Home Pool Pool & Spa Heaters Hayward Pool & Spa Heaters Hayward Universal H-Series Low NOx Induced Draft Pool & Spa Heater | 150,000 BTU | Natural Gas | W3H150FDN
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Hayward Universal H-Series Low NOx Induced Draft Pool & Spa Heater | 150,000 BTU | Natural Gas | W3H150FDN

Hayward Universal H-Series Low NOx Induced Draft Pool & Spa Heater | 150,000 BTU | Natural Gas | W3H150FDN

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Platinum Preferred Manufacturer
  • Part of the Hayward Energy Solutions family of products
  • Digital LED Control Panel
    Electronic control/display maintains water temperature; monitors heater performance with self-diagnostic capability

  • Cupro Nickel Heat Exchanger
    Totally Managed Flow provides exceptional corrosion resistance and erosion protection. Ideal for today’s salt-based electronic chlorination systems

  • Online part number W3H150FDN is the direct replacement for part number H150FDN.
The Hayward Universal H-Series gas heater is 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 on new or existing equipment pads to responsibly heat a pool or spa today and for years to come.
The forced draft system in the Universal H-Series constantly moves air through the combustion chamber at a precise flow rate eliminating outside weather variables that can affect heating performance. Wind conditions are eliminated and there is no need to install a high-wind stack.
Presenting Hayward's world-class heater with an Earth-friendly conscience¦the Universal H-Series heater! The Universal H-Series Low NOx heater has an 84 percent industry-leading thermal efficiency and complies with all current California air quality emission standards. The low NOx emission makes it a perfect choice for the environmentally concerned pool owner.
Enjoy a warmer pool this season without your fuel costs skyrocketing. Hayward's Universal H-Series heaters represent innovative heating technology for pools and spas. Its hydraulic performance also saves energy by reducing the circulation time of the pump. It can raise the temperature of an 800 gallon pool 30 degrees in less than an hour you'll feel the benefits the moment you step into the water. This approach to heating your pool is an efficient use of energy showing once again the commitment to developing earth-friendly products.
Other performance and efficiency-enhancing advances include stainless steel burners, corrosion-resistant Finn Plate heat exchangers with Cupro nickel, and insulated Fire Tile combustion chambers. This traps the heat unlike other forms of insulation delivering the highest degree of performance from every BTU. Equipped with an LED control panel it monitors heater performance for added convenience and maximum comfort with minimum effort. The ignition system delivers dependable lighting and reliable operations with just a touch of a button. The forced draft system constantly moves air through the combustion chamber to eliminate all outside weather variables affecting heating performance, such as wind conditions, eliminating the need to install a high-wind stack.
Additionally, the Universal H-Series heater is easy to install and combines advanced technology with universal-fit flexibility making it virtually compatible with any new or existing equipment pad. This heating mixture sustains your swimming season, adds to your comfort, is energy efficient, and reduces your fuel costs. This low NOx emissions heater is perfect for you and the environment all at the same time.
NOTE: Hayward Universal H-Series heaters meet the NOx emission standards set by the California South Coast Quality Air Management Commission for 2001 and the Texas Natural Resource Conservation Commission Code.
Superior Hydraulic Performance - New polymer header provides superior hydraulic performance to save energy and protect against the damaging effects of erosion from high flow conditions for improved reliability.
Designed for today's larger diameter plumbing systems with 2" x 2 1/2" CPVC unions.
Forced Draft System - Forced draft system constantly moves air through the combustion chamber at a precise flow rate, eliminating all outside weather variables that can effect the heating performance, such as high wind conditions without a high wind stack.
State-of-the-Art Finn Plate Heat Exchanger with Cupro Nickel - The patented single header "V" baffle design heat exchangers allow for long life, fast heating and virtually no condensation. All Hayward heat exchangers are now constructed with highly resilient Cupro Nickel for greater durability and longevity even in salt-based, high flow or aggressive water chemistry set ups.
L.E.D. Control Panel - Easy-to-read L.E.D. Control Panel provides digital temperature readout and diagnostics for quick identification of components that might need service.
Product Specifications:
Brand Hayward
Item Low NOx Pool Heater
Series Universal H-Series
Gas Type Natural
Headers Polymer
Control Type Digital Electric, Dual Thermostat
Tubing Material Cupro Nickel
BTUH Input 150,000
Cabinet Width 21 Inch
Cabinet Depth 29-1/2 Inch
Cabinet Height 24 Inch
Flue Diameter 6 Inch
Gas Connection 3/4 Inch
Water Connection 2 Inch x 2-1/2 Inch Unions
Voltage Rating 110/220 V
Frequency Rating 60 Hz
Phase 1-Phase

