How do I know if I have an existing warranty on my furnace, air conditioner or HVAC system? Look at the label on the exterior of the equipment for a manufacture date. If the equipment is less than five years old it may have a warranty, but also may not depending on the model. Warranty terms and conditions vary by manufacturer and the installing company. Hammond Plumbing & Heating 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 the age of your equipment or manufacturer warranty status.