Product Overview

The Hayward Universal H-Series In-Ground Natural Gas Heater with OmniX 400K ASME | HS400FDNASME is a high-performance commercial pool and spa heater designed for demanding aquatic environments that require powerful heating, durable construction, and modern equipment control.

Delivering approximately 400,000 BTU of heating capacity, the HS400FDNASME is ideal for commercial swimming pools, spas, hotels, resorts, apartment communities, recreation centers, schools, fitness facilities, and other applications requiring dependable year-round heating.

This model features ASME construction, making it specifically suited for commercial installations where ASME-rated equipment may be required by project specifications or local codes.

The HS400FDNASME combines Hayward's proven Universal H-Series heater platform with OmniX embedded intelligence and the Hayward Universal Display. This provides improved programming, equipment diagnostics, system information, and compatibility with supported Hayward automation platforms.

A durable cupro-nickel heat exchanger provides excellent resistance to corrosion and demanding water conditions, while Hayward's Low NOx combustion system provides efficient operation with reduced emissions.

Key Features

• 400,000 BTU commercial pool and spa heater
• Natural gas configuration
• ASME commercial-grade construction
• Integrated OmniX intelligence
• Hayward Universal Display
• Advanced equipment diagnostics
• Enhanced programming capabilities
• Cupro-nickel heat exchanger
• 84% thermal efficiency
• Low NOx emissions
• Forced-draft combustion system
• Designed for commercial pool and spa applications
• Front-access service design
• Efficient hydraulic performance
• Compatible with supported Hayward automation systems
• Ideal for new installations and commercial heater replacements

Product Specifications

Commercial ASME Construction

The main difference between the HS400FDNASME and a standard residential Universal H-Series heater is its ASME-rated commercial construction.

ASME heaters are designed for installations where commercial-duty equipment is required or specified. This makes the HS400FDNASME an excellent option for:

• Hotels and resorts
• Commercial swimming pools
• Apartment and condominium communities
• Recreation centers
• Schools and universities
• Fitness clubs
• Health facilities
• Municipal aquatic centers
• Commercial spas

Always confirm local mechanical, plumbing, gas, and building codes before installation.

OmniX Smart Control

Hayward's OmniX embedded intelligence adds modern control and diagnostic capabilities directly to the heater.

The Universal Display provides access to temperature settings, operating information, programming, and system diagnostics from an easy-to-use interface.

When incorporated into a compatible Hayward automation system, the heater can also become part of a centralized pool equipment control platform.

Cupro-Nickel Heat Exchanger

The HS400FDNASME uses a durable cupro-nickel heat exchanger, making it well suited for demanding commercial environments.

Cupro-nickel provides increased resistance to corrosion compared with traditional copper-only heat exchangers and is commonly preferred in commercial installations where equipment may operate for longer periods or experience more demanding water conditions.

Proper water chemistry must still be maintained to protect the heater and maximize equipment life.

Frequently Asked Questions

Is the HS400FDNASME a natural gas heater?

Yes. The HS400FDNASME is designed for natural gas.

How many BTUs is this heater?

This model is commonly rated as a 400,000 BTU heater, with approximately 399,900 BTU/hr input.

What does ASME mean?

ASME refers to construction designed to meet applicable standards established by the American Society of Mechanical Engineers. ASME-rated heaters are commonly used in commercial pool and spa applications.

Is this heater intended for commercial pools?

Yes. The HS400FDNASME is specifically designed for demanding commercial swimming pool and spa applications.

Does it include OmniX?

Yes. This model features Hayward OmniX embedded intelligence and the Hayward Universal Display.

Does it have a cupro-nickel heat exchanger?

Yes. The HS400FDNASME uses a cupro-nickel heat exchanger for improved durability and corrosion resistance.

What is the recommended water flow?

The heater is designed to operate within an approximate water-flow range of 30 to 125 GPM, depending on the installation.

Can this replace an older H400FDNASME?

The HS400FDNASME is part of Hayward's updated Universal H-Series platform and is a logical replacement option for many older H400FDNASME installations. Existing plumbing, gas supply, electrical, venting, and installation requirements should be verified before replacement.

Is professional installation required?

Professional installation is strongly recommended. A qualified pool heater or gas technician should verify gas sizing, ventilation, electrical connections, water flow, and all applicable local codes before operation.