It takes specialized knowledge and experience to replace an HVAC unit because it is a complicated and technical process. While some DIY enthusiasts may be able to handle simple maintenance jobs, a full replacement is typically beyond the capabilities of the average homeowner and should be handled by a qualified HVAC professional. Without the right training and equipment, replacing something can lead to improper installation, decreased efficiency, and even dangerous malfunctions. In addition, many states mandate that HVAC contractors be insured and licensed, which can offer homeowners additional security in the event that something goes wrong during the installation. A professional should always be hired to ensure the security and dependability of your HVAC system.