Mitsubishi Electric MXZ Air Conditioners

If the 7-segment LED display on the outdoor multi controller circuit board is not lit when all SW1 switches are off, it suggests a power supply problem to the board. This can be caused by faulty wiring, a tripped breaker, or issues with the power circuit board itself.

This error indicates an issue with the compressor's temperature, which could be too high or too low. This condition causes the system to shut down for protection.

This error indicates a superheat issue caused by an unusually low discharge temperature from the compressor. This typically suggests improper refrigerant flow or a related component issue.

This error indicates that the air conditioning system has detected a shortage of refrigerant. This condition can severely impact performance and lead to system damage.

This error covers a range of power supply issues including voltage fluctuations (too low or too high), a PAM (Pulse Amplitude Modulation) circuit error, a fault in the primary current sensor, or an open phase in the power supply.

This error indicates an abnormal temperature reading on the heat sink, which is critical for dissipating heat from power components. An overheated heat sink can lead to component failure.

This error indicates a malfunction within the power module of the outdoor unit. The power module is responsible for controlling the compressor and other power-hungry components.

This error indicates a problem with the outdoor unit's fan, which is essential for proper heat exchange and system operation. A malfunctioning fan can lead to overheating or poor performance.

This error indicates a fault with thermistor TH1, which monitors the compressor temperature. The sensor or its wiring is either open (broken circuit) or shorted (incorrect resistance).

This error signifies a fault with thermistor TH2, located on the suction pipe. It indicates an open or short circuit in the sensor's wiring or the sensor itself, affecting temperature readings.

This error indicates a fault with thermistor TH3, which measures the outdoor liquid pipe temperature. This suggests an open or short circuit in the sensor or its wiring.

This error indicates a problem with thermistor TH4, which measures the outdoor ambient temperature. The sensor or its wiring is either open (broken circuit) or shorted (incorrect resistance).

This error indicates a fault with thermistor TH5, which measures the HIC (Heat Integrated Circuit) pipe temperature. This suggests an open or short circuit in the sensor or its wiring.

This error indicates a fault with thermistor THM, which monitors the heat sink temperature. This suggests an open or short circuit in the sensor or its wiring.

This error occurs when using an M-NET remote controller and indicates a conflict or issue with the duplex address settings. This prevents proper communication within the M-NET system.

This error indicates a hardware malfunction within the transmission processor of the M-NET remote controller. This prevents the remote controller from effectively communicating with the system.

This error, specific to the M-NET remote controller, means the transmission bus is continuously busy. This could indicate communication overload or a continuous data stream issue from a device.

This error indicates a problem with signal communication between the M-NET remote controller and its internal transmission processor. This prevents the remote from correctly processing and sending commands.

This M-NET remote controller error means that a device on the network did not acknowledge receiving a transmission (No Acknowledge). This indicates a failure in communication with a specific networked component.

This error, specific to the M-NET remote controller, indicates that a device on the network failed to send a response frame within the expected timeframe. This suggests a communication timeout or unresponsive device.

A self-diagnosis check code appears on the wired remote controller or the outdoor unit's multi controller circuit board, signaling that the system has detected an operational abnormality or fault. This code is logged for diagnostic purposes.

This error, specific to the MA remote controller, indicates a problem receiving communication data from the air conditioning system. This prevents the remote from getting status updates or commands.

This error, specific to the MA remote controller, indicates a problem sending communication data to the air conditioning system. This prevents the remote from sending commands or settings.

This error, specific to the MA remote controller, indicates a problem sending communication data to the air conditioning system. This could be a repeated or different aspect of E1, preventing commands or settings from being transmitted.

This error, specific to the MA remote controller, indicates a problem receiving communication data from the air conditioning system. This could be a repeated or different aspect of E0, preventing status updates or commands.

This error indicates a problem with a valve in the refrigerant circuit. It could be a closed service valve during cooling operation or an issue with the 4-way reversing valve during heating.

This error indicates a mismatch in the total cooling or heating capacity of the connected indoor units compared to the outdoor unit's capacity. This mismatch prevents the system from operating correctly.

This error indicates a communication problem between the outdoor unit's multi-controller board and the power board. The air conditioning system will automatically stop operating.

This error indicates that the capacity code detected by the system is incorrect or invalid. This usually relates to the outdoor unit's configuration for its maximum operating capacity.

This error indicates that the system has detected more indoor units or branch boxes connected than the outdoor unit is designed to support. This prevents the system from operating due to exceeding its capacity limit.

This error indicates a malfunction with the high-pressure sensor (HS), which is crucial for monitoring the refrigerant system's high-side pressure. A faulty sensor can lead to incorrect pressure readings and system shutdown.

One or both of the F1 and F2 fuses on the outdoor multi controller circuit board have blown. This indicates a potential electrical problem with components like the solenoid valves (SV1, SV2, 21S4) or the bypass valve (SS), or their associated wiring.

This error indicates a malfunction with the low-pressure sensor (LS), which is crucial for monitoring the refrigerant system's low-side pressure. A faulty sensor can lead to incorrect pressure readings and system shutdown.

This error indicates a problem with the address settings of the connected indoor or outdoor units, possibly due to conflicts or incorrect configuration. Each unit requires a unique address for proper communication.

This error indicates that the combination of connected indoor and outdoor units is not compatible according to the system's design specifications. This prevents the system from operating as a unified air conditioning system.

The outdoor unit's fan is not rotating, which prevents proper heat exchange and can cause the system to malfunction or stop working. This often indicates a problem with the fan motor, its electrical supply, or the control board.

This error signifies that the system's high-pressure level is too high. This triggers an automatic shutdown of the unit to prevent damage.

This critical error indicates that the compressor has either experienced an interruption in its current supply or is mechanically locked, preventing it from starting or operating.

This error indicates a problem with the primary current sensor, which monitors the main electrical current flowing through the outdoor unit. An error here can lead to system shutdown to prevent electrical damage.

This error signifies that the compressor is drawing too much electrical current, which leads to an automatic shutdown to prevent damage. This can indicate a problem with the compressor or the system load.