By heating water only when it's needed, ENERGY STAR certified gas tankless water heaters cut water heating expenses, while lso providing continuous hot water delivery. Gas tankless models are a great choice for new construction and major remodeling, but are also becoming popular as a replacement for gas storage water heaters.
Current Specification Effective Date: January 2009
The specification covers high-efficiency gas storage, whole-home gas tankless, solar, and high efficiency electric storage water heaters. Products must meet minimum requirements for energy efficiency, hot water delivery, warranty period, and safety.