Tankless water heaters have revolutionized the water heating business. They produce an endless supply of hot water cheaper, cleaner, and faster than ever before. These heaters have offered home and business owners a substantial energy savings, as well as, a smaller carbon foot print. As with most new technology, tankless water heaters continue to evolve. The average direct vent tankless water heater will usually carry a low to mid 80’s energy factor. These heaters have been around since the late 1980s. The condensing tankless water heaters were introduced around the mid-1990s. These condensing heating units have proven to be even more energy efficient while reducing the heaters carbon footprint even more. The condensing tankless water heaters today now boast a 10% to 15% higher energy factor over the conventional tankless water heaters. It is not unusual to see condensing water heaters have an energy factor of 92% to 97%.