Pool Heater Universal H-Series Low Nox 350K BTU LP


MANUFACTURERHayward Pool Products

  (4.67 out of 5 Stars on 3 Ratings)

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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

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

350,000 BTU
Ask a Question

Asked on 10/08/2013 by Guest

Where can my heater be installed?

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?

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

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?

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?

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?

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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Customer Reviews

Ratings Summary

Average Rating:   (4.67 out of 5 Stars)

Recommended: (100%) 3 of 3 customers would recommend this product to a friend.

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

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The Most Helpful Review

15 of 15 people found the following review helpful:

   (5 out of 5 Stars) Awesome Heater

Reviewed By: from Jackson, NJ ()

Pros: Price, Works Quickly, Effective

Cons: nothing

This heater is awesome..It works so quickly and it is very easy to use..It was also cheaper on inyopools.com then other websites.. I love it !

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The Most Recent Reviews

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   (5 out of 5 Stars) Pool Heater

Reviewed By: from Olympia, WA ()

Pros: Price and good installation instructions

Cons: Can't track shipping on deliveries via truck carrier

Showed up ready to go with all instructions. It was easy to install, easy to light the first time and has been heating up our 22,000 gallon pool at a pretty good pace. Only thing I could complain about is the parts needed to vent the heater for indoor use are not included and I didn't know that I should get it. I could've done a little more research for sure, but some type of suggestion or a note on the info page would've been helpful, something like: For indoor use this venting part needs to be purchased. Maybe it was there and I missed it, as far as the heater goes, it was very easy to hook up and is working like a champ!

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   (4 out of 5 Stars)

Reviewed By: from Muncy, PA ()

Pros: Easy to install and operate.

I installed this product late last year and the installation and set-up was very easy. Overall I was very happy with this product.

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