A summary of 979 public air conditioner fault questions from technicians' groups (2021–2026): 795 (81%) have a fix most technicians agreed on or the poster confirmed; 279 (28%) give an error code, the rest only describe a symptom (not cooling, compressor cuts out after a few minutes, no ramp-up…).
Share of fault questions by brand
| Brand | Posts | Share | With a code | With a fix |
|---|---|---|---|---|
| Daikin | 206 | 21% | 54 | 183 |
| Panasonic | 77 | 8% | 20 | 64 |
| Toshiba | 76 | 8% | 21 | 60 |
| LG | 55 | 6% | 21 | 51 |
| Samsung | 37 | 4% | 13 | 31 |
| Sharp | 37 | 4% | 17 | 27 |
| Mitsubishi Electric | 31 | 3% | 8 | 22 |
| Aqua | 21 | 2% | 5 | 16 |
| Casper | 21 | 2% | 11 | 17 |
| Hitachi | 12 | 1% | 5 | 7 |
| Nagakawa | 11 | 1% | 5 | 9 |
| Fujitsu | 8 | 0.8% | 4 | 3 |
| Mitsubishi | 8 | 0.8% | 1 | 7 |
| Funiki | 7 | 0.7% | 3 | 6 |
| Midea | 7 | 0.7% | 5 | 7 |
| Electrolux | 6 | 0.6% | 4 | 5 |
| Gree | 6 | 0.6% | 5 | 5 |
| Mitsubishi Heavy | 4 | 0.4% | 1 | 2 |
| Sanyo | 3 | 0.3% | 3 | 3 |
| Beko | 2 | 0.2% | 2 | 1 |
| Asanzo | 1 | 0.1% | 1 | 1 |
| Comfee | 1 | 0.1% | 0 | 0 |
| Comfree | 1 | 0.1% | 1 | 1 |
| Elec | 1 | 0.1% | 1 | 1 |
| General | 1 | 0.1% | 0 | 1 |
| Racco | 1 | 0.1% | 0 | 0 |
| Sanaky | 1 | 0.1% | 1 | 1 |
| Skyworth | 1 | 0.1% | 1 | 0 |
| TCL | 1 | 0.1% | 0 | 1 |
| Trane | 1 | 0.1% | 1 | 1 |
| No brand named | 334 | 34% | 65 | 262 |
| Total | 979 | 100% | 279 | 795 |
Daikin · 206 posts, 21% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| F3 | 6 | 3% | Error F3 on Daikin units is usually caused by excessively high discharge line temperature, so check whether the power supply voltage is stable, whether the service valve is fully open, and whether the… |
| U4 | 5 | 2% | Error U4 indicates a communication fault between the indoor unit and the outdoor unit, caused by incorrectly connected signal wiring or a faulty board. Recheck the signal wire (verify the correct… |
| U0 | 4 | 2% | Error U0 on a Daikin unit is usually caused by a refrigerant shortage or a problem with the solenoid valve/valve coil. Check that the copper pipes are not kinked, check the sensors, then use a clamp… |
| E5 | 3 | 1% | Error E5 on a Daikin indicates a compressor cut-out (compressor protection). Measure the inlet and outlet air temperatures of the indoor unit, check whether the outdoor unit is dirty or has its… |
| 00 | 2 | 1% | Code 00 on a Daikin remote is usually not an actual error code but a normal status. To view the real error code, enter the self-diagnosis mode as described in the unit's manual (for example, press OFF… |
| CC | 2 | 1% | No agreed fix yet |
| E0 | 2 | 1% | Error E0 on a Daikin indoor unit is usually caused by a protection circuit on the outdoor unit (pressure switch relay, phase protection circuit) tripping and cutting out the outdoor unit after a few… |
| UA | 2 | 1% | The UA code on Daikin units is usually related to a communication fault between the indoor unit and the outdoor unit caused by the signal wire. Check and replace all 3 signal wires with… |
| E | 1 | 0.5% | No agreed fix yet |
| 10 | 1 | 0.5% | Error code 10 on this Daikin air conditioner is, in this case, caused by a blocked condensate drain line, which causes flooding or triggers the water-level float switch. Check and clear the drain… |
| 2E | 1 | 0.5% | No agreed fix yet |
| 4.3 | 1 | 0.5% | Carefully check the signal wires and power wires of the outdoor unit, especially the black wires that are loose or have poor contact. At the same time, check the probe sensor, the capacitor on the… |
| 4K | 1 | 0.5% | No agreed fix yet |
| 6.2 | 1 | 0.5% | Error 6.2 on Daikin units is usually caused by the expansion valve body / solenoid valve coil (valve coil) not closing fully, or a blocked refrigerant line (strainer, expansion valve body). Check the… |
| A5 | 1 | 0.5% | The A5 error on this Daikin domestic unit is, in this case, caused by low refrigerant, which makes the current drop and trips the compressor. Check the operating pressure, charge refrigerant by weight… |
| C4 | 1 | 0.5% | No agreed fix yet |
| C7 | 1 | 0.5% | Error C7 on Daikin units is usually related to the louver lift/swing motor or the limit switch, causing the unit to run only when operated manually. Check the louver lift switch, contacts and swing… |
