One of the most important things you buy when you buy a new Furnace or Air Conditioner is the warranty. There are 2 warranties, one from the Manufacturer for all the parts cost and the other from the installing Contractor for the labor to install the defective parts during the warranty period. Most Manufacturers have increased their parts warranty from 1 to 5 years, with some covering their top-of-the-line equipment for 10 years. The labor portion of the warranty you are buying will range from 1 year all the way up to 10 years. Be sure you know what you are buying and that the proposal plainly states the parts and labor portions of the product warranty.