{"product_id":"haywarduniversalhseriesnaturalgasheater400000btuslownoxw3h400fdnhppw3h400fdn","title":"Hayward | W3H400FDN | Universal H-Series Natural Gas Heater 400,000 BTUs, Low NOx","description":"\u003c!--split--\u003e\n\u003cp data-start=\"293\" data-end=\"735\"\u003e\u003cstrong data-start=\"293\" data-end=\"373\"\u003eThe Hayward W3H400FDN Universal H-Series 400,000 BTU Natural Gas Pool Heater\u003c\/strong\u003e is a high capacity, energy efficient heating solution designed for large residential pools and spas. Engineered with low NOx emissions to meet strict air quality standards, it delivers powerful and environmentally responsible heating performance. A durable cupro nickel heat exchanger ensures long term reliability, even in saltwater and high flow conditions.\u003c\/p\u003e\n\u003chr data-start=\"737\" data-end=\"740\"\u003e\n\u003ch3 data-start=\"742\" data-end=\"764\"\u003e\u003cstrong data-start=\"746\" data-end=\"762\"\u003eKey Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul data-start=\"766\" data-end=\"1445\"\u003e\n\u003cli data-start=\"766\" data-end=\"833\"\u003e\n\u003cp data-start=\"768\" data-end=\"833\"\u003e400,000 BTU heating capacity for large in ground pools and spas\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"834\" data-end=\"894\"\u003e\n\u003cp data-start=\"836\" data-end=\"894\"\u003eLow NOx emissions to comply with air quality regulations\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"895\" data-end=\"948\"\u003e\n\u003cp data-start=\"897\" data-end=\"948\"\u003eEnergy efficient design reduces operational costs\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"949\" data-end=\"1028\"\u003e\n\u003cp data-start=\"951\" data-end=\"1028\"\u003eCupro nickel heat exchanger for maximum corrosion resistance and durability\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1029\" data-end=\"1096\"\u003e\n\u003cp data-start=\"1031\" data-end=\"1096\"\u003eRapid heating performance to quickly reach desired temperatures\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1097\" data-end=\"1176\"\u003e\n\u003cp data-start=\"1099\" data-end=\"1176\"\u003eCompatible with Hayward automation systems for remote operation and control\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1177\" data-end=\"1255\"\u003e\n\u003cp data-start=\"1179\" data-end=\"1255\"\u003eUser friendly digital LED control panel for precise temperature management\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1256\" data-end=\"1332\"\u003e\n\u003cp data-start=\"1258\" data-end=\"1332\"\u003ePolymer header and bypass valve design for improved hydraulic efficiency\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1333\" data-end=\"1384\"\u003e\n\u003cp data-start=\"1335\" data-end=\"1384\"\u003eSuitable for coastal and harsh water conditions\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1385\" data-end=\"1445\"\u003e\n\u003cp data-start=\"1387\" data-end=\"1445\"\u003eQuiet operation for a more enjoyable backyard experience\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1447\" data-end=\"1450\"\u003e\n\u003ch3 data-start=\"1452\" data-end=\"1478\"\u003e\u003cstrong data-start=\"1456\" data-end=\"1476\"\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"1479\" data-end=\"2260\"\u003eThe Hayward W3H400FDN Universal H-Series Natural Gas Pool Heater delivers unmatched heating power for large in ground pools and spas, with a 400,000 BTU output that ensures fast temperature recovery and consistent warmth. Its low NOx design meets stringent environmental standards, making it an excellent choice for eco conscious pool owners. The cupro-nickel heat exchanger offers superior corrosion resistance, extending the unit’s lifespan in challenging water environments. Engineered with a polymer header and bypass valve for improved hydraulic performance, this heater minimizes pump run time and enhances energy savings. With simple digital controls and automation compatibility, the W3H400FDN offers high capacity heating that is efficient, durable, and easy to operate.\u003c\/p\u003e","brand":"Hayward","offers":[{"title":"Default Title","offer_id":50815350669624,"sku":"W3H400FDN","price":5099.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0808\/6319\/9544\/files\/2025_Universal_H_Series_Heater_W3H400FDP_Amazon_Assets_Carousel_02_939e.png?v=1777767668","url":"https:\/\/appaetechpoolsupply.com\/products\/haywarduniversalhseriesnaturalgasheater400000btuslownoxw3h400fdnhppw3h400fdn","provider":"AppaeTech Pool Supply","version":"1.0","type":"link"}