FBN2001 LOCHINVAR #FBN2001 'CREST' Stainless Steel Condensing Type1*1,999,000 BTU Input - 1,923,000 BTU Output @ 25:1 Turndown Ratio *Voltage: 115/1/60; 8" Vent, 8" Intake Opening, 4" Flanged Water, 1-1/2" Gas