Endless On-Demand Hot Water Consistent hot water when you need it that never runs out Continuously monitored water temperature and controlled flow rates ensure efficiency and consistent performance within 1 degree of selected temperature. Save Space EcoSmart tankless electric water heaters are 90 smaller than traditional tank heaters may be installed on wall or at point of use Dimensions 11.5 x 8 x 3.75 inches. Save Energy EcoSmart tankless electric water heaters are 99 thermal energy efficient Only heats water when called unlike a tank heater that maintains water temperature even when not being used.. EcoSmart ECO 11 Sizing 13-kilowatt tankless electric water heater ideal for providing hot water for a bathroom, small sink, office breakroom and other point-of-use or low-flow applications provides between 1.3 and 3.1 gallons-per-minute depending on the inlet water temperature refer to the sizing guide to select the proper solution.