A profile of piping, particularly for making a heat exchanger for a condensation boiler. The cross-section of the profile has a trapezoidal portion with two bases and two sides, and a triangular portion with a base and two sides. A first side of the trapezoidal portion coincides with the base of the triangular portion. The second side and the bases of the trapezoidal portion and the sides of the triangular portion form the inner walls of the profile. A first angle between the first base of the trapezoidal portion and the first side of the triangular portion adjacent thereto is 45°-135°, preferably 90°. A second angle between the second base of the trapezoidal portion and the second side of the triangular portion adjacent thereto is 180°-270°, preferably 225°. A coiled heat exchanger for condensation boilers providing said profile and a condensation boiler providing said heat exchanger are provided.