Repairing or replacing an HVAC system is risky. While it may be tempting to fix it yourself, it’s probably best if you don’t. Freon leaks are dangerous, causing dizziness, asphyxia, and other respiratory problems. Air conditioning and heating maintenance calls for a licensed professional who has undergone a rigorous training and certification process. Plus, a manufacturer may void your warranty if you, a homeowner without appropriate licensing, were to work on the system.