The answer to 'air conditioner blowing hot air' is that there are several common causes, including a refrigerant leak, a problem with the compressor, or a blocked or dirty air filter. Symptoms may include the AC unit running continuously but not cooling the air, warm air blowing from the vents, and high energy bills.
In some cases, the issue can be a simple DIY fix, such as changing a dirty air filter. However, more complex problems like a refrigerant leak or compressor failure usually require the expertise of a professional HVAC technician. Attempting to repair these issues on your own can be dangerous and may even cause further damage to the system.