The answer to a ductless system not working is that there can be several common causes, including a refrigerant leak, issues with the compressor or indoor unit, or problems with the electrical system. Symptoms may include the system not turning on, poor airflow, or the system running continuously without cooling the home.
To troubleshoot, you can first check the air filters and clean or replace them if needed. You can also inspect the outdoor unit for any visible damage or debris buildup. However, if the issue persists, it's best to call a professional HVAC technician to diagnose and repair the problem. Ductless systems require specialized knowledge and tools, so attempting complex repairs yourself could be unsafe and may void the warranty.