Protection during test run (pipe connection/flow problem)	Pipe connection or flow problem after installation; on some models it appears as F4	If it is after installation, contact the installer. In normal use, do a reset; if it continues, service is needed.
CH93	Indoor-outdoor communication error; on some models after 2021, the outdoor unit is without power	The plug of the separately plugged outdoor unit has come out or its fuse is off, communication cable problem	Check that the outdoor unit's plug is connected directly to a wall socket (do not use a multi-socket strip) and that its fuse is on. If the fuse keeps tripping, do not force it; service is required.

Source: lg.com · lg.com · manualslib.com

Daikin fault codes

Scope: Daikin residential split (RA), SkyAir and VRV systems. The code table is based on Daikin's common 'malfunction code' system for all series; some codes exist only on VRV/SkyAir and their meaning can vary by series.
How to read the code: When a fault occurs, the operation lamp on the indoor unit blinks. On residential wireless remotes: point the remote at the indoor unit and hold the TIMER CANCEL button for ~5 seconds; '00' blinks on the display; press the button repeatedly, and when you hear a long beep the code on the display is the valid code (a short beep or two beeps means no match). On wired controllers (e.g. BRC1E) the display shows 'Error: Press Menu Button', and the code is shown with Menu/Enter. To leave the code display, hold the same button for 5 seconds or wait 1 minute.

Code	Meaning	Likely cause	What can you do?
A1	Indoor unit electronic board (PCB) fault	Indoor unit board error	Do a safe reset. If it continues, service is needed.
A3	Drain level control system error (cassette/duct types, SkyAir/VRV)	Drain pump, float or blocked drain line	Switch the unit off; do not use it if water is dripping from the indoor unit. Service is required.
A5	Freeze protection (in cooling) / high pressure control (in heating)	Dirty filter, blocked air inlet/outlet, low airflow or gas problem	Clean the air filter, make sure nothing blocks the indoor unit's air inlet/outlet, and do a reset. If it continues, service is needed.
A6	Indoor unit fan motor fault	Fan motor locked, connector problem or foreign object caught in the fan	Do a safe reset. If it continues, service is needed.
C4	Indoor unit heat exchanger (coil) temperature sensor fault	Sensor open/short circuit or connection problem	Service required
C9	Indoor unit intake air (room) temperature sensor fault	Sensor open/short circuit or connection problem	Service required
E1	Outdoor unit electronic board fault	Outdoor unit board error or indoor-outdoor relay connection problem	Do a safe reset. If it continues, service is needed.
E3	High pressure switch (HPS) tripped	Dirty outdoor unit heat exchanger, blocked piping, faulty pressure switch	Remove items blocking the outdoor unit's air inlet/outlet. Service is required.
E4	Low pressure switch (LPS) tripped	Abnormal drop in low pressure (could be a gas shortage), sensor/board fault	Service required
E5	Compressor overload (OL) / overheating protection	Inverter compressor lock, high pressure difference, inverter board fault	Service required
E6	Compressor start error / compressor lock	Compressor or control board fault, service valve left closed	Service required
E7	Outdoor unit DC fan motor fault	Fan motor fault, connection problem or foreign object caught in the fan	From the outside, clear obstructions such as leaves, bags or snow in front of the outdoor fan. If it continues, service is needed.
E8	Input overcurrent (inverter compressor overcurrent)	Compressor, inverter capacitor, outdoor board or power transistor fault	Service required
F3	Discharge pipe high temperature protection	Gas shortage, discharge sensor fault or outdoor board problem	Service required
F6	High pressure control (in cooling) / gas overcharge	Excess refrigerant, sensor disconnection, insufficient outdoor unit ventilation	Clear the area around the outdoor unit. If it continues, service is needed.
H0	Compressor sensor system fault	Cable connection broken or board error	Service required
H6	Stop due to position detection sensor error	Compressor rotor position detection circuit fault	Service required
H8	DC current sensor fault	Outdoor unit board/sensor error	Service required
H9	Outdoor air temperature sensor fault	Sensor open/short circuit. Note: the Daikin India table lists H9 as the 'intake air sensor'; in the global Daikin table it is the 'outdoor air thermistor'. It can vary by series.	Service required
J3	Discharge pipe temperature sensor fault	Sensor open/short circuit	Service required
L4	Inverter heat sink temperature high	Insufficient outdoor unit ventilation, outdoor fan fault	Clear the area around the outdoor unit and the air outlet, and remove any direct sun or hot air buildup. If it continues, service is needed.
L5	Inverter output overcurrent (instantaneous)	Compressor winding fault, compressor start problem (mechanical lock), inverter board fault	Service required
U0	Refrigerant (gas) shortage	Gas leak or insufficient charge	Service required
U2	Supply voltage drop or main circuit overvoltage	Mains voltage fluctuation, sudden outage	Do a safe reset after the mains fluctuation has passed. If it continues, service is needed.
U4	Communication error between the indoor and outdoor unit	Communication cable, outdoor unit without power or board problem	Check that the outdoor unit's fuse is on and do a safe reset. If it continues, service is needed.
UA	Indoor and outdoor unit combination (mismatch) error	Incompatible indoor/outdoor unit pairing or setting error	Service required

