Universal H-Series Low NOx Heater 150K BTU - NG - W3H150FDN



Part # W3H150FDN

By Hayward Pool Products

  5 Average  



Part # W3H150FDN

Warranty 1 Year

Alternate Part #'s HAYW3H150FDN

Product Description

Universal H-Series Low NOx Heaters
For In-Ground Pools and Spas - Electronic Ignition Dual Thermostat

Now With Cupro Nickel Heat Exchanger!

NEW Hayward Universal H-Series Low NOx heater combines industry-leading hydraulic performance; environmentally responsible low NOx emissions and a standard cupro nickel heat exchanger with a low profile appearance, lighter weight design, independent left or right side electric, water and gas connections plus 2" x 2 1/2" CPVC union connections to provide the ultimate installation flexibility for new or existing equipment pads.

It also includes a forced draft system that constantly moves air through the combustion chamber at a precise flow rate. As a result, all outside weather variables that can affect the heating performance, such as wind conditions, are eliminated - without having to install a high-wind stack.

NOTE: The 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.


  • 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.
  • Our 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.
  • Easy-to-read L.E.D. digital Control Panel provides digital temperature readout and diagnostics for quick identification of components that might need service.
  • 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.
  • 1 Year limited warranty
  • Now with Cupro Nickel Heat Exchanger

Overall Dimensions

Product Specifications

150,000 BTU
141 lbs.
21-1/2 in.
0-10,000 ft.
Heat Exchanger:
Cupro Nickel
Special Feature:
Low NOx Emissions

?     Asked on 5/12/2021 by ken

would a 150k-btu-ng be sufficient to heat a 10.000 gal pool? I presently have a Hayward but don't know the size, looked but no find.

A  Answered on 5/12/2021 by InyoPools Product Specialist Danny R.

There are a few things to take into consideration while selecting a pool heater.  We wrote a good guide on this.  Here is the link...How To Select a Gas Heater For Your Pool or Spa

?     Asked on 6/10/2020 by Bob

I need to know what parts are needed to connect the water input and output to a 1 1/2 inch hose.

A  Answered on 11/24/2020 by InyoPools Product Specialist Hector F.

Hi Bob, these units come with the union kits for plumbing. If you need a reducer bushing to go from 2 inches to 1.5 inches you can locate those at any local hardware store. 

?     Asked on 5/19/2020 by jay

what is the difference between the h150fdn and the W3H150FDN

A  Answered on 5/19/2020 by InyoPools Product Specialist Hector F.

The W3H150FDN is really the online/alternate part number being the same model as the h150fdn. 

?     Asked on 4/15/2020 by

is this heater sufficient for a 14X28 inground pool ???

A  Answered on 12/2/2020 by InyoPools Product Specialist Megan C.

We will need the average depth of the pool to determine the total gallons of water. Please see Swimming Pool Calculations to help. If the pool is a rectangle and has an average depth of 5.0' the approximate gallons is 14,700 the minimum BTU Size would be 123,000BTU. The Hayward Universal H-Series LowNox Heaters start at 150K. In this example, yes, the 14,700-gallon pool can use the 150K heater, it will take approximately, 1-hour and 10-minutes to raise the temperature by 1-degree with the use of a Solar Blankets or Natural Chemistry COVER FREE 32 Oz - 07100 to prevent evaporation, 80% of heat loss is due to evaporation. Without the use of one of the options, it will take longer to increase the temperature levels. 

?     Asked on 4/11/2020 by paul steffanelli

With the piping of the heater is a salt generator placement the same as a standard clorine model

A  Answered on 4/11/2020 by InyoPools Product Specialist Patrick P.

Yes you will want the salt cell or in line chlorinator to be the last piece of equipment in your system and definitely after the heater.

?     Asked on 11/17/2019 by Daniel M McCarthy

About how long would it take to heat up an 8 foot round hot tub to around 100 degrees in 40 degree temperatures with the 150000 BTU heater?

