MHI R410A Systems

This code indicates a communication error between different parts of the indoor unit or between indoor and outdoor units.

This error occurs when one or more units (indoor or outdoor) have address settings at factory defaults (48 or 49) or when auto-addressing fails on a non-KX2 system.

This error, often indicated by 3 flashes, points to an incorrect setting of DIP switches (SWS) on the indoor unit PCB, or a wiring issue in a master/slave system.

This code indicates a malfunction of the indoor unit's fan motor, which can prevent proper airflow and heating/cooling.

This error indicates a failure of the sensor located within the remote controller, which is used to measure room temperature.

This code indicates a problem with the connection or communication between the indoor and outdoor units.

This error occurs when an indoor unit has a duplicated address number (U00-U47) or there is an error in the outdoor unit's address setting.

This error means the anti-phase device has detected that two phases of the mains power need to be swapped, or the L2 phase of the mains power has been detected as open.

This error indicates that abnormally low current or no current has been detected by the current transformer (CT) on L3, or an open phase on L3's secondary side of the contactor.

This error indicates that the outdoor unit's heat exchanger sensor (ThOR) is defective (open or closed circuit), has a poor connection, or the system is experiencing cooling high pressure.

This code indicates that the discharge temperature is abnormally high, there's insufficient refrigerant in the system, or the compressor discharge temperature sensor (THOD) is defective.

This error indicates that one or more of the outdoor unit's heat exchanger thermistors (Tho-R1 to Tho-R6) is defective or has a poor connection.

This error means the outside air temperature sensor (ThoA) is defective (open circuit resistance) or has a poor connection to the outdoor unit PCB.

This error indicates that the compressor discharge temperature sensor (ThOD) is defective (open circuit resistance) or has a poor connection to the outdoor unit PCB.

This error indicates the high-pressure switch (B3H or 63H1) has tripped, potentially due to system overcharge, closed service valves, or insufficient airflow over the condenser coil.

This error signifies that the power transistor for the inverter in the outdoor unit has overheated, indicating a potential issue with the inverter circuit or cooling.

This error indicates that the compressor in the outdoor unit is drawing an abnormally high electrical current, which can lead to overheating or damage.

This error indicates that the number of indoor units connected to a single outdoor unit has exceeded the system's maximum allowable limit.

This error indicates a transmission error in communication between the inverter and the outdoor unit's PCB, or a loose connection at the CnI terminal.

This error occurs when there's a conflict in address settings, or a combination of automatic, manual, and remote control addresses coexist on the same network.

This error indicates that the inverter in the outdoor unit is experiencing an over-voltage condition, meaning the input voltage is too high.

This error indicates a fault with the DC outdoor fan motor, which is crucial for heat dissipation from the condenser coil.

This error indicates either a low-pressure condition within the refrigerant system or that a low voltage has been detected in the electrical system.

This error indicates a fault with the inverter PCB (Printed Circuit Board) in the outdoor unit, or that a power transistor within the inverter has overheated.

This error indicates that the suction pipe thermistor (Tho-S) in the outdoor unit is disconnected, leading to incorrect temperature readings.

This error indicates that either the low-pressure sensor (PSL) or the high-pressure sensor (PSH) in the outdoor unit is disconnected or experiencing an output error.

This error indicates that the thermistor located under the compressor dome in the outdoor unit is disconnected, preventing accurate temperature monitoring.

This error signifies that the power transistor thermistor (FDCVA151-251) in the outdoor unit is faulty or has become disconnected.

This error indicates a refrigerant leak or a shortage of refrigerant in the system, specifically referenced by FDCVA151-251, affecting system performance.

This error indicates that the compressor is having trouble starting up, possibly due to electrical or mechanical issues.

This error indicates a problem with detecting the position of the compressor, which is essential for proper operation of inverter-driven compressors.

This error indicates that the indoor unit has triggered an emergency stop, usually due to a safety-related issue or an external command.

This code indicates that the electrical phases supplying the outdoor unit are reversed. This is a critical power supply issue.

This error means that the L3 phase of the power supply to the outdoor unit is open, indicating a loss of connection or power on that phase.

This code indicates that the 63L connector in the outdoor unit is open, suggesting a connection problem with a specific component.

This error signifies that the 49C connector in the outdoor unit is open, indicating a problem with its connection.

This error means there's a fault with the reverse phase detector circuit located on the outdoor unit's main circuit board.

This code signifies a fault within the input circuit of the outdoor unit, which could be related to how power is received and processed.

This error suggests that two or more connectors within the outdoor unit are open or disconnected, leading to a system malfunction.

This code indicates an open phase on the L2 line of the power supply or a disconnection of the 51CM connector in the outdoor unit.

This error means that the intake air sensor in the indoor unit is malfunctioning, providing incorrect or no readings.

This code indicates that the pipe sensor in the indoor unit is not functioning correctly, which can affect temperature regulation and defrost cycles.

This code indicates a system communication error related to transmitting or receiving signals within the indoor unit or between units.

This error indicates a problem with the drain sensor in the indoor unit, which monitors the water level in the drain pan.

This code indicates that the indoor unit's drain overflow protection system has detected an issue, likely due to a blocked drain or a faulty sensor.

This error indicates a problem with the indoor unit's coil frost protection or overheating protection modes, suggesting temperature regulation issues.

This error indicates a system error related to the address settings of the indoor unit, commonly found in multi-split systems.

This code indicates a general malfunction originating from the outdoor unit, suggesting a broader issue that requires further diagnosis.

This code signals abnormal high pressure in the system, specifically indicating the high-pressure switch (63H) has activated, or a 'direct cut' operation has occurred to protect the unit.

This error indicates that the outdoor unit is experiencing an abnormally high discharge temperature, or the inner thermostat (49C) has activated as a safety measure.

This error indicates that the discharge thermistor in the outdoor unit is either short-circuited or has an open circuit, leading to incorrect temperature readings.

This code means the outdoor unit's overheat protection mechanism has been triggered, or the outdoor thermistor is either short-circuited or open-circuited.

This error indicates that the outdoor unit's compressor has experienced an overload and has shut down to protect itself from damage.

This code signifies that the outdoor unit's compressor has drawn excessive current, activating the terminal relay as a protective measure.

This error code signifies a high-pressure condition in the outdoor unit, specifically linked to a closed ball valve.

This error indicates that the compressor has either failed to start up or has locked during operation, drawing excessive current and triggering a protective shutdown.

This code indicates a malfunction with the current sensor in the outdoor unit, which is responsible for monitoring the electrical current flow.

This code indicates that the system has detected abnormally low pressure within the outdoor unit, often due to a lack of refrigerant.