The invention is directed to a water heating assembly (10) comprising a heating element (12) and a tube (11). The heating element (12) is arranged within the tube (11) forming a gap (19) between the heating element (12) and an inner wall of the tube (11) and is adapted to heat water within the gap (19). The water heating assembly comprises a spacer element (13) arranged within the gap (19). The invention is further directed to a method for producing a water heating assembly according to the present invention as well as a method for heating water by using the water heating assembly according to the present invention.