Hayward Universal H-Series Pool Heater H400FDN

🔥 Core Specs

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• Model: H400FDN (also W3H400FDN newer number)
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• Heating Capacity: 400,000 BTU/hr
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• Fuel Type: Natural Gas
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• Ignition: Electronic (IID – no pilot light)
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• Emissions: Low NOx (environmentally compliant)
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🏊 What size pool it’s for

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• Ideal for:\n
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  • 20,000 to 40,000+ gallon pools
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  • Large spas + pool combo setups
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• Very fast recovery heater:\n
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  • Can raise temp roughly 1–2°F per hour depending on conditions
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⚙️ Key Features

🔩 Heat exchanger (big advantage)

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• Cupro-nickel heat exchanger
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• Excellent for:\n
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  • Saltwater pools
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  • Hard water conditions
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  • Long-term corrosion resistance
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🌊 Hydraulic efficiency design

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• “Totally Managed Flow” system
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• Reduces pump runtime (up to ~18% savings claimed)
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• Improves heating efficiency by balancing water flow through tubes
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⚡ Controls & electronics

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• Digital LED control panel
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• Self-diagnostics (error codes like IF, LO, HS)
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• Compatible with pool automation systems
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🌬️ Combustion system

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• Forced-draft design (blower-assisted)
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• Stable heating even in windy conditions
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