The answer to 'why is my central air not working' is that there are several common causes, including a faulty thermostat, a dirty air filter, problems with the compressor or condenser, or issues with the refrigerant. Symptoms can include the air not cooling properly, the system not turning on at all, or strange noises or smells coming from the unit.
In many cases, simple DIY troubleshooting and maintenance can resolve the issue, such as replacing the air filter or checking the thermostat settings. However, for more complex problems like compressor failure or refrigerant leaks, it's best to call in a professional HVAC technician who can properly diagnose and repair the system.