8-year limited Tank warranty, 8-year parts warranty for Residential applicationsIntelligent Control Logic-The internal microprocessor provides enhanced operating parameters and tighter differentials for precise sensing and faster heating response to optimize performance.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. (Price subject to change without notice. Check stock before order)