| E3 | 1 | 0.5% | Do not bypass the high-pressure switch, because it is a protective device that cuts out the compressor when pressure is high; bypassing it will cause the compressor to blow. Check the causes of high… |
| E6 | 1 | 0.5% | No agreed fix yet |
| E8 | 1 | 0.5% | No agreed fix yet |
| F4 | 1 | 0.5% | Error code F4 on a Daikin VRV is related to the outdoor unit's temperature or pressure sensor, not a humidity alarm. Determine the sub-code from the manufacturer's service manual, then check the… |
| FR | 1 | 0.5% | The FR code on Daikin units is usually caused by the indoor unit temperature sensor giving a false reading, most often when frost builds up on the copper pipe at the sensor head or when the sensor is… |
| J8 | 1 | 0.5% | Error code J8 on a Daikin unit indicates a fault in the liquid-line temperature sensor after the expansion valve (EEV). The technician should measure the sensor resistance (kOhm) and compare it with… |
| L5 | 1 | 0.5% | Error L5 on a Daikin R32 is usually caused by the compressor (block) or the contactor (cáp từ) tripping the protection, and rarely by the capacitor or the board. Disconnect the contactor and run a… |
| LS | 1 | 0.5% | Daikin error code L5 is usually an inverter board/module fault, which can be caused by a contactor short circuit burning out the board. Turn off the power, check whether the contactor is shorted, then… |
| PJ | 1 | 0.5% | Error PJ on Daikin units occurs because the new indoor unit board has not recognized the correct unit capacity. Set the correct model, then insert the capacity-setting resistor into the indoor unit… |
| R6 | 1 | 0.5% | Daikin code A6 relates to the indoor fan motor or the control circuit on the board, not R6. First measure the 3 wires of the indoor fan motor to check for a break; if the motor is still good, check or… |
| UO | 1 | 0.5% | The UO code on Daikin units is usually a refrigerant shortage: recover all the old gas, clean the coils, evacuate, then charge the exact weight in kg stated on the outdoor unit using an electronic… |
| 119 | 1 | 0.5% | No agreed fix yet |
| L1-54 | 1 | 0.5% | No agreed fix yet |
| Blinking lamps | 11 | 5% | Count the blinks and look them up in the exact model's lamp table. |
Panasonic · 77 posts, 8% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| H11 | 4 | 5% | Carefully check the signal wire connecting the indoor unit and outdoor unit, especially the wiring order according to the manufacturer's diagram. If the wiring is correct, check the indoor unit and… |
| F93 | 3 | 4% | Error F93 on Panasonic units is usually caused by a seized or weak compressor (block), which causes the compressor to fail to ramp up and then trip the protection. The approach confirmed by the lead… |
| H16 | 2 | 3% | Error code H16 on Panasonic units is usually related to abnormal current or power supply that causes the unit to trip its protection. Check the supply voltage, supply wiring and voltage stabilizer,… |
| 5 | 1 | 1% | Error 5 on Panasonic is usually caused by a faulty outdoor control board (inverter board), which trips the unit under load. Check the oil, refrigerant, fan and current draw first, then replace the… |
| F11 | 1 | 1% | No agreed fix yet |
| F30 | 1 | 1% | No agreed fix yet |
| F31 | 1 | 1% | No agreed fix yet |
| F35 | 1 | 1% | No agreed fix yet |
| F90 | 1 | 1% | No agreed fix yet |
| F99 | 1 | 1% | No agreed fix yet |
| H67 | 1 | 1% | No agreed fix yet |
| U23 | 1 | 1% | No agreed fix yet |
| Blinking lamps | 2 | 3% | Count the blinks and look them up in the exact model's lamp table. |
Toshiba · 76 posts, 8% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| 12 | 3 | 4% | No agreed fix yet |
| 04 | 2 | 3% | Rodent damage cut through wiring, causing a short circuit and damaging the protection circuit/components on the inverter board. The unit shows error 04 and trips when running at about 1.3A. Cut off… |
| 03 | 1 | 1% | Check that the copper pipe temperature sensors on the indoor and outdoor units are clamped in the correct position on the pipes. Check whether the sensor wiring has been chewed by rodents or is… |
| 07 | 1 | 1% | Check that the copper pipe temperature sensors on the indoor and outdoor units are clamped in the correct position on the pipes. Check whether the sensor wiring has been chewed by rodents or is… |
| 14 | 1 | 1% | Error 04 is a communication signal failure from the outdoor unit not reaching the indoor unit; error 14 is an inverter overcurrent, usually caused by moisture on the control board when rain blows in.… |
