Weil-McLain offers a complete line of commercial, cast iron gas boilers tailored for steam applications 315 - 8,660 kBTU/hour in natural draft or forced (power) designs. Available in natural gas or propane configurations, packaged or knock-down heat exchanger for boiler room assembly - Weil-McLain Commercial Gas Steam Boilers provide rugged, reliable and low maintenance heating solutions for light commercial through large institutional applications.