Hayward | W3H400FDP | Universal H-Series Propane Gas Heater 400,000 BTUs, Low NOx 

• In_Ground_Pool_Spa_Gas_Heater_Owners_Manual.pdf
• 2025_Hayward_Heat_Chill_Leave_Behind_TRIM_96_669d0196-044a-4506-a27c-84002b5df6b5.pdf
• CuproNickelSellSheet.pdf
• Hayward_Universal_H_Serise_Quick_Reference_Guide.pdf
• Indoor_Vent_Kit_Instructions_2021_442aa971-616d-47e5-a0ab-fc8840e9b6fe.pdf
• Universal_HSeries_Brochure_Bilingual.pdf
• Energy_Guide.pdf
• Universal_H_Serise_Low_NOx_Line_Drawing_Front.pdf

The Hayward W3H400FDP Universal H-Series 400,000 BTU Propane Gas Pool Heater delivers maximum heating power for large residential pools and spas. Built with low NOx emissions to meet strict air quality standards, it provides powerful, efficient, and environmentally responsible heating. A durable cupro-nickel heat exchanger offers exceptional corrosion resistance, making it ideal for saltwater and high-flow pool systems.

Key Features

• 400,000 BTU heating capacity for large in-ground pools and spas

• Low NOx emissions meet air quality regulations

• Energy-efficient design reduces operational costs

• Cupro-nickel heat exchanger for superior durability in harsh water conditions

• Rapid heating capability for quick temperature recovery

• Compatible with Hayward automation systems for remote operation and control

• Digital LED control panel for precise temperature adjustment

• Polymer header and bypass valve design for enhanced hydraulic efficiency

• Suitable for coastal and saltwater pool applications

• Quiet operation for an improved backyard experience

Product Overview

The Hayward W3H400FDP Universal H-Series Propane Gas Pool Heater is engineered for high-capacity heating performance and long-term reliability. With a 400,000 BTU output, it quickly raises and maintains water temperature, extending your swimming season with comfort and ease. Its low NOx design ensures compliance with stringent environmental regulations, while the cupro-nickel heat exchanger provides outstanding corrosion resistance in demanding conditions. The advanced polymer header and bypass valve optimize water flow, improving energy efficiency and reducing pump run time. Featuring user-friendly digital controls and compatibility with Hayward automation systems, this heater offers powerful, eco-friendly heating for large pools and spas.