A  Answered on 11/18/2019 by InyoPools Product Specialist Lennox H.

Hi, Daniel. Your missing the starting temperature, once you have that, use the Hayward Heater BTU Selection Guide to calculate heating time. 

?     Asked on 10/10/2019 by John Casale

I'm looking for the best option for a pool with 170' of surface area and approx 16,000 gallons of water. I live in Seminole Florida and gas is not an option in my community. My wife does not want to have a propane tank put in so we are hoping for an electric heater option. We have a solar cover we use during the winter months. Could you tell me about some options we have?

A  Answered on 10/10/2019 by InyoPools Product Specialist Lennox H.

Hi, John. A Heat Pump will be your best option. A minimum of 100K BTU unit will be sufficient. 

?     Asked on 8/12/2019 by Eugene

I have a 9000 gallon pool and not looking for quick heat. Will this 150 btu model work good for me?

A  Answered on 8/13/2019 by InyoPools Product Specialist Steve M.

Eugene, yes, the Hayward Pool Products Universal H-Series Low NOx Heater 150K BTU - NG would be sufficient to heat up your 9000 gallon pool. There are a number of factors to consider when sizing a heater and for that reason, we would suggest reading our article; "Sizing Your Pool Heater" 

?     Asked on 7/24/2019 by mark

I have h150fdn ihave display code of CE manuel says to replace the Display Interface Assembly and/or Key Pad. If code is still present, replace the ICB is this common and should i replace both

A  Answered on 7/25/2019 by InyoPools Product Specialist Lennox H.

Hi, Mark. It is mot common that more than one board can fail at the same time. You can't determine which board is bad without replacing the other. You should replace both the Integrated Control Board UHSLN - FDXLICB1930 and Display PCB UHSLN - IDXL2DB1930.

?     Asked on 6/15/2018 by Rick

I have a Hayward heater, model # H150FDN. The face plate fell off and I believe the small mother board right behind the plate is fried.

A  Answered on 6/16/2018 by InyoPools Product Specialist Lennox H.

Hi, Rick. Replacing the Bezel & Keypad Assembly - FDXLBKP1930 and the Display Board Only - IDXL2DB1930 are the parts you'll need. 

?     Asked on 6/2/2018 by jeffrey gallonio

i started my heater today ran fine then i shut it down an won't restart the code lo comes up on the screen

A  Answered on 6/3/2018 by InyoPools Product Specialist Lennox H.

Hi, Jeffrey. The LO error code references the Limit string open error. You will need to check the Limit Switch - FDXLHLI1930 or the Integrated Control Board - FDXLICB1930 to find out which part is bad and will need to be replaced. Also, it could be a bad Water Pressure Switch - FDXLWPS1930, confirm that the unit is getting at least 30 GPM. 

?     Asked on 5/9/2018 by

Is this a new Hayward 150000 BTU water heater model. I notice that there is a cover over the temperature gauges. But on the other Hayward 150000 BTU heaters, the temperature gauges does not have a plastic cover and they are different then other heaters i described. Which is the most up to date? The Hayward heater with the plastic cover or the heater without? I especially love the Hayward heaters with the cover. It protect against the rain and snow.

A  Answered on 5/11/2018 by InyoPools Product Specialist Lennox H.

Hi. This unit is the most recent H Series heater model by Hayward. 

?     Asked on 9/6/2017 by Nicolette Gardner

How long would it take for this heater to raise the temperature of a standard size in-ground jacuzzi about 15 degrees?

A  Answered on 9/8/2017 by InyoPools Product Specialist Lennox H.

Hi, Nicolette. The answer to your question will be based on the actual surface area of the spa. You can use the Hayward Heater BTU Selection Guide to calculate the temperature increase of your spa after calculating the surface area. 

?     Asked on 6/2/2017 by Kyle

How can I tell what year the model was manufactured?

