Abstract: A header-tank assembly for a fluid, including: a header, a cover, a first baffle forming an end wall for a fluid channel at an end of the header, a second baffle including a first opening configured to provide a fluidal communication between the header-tank assembly and a fluid loop, a distribution device located between the first baffle and the second baffle, the distribution device including a first open end and a second open end. The first open end of the distribution device is in a contact with the first baffle and the second open end is fluidly connected with the first opening of the second baffle. The first baffle includes a sealing portion configured to be fixed to the first open end of the distribution device to form a fluid-tight connection blocking the exit of the fluid from the first open end of the distribution device.