The answer to 'how to maintain ductless system' is to regularly clean the air filters, outdoor unit, and indoor unit, and schedule professional maintenance annually. Ductless or mini-split HVAC systems require some basic DIY maintenance to keep them running efficiently and prevent costly repairs down the line.
Start by cleaning the air filters every 1-3 months, depending on usage and environment. Gently rinse the filters with water and let them fully dry before reinstalling. Next, use a garden hose to spray down the outdoor condenser unit, removing any debris or dirt buildup. For the indoor unit, wipe down the front panel and use a soft brush attachment on a vacuum to clean the vents and coils.