Source: daikinindia.com · daikin.com · daikin.com

Mitsubishi Electric fault codes

Scope: Mitsubishi Electric wall-mounted (MSZ), Mr. Slim (PLA/PEA/SEZ/PLY etc.) split systems. On City Multi VRF the same faults appear on the controller as 4-digit codes (example matches are in the notes field). The meaning of codes can vary by series.
How to read the code: On a wired controller (e.g. PAR-21MAA) the code appears on the LCD display; the fault history is read by pressing the CHECK button twice. On wall-mounted units with wireless remotes, while the indoor unit operation lamp is blinking, point the remote at the indoor unit and press the CHECK button with a thin tip; '00' appears on the display; codes are sent one by one: if the indoor unit beeps twice that code is valid, 1 beep means no fault. On some models the fault is also indicated by the number of lamp blinks. On City Multi the code appears as 4 digits on the controller (e.g. 1302 = high pressure).

Code	Meaning	Likely cause	What can you do?
P1	Intake (room) temperature sensor (TH1) fault	Sensor open/short circuit or connector came off	Service required
P2	Pipe (liquid line, TH2) temperature sensor fault	Sensor open/short circuit or connector came off	Service required
P4	Drain sensor error / float connector open	Drain sensor or float connection problem	Service required
P5	Drain pump error / water overflow protection in the indoor unit	Drain pump fault, blocked drain line or pan	Switch the unit off; do not use it if water is dripping. Service is required.
P6	Freeze (in cooling) / overheating (in heating) protection	Dirty filter or heat exchanger, low airflow, fan motor problem, gas problem	Clean the air filter, clear the indoor unit air inlet/outlet and do a reset. If it continues, service is needed.
P8	Pipe temperature abnormality	No expected temperature change at the indoor unit during operation; gas leak, closed service valve, sensor coming off its position, reversed pipe/cable connection in multi systems	Service required
P9	Pipe (TH5, condenser/evaporator) temperature sensor fault	Sensor open/short circuit or connector came off	Service required
PA	Forced compressor stop (due to water leak abnormality)	Drain/water leak detection	Switch the unit off. Service is required.
Pb (PB)	Indoor unit fan motor error	Fan motor or driver circuit fault	Service required
E0 / E3	Controller transmission (communication) error	Controller cable, group/master-slave setting or board problem	Do a safe reset. If it continues, service is needed.
E1 / E2	Controller control board error	Wired controller fault	Service required
E4 / E5	Communication error between the wired controller and the indoor unit	Controller signal cannot be received; cable or board problem	Do a safe reset. If it continues, service is needed.
E6 / E7	Communication error between the indoor and outdoor unit	Connection cable, outdoor unit without power or board problem	Check the outdoor unit's fuse and do a safe reset. If it continues, service is needed.
