London Geothermal Heating & Cooling Contractor In London, Ohio, the geothermal heating and cooling contractor to call is Geo Source One Inc.. Our geothermal knowledge is second to none. And we provide the best products on the market in London - or anywhere else, for that matter: WaterFurnace geothermal heating and cooling systems! Try our Geothermal Savings Calculator. It'll show you why so many homeowners are going geothermal. The monthly savings are huge! We can tell you plenty of other good reasons, too. And when you’re ready install? We'll see to it that your WaterFurnace geothermal heating and cooling system is installed - and serviced – correctly! Contact Geo Source One Inc. today.