The answer to 'why is my evaporator coil blowing hot air' is that the evaporator coil is likely not functioning properly. This could be due to a refrigerant leak, a problem with the compressor, or a blocked airflow. When the evaporator coil is not working correctly, it will blow hot air instead of cold air.
Some common symptoms of an evaporator coil issue include the air conditioner not cooling the home effectively, the coil freezing up, and higher than normal energy bills. To troubleshoot the problem, you'll want to check the refrigerant level, ensure the compressor is working, and make sure the airflow to the coil is not obstructed.