About Sherman Co. LLC Your Des Moines Area Premier Geothermal Source You can look to Sherman Co. LLC for all your WaterFurnace Des Moines geothermal heating and cooling needs, including... planning assistance. complete comfort system installation. routine service and maintenance. emergency repair. energy-saving advice and consultation. Our highly qualified professional staff is committed to the total satisfaction of customers throughout the Des Moines area. After all, you've picked the best heating and cooling system on the market today. We make sure each system will live up to the expectations of, boosting your home's conditioning efficiency and helping you reduce energy costs. Contact Sherman Co. LLC today to get a free estimate and a cost savings analysis for your home.