E9	Indoor-outdoor communication error (transmission error on the outdoor unit side)	Communication line or outdoor unit board problem	Service required
EE	Indoor and outdoor unit combination/communication error	Incompatible indoor/outdoor unit pairing or connection error	Service required
Fb (FB)	Indoor unit control system error (memory error, etc.)	Indoor unit board fault	Service required
U1 / Ud	Abnormal high pressure (63H switch) / overheating protection	Outdoor fan fault, blocked/dirty outdoor heat exchanger, blockage in the system; dirty indoor filter in heating. City Multi equivalent: 1302.	Clear the area around the outdoor unit and clean the indoor filter in heating. If it continues, service is needed.
U2	Abnormally high discharge temperature / insufficient refrigerant	Gas shortage, thermistor problem, high ambient temperature. City Multi equivalent: 1102.	Service required
U3 / U4	Open/short circuit in outdoor unit thermistors (discharge, outdoor air, heat exchanger, etc.)	Sensor fault or connector came off. City Multi equivalent: 5104 / 5105.	Service required
U5	Outdoor unit heat sink temperature abnormal	Short circuit of the outdoor unit air outlet (hot air being drawn back in), thermistor problem. City Multi equivalent: 4230.	Clear the front and surroundings of the outdoor unit and prevent hot air buildup. If it continues, service is needed.
U6	Compressor overcurrent cutoff / power module abnormality	Compressor or inverter power module problem. City Multi equivalent: 4250.	Service required
U7	Superheat abnormality due to low discharge temperature	Expansion valve (LEV) or sensor problem. City Multi equivalent: 1520.	Service required
U8	Outdoor unit fan safety stop	Outdoor fan motor fault or obstruction caught in the fan	From the outside, clear obstructions in front of the outdoor fan. If it continues, service is needed.
U9 / UH	Over/under voltage, main circuit sync signal error or current sensor error	Mains voltage problem, compressor wiring or board fault	Do a safe reset after the mains fluctuation has passed. If it continues, service is needed.
UF / UP	Compressor overcurrent cutoff (UF: compressor lock)	Closed service valve, compressor wiring, compressor fault, outdoor unit air short circuit	Service required

Source: mitsubishielectric.com.sg · mitsubishi-electric.manymanuals.com · orionair.co.uk

Samsung fault codes

Scope: Samsung wall-mounted split, commercial (cassette/duct) and DVM VRF systems. Codes appear as 'E' + 3 digits on the indoor unit display, the wired controller and the outdoor unit board. On some older/newer models the first letter may be C or E, and the code may blink in two parts (e.g. C1 ↔ 21).
How to read the code: When a fault occurs, the indoor unit display blinks and shows the code (e.g. E121). On some models the display shows two parts such as 'C1/E1' and '21' in turn; this means E121. On a wired controller an error icon appears, and the code is seen by pressing the Test button. On the DVM/outdoor unit board it is shown with LEDs or a 7-segment display. Write down the code and pass it on to service.

