The answer to 'why is my air conditioner freezing up' is that the air conditioner is likely low on refrigerant or has a blockage in the refrigerant line. This can cause the coils to get too cold and freeze up, preventing proper airflow and cooling.
Some common symptoms of a freezing air conditioner include reduced airflow, ice buildup on the coils, and the compressor cycling on and off frequently. Causes can include a refrigerant leak, a dirty air filter, a problem with the blower fan, or issues with the thermostat or control board. Homeowners should first try changing the air filter and clearing any debris around the outdoor unit. But if the freezing persists, it's best to call in an HVAC professional to properly diagnose and repair the issue.