Starting Sept. 1, 2012, all residential boilers must be manufactured to meet new minimum federal efficiency standards. Residential gas hot water boilers must meet 82 percent AFUE; gas steam boilers, 80 percent; oil hot water boilers, 84 percent; and oil steam boilers, 82 percent.
The standards were established upon the passing of the Energy Independence and Security Act (EISA) in 2007.