In the 1971 film, the Exploding Candy was located in the Inventing Room instead of having its own room.
The Great Glass Elevator passes through the Exploding Candy Room while on its way to the Television Room. Oompa Loompas are busy firing off rounds of Exploding Candy at targets while the Elevator whizzes by somehow not getting blown up. Mike asks "Why is everything here completely pointless?" Charlie replies, "Candy doesn't have to have a point. That's why it's candy."
The machines in this room are broken because the Wonka bots were ruining the room and Charlie must collect candy ingredients in this room and make the Oompa Loompas work the machines.