The answer to 'why is my air conditioner not working' is that there are several common causes, including a dirty air filter, refrigerant leaks, electrical issues, and problems with the compressor or other components. Symptoms may include the unit not turning on, poor airflow, warm air blowing, or the system cycling on and off frequently.
If the air filter is dirty, it can restrict airflow and cause the system to overwork. Try replacing the filter and see if that resolves the issue. Refrigerant leaks can also prevent the system from cooling properly. This is a more complex problem that requires a professional HVAC technician to diagnose and repair. Electrical problems like a tripped circuit breaker or faulty wiring may also be the culprit. Finally, issues with the compressor or other internal components can lead to the system not functioning at all.