Heat exchanger for a high efficiency hot air heating appliance (1), with at least one segment (5) and with a primary section (14) and, viewed in the flow direction (A), followed by a secondary condensing section (15), whereby the segment (5) consists of at least one primary element (16) and at least two secondary condensing elements (19), that form part of the secondary condensing section (15) of the segment (5), and the inputs (20) of each of them are connected in parallel to the output (18) of the primary element (16) in such a way that the gas flow coming from the primary element (16) is divided over the secondary condensing elements (19) connected to it.