6-year limited Tank warranty, 6-year parts warranty for Residential applications Gas Control Convertible For Natural and Propane Gas - For flexibility to meet the varying needs of Manufactured Housing Installation. All models ship from factory designed for use with natural gas 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. Coregard™ Anode Rod - • Our anode rods have a stainless steel core that extends the life of the anode rod allowing superior tank protection far longer than standard anode rods. Blue Diamond® Glass Coating - Provides superior corrosion resistance compared to industry standard glass lining. Enhanced-Flow Brass Drain Valve - Our residential water heaters have a solid brass, tamper resistant,enhanced-flow, ball type, drain valve.