The answer to 'why is my ductless system blowing hot air' is that there could be several common causes, including a refrigerant leak, a problem with the compressor, or an issue with the reversing valve. Ductless systems use heat pump technology to both heat and cool your home, and when they're in heating mode, they should be blowing warm air. However, if there's a problem with the system, it may end up blowing hot air even when you have it set to cool.
Some of the most common symptoms of a ductless system blowing hot air include the air not feeling as cool as it should, the system running constantly without cooling your home, and potentially higher than normal energy bills. To troubleshoot the issue, you'll want to check the air filters, make sure the outdoor unit is clear of debris, and verify that the thermostat is set properly. If those basic checks don't resolve the problem, it's best to call in a professional HVAC technician to diagnose and repair the issue, as ductless systems can be more complex than traditional forced-air systems.