By Hayward Pool Products



Model # W3H250FDP

Warranty 1 Year

Alternate Part #'s HAYW3H250FDP

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

250,000 BTU
165 lbs.
28 in.
0-10,000 ft.
Heat Exchanger:
Low NOx
Heater Type:

?     Asked on 4/21/2015by 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 5/4/2015by 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!

A  Answered on 5/5/2015 by InyoPools 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 5/8/2015by Gabriel Suarez

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

A  Answered on 5/9/2015 by InyoPools Product Specialist Patrick P.

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

?     Asked on 8/30/2015by Inyo Visitor

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

A  Answered on 9/3/2015 by InyoPools 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 7/3/2016by Alvin Alexander

I currently have an older model of this unit. I have a vertical vent pipe that vents through the roof. Can I operate this newer unit without the vent pipe?

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

Hi Alvin, This unit will also require a vent kit for indoor installation.


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