Hayward® Universal H‑Series H400FDN Natural Gas Pool Heater – 400K BTU, Low NOx

Natural gas pool heater delivering 400,000 BTU of heating power with low‑NOx emissions that meet strict air quality standards. Built with a cupro‑nickel heat exchanger for superior corrosion resistance — ideal for saltwater and chemically aggressive environments. Universal left‑ or right‑side connections, digital LED control panel, and efficient hydraulic design simplify installation and operation while improving energy efficiency. Designed for reliable, consistent heating of in‑ground pools and spas.