The Hayward Universal H-Series 400,000 BTU Low NOx Natural Gas Heater (W3H400FDN) provides robust heating for pools of all sizes and works with any sanitizing system, including saltwater. Its user-friendly L.E.D. control panel offers clear temperature readings and diagnostic information for easy management. Engineered for energy efficiency, the heaters advanced hydraulic performance reduces circulation pump run time. The exclusive cupro-nickel heat exchanger enhances durability by resisting corrosion and erosion, making it perfect for salt-based pools. An electronic control system ensures consistent water temperature and features self-monitoring technology for optimal operation. With a forced draft system that regulates airflow and voltage adaptability for easy installation, this heater meets environmental regulations. It also includes a 3-year limited manufacturers warranty for added peace of mind.