BTU Rating
Gas Type
Natural Gas
Q & A
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Browse 39 questions Browse 39 questions and 48 answers
my pool is approx 13000 gal. what do you recommend?
earl m on May 1, 2016
BEST ANSWER: Well I have an 18 ft x 5ft pool and it heats the water at about 1 degree an hr. Thats pretty quick. I don't think you should have any troubles.
how many btu's would i need....my inground is 17 by 32 with 8' deep end?
jeff s on Feb 4, 2016
BEST ANSWER: I believe you need to calculate how many gallons of water you have which should be easy given the dimenstions you have provided. Length x width x average depth x 7.5 = volume (in gallons). From there the BTUs required to heat the amount of water in a given amount of time - i.e., the more BTUs, the faster to get water to required temperature. Basically any amount of BTUs will heat the pool but consider time vs electric/gas to get water to preferred temperature.
can this be ordered with the water hook-ups on the left side?
A shopper on May 4, 2016
BEST ANSWER: yes. i saw a manufacturer demo where it said reverse hookups for water and gas lines.
can i turn gas supply off with valve at heater?
A shopper on Jun 20, 2017
The natural gas line is already there Do you install the heater if I purchase it through you ?
This will be my 2nd Hayward heater. I would do it myself, I can't I'm handicapped.
A shopper on Apr 19, 2016
BEST ANSWER: Sorry to hear. My neighbor and I installed my heater. All you need is two healthy people you can direct to install. I do not install heaters.
I have a Hayward HeatPro 21002 electric heater that is 100,000 BTU and was wanting to switch to natural gas and was looking at the Hayward H150FDN. Is this a unit that would work or is there something else that you would recommend for my ingrained pool?
Shawn C on May 2, 2017
Does the H series have electronic ignition?
sondra on Apr 29, 2016
BEST ANSWER: Yes if by electronic you mean No Pilot light. Heater is wired to power (comes set up for 220v but can easily be set to 110) and connected to gas. When pool or spa pump is running it senses water flow and when you turn heater on it lights itself.
Shipping cost?
A shopper on May 30, 2016
BEST ANSWER: Sorry, I am not sure but it seems that there was a fixed price for shipping. It is a big heavy item.
Do I need a timer switch with the H150FDN and a vent adaptert I am replacing a Jandy Kite 2?
Francis O on Mar 16, 2017
BEST ANSWER: A timer switch is not necessary. THe heater will automatically turn off when water stops flowing through the unit.
What are the dimentions of this unit?
Joe R on May 26, 2017
does it have a built in bypass?
A shopper on Mar 15, 2017
BEST ANSWER: No bypass. Only standby for heater. Water still flows through all the time.
Will this heater work for a 21' above ground pool?
angel r on Jul 31, 2018
BEST ANSWER: Yes, I have a 21' above ground pool and it works great. Will typically get it temperature overnight, perhaps less time, but we like it at 89 degrees. The digital thermostat is so easy, just set a temp and walk away.
does it come with inlet-outlet plumbing connectors or do i need a connector kit? what about exhaust? what size is the exhaust?
A shopper on Jul 19, 2016
BEST ANSWER: Yes it comes with the connectors, they will be glued to your plastic pipe. My unit is used outdoors , so I don't have exhaust connections.
Heater for 35000 gallon pool?
A shopper on Sep 16, 2020
BEST ANSWER: I use this heater on a 10000 gallon pool and it works fine but on a 35000 gallon you will probably use a lot more gas to heat it. I would suggest going with a higher BTU heater for your size of pool.
I bought this one about a 1 1/2 years ago and it still works fine. My question is it used to heat the water about one degree in one hour. Now it takes almost 2 hours to increase by one degree. Should I call a pool heater technician to come by. I live in VaBch. Someone told me I need a new heat exchanger. I don't want to buy something I don't need. Any info will help?
Stephen A on Jan 29, 2020
