Compact and efficient, circulation heaters may be used in forced or natural circulation systems to heat flowing gasses or liquids. Pipe plug or flanged immersion heater, vessel, insulation, terminal enclosure. mounting brackets and inlet and outlet connections are included. Installation is simple with only basic wiring and piping connections required. An integral thermostat is included on Series 1, 2, 3, and 5 items. An installation and maintenance manual is included.