Universal H-Series Low NOx Heater 200K BTU - NG - W3H200FDN



Part # W3H200FDN

By Hayward Pool Products



Part # W3H200FDN

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

200,000 BTU
154 lbs.
24-3/4 in.
0-10,000 ft.
Heat Exchanger:
Cupro Nickel
Special Feature:
Low NOx Emissions

?     Asked on 6/6/2019 by Universal H-Series Low NOx Heater 200K BTU - NG

Where is the owner's Manual? It wasn't in the delivery box and I can't find it on your web page.

A  Answered on 6/6/2019 by InyoPools Product Specialist Lennox H.

Hi. The manual is located in the service area, to retrieve it, you must remove the access panel. You can download it using this link, Hayward Universal H-Series Owner's Manual, and Hayward H-series LoNox Installation Guide.

?     Asked on 5/26/2019 by christine

how to i increase the temperature

A  Answered on 5/29/2019 by InyoPools Product Specialist Michelle B.

Hello,You would push the red arrow point upwards.

?     Asked on 8/21/2018 by Don

Can this heater be used for an in-ground vinyl lined pool?

A  Answered on 8/21/2018 by InyoPools Product Specialist Lennox H.

Hi, Don. Yes, this heater can be used to heat an inground vinyl liner pool. 

?     Asked on 6/24/2018 by Freddy

Hi, I have a 16x26 x52 above ground pool which is partially in the ground, i would like to know if the universal H-series Low NOx 200k BTU natural gas heater powerful enough for this size pool

A  Answered on 6/30/2018 by InyoPools Product Specialist Alex V.

Freddy, Yes the heater would be large enough for your pool. Please make sure that your gas lines are large enough for the heater.

?     Asked on 7/25/2017 by Gus Cerku

What size gas line and is it 110 v system?

A  Answered on 7/25/2017 by InyoPools Product Specialist Lennox H.

Hi, Gus. The gas line size would be based on the run from the gas regulator. This unit can also be wired for 110 volts. 

?     Asked on 7/20/2016 by

display pad will not work stuck on one temp can not adjust or shut off ??

A  Answered on 7/23/2016 by InyoPools Product Specialist Lennox H.

Hi, The problem could be with the Bezel & Keypad Assembly (FDXLBKP1930) not communicating with the Display Board (IDXL2DB1930) and vice vesa.

?     Asked on 6/8/2016 by simpson

we are installing the system ourselves. (or we could not afford it) so, the system comes with a connection for 220. what size GFI breaker should we use and wire size ?. Thanks. for: HAYWARD UNIVERSAL H SERIES HEATER H200FDN 200000 BTU 200K LOW NOX

A  Answered on 6/9/2016 by InyoPools Product Specialist Joe S.

Code requirements for electrical connection differ from county to county, state to state, as well as local municipalities. Install equipment in accordance with the National Electrical Code and all applicable local codes and ordinances.

?     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 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.


Est. Repair Time

4 to 8 hrs

Tools Needed

Screwdriver, Socket Set, Adjustable Wrench, Hacksaw

1     0

No Existing Heater

Written on 3/7/2019 by Guest

My pool did not have a heater so this was a more involved install than most of my other purchases. The heater comes well packaged on a wood pallet. After moving into place I had to make several PVC sections fit my pool pad and equipment.

The gas feed connection was the most difficult part. Use only gas line Teflon tape (yellow) for this connection. Once connected and plumbed I wired this back to my Hayward Logic Pro system.

Control setup was just as the manual said. The heater fired the first time and has made my pool enjoyable earlier and later than ever before. This is my second year with this heater and it works just as well as the day I installed it. Just be careful to keep your water chemistry right and the heater should have a long life.

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