When the government created AFUE ratings, the goal was to help consumers understand differences in the efficiency of heating systems. The ratings show the percentage of fuel that is used to heat a home. Unfortunately, AFUE ratings don’t help consumers make educated decisions about a hot water heating system’s efficiency because it only measures some chimney related losses. We'll go over AFUE versus real boiler and combi boiler efficiency, and how Energy Kinetics boilers always come out on top when comparing true efficiency.