The answer to 'how to fix ductless system' is to first identify the specific issue you're experiencing, such as a refrigerant leak, frozen coils, or a malfunctioning compressor. Once you've determined the problem, you can take steps to address it, which may include cleaning the air filters, clearing any blockages, or repairing or replacing faulty components.
It's important to follow all safety precautions when working on a ductless HVAC system, such as turning off power to the unit, wearing protective gear, and handling refrigerants carefully. Regular maintenance, such as cleaning the unit and checking for any issues, is also recommended to keep your ductless system running efficiently.