Code	Meaning	Likely cause	What can you do?
CF	Filter cleaning reminder (not a fault)	Filter usage time has expired	Clean the indoor unit filters and reset the reminder from the remote.
dF	Automatic defrost is running in heating (not a fault)	Frost on the outdoor unit heat exchanger is being melted	Wait; the indoor fan may stop briefly, and steam coming from the outdoor unit is normal.
E101 / E102	Communication error between the indoor and outdoor unit	Communication cable connection, outdoor unit without power or board problem	Do a safe reset. If it continues, service is needed.
E121	Indoor unit room temperature sensor error	Sensor open/short circuit	Service required
E122	Indoor unit pipe (evaporator inlet) sensor error	Sensor open/short circuit	Service required
E154	Indoor unit fan motor speed error	Fan motor cannot reach the requested speed (motor/board fault or obstruction at the fan)	Do a safe reset. If it continues, service is needed.
E162	Indoor unit EEPROM (memory) error	Faulty/erased data in the main board memory	Service required
E201	Indoor-outdoor unit count/pairing mismatch (multi/DVM)	Indoor unit count setting on the outdoor unit is wrong or a connection is missing	Service required
E202	Indoor-outdoor communication error (no communication for 1 minute)	Power or communication cable connection problem	Check the outdoor unit fuse and do a safe reset. If it continues, service is needed.
E203	Communication error between the outdoor unit main board and the inverter board	Outdoor unit board connection or board fault	Service required
E221	Outdoor ambient temperature sensor error	Sensor open/short circuit or connection problem	Service required
E231 / E237	Outdoor unit condenser (coil) temperature sensor error	Sensor open/short circuit or position/connection problem	Service required
E251	Compressor discharge temperature sensor error	Sensor open/short circuit	Service required
E416	Excessive rise in compressor discharge temperature	Gas shortage, flow problem or sensor problem	Service required
E422	Electronic expansion valve (EEV) or service valve closed error	Closed service valve or EEV fault	Service required
E440 / E441	Outdoor temperature is outside operating limits (E440 heating, E441 cooling blocked)	Outdoor air is not within the allowed range for the selected mode (in one service manual: above 30°C for heating, below -5°C for cooling; may vary by model)	Not a fault; the unit runs when the outdoor temperature returns to the suitable range. Check the mode setting.
E458	Outdoor unit fan motor error	Fan motor fault or obstruction caught in the fan	From the outside, clear obstructions in front of the outdoor fan. If it continues, service is needed.
E461	Compressor start-up error	Compressor connection or compressor fault	Service required
E462	Total current (I-trip) / PFC overcurrent error	Supply problem, gas charge problem, outdoor fan not running	Clear the area around the outdoor unit and do a safe reset. If it continues, service is needed.
E464	IPM (power module) overcurrent error	Gas charge, compressor connection, closed service valve, obstruction around the unit	Remove obstructions around the indoor and outdoor units. If it continues, service is needed.
E465	Compressor overload / voltage limit (V-limit) error	Compressor connection or compressor problem	Service required
E466	DC link voltage too low/high	Mains voltage or AC supply connection problem	Do a safe reset after the mains fluctuation has passed. If it continues, service is needed.
E467	Compressor rotation error (compressor cable missing)	Compressor connection or compressor fault	Service required
E554	Gas leak error	Refrigerant leak or shortage	Service required
E556	Indoor and outdoor unit capacity mismatch	Incompatible model pairing	Service required

Source: samsung.com · samsung.com · manualsdump.com

Toshiba fault codes

Scope: Toshiba commercial split (RAV/Digital-Super Digital Inverter) and SMMS/SMMS-i VRF systems. Check codes appear on the wired controller and on the 7-segment display of the VRF outdoor unit interface board. Some codes exist only on VRF; the meaning can vary by series.
How to read the code: On a wired controller the check code appears on the display (the fault history can be read with the CHECK button). On wireless models, the blinking combination of the Operation/Timer/Ready lamps on the indoor unit shows the code; when a fault is detected all lamps blink quickly and the unit beeps for ~10 seconds. On SMMS VRF it also appears on the 7-segment display of the outdoor unit interface board.