| 1F | 1 | 1% | No agreed fix yet |
| 4.2 | 1 | 1% | Error code 4.2 on a Toshiba inverter typically relates to pressure protection or overload when refrigerant is low or the outdoor unit fan runs weakly. Check the pressure on both sides, charge R410A to… |
| 5A | 1 | 1% | Error code 5A means the unit has ramped up but has not yet reached its maximum capacity. Check the outdoor unit's position and heat dissipation, the refrigerant charge, whether the contactor wiring is… |
| E9 | 1 | 1% | No agreed fix yet |
| EA | 1 | 1% | Error code EA on the Toshiba DC1000 is not a standard error code of the manufacturer, so the control circuit should be checked. You may replace the CPU board (control board), or carefully inspect the… |
| EF | 1 | 1% | No agreed fix yet |
| LF | 1 | 1% | Check whether the compressor current is abnormally high, and check the pressure and refrigerant charge to see whether they are sufficient. If the current is high or the refrigerant is low, the root… |
| OE | 1 | 1% | No agreed fix yet |
| 02-1C | 1 | 1% | No agreed fix yet |
| 031F | 1 | 1% | Error 031F is usually related to the outdoor unit board when the load increases at high temperature, while the sensors and refrigerant have already been checked. Check the outdoor unit fan and coil,… |
| 1C02 | 1 | 1% | Error code 1C02 on Toshiba units is usually caused by poor contact at the outdoor unit sensor/thermistor connector or the pin sockets on the board. Check and re-solder the contact pins directly. At… |
| Blinking lamps | 6 | 8% | Count the blinks and look them up in the exact model's lamp table. |
LG · 55 posts, 6% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| CH38 | 7 | 13% | Check the suction line pressure with a gauge after recovering the refrigerant to determine whether the system is undercharged. At the same time, check the compressor-top thermistor, the pipe sensor,… |
| CH90 | 2 | 4% | LG error code CH90 together with the pressure dropping from 260 to 180 while the unit runs indicates the unit is short of refrigerant gas or has a gas leak. Check for refrigerant leaks along the… |
| F5 | 1 | 2% | The common cause is water entering the connector, motor, or board of the indoor unit fan after cleaning. Disconnect the connector, thoroughly dry all wet components, then reassemble and check that the… |
| DE1 | 1 | 2% | Error code DE1 on LG units is usually related to a communication fault or the control board. Visually inspect the board on the indoor unit and the outdoor unit for burnt or blown components or damaged… |
| CH05 | 1 | 2% | Error CH05 on an LG unit is a communication error between the indoor unit and the outdoor unit. Check the three communication wires at the outdoor unit, especially the connections on the terminal… |
| CH29 | 1 | 2% | No agreed fix yet |
| CH36 | 1 | 2% | Check the power supply input to the indoor unit board/power supply, especially the L and N supply wires, and check the sensor connections. Switch off the circuit breaker, wait a while, then switch it… |
| CH61 | 1 | 2% | Error CH61 means the outdoor unit pipe temperature is high; the unit runs for a few seconds and then cuts out the compressor. Check that the sensor is installed in the correct position, check for… |
| Blinking lamps | 6 | 11% | Count the blinks and look them up in the exact model's lamp table. |
Samsung · 37 posts, 4% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| C422 | 2 | 5% | Error C4-22 on a Samsung unit, where compressor current rises above 1A and then cuts out, is usually caused by a faulty compressor or a faulty power module. Measure the resistance of the compressor… |
| 15 | 1 | 3% | Error code 15 on a Samsung unit is usually related to the temperature sensor or the heat exchanger coil. Check the resistance and the sensor head, and replace them if the values are wrong. Test each… |
| 22 | 1 | 3% | Error C4 22 on a Samsung Inverter air conditioner is usually a temporary fault caused by protection or sensor issues in the indoor unit or outdoor unit, so turn off the circuit breaker (CB) for a few… |
| 3A | 1 | 3% | No agreed fix yet |
| C4 | 1 | 3% | Error code C4-22 on a Samsung unit is usually related to the current sensor and the compressor current-draw circuit (compressor/control board). Check the connecting wires, the crimp terminals and the… |
