Product Overview

The Hayward H-Series Natural Gas Heater W3H135FDN is a 135,000 BTU pool heater designed to provide dependable, on-demand heating for above-ground pools and compatible residential pool or spa applications. Built with Hayward’s trusted heater technology, this unit delivers fast heat-up performance, efficient operation, and user-friendly controls for comfortable swimming conditions.

Powered by natural gas, the W3H135FDN is ideal for pool owners who want reliable heating performance without relying only on solar heat or seasonal weather. Its 120/240 V, 60 Hz, single-phase electrical compatibility makes it suitable for many standard residential equipment installations.

Fast, Reliable Heating Performance

The Hayward H-Series 135K BTU heater is designed to help bring pool water to a comfortable temperature and maintain that temperature more consistently. Whether used to extend the swim season, warm cooler water, or support spa-style comfort in compatible setups, this heater provides dependable performance for everyday pool enjoyment.

Its 135,000 BTU output makes it a practical heating option for smaller pools, above-ground pools, and lighter residential heating loads.

Built for Durability and Easy Operation

The W3H135FDN features durable heater construction designed for outdoor pool equipment environments. Its cupro nickel heat exchanger helps provide added resistance against corrosion and damage caused by challenging water chemistry conditions.

An intuitive electronic control panel makes temperature adjustment simple, allowing pool owners to manage heating operation with ease.

Key Features

• Genuine Hayward H-Series natural gas heater
• 135,000 BTU heating capacity
• Natural gas fuel configuration
• 120/240 V electrical compatibility
• 60 Hz, single-phase operation
• Designed for above-ground pools and compatible residential applications
• Cupro nickel heat exchanger for enhanced corrosion resistance
• Low NOx emissions design
• Electronic ignition for easy startup
• User-friendly electronic control panel
• Fast speed-to-heat performance
• Hydraulic design helps support efficient water flow
• Built for outdoor pool equipment pad installation
• Suitable for pool heating and compatible spa applications when properly sized
• Designed for dependable residential heating performance

Product Benefits

More Comfortable Swim Time

The 135K BTU output helps warm pool water so customers can enjoy more comfortable swimming conditions during cooler days, evenings, and shoulder-season months.

Reliable Natural Gas Heating

Natural gas provides strong, consistent heating performance, making this heater a practical option for pool owners who want dependable on-demand heat.

Corrosion-Resistant Heat Exchanger

The cupro nickel heat exchanger helps protect against corrosion and premature failure caused by unbalanced water chemistry, supporting longer equipment life.

Easy Temperature Control

The electronic control panel allows simple temperature adjustment and straightforward heater operation.

Efficient Water Flow Design

The heater’s hydraulic design helps move water efficiently through the unit, supporting dependable heating performance and system operation.

Ideal For

This heater is ideal for:

• Above-ground pools
• Smaller residential pool applications
• Compatible pool and spa heating setups
• Homes using natural gas as a fuel source
• Replacing an older 135K BTU gas heater
• Pool owners wanting faster heat-up than solar alone
• Installations requiring 120/240 V, 60 Hz, single-phase compatibility
• Customers looking for a dependable Hayward gas heater

Compatibility

The Hayward W3H135FDN is designed for natural gas installations and above-ground pool heating applications. It may also be suitable for compatible residential pool or spa systems when properly sized and installed by a qualified professional.

Before ordering, confirm:

• Fuel type: Natural gas
• Heating capacity: 135,000 BTU
• Electrical requirements: 120/240 V, 60 Hz, single phase
• Pool size and desired heat-up time
• Gas line sizing and installation requirements
• Plumbing flow rate requirements
• Local building, gas, and electrical codes
• Professional installation requirements

This heater should not be used with incompatible soft-sided pools or systems that cannot meet the required flow and installation specifications.

What’s Included

• One Hayward H-Series Natural Gas Heater, 135K BTU
• Electronic control system
• Cupro nickel heat exchanger
• Factory-installed heater components
• Manufacturer documentation, where supplied by packaging

Gas line components, venting materials, electrical whip, plumbing fittings, equipment pad materials, and installation labor are not included unless specified separately.

Specifications

Customer-Facing Q&A

Q: What type of fuel does the Hayward W3H135FDN use?
A: The W3H135FDN uses natural gas.

Q: How many BTUs is this heater?
A: This heater is rated at 135,000 BTU.

Q: What voltage does this heater require?
A: The W3H135FDN is designed for 120/240 V, 60 Hz, single-phase electrical operation.

Q: Is this heater for above-ground or in-ground pools?
A: This model is commonly used for above-ground pool heating applications. Always confirm sizing and installation compatibility before purchase.

Q: Does this heater have a cupro nickel heat exchanger?
A: Yes. The W3H135FDN features a cupro nickel heat exchanger for enhanced corrosion resistance.

Q: Is this a propane heater?
A: No. This model is configured for natural gas. Do not use it with propane unless the heater model specifically supports propane.

Q: Does this heater require professional installation?
A: Yes. Gas heaters should be installed by qualified professionals according to local gas, electrical, plumbing, and building codes.

Q: What is the barcode for this product?
A: The UPC / Barcode is 0610377407113.