Hayward H-Series Pool Heaters – Powerful, Proven Performance
Hayward H-Series Pool Heaters: Reliable Heat for Real-World Pools
The Hayward Universal H-Series is one of the most proven gas pool heater lines in the industry. Built for fast heat-up, consistent performance, and long-term durability across a wide range of residential and commercial pool and spa setups.
Download the Hayward H-Series Brochure (PDF)What Makes the Hayward H-Series Different?
Hayward designed the Universal H-Series for efficiency, reliability, and installation flexibility. These heaters feature a cupro-nickel heat exchanger for superior corrosion resistance, making them ideal for both traditional chlorine and saltwater pool environments. They deliver fast heat-up times, low NOx emissions, and consistent performance across all pool sizes — backed by decades of proven field performance.
Explore the Hayward H-Series Lineup
Compare models to find the right fit for your pool size, fuel type, and performance needs.
Model Comparison at a Glance
| Feature | H250FDN | H400FDN / W3H400FDP | H400FDNASME |
|---|---|---|---|
| BTU Output | 250,000 | 400,000 | 400,000 |
| Thermal Efficiency | 83–84% | 83–84% | 83–84% |
| Fuel Type | Natural Gas | Natural Gas or Propane | Natural Gas |
| Heat Exchanger | Cupro-Nickel | Cupro-Nickel | Enhanced Cupro-Nickel |
| ASME Certified | No | No | Yes |
| Low NOx | Yes | Yes | Yes |
| Best Application | Mid-sized residential pools | Larger pools & spa setups | Commercial & high-demand |
How to Choose the Right H-Series Heater Size
Choosing the right heater size directly impacts both performance and operating cost. An undersized heater heats your pool slowly and runs constantly; an oversized one wastes fuel. Use this quick guide as a starting point:
- Small to mid-sized pools: H250FDN
- Larger pools or spa-heavy use: H400FDN (Natural Gas) or W3H400FDP (Propane)
- Commercial or high-demand setups: H400FDNASME
Climate, desired heat-up speed, spa usage, and fuel type all play a role in the final selection. Contact us for a personalized recommendation.
Natural Gas vs. Propane: What to Know
The main difference between natural gas and propane heaters comes down to fuel source — not performance. Both options deliver the same heating power and efficiency.
Natural Gas
Ideal for homes with an existing gas line. Continuous supply, no tank refills needed. Model: H400FDN
Propane (LP)
Best for rural properties or homes without a natural gas connection. Same performance, different fuel setup. Model: W3H400FDP
Why Cupro-Nickel Heat Exchangers Matter
The H-Series uses a cupro-nickel heat exchanger, specifically engineered to resist corrosion from salt systems and pool chemicals. This is one of the key reasons the H-Series has remained a trusted option for both residential and commercial applications for decades.
Best Fit Applications:
- Homeowners upgrading older gas heaters
- Pools with attached spas needing fast heat-up
- Saltwater pools requiring corrosion resistance
- Buyers looking for reliable, proven heater performance
See the Hayward H-Series in Action
Frequently Asked Questions
What is the difference between the Hayward H250 and H400?
The H250FDN provides 250,000 BTU output, making it ideal for small to mid-sized pools. The H400FDN delivers 400,000 BTU for larger pools, faster heat-up times, and higher-demand setups including pools with attached spas.
Is the Hayward H250 enough for a pool and spa combination?
Yes, for many mid-sized pool and spa setups the H250FDN is sufficient. However, larger pools or setups with heavy spa usage typically benefit from the higher output of the H400FDN.
What is the difference between natural gas and propane pool heaters?
The main difference is the fuel source. Performance and heating power are identical. The choice depends on whether your property has an existing natural gas line or uses a propane (LP) tank.
What is the Hayward W3H400FDP?
The W3H400FDP is the propane version of the H400 heater. It delivers the same 400,000 BTU performance as the natural gas H400FDN model but is specifically designed for liquid propane (LP) fuel systems.
What makes the Hayward H-Series reliable?
The combination of a cupro-nickel heat exchanger, a proven forced-draft combustion design, and consistent performance across residential and commercial applications makes it one of the most dependable heater lines available.
What is the difference between standard and ASME Hayward H-Series models?
ASME models like the H400FDNASME are built for commercial applications. They include additional certifications, thicker headers, and enhanced durability features designed for high-demand, continuous operation.
How do I choose the right Hayward H-Series heater size for my pool?
The right heater size depends on pool surface area, spa usage, climate, desired heat-up speed, and fuel type. As a general guide: the H250FDN suits small to mid-sized pools, the H400FDN or W3H400FDP suits larger pools or spa-heavy setups, and the H400FDNASME is designed for commercial or high-demand applications. Contact Aqua Terra Backyard for a personalized recommendation.
Looking for Hayward Heater Guidance?
If you are considering a Hayward H-Series heater, Aqua Terra Backyard can help you choose the right model based on your pool size, usage, and performance goals.
Call 631-678-6506 or contact us for product guidance and availability.
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