The answer to 'how to clean ductless system' is to regularly clean the indoor and outdoor units of your ductless HVAC system. This helps maintain efficiency and prevent issues. Start by turning off power to the system, then use a soft cloth or brush to gently wipe down the indoor unit's air vents and coils. For the outdoor unit, clear away any debris or vegetation around it, then use a garden hose to rinse off the coils and fans.
It's also important to clean the air filters every 1-3 months, or as recommended by the manufacturer. You can remove and rinse the filters with water, then let them fully dry before reinstalling. If your system has a drain line, check it for clogs and flush it out as needed. For more complex cleaning or maintenance, it's best to contact a professional HVAC technician.