Three-way valve with two flaps comprising common control means (9) for the two flaps and actuation means (12, 13, 50) arranged to drive, each one, in pivoting motion, one of the two flaps, from one to the other of its opening and closing position of one of the passageways, with a time phase shift such that, in a first stage the common control means pivot the second flap, the first flap remaining in a standby position under the action of return means, and in a second stage said control means, while continuing to pivot the second flap begin to pivot the first flap, characterized in that said second actuation means (12, 50) comprises a return drive means (71) making it possible to pivot the second flap (5) toward its first position under the action of the common control means (9) in the event of a failure of said return means.
