How do you get the TM heatwave on Pokemon?

Answer 1

Heatwave is not a TM in any pkmn game. it is a learned move that Pokemon such as charizard learn at low levels (so that you must remember them w/ the move tutor) or, for some is a egg move so pkmn (like vulpix) must know it when hatched from an egg.

Answer 2

Heat Wave cannot be found as a TM instead it can only be acquired as a level-up move or as an egg move. Charizard will learn it in Diamond, Pearl, Plaitnum and in all following games, Growlithe will also learn it in Diamond and Pearl and in all following seasons, Moltres will learn it in Ruby, Sapphire, FireRed and in all following seasons as will Torkoal. Heatran will learn it via level-up in Diamond and Pearl and in all following games and Volcarona will learn it in all of its games since its debut.