The answer to 'central air not working' is that there can be several common causes, including a malfunctioning compressor, clogged air filters, refrigerant leaks, or electrical issues. Symptoms may include the unit not turning on, warm air blowing, or the system short-cycling.
Some simple DIY troubleshooting steps include checking the circuit breaker, replacing the air filter, and ensuring the outdoor unit is clear of debris. However, more complex issues like refrigerant leaks or compressor problems will likely require a professional HVAC technician to diagnose and repair. It's generally best to call a licensed professional if you're unsure of the cause or don't feel comfortable performing the repairs yourself.