The answer to 'why is my mini split blowing cold air' is that there could be several common causes, including a refrigerant leak, a problem with the compressor, or an issue with the thermostat or control board. Mini split systems are a type of ductless HVAC system that use an outdoor compressor/condenser unit and an indoor air-handling unit to provide heating and cooling.
Some common symptoms of these issues include the unit blowing cold air even when set to heat mode, the system not reaching the desired temperature, or the compressor not running at all. Potential solutions could involve repairing or replacing refrigerant lines, the compressor, or electronic components. However, these types of repairs often require professional HVAC expertise, so it's generally best to call a qualified technician to diagnose and fix the problem.