bsi138Crown Boiler BSI379, BSI276, BSI138, BSI345, BSI103, BSI172, BSI241, BSI310, BSI207, BSI069 User Manual. Download. Specifications and Main Features. Frequently AskedBermuda 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