All Carrier products, including air handler units, come with a limited parts warranty. This is usually a 10-year warranty, depending on the specific product purchased.
Some Carrier products also have different parts with different warranties. In addition to standard warranties, Carrier offers several extended warranties one may purchase that include parts, labor or both parts and labor. These special extended warranties can be purchased for a length of time ranging from 1 year all the way up to 10 years.
More information about the warranty for a specific product is available online at the official Carrier site. If one is unable to find warranty information online, then it is possible to contact the closest experienced Carrier dealer for further information about the different warranties and their respective parameters of coverage.