When there is a problem with your Mitsubishi Heavy Industries-Haier air conditioning, you need to know the meaning of the fault code displayed on the thermostat and how to troubleshoot it. In this article, we will provide you with some useful information to help you troubleshoot your Mitsubishi Heavy Industries-Haier air conditioning.
1. Mitsubishi Heavy Industries-Haier Air Conditioning Error Codes
Here are some common Mitsubishi Heavy Industries-Haier air conditioning fault codes.
1.1 Wired Remote Controller (Thermostat) Model Fault Codes
No error code
Fault content: power supply problem; fuse blown; poor connection of X, Y, Z signal lines; defective wired controller.
E1
Fault content: Poor communication between the wired controller and the inner control board.
For a fixed frequency multi-split air conditioning unit, when a wired controller controls multiple indoor units, E1 may occur if one of them is powered off or their addresses are duplicated.
E2
Fault content: The indoor unit addresses are duplicated or more than 49 (KX4) or 128 (KX6) indoor units in one signal line system.
E3
Fault content: The outdoor unit cannot be detected; the outdoor unit has no power.
If the fuse of the CNK terminal of the inner control board signal line is blown, E3 error code will appear. If the fuse is blown, plug in the CNK2 terminal instead.
E5
Fault content: Poor communication between indoor and outdoor units; outdoor unit power supply is OFF.
If E5 appears on multiple indoor units, generally the power of the outdoor unit is OFF.
E6
Fault content: The indoor heat exchanger temperature sensor is disconnected.
E7
Fault content: The indoor ambient temperature sensor is disconnected.
E8
Fault content: Overload protection during heating.
The heat exchanger temperature of the internal unit exceeds 68°C (VX6, KX6, and KX4 do not have this fault).
E9
Fault content:
①The float switch of the indoor unit operates (for indoor units with a drain pump), the drain pump is broken or the drain outlet is blocked, and the water cannot be drained out (limited to internal units with with float switches, such as duct type (ultra-thin and thin types), embedded type).
②For units without float switches, the power supply voltage is too low (less than 70% of the rated voltage).
③For the 20P cabinet units, it is caused by excessive current of the internal fans, excessive compressor exhaust temperature, or high-voltage protection.
E10
Fault content: One wired controller controls too many internal units (more than 17 units).
E11
Fault content: Use the wired controller to set the address of the indoor unit, and one controls more than 2 indoor units.
E12
Fault content: The indoor unit address switch setting is poor.
E14
Fault content: For fixed-frequency multi-split units, poor communication between the indoor master and slave machines; poor address setting.
E15
Fault content: The outlet air temperature sensor of the indoor unit is disconnected (applicable to KX duct-type fresh air system with outlet air sensor).
E16
Fault content: DC motor is running poorly; for AC motor models, the indoor control board is defective.
E21
Fault content: Poor contact of the limit switch on the RFT-A unit panel.
E28
Fault content: The temperature sensor on the wired controller is disconnected (when setting the temperature sensor of the wire controller is valid).
E30
Fault content: The connection between the indoor and outdoor units does not match; the outdoor unit number corresponding to the indoor unit is the indoor slave unit number.
E31
Fault content: The outdoor unit addresses are duplicated.
E32
Fault content: The power supply is out of phase or reversed.
E33
Fault content: Compressor overcurrent (excessive current during operation).
E34
Fault content: T-phase power supply of 52C2 secondary side is out of phase (the current detected by KX master unit CT2 is 0).
E35
Fault content: Overload operation during cooling (heat exchange temperature of the outdoor unit exceeds 70°C).
E36, E36-1, E36-2
Fault content: The compressor discharge temperature is abnormal (that of KX, KX4, or KX6 exceeds 130°C). E36-3 means low superheat at the bottom of the compressor.
E37
Fault content: The outdoor heat exchanger temperature sensor is disconnected.
E38
Fault content: The outdoor ambient temperature sensor is disconnected.
E39
Fault content: The compressor discharge temperature sensor is disconnected.
E40
Fault content:
①High voltage switch 63H1 operates;
②The internal thermal protection 49C of the compressor operates;
③The compressor discharge temperature switch operates (10P unit machine) or the discharge temperature is too high (LX);
④The power supply voltage is too low (unit machine).
E41\E51
Fault content: The power module temperature is too high (KX, KX4, KX6 machines). E51 may also be a frequency conversion board failure.
E42
Fault content: Compressor overcurrent (excessive current during startup).
E43
Fault content: The number or the capacity of indoor units connected exceeds the specified value.
E45
Fault content: Frequency conversion control board communication abnormality.
E46
Fault content: Automatic addresses, manual addresses and wired controller setting addresses are mixedly used in the same signal line system.
E48
Fault content: Abnormal outdoor DC fan (TX, KX4, KX6 machines).
E49
Fault content: Low pressure abnormality (PSL), (TX, KX4, KX6 machines).
E53
Fault content: Suction pipe temperature sensor disconnected (Tho-S) (KX4, KX6 machines).
E54
Fault content: High pressure sensor disconnection (PSH) (KX4, KX6 machines).
E55
Fault content: The temperature sensor at the bottom of the compressor is disconnected.
E56
Fault content: The power transistor temperature sensor is disconnected (Tho-P1) (KX4, KX6 machines).
E57
Fault content: Low-pressure switch 63L operates (KX); insufficient refrigerant; compressor not running (unit machine).
E59
Fault content: Compressor startup failure (CM) (TX, KX4, KX6 machines).
E60
Fault content: Abnormal compressor rotor position detected (CM1).
E61
Fault content: Communication abnormality between the outdoor master and slave units.
E62
Fault content: The addresses of the outdoor slave units are improperly set.
E63
Fault content: Emergency stop (KX4, KX6 machines).
E75
Fault content: The signal line is poorly connected or it is short-circuited. (Applicable to centralized/central controller).
1.2 Wireless Remote Controller Model Fault Codes
Fault Name ---- Times Yellow Light Flashes
1. Indoor heat exchange sensor failure (E6) ---- 1 time
2. Indoor ambient temperature THi-A fault (E7) ---- 2 times
3. Poor communication between indoor and outdoor units (E5) ---- 3 times
4. Abnormal drainage (E9) ---- 4 times
5. Insufficient refrigerant (E57) ---- 5 times
6. Overload during heating (E8) ---- 6 times
7. Abnormal outdoor defrost sensor (E37)/filter signal ---- 7 times
8. Communication failure between wired controller and indoor unit (E1) ---- 8 times
9. Other faults beside the above faults ---- 9 times
2. Conclusion
Mitsubishi Heavy Industries-Haier Air Conditioning Fault Codes are a very useful tool that can help you determine what is wrong with your air conditioning unit. When your air conditioning unit malfunctions, first check the thermostat control panel for fault codes and follow the solutions provided in this article to fix the issue. If you cannot solve it, please contact a professional technician for repair.
