How do I know if I have an existing warranty on my furnace, air conditioner or HVAC system?Findthe label on the outer surface of the system component for a manufacture date. If the equipment is less than five years old it may have a warranty, but also may not based on the manufacturer. Warranty terms and conditions vary by manufacturer and the installing company. Donelson Air Service Experts Heating & Air Conditioning can verify the warranty status of your heating and cooling system via System Inspection. We also offer a Platinum PLUSTM Protection Plan for home heating and air conditioning systems, regardless of how old your equipment is or manufacturer warranty status.