Sullivans Island, South Carolina, Geothermal AGL Services Heating & Air Conditioning is the premier WaterFurnace geothermal contractor in Sullivans Island, South Carolina. We'll help you understand all the advantages of geothermal heating and cooling. We’ll make sure your WaterFurnace system is properly installed, too. And when it comes time for service? Nobody in Sullivans Island can beat our service! Contact AGL Services Heating & Air Conditioning today. Like a little up-front look at the savings a WaterFurnace geothermal heating and cooling system can give you? Use our simple Geothermal Savings Calculator.