Bosch gas tankless water heaters are designed to preheat the incoming cold water by using the captured heat from the exhaust gases. These heaters feature an electronic ignition system and a patented burner design that offers up to 98 percent of thermal efficiency. They are further integrated with a space-saving design for easy installation, operation and simple maintenance, and a built-in freeze protection facility to protect the unit when the temperatures fall below the freezing point. Choose from a wide range of these water heaters, available in NG and LP variants on Raptor Supplies.