Hayward Pool Heater Universal H-Series Low Nox 250K BTU LP


MANUFACTURERHayward Pool Products

  (4 out of 5 Stars on 1 Ratings)

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Product Desciption

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

Technical Specifications

Model # BTU Input Gas Type Heater Width Weight
H250FDN 250,000 Natural 28" 165 lbs.
H250FDP 250,000 Propane 28" 165 lbs.
H350PDN 350,000 Natural 33 1/4" 195 lbs.
H350FDP 350,000 Propane 33 1/4" 195 lbs.
H400FDN 400,000 Natural 36 1/2" 197 lbs.
H400FDP 400,000 Propane 36 1/2" 197 lbs.

Overall Dimensions

250,000 BTU
165 lbs.
28 in.

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Ask a Question

Asked on 08/30/2015 by

I want to change my CPS 1320 heater to a current model what do you suggest, roughly a 30000 gal pool

Inyo Answer

Answered on 09/03/2015 by Product Specialist Lennox H.

Hi, For your size pool I would recommend the H300FDP. If you would like to heat the pool faster you can go with a larger size unit also.


Asked on 05/08/2015 by Gabriel Suarez

I have a in-door pool with 22000 gallons, I want to buy your: Hayward, H250FDP, will be OK?

Inyo Answer

Answered on 05/09/2015 by Product Specialist Patrick P.

Hi Gabriel, This would be the correct sized heater for a 22,000 gallon pool.


Asked on 05/04/2015 by Emilio Ramirez

Im interested in a pool heater for an outside pool with following dimensions: 30 feet long x 10 feet wide 5.5 feet deep. I have LP gas, and would like to be able to use it in the fall temperatures may be -5 Deg Celsius. Will a 250 be suitable for this pool? I run a single speed 3/4 H.P. pump/filter Thanks!

Inyo Answer

Answered on 05/05/2015 by Product Specialist Patrick P.

Hi Emilio, Yes this heater would suit your needs. Based on the information you supplied on your pool you would expect to see a 1-2 degree (Fahrenheit) temperature rise per hour. In the colder months we would definitely suggest a Swimming Pool Solar Cover as this will significantly reduce your operational costs of the heater.


Asked on 04/21/2015 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?

Inyo Answer

Answered on 04/21/2015 by 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 10/08/2013 by Guest

Where can my heater be installed?

Inyo Answer

Answered on 10/08/2013 by 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 01/17/2013 by Guest

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

Inyo Answer

Answered on 01/17/2013 by 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

Inyo Answer

Answered on 10/18/2012 by 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?

Inyo Answer

Answered on 10/10/2012 by 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 01/16/2012 by Guest

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

Inyo Answer

Answered on 01/16/2012 by 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?

Inyo Answer

Answered on 12/29/2011 by 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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Ratings Summary

Average Rating:   (4 out of 5 Stars)

Recommended: (100%) 1 of 1 customer would recommend this product to a friend.

1 Rating 5 star: (0) 4 star:   (1) 3 star: (0) 2 star: (0) 1 star: (0)

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The Most Helpful Review

4 of 4 people found the following review helpful:

   (4 out of 5 Stars)

Reviewed By: from Bell Isle,FL ()

Pros: easy installation. to carry.

Cons: Electical /gas connectins are in the same panel

This is a great heater, I love the small compact size.
Is also very quiet, very durable and easy access to work and replace any parts. I would recommend to any pool / spa owner.
Hayward products are very reliable,easy to order and friendly sales people to talk too. I will be looking forward to be selling and Installing this product in the future. thanks

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