| C44 | 1 | 3% | Error C4 22 on a Samsung Inverter air conditioner is usually a temporary fault caused by protection or sensor issues in the indoor unit or outdoor unit, so turn off the circuit breaker (CB) for a few… |
| C163 | 1 | 3% | Error code C1 63 means the unit has been set to Fahrenheit by an accidental button press. Use the remote to enter the correct setting key sequence to switch back to Celsius, which resolves the issue. |
| E108 | 1 | 3% | Error E108 on the Samsung multi system is caused by duplicate communication addresses between the indoor units. Recheck the signal wire wiring between the indoor and outdoor units, then reset the… |
| E201 | 1 | 3% | When the indoor units were removed for cleaning, the system lost the indoor unit addresses, so it displays E2 01 (communication error). Reassign the indoor unit addresses according to the… |
| EL01 | 1 | 3% | No agreed fix yet |
| Blinking lamps | 3 | 8% | Count the blinks and look them up in the exact model's lamp table. |
Sharp · 37 posts, 4% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| 02 | 1 | 3% | Error code 02 on this Sharp unit, in this case, is related to the oil trap not being installed when the outdoor unit is installed more than 5 m higher than the indoor unit. Check the height difference… |
| 09 | 1 | 3% | No agreed fix yet |
| 18 | 1 | 3% | Error 18 on a Sharp unit is usually caused by a faulty indoor unit temperature sensor (probe) or a broken, loose, or burnt signal wire. Check and replace the sensor, then check the connection wiring… |
| 26 | 1 | 3% | No agreed fix yet |
| 10-2 | 1 | 3% | Error 10-2 on Sharp units is usually caused by an open solder joint or a loose connection on the outdoor unit control board (the outdoor control PCB). Solution: check and replace the terminal block… |
| 19-0 | 1 | 3% | No agreed fix yet |
| C06 | 1 | 3% | No agreed fix yet |
| Blinking lamps | 10 | 27% | Count the blinks and look them up in the exact model's lamp table. |
Mitsubishi Electric · 31 posts, 3% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| 1 | 3 | 10% | Error 1 that appears after running 15-20 minutes and then cutting out is usually caused by a faulty outdoor unit control board (outdoor board). Check the LED indicators on the board; if the board is… |
| Blinking lamps | 5 | 16% | Count the blinks and look them up in the exact model's lamp table. |
Aqua · 21 posts, 2% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| E7 | 1 | 5% | No agreed fix yet |
| F1 | 1 | 5% | Error F1 on an AQUA Inverter unit is usually related to the room temperature sensor or the indoor unit control board. Check the connectors and the sensor first, then check the board; if the board is… |
| F28 | 1 | 5% | Check the fan and the outdoor unit, clean them and make sure heat dissipation is good; avoid direct sunlight and shield the outdoor unit. At the same time, check whether the board is damp after rain,… |
| Blinking lamps | 2 | 10% | Count the blinks and look them up in the exact model's lamp table. |
Casper · 21 posts, 2% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| L4 | 2 | 10% | No agreed fix yet |
| 5E | 1 | 5% | Check the power supply and the error indicator light on the outdoor unit board, then check that the signal wires 1-2-3 between the outdoor unit and the indoor unit are connected in the correct order,… |
| E0 | 1 | 5% | Casper error code E0 is usually a communication fault between the indoor unit and the outdoor unit, most often caused by incorrectly connected signal wires. Check that the 1-2-3 (N, L, S) wires are… |
| E5 | 1 | 5% | E5 is a communication error between the outdoor unit and the indoor unit. Check and retighten the signal wire, especially the connections at terminal block 1-2-3; if the aluminum wire is oxidized,… |
| L0 | 1 | 5% | Error code L0 on a Casper unit is usually related to unstable voltage or power supply, especially when the electricity is weak during peak hours. Measure the voltage at the moment the unit shows the… |
| L7 | 1 | 5% | Error L7 on a Casper inverter air conditioner is usually caused by water entering the outdoor unit control board (outdoor unit board) after cleaning. Inspect and dry the outdoor unit board; if the… |
