The answer to 'why is my mini split freezing up' is that a frozen evaporator coil is a common problem with mini split air conditioning systems. This can be caused by low refrigerant levels, a blocked air filter, low airflow, or the system running in cooling mode when the outdoor temperature is too low.
Symptoms of a frozen mini split include ice buildup on the indoor unit, reduced airflow, and the system not cooling effectively. If left unchecked, a frozen coil can lead to compressor damage and other expensive repairs. Homeowners should first check the air filter and ensure it is clean, then monitor the system for any ice buildup. If the problem persists, it's best to call in a professional HVAC technician to diagnose and repair the issue.