Abstract: A heat exchanger assembly for a vehicle heating device includes inner heat exchanger housing (12) and outer heat exchanger housing (14). A fluid flow space (24) is formed between the inner heat exchanger housing and the outer heat exchanger housing. Flow guiding formations (40, 42), along circumferential walls (18, 22) of the housings, divide a portion of the fluid flow space into a first partial flow space (44) and a second partial flow space (46). A fluid inlet opening (49) opens to the first partial flow space and at least one fluid outlet opening (51) opens to the second partial flow space (46). A press fit formation (94) fixes the inner heat exchanger housing in relation to the outer heat exchanger housing and includes the first flow guiding formation and the second flow guiding formation and/or the press fit formation is in an end region (32) of the circumferential walls.