The answer to 'why is my mini split blowing hot air' is that there could be several common causes, including a refrigerant leak, a problem with the reversing valve, or a malfunctioning compressor. Symptoms may include the air conditioning not cooling properly, the unit blowing hot air even when set to cool, or the system short-cycling.
Some potential solutions include checking the refrigerant level, cleaning or replacing the air filters, and inspecting the reversing valve and compressor for any issues. However, many mini split repairs should be handled by a professional HVAC technician, as they require specialized knowledge and tools to diagnose and fix properly.