BEST ANSWER: That heater should not have the loss of performance within a year and a half that you are experiencing. Replacing the heat exchanger is not the cure. Usually, a loss of performance like you have is due to flow issues. Pool heaters have internal assemblies that regulate the flow of water into the exchanger while allowing some water to bypass. To work efficiently the water in the exchanger likes to be about 165 degrees. To control that some manufactures use a thermal regulator that is basically the same as the thermostat in your car. The other part of the system is the flow control or bypass assembly. The bypass allows water to go around the exchanger and then mix with the hot water coming out of the exchanger. Your heater uses part number FDXLFHA1930 which is the whole header inlet and outlet assembly. The bypass cartridge kit is FDXLBPK1930. I would inspect the bypass cartridge first as it is easy to screw off of the manifold assembly. Look for damage to springs or broken parts. The whole manifold assembly is eight nuts and some gaskets. If you are handy, removing your inlet and outlet pipe union adapters is easy and you will need part number SPX3200UG union gaskets when you assemble. The manifold kit should have all the gaskets included. You will need to remove the two side panels from around the manifold. Total parts for this is under $200.00 without tax and shipping. Be careful assembling the unions, hand tighten only, NO channel locks or pipe wrenches!
Hayward H-Series Header Assembly | FDXLFHA1930
Hayward H-Series Header Assembly | FDXLFHA1930
Hayward Union Gasket 50 Duro EPDM 2PK | SPX3200UG
Hayward Union Gasket 50 Duro EPDM 2PK | SPX3200UG
Hayward H-Series Bypass Cartridge Kit | FDXLBPK1930
Hayward H-Series Bypass Cartridge Kit | FDXLBPK1930
Is this new or refurbished?
A shopper on Apr 28, 2018
It's new and I love mine. I only have an 18ft pool and it heats it at about 1 degree an hour
I have a 17,500 gallon above ground pool. Which gas heater do you recomend?
Wanda S on Apr 23, 2017
BEST ANSWER: It all depends if you have natural gas or propane and will it be hardwired in or do you need a corded heater. I'll attach a couple examples.
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Natural Gas without Cord - 125000 BTU - 461058
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Natural Gas without Cord - 125000 BTU - 461058
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas without Cord - 125000 BTU - 461060
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas without Cord - 125000 BTU - 461060
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Natural Gas with Electrical Plug-In Cord - 125000 BTU - EC-462024
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Natural Gas with Electrical Plug-In Cord - 125000 BTU - EC-462024
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas with Electrical Plug-In Cord - 125000 BTU - EC-462025
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Propane Gas with Electrical Plug-In Cord - 125000 BTU - EC-462025
I see that there are above pool heaters and built in pool heaters. Is this heater OK for above ground pools?
A shopper on May 26, 2021
BEST ANSWER: Not exactly sure. My pool is in ground. Has a setting for hot tub so “maybe” or probably. Suggest calling manufacturer for their assessment.
Can the W3H200FDN be used with a 24' diameter above ground pool?
DAVID B on Feb 15, 2020
BEST ANSWER: Yes it can. Although these heaters will also work and are more affordable.
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Natural Gas without Cord - 125000 BTU - 461058
Pentair MasterTemp 125 Low NOx Pool Heater - Electronic Ignition - Natural Gas without Cord - 125000 BTU - 461058
Raypak 156A Above Ground Pool and Spa Heater | Digital Controls Electronic Ignition | Natural Gas 150K BTU | P-M156A-EN-C 014802 P-R156A-EN-C 014784
Raypak 156A Above Ground Pool and Spa Heater | Digital Controls Electronic Ignition | Natural Gas 150K BTU | P-M156A-EN-C 014802 P-R156A-EN-C 014784
I have a Hayward 250,000btu heater that requires replacement. Can I replace it with the 400,000btu model? If yes, do I need a new gas regulator as the current one is rated up to 300,000btu
A shopper on Jan 26, 2020
BEST ANSWER: Upgrading a 250,000 BTU heater to a 400,000 BTU heater makes sense. Having the correct gas supply is the first requirement to consider. A call to your gas supplier usually results in their willingness to install a larger gas meter. They want to sell you the gas so this is usually done for free.

