bsi138Crown Boiler BSI138 user manual. Topics manualsbase, manuals, Collection manuals_contributions; manuals; additional_collections Language English Item Size 23.5M .Bermuda Gas Fired Cast Iron Steam Boiler BSI series, Sea Level. BtuH Input: 138,000; Gas Type: NG; Sections: 5; AFUE: 82.0%; Flue Diam.: 6; Width: 19-14; Heht