L.E.S. Inc. began operations March 1, 1978 with the goal of providing energy conserving heating plant equipment and control packages to commercial and industrial customers. In 1985, to reduce shipping costs and speed assembly, L.E.S. moved its production operations to the Aldrich Company plant. L.E.S. assembles, tests, and ships packaged boilers, custom-built energy management packages, and boiler feed systems in Wyoming, IL and is responsible for the design, sales, and performance of these products.

Power & Heat Systems custom installs a number of products from L.E.S., a company known for their high quality Scotch Box boiler design, which offers firebox footprint with Scotch high efficiency. These L.E.S. boilers will fit through a 36 inch door. Boilers are available for hot water or low pressure steam. The advanced design carries a five (5) year warranty against thermal shock. L.E.S. boilers attain efficiencies of 83% and higher.