We're Sinking Spring's Primary Geothermal Contractor! Sinking Spring, Pennsylvania, homeowners have all sorts of reasons for desiring a geothermal heating and cooling system: phenomenal year-round comfort – no matter how extreme the seasonal variations stable operating performance energy efficiency (They’d be hard-pressed to find a more "green," more natural way to heat and cool their homes!) significant – often extraordinary – savings on their energy bills premium installation and service from Paul W. Essig Inc., Sinking Spring's geothermal experts. Learn more about what a geothermal heating and cooling system can do to benefit your family's comfort. Look at our Geothermal Savings Calculator. Then contact Paul W. Essig Inc.. We sell, install, and maintain WaterFurnace geothermal systems, the very best in the industry today.