Code	Meaning	Likely cause	What can you do?
E01	Communication error between controller and indoor unit (detected on the controller side)	Controller cable, main (master) indoor unit switched off	Do a safe reset. If it continues, service is needed.
E03	Indoor unit cannot receive a signal from the controller	Controller or communication adapter cable problem	Do a safe reset. If it continues, service is needed.
E04	Indoor-outdoor communication circuit error (detected on the indoor unit side)	Interconnection cable fault, outdoor/indoor board fault, outdoor unit not running	Check the outdoor unit's fuse and do a safe reset. If it continues, service is needed.
E08	Indoor unit address conflict	Wrong group/address setting	Service required
E10	MCU communication error inside the indoor unit board	Indoor unit board or supply problem	Service required
F01	Indoor unit heat exchanger sensor (TCJ, liquid) fault	Sensor open/short circuit or came off its position	Service required
F02	Indoor unit heat exchanger sensor (TC/TC2) fault	Sensor open/short circuit or came off its position	Service required
F04	Outdoor unit discharge sensor (TD) fault	Sensor open/short circuit	Service required
F06	Outdoor unit heat exchanger sensor (TE/TS) fault	Sensor open/short circuit	Service required
F08	Outdoor ambient temperature sensor (TO) fault	Sensor open/short circuit	Service required
F10	Indoor unit return air (room) sensor (TA) fault	Sensor open/short circuit	Service required
H01	Compressor fault / inverter compressor overcurrent	Compressor or inverter driver problem	Service required
H02	Compressor lock (overcurrent right after starting)	Compressor mechanical lock or driver fault	Service required
H06	Low pressure protection tripped	Gas shortage/leak or pressure sensor problem	Service required
L29	Outdoor unit IPDU (inverter board) count/communication error	Outdoor unit board connection or board fault	Service required
L30	Indoor unit external interlock input active	Stop signal from an external device (fire alarm, etc.) connected to the indoor unit board	Ask the person in charge about the status of the building automation/external devices. Service is required.
L31	Phase detection protection (phase sequence/phase loss) – RAV series	Reverse phase or phase loss in the three-phase supply, outdoor board fault	If work has recently been done on the electrical installation, tell the electrician. Service is required.
P03	Discharge temperature too high	Gas leak, expansion valve (PMV) fault, TD sensor problem	Service required
P04	High pressure protection tripped	Overload in the cooling cycle, dirty/blocked outdoor heat exchanger, sensor problem	Clear the area around the outdoor unit and the air outlet. If it continues, service is needed.
P07	Outdoor unit heat sink overheating	Insufficient outdoor unit ventilation or board problem	Clear the area around the outdoor unit and prevent hot air buildup. If it continues, service is needed.
P10	Indoor unit overflow (float) error	Drain pump failure/blockage, float error	Switch the unit off; do not use it if water is dripping. Service is required.
P12	Indoor unit DC fan motor error	Fan lock, driver overcurrent protection, board problem	Do a safe reset. If it continues, service is needed.
P19	4-way valve (heating/cooling changeover) error	4-way valve fault or heat exchanger sensor problem	Service required
P22	Outdoor unit DC fan motor error	Fan lock, position detection error, driver overcurrent	From the outside, clear obstructions in front of the outdoor fan. If it continues, service is needed.
P26	Inverter overcurrent protection (G-Tr short circuit)	Short circuit in the compressor motor winding or IPDU wiring error	Service required
P29	Compressor position detection circuit error	IPDU (inverter board) fault	Service required

Source: toshiba-aircon.com.sg · klimaclassic.blob.core.windows.net · toshiba-aircon.co.uk

Carrier / Alarko Carrier fault codes

Scope: Alarko Carrier light commercial series (cassette 42TSV, ceiling 42FTV, duct 42SMV, floor-standing 42CFV/CFH indoor units; 38VN/38HN outdoor units) – Midea-based platform. The same letter code means different things on the indoor and outdoor unit; numbering differs on wall-mounted Carrier splits and fixed-speed floor-standing types (it can vary by series). It must always be stated whether the code appears on the indoor or the outdoor unit display.
How to read the code: It is shown on the digital display of the indoor unit (E1, EC, etc.) or by the blinking combination of the Operation/Timer/Defrost/Alarm lamps (fast blink 5 Hz, slow 0.5 Hz). Outdoor unit codes appear on the display/LED of the outdoor unit board; the indoor unit shows 'Ed' (outdoor unit fault).

