Intelligent Control Logic The internal microprocessor provides enhanced operating parameters and tighter differentials for precise sensing and faster heating response to optimize performance. Uses a thermopile to generate the power needed to operate the electronic gas control without requiring an external power source. The electronic gas control incorporates an LED status indicator that monitors system operation and service diagnostics. High Uniform Energy Factors Eco-friendly non-CFC foam insulation, heat traps and specially designed combustion chamber combine to produce a high Uniform Energy Factor for maximum savings on operating costs. Green Choice® Gas Burner Patented eco-friendly burner design reduces NOx emissions by up to 33% and complies with Low-NOx emission requirements of less than 40 ng/J. Self Cleaning Dip Tube Helps reduce lime and sediment buildup and maximizes hot water output. Made from long-lasting PEX cross-linked polymer.