MT2V1000NACK1PXH Laars 999,000 BTU Mighty Therm2 Volume Natural Gas Water Heater The Mighty Therm2 has been specifically designed to meet the needs of the replacement market by offering simple and straightforward controls with 2-stage firing and 85% thermal efficiency. Mighty Therm2 boilers and water heaters feature convenient, modular construction that separates the burner trays, gas train, and blower assembly. All models use lightweight insulation, glass-lined cast iron or bronze headers, and non-ferrous waterways. The 10 tube heat exchanger design uses finned tubing for the quickest and most efficient heat transfer. Usage : V = Volume Water SIZE : 1 0 0 0 = 999,000 BTU/h input Fuel : N = Natural Gas ALTITUDE : A = 0–10,000 feet Location : C = Indoor and Outdoor Firing Mode : K = Two-stage Revision : 1 = First version of design Heat Exchanger : P = Glass-lined cast iron / cu-nickel / bronze trim Option Code : X = Standard unit Pump Options : H = Pump mounted MT2V, TACO, hard water pump