A  Answered on 6/3/2017 by InyoPools Product Specialist Patrick P.

There should be a mfg. date on the label of the heater, or if you find a serial # you can contact Hayward at www.haywardpool.com and they will be able to tell you the year of mfg.

?     Asked on 5/30/2017 by Dimi

Does this heater require its own electric hook up or can I feed it from my existing 120V pump? Also, is it equipped with a fireman switch? Thank you

A  Answered on 6/3/2017 by InyoPools Product Specialist Lennox H.

Hi, Dimi. This unit requires an electrical hook, the source of the supply doesn't matter. A fireman switch is not included with the unit.

?     Asked on 2/15/2017 by Francoise

I plan to build my own pool and the architect needs the pump and heater information. The outside, inground pool is going to be 10' x 20' with an average depth of 5'. I will be using 2-1/2" PVC pipe and I calculated 20' feet of head. I think the Hayward SP2600X5 pump will work. Can you please confirm my calculations and let me know what size water heater I will need. I want to be able to swim in water that is 70 degrees Fahrenheit in the winter when the temps at times fall to the mid 30's.

A  Answered on 2/15/2017 by InyoPools Product Specialist Scott W.

Good afternoon Francoise, I would recommend at least the 200,000 BTU model, part number H200FDN, though if you are going to have a saltwater pool I would recommend the heater with a cupro-nickel heat exchanger to prevent corrosion and leaks to your heat exchanger, part number TR250NA. As for the SP2600X5, that will work just fine just as long as you do not have any water features. If that is the case then I will need to know all the features so I can calculate the correct horsepower for your pump.

?     Asked on 10/15/2016 by Dona

Can I have my outside pool heater running during in a heavy rain and wind storm with possible thunder and lightening?

A  Answered on 10/17/2016 by InyoPools Product Specialist Lennox H.

Hi, Dona. This unit can be run under those weather conditions as long as the proper safeguards are in place to protect the unit from flooding and being strike by lighting. You can review the Hayward Universal H-Series Owner's Manual for more info.

?     Asked on 7/29/2016 by

what size pipe do you use for a 150,000 btu lo nox heater

A  Answered on 7/30/2016 by InyoPools Product Specialist Lennox H.

Hi, This unit has 2"/2-1/2" unions for the water connections.

?     Asked on 6/3/2016 by Bill

Do you have a manual bypass valve kit for a H150FDN pool heater?

A  Answered on 6/10/2016 by InyoPools Product Specialist Lennox H.

Hi Bill, You can build your own external manual bypass using a 3-Way Valve and Tee. Or if you're looking to replace the Bypass Cartridge Kit-FDXLBPK1930, that part is available.

?     Asked on 5/24/2016 by Scott

Will this heater work with a 16 x 32 above ground pool?

A  Answered on 5/29/2016 by InyoPools Product Specialist Alex V.

Scott, For a 16' x 32' pool, I would recommend at least 200-250k btu. The lower the btu, the longer it will take to heat the pool.

?     Asked on 5/23/2016 by Joe

Will the Hayward H1001D1 100,000 BTU unit work at an elevation of 3500 ft??

A  Answered on 5/28/2016 by InyoPools Product Specialist Joe S.

Yes this unit will work up to an elevation rating up to 7,700 feet.

?     Asked on 2/15/2016 by Akbar Hussein

our pool is 45 feet long and 42 ft wide. what Hayward natural gas pool heater needed? What controller ? Thanks Akbar Daysinn41810@gmail.com

A  Answered on 2/15/2016 by InyoPools Product Specialist Christian R.

The heater that would reach the heating requirements would be the H400FDN.

?     Asked on 8/1/2015 by

Can above ground pool heaters be used on inground pools?

A  Answered on 8/5/2015 by InyoPools Product Specialist Alex V.

