Disclosed is a heating unit which can comprise a tube, or pipe, having an aperture therein which can be configured to receive a heating element. In various embodiments, the heating element can comprise a resistive element which can be configured to generate heat when a voltage differential is applied thereto. In certain embodiments, the heating unit can further comprise a collar which is threadably engaged with the tube, wherein a flame path, or exhaust path, can be defined between threads on the pipe and threads on the collar, for example. In certain embodiments, the flame path can comprise a passageway defined between the circumference, or perimeter, of the tube and the collar. Such a flame path can be configured to allow pressurized gasses to safely escape from the tube along a predetermined path.