Lochinvar® FTXL™ Fire Tube Boiler Boiler With Control and Safety Device, Model: FTX500, 120 V, 6 A, 14.9 hp Power, 60 Hz Frequency, 1 ph, Up to 98.3 % AFUE, 500000 Btu/hr BTU, 12 gal Capacity, 49 gpm Flow Rate, 160 psi Pressure, NPT Connection, Natural Gas Fuel, Direct Vent, Modulating Burner, CFM Rating: 105 cfm, Chimney/Breeching/Vent Size: 4 in, 489000 Btu/hr DOE Heating, Ignition System: Direct Spark, Direct Spark Ignition, Net BTU Rating: 425 mbh, 73.02 sq-ft Area, Wall Mounting, Stainless Steel, Dimensions: 53-1/4 in H x 26-1/4 in W x 23-1/2 in D, Additional Information: 1 in Gas Connection, 2 in Water Connection