| P0 | 1 | 5% | Error code P0 on Casper units is usually related to the outdoor unit, the compressor or the control board. Check with a multimeter on the resistance range by testing continuity across the three… |
| P4 | 1 | 5% | No agreed fix yet |
| ECS3 | 1 | 5% | The EC S3 code on Casper units is usually related to the temperature sensor or the outdoor unit. Check and thoroughly clean the outdoor unit and the sensor. If the error persists after replacing the… |
| Blinking lamps | 1 | 5% | Count the blinks and look them up in the exact model's lamp table. |
Hitachi · 12 posts, 1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| Blinking lamps | 5 | 42% | Count the blinks and look them up in the exact model's lamp table. |
Nagakawa · 11 posts, 1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| E4 | 1 | 9% | No agreed fix yet |
| E5 | 1 | 9% | Check the 3 signal wires between the indoor unit and the outdoor unit with a multimeter for breaks, short circuits, or loose crimped terminals. If the wires are normal, next check the outdoor control… |
| EE | 1 | 9% | No agreed fix yet |
| Blinking lamps | 2 | 18% | Count the blinks and look them up in the exact model's lamp table. |
Fujitsu · 8 posts, 0.8% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| 02 | 1 | 12% | No agreed fix yet |
| 56 | 1 | 12% | No agreed fix yet |
| 9C | 1 | 12% | Error code 9C on Fujitsu units is usually caused by a connection fault in the control wiring / signal wire between the indoor unit and the board, especially after the unit has been dismantled for… |
| ER | 1 | 12% | No agreed fix yet |
| Blinking lamps | 1 | 12% | Count the blinks and look them up in the exact model's lamp table. |
Mitsubishi · 8 posts, 0.8% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| CL | 1 | 12% | No agreed fix yet |
Funiki · 7 posts, 0.7% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| SC | 1 | 14% | Error code 5C is a fault in the indoor unit coil temperature sensor, not SC or FC. Check the sensor connection wiring and the sensor itself; if faulty, replace it with a new coil sensor and clip it at… |
| EC51 | 1 | 14% | No agreed fix yet |
| EH03 | 1 | 14% | EH03 on Funiki units is usually caused by the indoor unit control board not receiving feedback from the fan. First measure the fan capacitor and carefully inspect the signal wire (check for… |
Midea · 7 posts, 0.7% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| F5 | 1 | 14% | No agreed fix yet |
| P3 | 1 | 14% | Check whether the outdoor unit fan is running, since a faulty fan causes high pressure and overheating. Then measure the compressor current and check the refrigerant pressure; suspect overload or a… |
| EH00 | 1 | 14% | Error code EH00 on a Midea Inverter unit is usually a fault on the indoor unit board (EEPROM or control circuit). Check the indoor unit board for short circuits, burn marks, moisture or water ingress,… |
| Blinking lamps | 2 | 29% | Count the blinks and look them up in the exact model's lamp table. |
Electrolux · 6 posts, 0.6% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| F1 | 2 | 33% | Error F1 on an Electrolux inverter air conditioner is usually caused by a faulty temperature sensor, especially the sensor on the outdoor unit. Check the sensor and the power/signal wiring, replace… |
| E | 1 | 17% | Error code F1 on Electrolux units is usually related to the sensor or signal wire on the outdoor unit, not just the room sensor. Check the signal wire connection and the outdoor unit sensor first; if… |
| P0 | 1 | 17% | Error code P0 on an Electrolux inverter air conditioner is usually caused by a failed inverter board in the outdoor unit (outdoor board). Check the outdoor board, the IPM power module, and the power… |
| P1 | 1 | 17% | Error P1 that appears intermittently on an inverter unit usually relates to the outdoor unit control board or the power supply. Measure the power supply and check the indoor and outdoor connection… |
Gree · 6 posts, 0.6% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| E1 | 2 | 33% | The E1 error on this GREE unit is caused in this case by excess refrigerant, which makes the discharge pressure too high, the compressor run for a long time, and the sensor report no cooling. Measure… |
| E3 | 1 | 17% | The E3 error on Gree units is usually caused by protection cut-out due to abnormal pressure or water, not by the board. Check the phase sequence and the 3-phase power connection, the condensate drain… |
