Tankless Hot-H2o Systems is Chicago's #1 Professional Residential & Commercial Tankless Water Heater Installation & Service Co, located in Chicago and Lake County, IL. Serving Chicago & all of the surrounding suburbs including some parts of Southern Wisconsin. Let us size up and design and install the best, Natural gas, propane or electric tankless hot water system for You're application. Standard and Condensing units available. Low Nox emissions helping to preserve a global envirronment & protect our childrens future, Cutting edge technology.