bsi138Bermuda 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; HehtDownload installation instructions for Crown Boiler BSI379, BSI241, BSI276, BSI345, BSI103, BSI138. Learn more about Viii System Piping, General Piping Notes.