Abstract: A drum heater assembly includes an inner body defining a cylindrical interior space shaped to receive a drum containing a material in the drum, and an elongated heating panels coupled to exterior surfaces of the inner body. The heating panels include heating elements configured to generate heat toward the interior space. The drum heater assembly also includes outer doors coupled with the heating panels such that the heating panels are disposed between the outer doors and the inner body. The inner body is configured to open to remove the drum and insert another drum into the interior space for heating by the heating panels.