Rheem Gas Heaters were created to help lessen the workload in trying to find a new gas heater. These gas heaters are perfect for first time installations as well as replacements. Rheem Gas Heaters for systems that require large amounts of hot water. These gas heaters come in different styles, Top, Front, Side and Rear In and Outlet connections. Another great piece of information about these gas heaters is that they are designed as a space saver. They have smaller heights and a small jacket diameter. This design offers an easier and more flexible install.