| E6 | 1 | 17% | Gree error E6 is usually a communication fault between the outdoor unit and the indoor unit. Carefully check the signal wire and the crimped connectors, make sure the wire cross-section is adequate… |
| H4 | 1 | 17% | Gree error H4 is usually caused by current exceeding the threshold due to heavy load, a restricted refrigerant line, or a blocked expansion valve. Check that the outdoor unit is clean, measure the… |
Mitsubishi Heavy · 4 posts, 0.4% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| Blinking lamps | 1 | 25% | Count the blinks and look them up in the exact model's lamp table. |
Sanyo · 3 posts, 0.3% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| ED | 1 | 33% | An ED error on a SANYO inverter is usually caused by the connecting wire between the two boards or by a faulty power board. First check the connecting wire carefully. If the wire is fine, check and… |
| F2 | 1 | 33% | Error code F2 on a Sanyo air conditioner is usually caused by a fault in the indoor unit temperature sensor. Check the resistance of the temperature probe, or replace the indoor unit sensor with a… |
| F12 | 1 | 33% | Error code F12 on a Sanyo air conditioner is usually caused by a faulty board (control board or power board) in the outdoor unit. Check the outdoor unit board and replace it with a new board of the… |
Beko · 2 posts, 0.2% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| E1 | 1 | 50% | Error E1 appearing at startup and only at night may be caused by a faulty 12 MHz crystal or control IC on the control board, which prevents the relay from closing. Check the crystal and the control… |
| E7 | 1 | 50% | No agreed fix yet |
Asanzo · 1 post, 0.1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| F3 | 1 | 100% | Check and fully open both service valves (liquid valve and gas valve) of the outdoor unit, since a partially closed valve can cause error F3 due to abnormal pressure or discharge temperature. After… |
Comfree · 1 post, 0.1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| PC04 | 1 | 100% | Error code PC04 is usually related to a signal transmission fault between the outdoor unit and the indoor unit, so check the signal wire and the connection ports. If the fault persists, suspect the… |
Elec · 1 post, 0.1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| FC | 1 | 100% | Error code FC on this Elec unit is usually caused by a fault on the indoor unit board or a display board connection causing signal loss, so first check the display plug connection, try a different… |
Sanaky · 1 post, 0.1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| Blinking lamps | 1 | 100% | Count the blinks and look them up in the exact model's lamp table. |
Skyworth · 1 post, 0.1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| L2 | 1 | 100% | No agreed fix yet |
Trane · 1 post, 0.1% of all
| Code | Posts | Of the brand | Most agreed fix |
|---|---|---|---|
| E5 | 1 | 100% | Error E5 appears about 1 hour after the compressor starts, so check the compressor insulation. Use a megger to test whether there is electrical leakage from the compressor to the casing. At the same… |
Overall
- Communication errors (Daikin U4, UA, Panasonic H11, Toshiba 12, Casper E5): mostly wiring first, board last – check the signal wires, the terminal block, the wire order and a power cable of the right size before replacing a board.
- Low-refrigerant codes (Daikin U0, LG CH38): mostly a real low charge or a blocked expansion valve, not the board – find the leak, evacuate, charge to the label.
- Sharp 9 blinks: most often the indoor pipe sensor (about 3.3 kΩ); on a heating-only unit, check the reversing valve.
- Panasonic H11 after a new board and wires: unplug the louver motor and test – a shorted louver-motor driver IC also breaks communication.
Note: this is technicians' field experience, not a manufacturer's document. Code meanings and measured values can differ by model – check the exact model before repairing. Open a code to see its repair cases.
Safety: switch off both the indoor and the outdoor unit before opening a cover or touching a board; the capacitors on the outdoor board stay charged for a while after power-off - wait for the board's lamps to go out and measure before touching. Refrigerant and high-voltage work belongs to a certified technician.