Mitsubishi Electric · Air Conditioning
This fault occurs if there's an error in the number of connected units, often due to loss of M-Net voltage, power issues, or incorrect outdoor box settings.
Click steps to track your progress.
Check the M-Net wiring for shorts or breaks.
Ensure the BC unit is receiving power.
Verify the SW5 setting on the outdoor unit.
Confirm the correct type of outdoor box is used.