🔥 Core Specs
- Model: H400FDN (also W3H400FDN newer number)
- Heating Capacity: 400,000 BTU/hr
- Fuel Type: Natural Gas
- Ignition: Electronic (IID – no pilot light)
- Emissions: Low NOx (environmentally compliant)
🏊 What size pool it’s for
- Ideal for:
- 20,000 to 40,000+ gallon pools
- Large spas + pool combo setups
- Very fast recovery heater:
- Can raise temp roughly 1–2°F per hour depending on conditions
⚙️ Key Features
🔩 Heat exchanger (big advantage)
- Cupro-nickel heat exchanger
- Excellent for:
- Saltwater pools
- Hard water conditions
- Long-term corrosion resistance
🌊 Hydraulic efficiency design
- “Totally Managed Flow” system
- Reduces pump runtime (up to ~18% savings claimed)
- Improves heating efficiency by balancing water flow through tubes
⚡ Controls & electronics
- Digital LED control panel
- Self-diagnostics (error codes like IF, LO, HS)
- Compatible with pool automation systems
🌬️ Combustion system
- Forced-draft design (blower-assisted)
- Stable heating even in windy conditions
