The answer to 'central air freezing up' is that a frozen air conditioning unit is a common issue, often caused by low refrigerant levels, a dirty air filter, or a blocked airflow. Symptoms include ice buildup on the coils, reduced airflow, and poor cooling performance. To fix a frozen AC unit, you'll need to identify and address the root cause, which may involve adding refrigerant, replacing the air filter, or clearing any blockages.
If the issue is due to low refrigerant levels or a refrigerant leak, it's best to call a professional HVAC technician, as they have the proper tools and expertise to safely handle refrigerants. For problems like a dirty air filter or blocked airflow, you may be able to address the issue yourself, but it's important to follow the manufacturer's instructions carefully to avoid further damage.