Rinnai RUCS75iN Tankless Water Heaters, White Professional installation required; call 84-GO-Rinnai for assistance. ENERGY STAR Qualified with an Energy Factor of .93 / Uniform Energy Factor of .90 Save time with hot water whenever and wherever you need it, any size home, even for simultaneous uses at multiple fixtures Save energy and reduce utility costs by operating only when hot water is needed Maximum output, minimum space. Suitable for installation in non-traditional spaces such as crawl spaces and attics