Hayward W3H400FDN Universal H-Series 400,000 BTU natural gas Low NOx pool heaterHayward Universal H-Series Natural Gas 400,000 BTU Low NOx Pool Heater, W3H400FDN In stock$5,09900 Web Price
Hayward W3H400FDN Universal H-Series 400,000 BTU natural gas Low NOx pool heater
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Hayward Universal H-Series Natural Gas 400,000 BTU Low NOx Pool Heater, W3H400FDN

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Quick overview

  • Natural gas This is the natural gas model. The propane version of the same heater is a separate Hayward part number.
  • 400,000 BTU The top output in the Universal H-Series range, sized for larger pools and faster heat up.
  • Low NOx Built to Low NOx requirements, which many jurisdictions ask for on a new gas heater installation.
  • Universal H-Series Hayward positions the line around installation flexibility for the service professional.
  • Two part numbers on record Cataloged as W3H400FDN and also listed as H400FDN, so either number points here.
  • Freight delivery A complete gas heater travels on a pallet rather than by parcel carrier.
Full description and specifications ↓

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Hayward TurboCell T-15 Salt Cell for Inground Pools up to 40,000 Gallons, W3T-CELL-15 Hayward Genuine OEM SP1082 Skimmer Basket, SPX1082CA Hayward Genuine OEM Vari-Flo XL Filter Valve Key Cover Handle Assembly, SPX0714BA Hayward H-Series Bezel & Keypad Assembly, FDXLBKP1930
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Product details

The Hayward Universal H-Series is the 400,000 BTU natural gas pool heater in Low NOx form, part W3H400FDN. It is the largest output in the residential H-Series range.

Why the Universal H-Series

Hayward built the Universal H-Series around the installer. The line is aimed at energy efficient, high output heating that adapts to the equipment pad it lands on, which is why it turns up so often on service replacements rather than only on new builds.

Fuel and emissions

This heater burns natural gas. If your pad runs on propane, the propane version is a separate model, so check the gas supply before ordering. The Low NOx rating matters too: a number of regions only allow Low NOx gas heaters on new installations, and this unit is built to that standard.

Part numbers and delivery

You may see this heater listed as W3H400FDN or as H400FDN. Both point to the same 400,000 BTU natural gas Low NOx unit. It ships by freight on a pallet, so allow for a delivery appointment.

Specifications
Brand Hayward
Manufacturer part number W3H400FDN
Also listed as H400FDN
UPC 0610377387255
Type Gas pool heater
Series Universal H-Series
Fuel Natural gas
Output 400,000 BTU
Emissions Low NOx
Shipping weight 400 lb
Ships Freight

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Questions and answers

What people ask about this product, answered by our pool techs.

Is this the natural gas or the propane heater?
Natural gas. The listing is the 400,000 BTU natural gas Universal H-Series. Propane is a different Hayward model.
Why do I see two part numbers?
Hayward stock for this heater appears as W3H400FDN and also as H400FDN. Both refer to the 400,000 BTU natural gas Low NOx Universal H-Series.
What does Low NOx mean for my install?
It refers to the heater meeting Low NOx emissions requirements. Many regions only permit Low NOx gas heaters on new installations, so it is worth checking your local rule before you buy.
How does it ship?
By freight. A complete gas heater of this size goes on a pallet, so plan for a delivery appointment rather than a parcel drop.
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