¹Based on comparison of a Ruud^® Ultra^® Series Condensing Tankless Water Heater (natural gas) with .96 EF and a 50-gallon standard residential natural gas tank-type water heater with a 0.60 EF; Savings claim based on difference in annual operating costs from DOE over the 12-year warranty period of the Ruud tankless unit; Savings higher for liquid propane models. ²According to a 2015 survey of tankless contractors by Hanover Research on behalf of Ruud. ³Savings per News Bulletin released by the United States Department of Energy / Oak Ridge National Laboratory, November 2002 study on water and energy savings in residential homes using hot water recirculating system. ⁴Results may vary based on your location; Consult a tax professional regarding your individual tax situation and ability to claim a tax credit related to the purchase of qualifying Ruud^® product. ⁵Installation conditions vary; Consult the Ruud Use and Care Manual, the Ruud Gas Piping Facts brochure (TK-GPF-12), the National Fuel Gas Code (NFPA 54, ANSI Z223.1), and any other local gas codes when installing a Ruud Tankless Water Heater. ⁶Availability claim based on review of U.S. customers in April of 2016 and Canadian customers in May of 2016. ⁷EcoNet is built into certain Ruud Tankless Water Heaters and available as an accessory for models produced after 1/2010; WiFi broadband Internet connection required. Download the FREE EcoNet App from the App Store for Apple iPhone, iPad and iPod users, and Google Play for Android users to set up your EcoNet WiFi Kit; notifications are dependent upon external providers (phone carrier, cell phone, email, and installation factors, such as walls, location, etc.); Ruud cannot guarantee notifications will be received by the intended recipient; Leak Detection feature not available on outdoor models.