The new Knight residential boiler line is available in seven models with inputs from 80 to 500 MBH. The line offers a fully modulating burner with a 5:1 turndown, which allows the boiler to generate as much or as little heat as necessary to provide a consistent indoor temperature. It has a 92% AFUE efficiency rating, and its self-diagnostic features will interface with a computer PC to assist service calls and show trends in energy consumption.