MT2V0400NACC3PLN Laars 399,900 BTU Mighty Therm2 Volume Natural Gas Water Heater Laars Heating Systems designed the Mighty Therm2 200-400 series,to be easy to use, install and maintain. It utilizes basic cap & bulb temperature controls and features a low voltage terminal strip for straightforward troubleshooting. It operates at an environmentally friendly 85% efficiency. The compact modular design, top or rear venting options, and the ability to be installed either indoor or outdoor results in installation flexibility. Usage : V = Volume Water SIZE : 4 0 0 = 399,900 BTU/h input Fuel : N = Natural Gas ALTITUDE : A = 0–10,000 feet Location : C = Indoor and Outdoor Firing Mode : C = On-Off (standard) Revision : 3 = Revision Level 3 (MT2V only) Heat Exchanger : P = Glass-lined cast iron / cu-nickel / brz trim Option Code : L = Low temperature control (std. MT2V) Pump Options : N = Pump mounted, normal water, Taco