Founded in 1881 in Chicago by Isadora and Benjamin Weil, Weil-McLain was originally named Weil Brothers.

In 1918, after acquiring a main supplier, J.H. McLain Company, the company was renamed Weil-McLain and boiler plant operations moved to Michigan City, Indiana.

Throughout the 20th century, Weil-McLain grew to be the largest U.S. manufacturer of cast iron boilers and a leader in the hydronic industry.


In 1999, Weil-McLain expanded its boiler line and entered the oil furnace market by acquiring Williamson Thermoflo.

In 2005, after outgrowing the original Michigan City manufacturing facility, Weil-McLain opened a manufacturing plant and distribution facility in Eden, North Carolina.

In 2012, Weil-McLain opened an administrative office in Burr Ridge, Illinois (a suburb of Chicago). The Michigan City, Indiana location continues its cast iron foundry operations and houses a state of the art laboratory and testing facilities alongside an engineering and development center.

Today, Weil-McLain maintains its status as a leader in hydronic heating with approximately 600 employees focused on providing Simplified Solutions for our Complex World.