Rinnai Condensing Combi BoilerAn ideal solution for residential home-heating and water-heating needs, the Rinnai E50C Condensing Combi Boiler is cost effective to install, requiring fewer pumps and no primary secondary piping for common installations. Designed for smaller residential applications with up to 1.5 baths, similar to a Cape Cod-style cottage, the E50C touts one of the highest efficiencies available, 95.6 percent AFUE, which translates into reduced monthly energy bills for homeowners.