#1 Home Improvement Retailer

Internet #311793698

Model #W3H400FDN

Store SKU #1004869551

Universal H-Series 400,000 BTU Natural Gas Pool Heater

Apply Now
$undefined.00 /mo* suggested payments with months* financingApply Now
  • Offers heating that is energy efficient and environment friendly
  • Patented bypass design ensures better hydraulic performance
  • Can be flexibly installed on new or existing equipment pads
  • View More Details
0 in stock
Text to Me
How to Get It

Product Overview

The Universal H-Series Heater is an energy efficient, high performance, installation adaptable commitment to the pool service professional. An industry leading hydraulic design reduces circulation pump run time. The energy efficiency of the Universal H-Series gas heater combines with environmentally friendly low NOx emissions, a standard cupro nickel heat exchanger and ultimate installation flexibility on new or existing equipment pads to responsibly heat a pool or spa today and for years to come. The forced draft system in the Universal H-Series constantly moves air through the combustion chamber at a precise flow rate eliminating outside weather variables that can affect heating performance. Wind conditions are eliminated and there is no install a high-wind stack. Patented bypass design for superior hydraulic performance. 2 in. x 2-1/2 in. CPVC union plumbing connections are perfect for todays larger plumbing systems. Easy to read LED control panel. For indoor/outdoor use note: HAYWARD Universal H-Series heaters meet or exceed the SCAQMD and the SJAPCD low NOx emissions standards in all low NOx areas that apply the SCAQMD standard.
  • Model W3H400FDN
  • Excellent salt water and chemical corrosion resistance
  • Same water velocity through all tubes for faster heating
  • Common union for installation or service, adapts to larger plumbing recommended for greater efficiencies
  • State-of-the-art fin plate heat exchanger with cupro-nickel
  • Professional Installer Recommended
  • Electronic Digital Control
  • 2" PVC Threaded Union
  • 1 Year Manufactures Warranty
  • California Customers Please Note: South Coast Air Quality Management District ( SCAQMD) Area of Jurisdiction REQUIRES a Low Nox Heater be installed. The following 6 California Counties are affected: Los Angeles, San Bernardino, Ventura, Orange, Riverside, & Kern. Installing a non-compliant heater in these counties will void the manufacturer's warranty and could result in a fine from your local code enforcement.
  • Item cannot be refunded/returned without approval and authorization from Home Depot
  • For Indoor Installation a vent top must be purchased separately
  • Easy-to-read L.E.D. digital Control Panel
  • Shop our wide selection of Hayward Pool Heaters

Additional Resources

From the Manufacturer

You will need Adobe® Acrobat® Reader to view PDF documents. Download a free copy from the Adobe Web site.



Product Depth (in.)29.5Product Height (in.)24
Product Width (in.)34


BTU Rating400000ControlsDigital
FeaturesNo Additional FeaturesFuel TypeNatural Gas
Heat ExchangerCupro-NickelIgnition TypeContinuous Spark
Outdoor Living Product TypePool HeatersPool Gallons (approx)40000
Pool TypeIn GroundProduct Weight (lb.)195

Warranty / Certifications

Manufacturer Warranty1 year warranty

Questions & Answers

Typical questions asked about products:

  • Is the product durable?
  • Is the product easy to use?
  • What are the dimensions of the product?

Customer Reviews

  • 3
    out of 4 reviews
  • 0%recommend this product
Filter by:
Showing 1-4 of 4 reviews
Less than two years later the heater is broken...
Less than two years later the heater is broken
  • Verified Purchase
Can not get heater to run . Contacted Hayward the people they recommend to fix it will not return...
Can not get heater to run . Contacted Hayward the people they recommend to fix it will not return my calls.
Excellent Pool Heater.. it heats up entire pool of 20k...
Excellent Pool Heater.. it heats up entire pool of 20k gallons in about 3 to 4 hours...awesome.. highly recommend it..
1 found this review helpful
Rating provided by a verified purchaser...
Rating provided by a verified purchaser
Showing 1-4 of 4 reviews