EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology Lifetime warranty Save up to 60-percent on your water heating cost with an ECOSMART electric tankless water heater Never run out of hot water with an ECOSMART tankless water heater Patented Self Modulating Technology and design ECOSMART tankless water heaters are 99.8-percent energy efficient.Uniform Energy Factor:0.98