Geothermal.contractors

B.F. Mahn & Sons Inc. has served De Soto, Missouri since 1868 — now in its sixth generation and recognized as the oldest business in Jefferson County. The company installs, maintains, repairs, and replaces geothermal heat pump systems across De Soto and 20+ surrounding communities. As an authorized American Standard dealer and Mitsubishi Electric Diamond Contractor, they offer vertical borehole, horizontal trench, pond/lake, and open-loop well water configurations — matching the system to each site's land and geology. Geothermal heat pumps harness the earth's stable subsurface temperature to deliver efficient heating and cooling year-round. Verified active operator per bfmahn.com (Bundle 5 import 2026-05-29)