Differentiating between HVAC system repair needs and routine maintenance involves several indicators. Look for irregularities like unusual noises, reduced airflow, or inconsistent heating/cooling. Visible leaks, unusual odors, or frequent cycling can signal potential problems requiring repair. Conversely, routine maintenance involves scheduled tasks like filter replacement, coil cleaning, and system inspections aimed at preventing issues and optimizing performance. If unsure, consult HVAC professionals to diagnose and address specific concerns promptly, ensuring efficient system operation.