Name: Universal H-Series Heater 500,000 BTU - Natural Gas, Low NOx
SKU: H500FDN
Availability: InStock

Features

Hayward Universal H-Series gas heaters are the “universal” energy efficient remedy for any new or existing pool or spa. An industry-leading hydraulic design reduces circulation pump run time to provide energy savings of up to 18% when compared to less efficient competitors. 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 to responsibly heat a pool or spa today and for years to come.

Features and Benefits

Standard cupro nickel heat exchanger
Excellent salt water and chemical corrosion resistance
Exclusive "Totally Managed" cupro nickel heat exchanger water flow
Same water velocity through all tubes for faster heating
Patented header by-pass design
Reduction in pump run-time results in significant cost savings
2" x 2 1/2" CPVC union plumbing connections
Forced draft system constantly moves air through the combustion chamber at a precise flow rate, eliminating the need for a high-wind stack
Low NOx emissions - meets clean air quality standards

NOTE: Hayward Universal H-Series heaters meet or exceed the South Coast Air Quality Management District (SCAQMD Rule 1146.2) Low NOx emissions standards in all Low NOx areas that apply the SCAQMD standard.

EXPERT LINE products can only be purchased through your local pool professional or in-store. Exclusions, other terms, and conditions may apply.
3+ Year Parts and Labor Warranties*

*When sold by a Hayward Rewards® partner. Exclusions, other terms and conditions may apply.

Active Defrost	No
Application	New Construction, Renovation, Aftermarket
Boost Mode	No
Brand	Hayward
Channel	Expert Line
Circuit Amps	5.5
Compressor Speed	N/A
Cooling Capability	No
Fuel Type	Natural Gas (NA)
GTIN	610377267953
Heating Capacity (BTU/hr)	500,000
Hertz - Heaters	60 Hz
Kilowatts	147 kW
Warranty - Labor	1-year
Low Ambient Operation	Yes
Master Carton Qty	1
Maximum Breaker Size (Amps)	15
Minimum Operating Temperature	40 °F
Pallet Qty	1
Warranty - Parts	3-year
Phase - Heaters	1
Pool Type	In Ground
Product Dimensions	24 " x 40 " x 29.5 "
Product Height	24 in
Product Length	29.5 in
Product Weight	245 lb
Product Width	40 in
Rear Clearance - Heaters	6"
Refrigerant	No
Series Heaters	Universal H-Series Low NOx
Shipping Dimensions	30.6 " x 32.8 " x 44.1 "
Shipping Weight	237 lb
Side Clearance - Heaters	12"
Silent Mode	No
Sub Brand	N/A
Voltage - Heaters	120/240V
Water Flow Rate Max	125
Water Flow Rate Min	40

Questions & Answers

15 answered question(s)

Ken Verified User

06/24/26

Q: I own a H400FDNBH pool heater and need to replace the control board again due to Haywards faulty design. I have heard that Hayward has finally developed a fix for this flaw that includes a cover for the board. I have also heard that this requires replacing the entire front panel. I am looking for those part numbers.

A:

Hello, please use our website's dealer locator to find the closest Hayward Authorized Service Center(HASC). A HASC may be needed to address this issue. Link to dealer locator: https://hayward.com/dealerlocator

By Hayward Support

Deborah Verified User

06/24/26

Q: Hi, looking to replace an old Hayward H350 ED1 pool heater. Pool is SALT 20x40 rectangular. I was looking at the universal H series, but I have to go with either 250btu or 400btu. What do you recommend?

A:

Hi we would recommend the H400FD heater for this pool. You should contact a local Hayward Authorized Dealer to verify gas line size prior to installation to avoid issues with the new heater. You can find a list of them by clicking on the Dealer Locator...

By Hayward Support

Marcos Verified User

06/24/26

Q: Podrías realizarme una cotización de un caldero de 400000 BTU a gas natural y una de 125000 BTU a gas natural. Por favor

A:

No vendemos directamente, pero puedes encontrar una lista de concesionarios autorizados locales de Hayward haciendo clic en la pestaña Localizador de concesionarios en la página de inicio de nuestro sitio web Hayward.com

By Hayward Support

Steve Maki Verified User

06/24/26

Q: Which model natural gas heater do you recommend for an in ground spa? It is 6x6 ft circular spa. It is connected to a pool, but I intend to use it only for the spa.

