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Hayward H400FDN W3H400FDN Natural Gas Pool Heater 400K Low NOx Heater
Hayward W3400FDN Pool Spa Heater

Our Price: $4,739.00
Sale Price: $3,999.00
Savings: $740.00
Special Instructions: We are an authorized Hayward dealer!

Availability:: Est. 7-10 business days for freight delivery.
Product Code: W3H400FDN


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Additional Shipping:
WA, OR, SD, ND, MT, WY, ID, LI, SINY, Nantucket, Martha's Vineyard - Freight Surcharge $200

Description Warranty

Hayward W3H400FDN is Natural Gas - The cupro-nickle heat exchanger places it above its competitors (Pentair, Jandy, Raypak) at similar prices. 84% Thermal Efficiency.

The Hayward W3H400FDN is a natural gas pool and spa heater designed to efficiently heat large bodies of water. It is part of the Hayward H-Series lineup, known for its reliability, performance, and energy efficiency.

With a heating capacity of 400,000 BTU (British Thermal Units), the W3H400FDN is suitable for residential and commercial pools and spas of considerable size. It utilizes natural gas as its fuel source, providing quick and effective heating to maintain comfortable water temperatures.

The W3H400FDN heater features advanced technology and a user-friendly interface for easy operation and precise temperature control. It includes an electronic ignition system, which eliminates the need for a pilot light and allows for automatic ignition, enhancing convenience and energy savings.

Equipped with a durable cupro-nickel heat exchanger, the heater offers excellent resistance to corrosion and erosion, extending its lifespan and ensuring efficient heat transfer. The unit also incorporates a digital LED control panel for easy monitoring and adjustment of temperature settings, timers, and diagnostic codes.

The W3H400FDN heater prioritizes safety with various built-in features. It includes a water pressure switch that prevents the heater from operating if the water flow is insufficient, as well as a high-limit temperature control to protect against overheating. Additionally, it has a rust-resistant polymer header for long-lasting performance in various weather conditions.

Installation of the W3H400FDN requires professional expertise to ensure proper gas and electrical connections, as well as compliance with local regulations. Regular maintenance, including cleaning and inspections, is crucial to keep the heater operating optimally and prolong its lifespan.

Overall, the Hayward W3H400FDN natural gas pool and spa heater provides powerful heating capabilities, user-friendly controls, and reliable performance, making it a popular choice for those seeking efficient and effective temperature control for their swimming pools or spas.

The new Hayward W3H400FDN Universal H-Series is a totally new gas heater design that combines industry leading hydraulic performance, environmentally responsible low-NOx emissions and superior reliability with the installation flexibility to easily adapt to new or existing pools and spas for what just might be the most perfect combination of features and benefits ever offered in an in-ground pool and spa heater.

Hayward's W3H400FDN Universal H-Series gas heater adapts to each pool and spa owner's needs to make life a little more flexible and convenient.

NOTE: The Hayward W3H400FDN Universal H-Series of heaters meet the NOx Emission standards set by the California South Coast Quality Air Management Commission for 2001 and the Texas Natural Resource Conservation Commission Code.

(This item is new in box)


Great Low Profile Appearance

Environmentally Responsible Low NOx Emissions

Patent Pending Polymer Header Design for Industry Leading Hydraulic Performance

Totally Managed Cupro Nickel Heat Exchanger Flow for Superior Reliability

2" x 2 1/2" CPVC Union Plumbing Fittings

The Right Connections for Easy Installation, Service and Use

Ultimate Installation Flexibility for New or Existing Equipment Pads

Independent Left or Right Side Electric, Water and Gas Connections

25% Lighter Weight Means Less Physical Effort to Install

Only Front Panel Access Required for Installation and Service

Easy Gas Valve Adjustment

Easy Dual Voltage Conversion with Fuse Protected Circuit Boards

Overall Dimensions 37" width, 24" height, 29.50" depth 197lbs.

Shipping included with liftgate in the continental U.S.

Heater Parts List

  • WARNING: The following product(s) can expose you to chemicals which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.p65warnings.ca.gov

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