No real discussion of the Fire Booster is made, except for the finding of a painting in Episode 31: No Paynn, No Gain and the discussion of Red Draconium being part of the 5 colours of balance. Just as with the other Boosters, one existed 3000 years ago and helped stop the Dragon-Human War, and one will most likely exist again should the series continue.
It seems very likely that Kitt Wonn will become the next Fire Booster, as her primary draconium influence is Red, and she is a close ally of the Dragon Booster. She was also seen paying her respects to a portrait of the original Fire Booster located in The Academy. During Episode 7: The Horn of Libris, Kitt's energy is one of the ones used by Beaucephalis to balance the anger in Libris, where 3 other colours at the same time were taken from confirmed Boosters. As of current standings, she has not found the amulet or gauntlet.
In the unreleased Episode 0: The Alchemist, it is revealed that Connor Penn eventually found the Bone-Marks of the original Energy, Fire and Power Boosters. It is highly likely that he still has them stored away somewhere today, and if Kitt does indeed become the Fire Booster, she may be given the Red Draconium bone-mark of Iympetus so that Wyldfyr can be made strong and pure.