The answer to 'mini split freezing up' is that a mini-split air conditioner can freeze up for a few common reasons, including low refrigerant levels, a dirty air filter, or a problem with the unit's defrost cycle. If your mini-split is freezing up, it's important to address the issue quickly to prevent further damage to the system.
Some of the most common symptoms of a frozen mini-split include reduced airflow, ice buildup on the coils or outdoor unit, and the system shutting off unexpectedly. In many cases, you can try to troubleshoot and fix a frozen mini-split yourself, but it's important to know when to call in a professional HVAC technician.