www.pmmag.com/articles/96700-stiebel-eltron-electric-tankless-water-heater-for-solar-backup

Stiebel Eltron electric tankless water heater for solar backup
September 25, 2014
Stiebel Eltron’s Tempra 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.

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.