Stiebel Eltron’sTempra Plus whole-house tankless electric water heater is 99% efficient and features Advanced Flow Control to automatically keep output temperature constant and supply a continuous hot water flow. It provides a minimum of 15% to 20% energy savings and water savings, and includes a three-year warranty.electric tankless water heater

At a  space-saving 17” by 15” by 5”, the Tempra Plus is easily installed with no venting. Tempra Plus units are ideal backups for solar thermal systems.