The answer to 'central air not working' is that there are several common causes, including a tripped circuit breaker, a clogged air filter, low refrigerant levels, or a malfunctioning compressor. Symptoms may include warm air blowing, the system not turning on, or high energy bills.
For minor issues like a tripped breaker or dirty filter, homeowners can often troubleshoot and fix the problem themselves. However, for more complex problems like refrigerant leaks or compressor failure, it's best to call a licensed HVAC technician. Attempting to service the system yourself could be dangerous and may void the warranty.