The second part of that gas requirement is the size of pipe and the length from the meter to your appliance. There is a uniform code of specifications that dictate size of pipe and length from meter. This table is usually found in the installation manual of gas pool heaters. You can find a manual, usually under the heater of choice on our website. The specifications are the same for all heaters so the manual for any heater should have the uniform table for gas supply.

Gas type is also to be considered as Natural Gas and Propane have different specifications. Unlike natural gas, Propane can be two staged which means they can turn up the volume coming out of the tank and then install a regulator at the heaters location.

Two criteria should be used when sizing a gas pool heater. The gas supply and how much you want to spend. If your supply is limited, that will dictate what size of heater you are going to be able to install. I will always recommend installing the largest heater that fits the criteria. Yes, bigger is better and more efficient.

There is also another consideration when installing a pool heater and that is if it is being used for a salt water system. A cupro-nickle heat exchanger is a must for salt pools, as a standard copper exchanger will fail within weeks.

You cannot make a knowledgeable decision without information. Call us, we try very hard to give you the information needed.
If I purchase a 150K btu unit is this sufficient to heat a 750 gallon spa? Assume a 30 minute heat period what will be the temperature rise at the end of 30 minutes
A shopper on Nov 2, 2019
BEST ANSWER: Yes, a 150,000 BTU heater will heat your 750 gallon spa. For specifics about heat time and costs for natural gas and propane, we have a blog article that gives you formulas that you can punch in numbers and it will yield results that are pretty accurate.


