Carrier Corp. announced Nov. 27 that it is extending the warranty on its 90 percent-plus efficient gas furnaces.

The company will now offer a 20-year parts-and-labor guarantee on the units’ secondary heat exchangers.

The settlement comes in response to a class-action lawsuit filed by U.S. and Canadian consumers who say their secondary heat exchangers failed prematurely in 90 percent-efficiency Bryant, Carrier, Payne and Day & Night models made between 1989 and 2007.

Despite the agreement, Carrier says its heat exchangers are reliable and performed properly. Under its terms, homeowners whose units fail can choose to have it repaired or take a credit toward the purchase of a new system. Customers who have already replaced their heat exchangers will receive reimbursement.