Hello, As long as the heater is sized correctly for the pool size, you can use an above ground heater for an in-ground pool. Please double check the gas line requirements to ensure that you will be able to have the heater installed with no issues.

?     Asked on 7/23/2015 by troy

i have a 16 x 32, what size heater do i need?

A  Answered on 7/23/2015 by InyoPools Product Specialist Lennox H.

Hi Troy, The Hayward Pool Heater Universal H-Series Low Nox 200K BTU NG will be a better size for your pool.

?     Asked on 4/21/2015 by George

I want to install the Hayward Lownox heater on my pool but I live in the mountains at 3,000 foot elevation; do I need to buy a special high elevation heater?

A  Answered on 4/21/2015 by InyoPools Product Specialist Matt S.

Hello George, The Hayward Universal Low Nox are self adjusting up to 10,000 feet of elevation. Any installation above 2,000 feet will require a special restriction plate to be installed. Luckily, that plate comes standard with every heater so no need to purchase it separately.

?     Asked on 3/28/2015 by chris

Can I hook up an inground heater to an above ground pool?

A  Answered on 3/30/2015 by InyoPools Product Specialist Robert M.

Hello Chris - The inground heaters can be used on above ground pools.

?     Asked on 10/8/2013 by Guest

Where can my heater be installed?

A  Answered on 10/8/2013 by InyoPools Product Specialist Patrick P.

There are specific venting requirements and clearance distances that must be met to ensure proper operation. Consult the owner’s manual for exact specifications for your model of heater.NOTE: Gas fired heaters should be diagnosed and repaired by trained personnel.

?     Asked on 10/7/2013 by Guest

Is it possible to convert this heater from natural gas to propane?

A  Answered on 10/7/2013 by InyoPools Product Specialist Patrick P.

Yes, it is possible to convert this heater from natural to propane gas as there is a conversion kit for it. To view and purchase this kit you you will need to click here.

?     Asked on 1/17/2013 by Guest

Is a vent required for typical outside installation for the Hayward 150k Ng Lo Nox heater?

A  Answered on 1/17/2013 by InyoPools Product Specialist Patrick P.

For the Hayward  Lo Nox heater, you would not need to purchase an additional vent if you are using it outside. If you are installing the heater outside, we recommend you purchasing a heater cover. This will protect your heater from debris, rain, snow, heat- or pretty much anything that could get caught in your heater. The Weather-Out Pool Heater Cover  can be viewed on our website.

?     Asked on 10/18/2012 by Guest

What is the elevation rating for the Hayward H-Series Low Nox Heaters

A  Answered on 10/18/2012 by InyoPools Product Specialist Patrick P.

Per Hayward, the Hayward H-Series Low Nox Heaters have an elevation rating up to 7,700'

?     Asked on 10/10/2012 by Guest

What is the difference between an Electronic and Millivolt ignition?

A  Answered on 10/10/2012 by InyoPools Product Specialist Patrick P.

The basic answer is that Millivolt is the old style of ignition, using a standing pilot light. While the electronic ignition uses a spark start system like a gas grill. Electronic ignitions are more efficient in gas usage and also are better suited for high wind areas where a pilot light might get extinguished.

?     Asked on 1/16/2012 by Guest

Will a gas heater operate at the low speed of a dual speed motor?

A  Answered on 1/16/2012 by InyoPools Product Specialist Patrick P.

Probably not - Most gas heater will shut off at low GPM levels (20-40) to keep the heater cores from overheating - 20 for 200 BTUs, 40 for 400 BTUs. Depending on your pool system you might get these GPM levels at the low speed but generally these heaters must be run at the motor's high speed.

?     Asked on 12/29/2011 by Guest

How do you know if a pool heater is a propane heater or a natural gas heater?

A  Answered on 12/29/2011 by InyoPools Product Specialist Patrick P.

Typically in the product name we use the abbreviation of "LP" for propane or "NG" for natural gas. Click here for a full listing of our >Pool Heaters.


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