Code	Meaning	Likely cause	What can you do?
E1 (indoor unit)	Communication error between the indoor and outdoor unit	Signal cable broken/reversed, interference, unshielded cable or board fault	Cut the unit's power and restore it after a few seconds. If it continues, service is needed.
E2 (indoor unit)	T1 (room temperature) sensor open/short circuit	Sensor or connector fault	Service required
E3 (indoor unit)	T2 (indoor coil midpoint) sensor open/short circuit	Sensor or connector fault	Service required
E4 (indoor unit)	T2B (indoor coil outlet) sensor open/short circuit	Sensor or connector fault	Service required
E7 (indoor unit)	Indoor unit EEPROM (memory) fault	EEPROM chip or indoor board fault	Do a safe reset. If it continues, service is needed.
E8 (indoor unit)	Indoor fan speed out of control (DC motor models)	Fan jam, bearing failure, motor or board problem	Do a safe reset. If it continues, service is needed.
EC (indoor unit)	Refrigerant leak protection	Gas leak (especially at valve connections), capillary tube blockage, T2 sensor coming off its position	Service required
Ed (indoor unit)	Outdoor unit fault (details on the outdoor unit display)	An error/protection is active on the outdoor unit or the outdoor unit is without power	Check that the outdoor unit's fuse is on. Service is required.
EE (indoor unit)	Water full (drain overflow) fault	Water level switch, drain pump failure or blocked discharge	Switch the unit off; do not use it if water is dripping. Service is required.
P0 (inverter floor-standing indoor unit)	Evaporator low temperature protection	Dirty filter, low airflow, low set temperature or gas problem	Clean the filter and clear the air inlet/outlet. If it continues, service is needed.
E0 (outdoor unit)	Outdoor unit EEPROM fault	Outdoor main board memory fault	Service required
E2 (outdoor unit)	Indoor-outdoor communication fault	Communication cable or board problem	Do a safe reset. If it continues, service is needed.
E3 (outdoor unit)	Communication fault between the IPM board and the outdoor main board	Signal cable between boards or board fault	Service required
E4 (outdoor unit)	T3 (condenser) or T4 (outdoor ambient) sensor open/short circuit	Sensor or cable fault	Service required
E5 (outdoor unit)	Compressor voltage protection	Abnormal mains voltage, connection or bridge diode/reactor problem	Restart the unit when the mains returns to normal. If it continues, service is needed.
E6 (outdoor unit)	PFC module protection (single-phase models with PFC board)	PFC module or connection fault	Service required
P0 (outdoor unit)	Compressor top (shell) temperature protection	Gas shortage, capillary blockage or protector failure	Service required
P1 (outdoor unit)	High pressure protection (model-specific)	High pressure switch/connection problem, very high ambient temperature, dirty condenser	Clear the area around the outdoor unit. If it continues, service is needed.
P2 (outdoor unit)	Low pressure protection (model-specific)	Gas shortage/leak or pressure switch problem	Service required
P3 (outdoor unit)	Compressor current protection	Overload, supply or compressor problem	Service required
P4 (outdoor unit)	Compressor discharge temperature protection	Gas shortage or flow problem	Service required
P5 (outdoor unit)	Condenser high temperature protection	Dirty condenser, insufficient outdoor unit ventilation, outdoor fan problem	Clear the area around the outdoor unit and remove items blocking the air outlet. If it continues, service is needed.
P6 (outdoor unit)	IPM module protection	Power module, compressor or supply problem	Service required
P7 (outdoor unit)	Evaporator high temperature protection (in heating)	Insufficient indoor unit airflow in heating (dirty filter)	Clean the indoor unit filter and clear the air inlet/outlet. If it continues, service is needed.

Source: paperzz.com · alarko-carrier.com.tr

Arçelik / Beko fault codes

Scope: Arçelik and Beko wall-mounted split air conditioners (Arçelik and Beko are products of the same group; the Arçelik support page also covers Beko models). The CH code list is Arçelik's official list; older series or those with different suppliers may use E/F codes, and their meaning can vary by series.
How to read the code: The code appears on the indoor unit display as 'CH' + a number. According to Arçelik, for a CH error first switch the air conditioner's breaker off and back on after 3 minutes; if the error is temporary the code disappears. Model information is on the grey label at the bottom of the indoor unit.

