A tankless water heater is generally considered more energy efficient because they heat water only as it is needed. When the tap is turned on, the heater goes to work and supplies continuous hot water. A tankless water heater often requires less space and can hang on a wall, but may require larger gas lines, special venting or additional electric circuits that add to the upfront costs. However, a tankless water heater has a life expectancy of 15-20 years and may reduce water heating bills by as much as 30 percent. if a replacement or installation of a tankless water heater is necessary, an Advantage Plumbing water heater expert will help you determine which one is right for your home and budget, taking into consideration your family’s water heating needs and energy usage expectations.