he Polaris® has a high grade 444 stainless steel tank with brass connections for years of dependable, trouble-free service - no anode required. 10-year limited Tank Warranty, 10-year Limited Parts warranty for Residential applications Condensing Design - Helical internal heat exchanger keeps hot combustion gases in the tank longer to transfer more heat into the water Whisper Quiet Operation - Ultra quiet blower and burner minimize noise Power Direct Vent Design – Vents with PVC, CPVC or Polypropylene (solid core only) though a sidewall or roof Advanced Electronic Control – Large touchscreen display offers precise temperature control and advanced diagnostics Ultra-Low NOx – Enhanced Ultra-low NOx burner complies with SCAQMD Rule 1146.2 and other Air Quality Management Districts with similar requirements for NOx emissions of less than 14 ng/j Fully Serviceable from the Front – Two front access panels expose all serviceable parts Certified to ANSI Z21.10.3 – CSA 4.3 standards and meets the current edition of ASHRAE/IES 90.1