Abstract: A hybrid heater that includes a structural mass into which passages are provided to create a labyrinth for chemical flow through the structural mass, the passages being sized and disposed to receive a plurality of heater rods such that the chemical is traversed through the passages in direct contact with the heater rods. A coiled spring may be disposed or other spiral arrangement provided in the space between and against the walls of the passages and the heater rod to facilitate flow uniformity around the rods. A temperature sensor may be provided in direct contact with the heating element and may be fitted with a mass sleeve to draw off any excess heat on the sensor during transitions.