Stiebel Eltron Tempra 24 Plus Water Heater is compared to a conventional electric tank water heater, a water heater will typically use 15-20% less energy, although savings can be substantially higher depending on usage habits. Conventional electric tank water heaters continually store hot water and as a result lose 15-20% of the total energy they consume to the environment around them. This is called standby heat loss. Gas or oil tank water heaters are even less efficient due to the fact that they also must be vented to the outdoors. A water heater does not need to be vented, and does not store full temperature hot water waiting for you to use it. Certified to ANSI/UL Std. 499, Conforms to CAN/CSA E335-1 & E335-2-35. Tested and certified by WQA against NSF/ANSI 372 for lead free compliance. An ISO 9001 Certified. Tempra Plus has Advanced Flow Control and its works by slightly reducing the flow of water. Technical Specifications: Phase: single 50/60 Hz; Voltage: 240 V or 208 V; Wattage: 24 KW/18 KW; Amperage draw: 2 x 50 A 2 x 44 A; Number and min. recommended size of circuit breakers1 (DP): 2 x 50 A; Number of runs and min. recommended wire size2 (copper): 2 x 6/2 AWG; Maximum temperature at 1.50 GPM: 92 degree F/82 degree F; Maximum temperature at 2.25 GPM: 73 degree F/54 degree F; Maximum temperature at 3.00 GPM: 54 degree F/41 degree F; Maximum temperature at 4.50 GPM: 37 degree F/27 degree F; Min. water flow to activate unit: 0.50 GPM/1.9l/min; Weight: 16.1 lb/7.3 kg; Nominal water volume: 0.26 gal/1l; Max. inlet water temperature: 131 degree F / 55 degree C; Working pressure: 150 PSI / 10 BAR; Tested to pressure: 300 PSI / 20 BAR; Water connections: 3/4" NPT.