Device and method for servicing heat exchanger

The device of the invention 10 comprises an attachment plate 14 having at least one means for fixing it against the underside 4a of the tube plate 4, which means is intended to be introduced into a hole 6 in the tube plate, a turret 15 comprising a part mounted so that it can rotate about an axis perpendicular to the attachment plate 14 and at least one tool 24 for carrying out interventions in the water box 2 of the heat exchanger and carried by a means for supporting the tool 24 in terms of translation with respect to the rotary part of the turret 15 and means for moving and actuating the tool 24, these means being remote controlled. The device 10 comprises a guide beam 16 mounted so that it can move in terms of translation on the rotary part of the turret 15 in its longitudinal direction 16a, and a carriage 20 for supporting the tool 24 and mounted so that it can move on means of guidance of the beam 16. The device additionally comprises a head plate 36 allowing the attachment plate 14 to be fitted automatically inside the water box from outside the water box by pulling on a lifting cable. The method for carrying out interventions may be implemented in particular for plugging tubes 5 of a steam generator.