Code	Meaning	Likely cause	What can you do?
F1–F5	Fan speed level indicator (not a fault)	On models 18321 (Arçelik) / 31821 (Beko) produced in April 2017, the level is shown when the fan speed is changed	No action needed; this is normal.
CO	Auto Clean (smart cleaning) is running (not a fault)	The Auto Clean button was pressed on the remote; after the unit is switched off it dries/cleans itself for ~30 minutes	Wait, or turn the feature off by pressing the same button again.
CH01	Indoor unit room temperature sensor error	Sensor or connection fault	Switch the breaker off and on after 3 min. If it continues, service is needed.
CH02	Indoor unit inlet pipe sensor error	Sensor or connection fault	Switch the breaker off and on after 3 min. If it continues, service is needed.
CH03	Wired remote controller error	Wired controller or connection problem	Service required
CH04	Float switch error (optional, drain)	Drain/float problem	Service required
CH05 / CH53	Communication error between the indoor and outdoor unit	Communication cable, outdoor unit without power or board problem	Switch the breaker off and on after 3 min. If it continues, service is needed.
CH06	Indoor unit outlet pipe sensor error	Sensor or connection fault	Service required
CH09	Indoor unit EEPROM error	Indoor unit board memory error	Service required
CH10	Indoor unit BLDC fan motor impeller lock	Fan motor lock or motor fault	Switch the breaker off and on after 3 min. If it continues, service is needed.
CH21	DC current (IPM) error	Inverter power module protection	Service required
CH23	DC link low voltage error	Supply voltage or board problem	Switch the breaker off and on after 3 min. If it continues, service is needed.
CH26	DC compressor position error	Compressor or driver circuit problem	Service required
CH29	Compressor phase error / overcurrent error	Compressor or driver problem	Service required
CH32	Compressor discharge line pipe sensor overheating error	Gas shortage or flow problem	Service required
CH34	High pressure sensor – high pressure error	Dirty condenser, insufficient outdoor unit ventilation	Clear the area around the outdoor unit. If it continues, service is needed.
CH35	Low pressure sensor – low pressure error	Gas shortage/leak	Service required
CH36 / CH38	Refrigerant (gas) leak error	Gas leak or insufficient charge	Service required
CH44	Outdoor air sensor error	Sensor or connection fault	Service required
CH51	Capacity exceeded (wrong indoor/outdoor unit pairing)	Incompatible indoor/outdoor unit combination	Service required
CH61	Condenser pipe temperature high error	Insufficient outdoor unit ventilation, dirty condenser	Clear the area around the outdoor unit and the air outlet. If it continues, service is needed.
CH62	Main board heat sink sensor temperature high	Insufficient outdoor unit ventilation or board problem	Clear the area around the outdoor unit. If it continues, service is needed.
CH67	Outdoor unit BLDC fan motor lock error	Obstruction in front of the outdoor fan or motor fault	From the outside, clear obstructions in front of the outdoor fan. If it continues, service is needed.
CH72	4-way valve position error	4-way valve or control problem	Service required
CH93	Indoor-outdoor communication error	Communication cable or outdoor unit supply problem	Switch the breaker off and on after 3 min. If it continues, service is needed.

Source: arcelik.com.tr · arcelik.com.tr

Vestel fault codes

Scope: Vestel inverter wall-mounted split air conditioners (ER/SR codes, after 2015) and older series with LED/LCD indicators (Platinum A, Air Plus A, Ecoplus). Older series use LED combinations; the meaning of codes can vary by series.
How to read the code: On inverter models the code appears on the indoor unit display as 'ER 06', 'SR 01' and so on; service also looks at the number of blinks of the LED on the outdoor unit board (e.g. 9 blinks + 3 s pause = communication error). On older models with LED indicators, the blinking combination of the Operation/Timer/Fan/Turbo lamps indicates the fault. Protection codes shown by the outdoor unit LED often do not mean a fault; they indicate the unit went into protection because of ambient/mains conditions.