A:

Hi, we would recommend the H250FD heater for this application.

By Hayward Support

Loretta S Verified User

06/24/26

Q: Hi your propane pool heater Calculator for a pool 18 x 6 pool recommends 250 BTU. our pool is above ground pool with 18 inches into the soil. Do you still recommend 150 BTU propane heater, which you stated in your last answer? And which pump do you recommend to go with the propane heater? please advise thank you

A:

Hi, with this unique pool situation, we would recommend you contact a local Hayward Dealer for help is sizing your equipment. You can find a list of them on the home page of our website Hayward.com

By Hayward Support

Loretta S Verified User

06/24/26

Q: I am installing a radiant pool 6’ wide x 18’ long x5’ high with a propane heater. Can you please tell me which model I should purchase?

A:

Hi, we would recommend a H150FDP 150,000 btu heater for a small inground pool. The H135IDP would be the 135,000 btu heater designed for above ground pools.

By Hayward Support

Bill Perroz Verified User

06/24/26

Q: My pool is 20'x40' with an average depth of 6 feet. Is this heater the right size for my pool? Also, what is the natural gas pipe inlet size for this heater?

A:

Hi, this heater would work well for a pool that size. The inlet connection is 1"

By Hayward Support

Steve Verified User

06/24/26

Q: I just had a model H500FDN heater installed. Do I need a regulator installed in the natural gas supply line on the outside of the unit? My plumber said that the pressures at the manifold and inlet are within the ranges notated in the installation instructions.

A:

Hi, you would only need a regulator at the heater if the gas pressure at the heater was above the required pressure. We would defer to the installer to ensure the pressures are correct.

By Hayward Support

Karen Engst Verified User

06/24/26

Q: Anyone who services Hayward near me in Klee

A:

Hi, you can find a list of servicers in your area by clicking on the Dealer Locator tab on the home page of our website Hayward.com

By Hayward Support

Jim Hall Verified User

06/24/26

Q: What is the effenciency rating of the H series heaters

A:

HI, they range from 82.7 for the H150 to 84% for the H400

By Hayward Support

Drew Morgan Verified User

06/24/26

Q: I have a Hayward natural gas heater. Can it be converted to burn propane?

A:

Hi, yes it can, but it should only be done by a qualified gas service center. For help with this contact a local Hayward Authorized Service Center. You can find a list of them by clicking on the Dealer Locator tab on the home page of our website Hayward...

By Hayward Support

Andrew case Verified User

06/24/26

Q: In a situation where the pool heater is a little close to the house do they make a diffuser that goes on top of the heater to divert the exhaust away?

A:

Hi, we do not. The heater will have to be moved to give proper clearance to the house.

By Hayward Support

Mary Verified User

06/24/26

Q: I just had an H250FD heater installed. My pool pump/ filter run 12hours per day on a timer. I understand that the heater will not run while the pump is off. Do I need to turn the heater on and off each day while the pump is running or will it automatically restart each day once the pump turns on?

A:

Hi, the heater will only run when the pump is running if installed correctly, and will cut on and off as needed to keep the temperature at the set point as long as the pump is running.

By Hayward Support

Bruce Robert Verified User

06/24/26

Q: Looking into replacing my pool heater--I have an old pentair. My pool is salt and 20' by 40' in ground and I am wondering what you would recommend. I have a gas line hooked up to the heater. Also, what would it cost to have it installed and do you have a company to install it.

A:

Hi, we do not sell direct, but you can find a list of local Hayward Authorized Dealers by clicking on the Dealer Locator tab on the home page of our website Hayward.com

By Hayward Support

judy Stadt Verified User

06/24/26

Q: Hello. Please tell me how to turn on my Gas Heater.

A:

Hi, due to safety concerns we do not troubleshoot gas heaters with consumers. You can find a Hayward Authorized Service Center (HASC) in your area on our website Hayward.com by clicking on the Support Tab, then click Warranty, then in "purpose of...

By Hayward Support

Universal H-Series Heater 500,000 BTU - Natural Gas, Low NOx

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Universal H-Series Heater 500,000 BTU - Natural Gas, Low NOx

Features

Manuals

Literature

Line Drawings

Questions & Answers

Related Parts

Americas

United States

Canada

Latin America

Europe

United Kingdom

France

Germany

Spain / Portugal

Italy

Oceania

Australia

New Zealand

Other Regions

Asia

Africa

Middle East