Commercial Hydronic Baseboard Heaters • Copper heater elements: max. pressure 194 psi at 300°F Steel heater elements: max. pressure 660 psi at 650°F2-pc. design for simple installation; order heater element and enclosure separately. Sloped top prevents blocking of louvers. Enclosures and accessories have primed finish suitable for painting. Enclosures include top panel, front panel, partial backplate, adjustable hangers with hardware, slide cradles, and brackets. Suitable for hot water or steam heating systems.