A vent assembly has a locking mechanism to retain its cover on its base. The locking mechanism includes a latch and linkage coupled with the latch to move the latch between a locked and an unlocked position. A post member extends from the cover to cooperate with the latch such that in a locked condition, the cover is locked with the base in a closed position. When the latch is moved to a second position, the cover is enabled to pivot away from the base to an open position.