To raise the temperature of the water 20 degrees with an average of 70 degrees outside with a 150,000 BTU heater, it will take about 49 minutes. If you install a 300,000 BTU heater it is just 25 minutes and a 400,000 is 19 minutes. There are variables that you also need to consider. The smaller heater may never be able to heat the spa if the outside temperatures plummet to near freezing and you are trying to get a 50 degree heat rise for the water. I will always recommend purchasing the largest heater that you have a gas supply for and how much you can afford. When heating a pool or spa, bigger is better and more cost effective.
can this be used with a salt generator?
Mary H on May 12, 2019
Is this unit enough for a 25k pool?
A shopper on Feb 25, 2018
BEST ANSWER: It depends where you live and the heat rise ratio you want
Check the specs to see
What does it mean when the screen says LO and how can it be fixed?
A shopper on Jun 15, 2017
BEST ANSWER: It means there is not enough water flowing through the unit. Filter may be clogged or restricted. It goes off if you restore the water flow.
Is this heater big enough for a 17000 gallon pool?
A shopper on May 16, 2017
BEST ANSWER: I have an 18ft x 5ft pool and the 150k heats the water at about 1 degree an hour. It should be alright for you
will it work with propane gas?
margaret t on May 1, 2017
BEST ANSWER: No, you will need the attached heater.
Hayward Universal H-Series Low NOx Induced Draft Pool & Spa Heater | 150000 BTU | Propane | W3H150FDP
Hayward Universal H-Series Low NOx Induced Draft Pool & Spa Heater | 150000 BTU | Propane | W3H150FDP
If I'm installing this below my deck, do I need a vent pipe?
S. Hurley on Sep 15, 2016
BEST ANSWER: If it is in an enclosed area you would require venting
I want to add to an already installed in ground pool 14X28 with a deep in of 6 feet. It has a vinyl lining. My home is total electric so I do not have any gas. Can the Hayward Universal H-Series Pool Heater 150,000 work for me and what else will I need to install along with it? If not what are your recommendations
Alston pool on May 11, 2016
BEST ANSWER: No heater runs on gas or propane. You will need an electric heater.
My pool holds about 28,000 gallons what size heater do I need?
Dave B on May 19, 2021
where is electric connection?
jerry c on May 16, 2021
4.6 / 5.0
10 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Rated 5 out of 5
Great Buy!
This is the second Hayward pool heater that I have owned. This one is more compact than my old one - I would thoroughly recommend it.
April 10, 2013
Rated 5 out of 5
H- series Gas heater
As an installer, A very efficient, fast heating model. the upgrades you have made to this model are awesome, shouldnt have to do a lot maintaining (dirt dobbers and wasp nest clogging the gas tubes).
August 9, 2019
over 2 years ago
Rated 5 out of 5
Direct replacement with very little alteration.
Easy to install, very good instruction manual. Heats the spa quickly and efficiently
August 21, 2016
over 5 years ago
Rated 5 out of 5
Works well
Had the heater installed by trained installer. It has worked very well at keeping the pool comfortable.
June 19, 2019
over 4 years ago
Rated 5 out of 5
I’d recommend it.
Simple. I hooked it up and it just works. Works very well. I’d recommend it.
June 29, 2020
over 3 years ago
Rated 5 out of 5
Fantastic, perfect for my 27 foot round pool, heats fast, is quiet and energy efficient, love it.
June 8, 2019
over 4 years ago
Rated 1 out of 5
Customer service needs work
I love my heater. It is the post experience I had with someone from your company. They called and tried to charge me a delivery fee and did not believe my explanation ans wanted to come get my heater. This will be the last product I buy from your company
June 4, 2021
2 months ago
Rated 5 out of 5
Hayward Universal H-Series Low NOx Induced Draft Pool & Spa Heater | 150000 BTU | Natural Gas | H150FDN
Fantastic pool heater by a reputable provider that backs up their product! Pool Supply Unlimited price point for this heater was wonderful and very competitive with our businesses and they were very accommodating from a delivery perspective as well!
July 26, 2017
over 4 years ago
Rated 5 out of 5
Great heater!
This heater is being used on a 21' above ground pool and works perfectly!
July 31, 2018
over 3 years ago
Rated 5 out of 5
Love it.
It replaced my old Pentax which lasted about 1 yr with no problems then nothing but problems for the next 6. The Hayward seems to be built so much better. It heats the pool water at about 1 degree an hr. I love it.
April 28, 2018
over 5 years ago
Hayward Pool Products warranties all items sold over the internet for a period of one year, parts only, no labor, ONLY when purchased from a Hayward Authorized Online Reseller.
  • Salt cell replacements W3T-CELL15, W3T-CELL-9, and W3T-CELL-3 include a three year, parts only warranty, when purchased from a Hayward Authorized Online Reseller.
Pool Supply Unlimited is a Hayward Authorized Online Reseller.
For Hayward warranty registration information, and to submit online, please visit www.hayward-pool.com
This information was updated on 4/15/2020. For the most current information and full warranty policy please visit www.hayward-pool.com

 Adobe Acrobat PDF Warranty Information
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Pool Supply Unlimited is an e-commerce company that loves water. We love to pump it, filter it, heat it, chlorinate it, light it up and stare at it while we're barbequing a fat, juicy steak. There are real pool professionals working here. Our guys have seen thousands of pools in their careers, no exaggeration. We are based in Southern California and can land most products to your door (within the 48 contiguous states) in less than a week.
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