A boiler works by heating water to create either hot water or steam which is distributed through pipes to steam radiators, baseboard radiators or radiant floor systems. A boiler's efficiency is measured by annual fuel utilization efficiency (AFUE) which measures the amount of heat actually delivered to your house compared to the amount of fuel that you must supply to the boiler. Note that the AFUE refers only to the unit's fuel efficiency, not its electricity usage. Energy Star products must have a AFUE rating of 85% or greater, meaning that 85% of the fuel you supply to the boiler goes directly into heating your home and that only 15% is wasted. All Ohio Mechanical, Inc Plumbing and Heating is proud to offer high efficiency boilers and would be happy to recommend the right boiler for your home or commercial property.