Abstract: A heat exchanger for a heating appliance, comprising a channel for conveying a heated gas in a longitudinal direction of said channel and a multitude of fins for conveying a liquid, said fins being provided with an inlet and an outlet, which open in a common plane, wherein the fins are provided on a wall of the channel, extending into said channel, wherein the inlets and outlets of the fins open in the plane of the wall and wherein the heat exchanger further comprises connecting elements for connecting at least one outlet to at least one inlet of separate fins.