Code	Meaning	Likely cause	What can you do?
SR 01 (formerly ER 01)	Indoor unit ambient (room) sensor open/short circuit	Sensor fault. The unit does not stop; it ignores the room sensor and keeps running as if at 24°C.	The unit keeps running but service is required.
ER 02	Compressor cable not connected / software-compressor mismatch	Outdoor unit connection or board problem (outdoor LED: 25 blinks)	Service required
ER 03	Indoor unit pipe sensor open/short circuit	Sensor fault	Service required
ER 04	Indoor unit fan motor error	Fan jam, rubbing or motor/board fault	Do a safe reset. If it continues, service is needed.
ER 05	Indoor unit setup (configuration data) not done/erased	Board parameter data missing	Service required
ER 06	Indoor and outdoor unit communication error	Connection cable or board problem, outdoor unit without power (outdoor LED: 9 blinks)	Do a safe reset. If it continues, service is needed.
ER 07	Refrigeration system error (gas low/empty)	Gas leak or insufficient charge (outdoor LED: 7 blinks)	Service required
SR 08	Outdoor unit pipe sensor open/short circuit	Sensor fault (outdoor LED: 14 blinks)	Service required
ER 09	Model mismatch between units	Incompatible indoor/outdoor unit pairing (outdoor LED: 22 blinks)	Service required
ER 10	Electronic board heat sink sensor open/short circuit	Sensor/board fault (outdoor LED: 15 blinks)	Service required
ER 11	Compressor start protection	Compressor or driver board problem (outdoor LED: 11 blinks)	Do a safe reset. If it continues, service is needed.
ER 13	Compressor overcurrent error (during operation)	Overload, supply or compressor problem (outdoor LED: 13 blinks)	Clear the area around the outdoor unit. If it continues, service is needed.
ER 14	Compressor overcurrent error (at initial start)	Compressor or driver problem	Service required
ER 15	Outdoor unit ambient sensor open/short circuit	Sensor fault (outdoor LED: 16 blinks)	Service required
ER 16	Compressor discharge sensor open/short circuit	Sensor fault (outdoor LED: 17 blinks)	Service required
HL	Low/high voltage protection at start-up (mains-related)	Mains voltage is outside limits (outdoor LED: 18 blinks)	The unit runs when the mains voltage returns to normal; if it repeats often, have the electrical installation checked. If it continues, service is needed.
ER 17	High voltage error during operation (board/reactor-related)	Board or reactor fault	Service required
ER 18	Outdoor unit setup not done/erased	Outdoor board parameter data missing	Service required
ER 19	Wi-Fi module communication error	Communication problem between the Wi-Fi module and the board	Do a safe reset. If it continues, service is needed.
ER UE	UVC LED error	UV-C sterilization LED module fault	Service required
ER PS	Air quality sensor open/short circuit	Sensor fault	Service required
E1 (Platinum A / Air Plus A)	Magnetic field warning affecting the electronic board	Electromagnetic interference from nearby devices	Move strong electromagnetic sources away from the indoor unit and reset. If it continues, service is required.
E6 (Platinum A / Air Plus A)	Mains voltage too high/low fault	Mains voltage fluctuation	This warning code does not require service (a service call would be charged). Reset once the voltage returns to normal.
E7 (Platinum A / Air Plus A)	Electronic board memory has been erased	Board memory data loss	Service required
88	3-minute protection after a power outage	Waiting period to protect the compressor after power returns	Wait 3 minutes; no service is needed.
FW	Filter cleaning warning	Time to clean the filters	Clean the filters, then reset the warning by holding the (+) and (−) buttons on the remote for 5 seconds.

Source: static.vestel.com.tr · static.vestel.com.tr · scribd.com

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