Raypak digital low NOx natural gas heater 399k BTU review

Nothing can be better than warm pool water in the winter morning. Getting warm pool water is really challenging if you do not have an efficient pool heater. But, things can appear totally different if you have the Raypak digital low NOx natural gas heater 399k BTU to warm the pool water. Well, guys in this article, I will provide one of the best Raypak Natural Gas pool heater reviews in the market now. Let’s dive into the article.

It is needless to say that when fall approaches or the first frost of winter is felt in the wind or the spring or summer, you can always control the temperature of your pool or spa to your liking. The Raypak digital natural gas pool heater 399k BTU helps you receive greater enjoyment from your pool or spa.

This unique Raypak digital gas pool and spa heater allow you to maintain the right temperature for your pool or spa, without any constant monitoring. The Raypak 399 BTU pool heater was built to resist diverse weather conditions and thus provides a convenient, efficient, and versatile option for spaces that demand these characteristics.

You keep enjoying your heater all year long; just make sure to go for a corrosion-resistant galvanized metal cabinet with a copper fin tube heat exchanger and a bevy of superior engineering materials. Now, keep reading the guide to know more about Raypak 9243 Gas pool heater.

Specifications of the Raypak digital low NOx pool heater BTU 399k

  • Product Dimensions: 45 x 34 x 30 inches
  • Brand: Raypak
  • Fuel Efficiency: 399,000 BTU
  • Heat Exchanger: Copper
  • Ignition: Electronic
  • Installation Type: Commercial
  • Pool Type: In-Ground
  • Controls: Digital

Prominent Features of the Raypak digital low NOx natural gas heater 399k BTU

Raypak digital natural gas pool heater 399k btu

PolyTuf Textured Powder Coating

The Raypak digital low NOx natural gas heater 399k BTU has a more durable polyester-coated, non-corrosive wardrobe than solvent or water-borne wardrobes. The sheet metal undergoes a 7-step wash technique for each stage. Ensuring the paint has a great bond is critical. You will find galvanized metal on the inside of the finish that gives great corrosion resistance and long-term durability.

Wind-Resistant Design

The Raypak 399k BTU natural gas heater has a unique low-profile design that draws air naturally in installations with the outdoors. It’s considered such a smartly thought-out design that it is practically self-defending against the obstacles that tend to stall standard pool. As long as weather is moderate, fall foliage, wind, airborne debris, rain, downdrafts, updrafts, sleet, and snow do not impair heating performance.

Cast-Iron Headers

Reinforced cast-iron headers, with ceramic-lined waterways, meet the challenging ASME standards. An ASME-approved metal header design offers high working pressures. Each batch of Raypak 9243 Gas pool heater is tested in an independent laboratory upon arrival, and ASME inspects each batch. Until after stress analysis and metal composition tests have been passed, the material has not been permitted for use in an ASME unit.

Heat Exchanger

To improve the heat exchange efficiency, the fin tubes of the heat exchanger are all fabricated from a single piece of extruded copper. By its integral-fin construction, this heater can transfer maximum heat and stay that way.

Stainless Steel Tube Sheet

A completely nonferrous watercourse is made possible using stainless steel tube sheets, resulting in your pool being completely rust-free.

Water Connections

To help ensure your setup is safe and simple, Raypak digital natural gas pool heater 399k BTU includes two slip-fit CPVC water connections.

Condensation Protection

Low incoming water temperatures prevent condensation from occurring inside the Unitherm Governor. It ensures that the water flow is automatically adjusted to keep the heat exchanger water temperature at or above 105°F. Heater life is lengthened by not allowing water to condense, rust, or grow scale due to poor water flow rates or temperature.

High Flow Rates

In addition to the main gas valve, the Raypak 399k BTU natural gas heater comes with an automated bypass valve installed in the header. To handle water flow up to 125 GPM, the heater is equipped.

Burner Tray

Burners are constructed of stainless steel, with other metals utilized in sections where heat sensitivity is a concern. To remove the tray and burners for servicing, innovative design means quick removal of the equipment.

Fire Tile

To maintain effective heater operation while keeping the outside jacket cool, use a ceramic fiber combustion box. The heater will not hold residual heat with this space-age material installed, therefore avoiding the expense of metal heat sinks.


The Raypak digital natural gas pool heater 399k BTU keep their efficiency rating at the highest level. They are certified to meet all federal and state requirements.

Benefits of Using Raypak digital low NOx natural gas heater 399k BTU

Raypak natural Gas pool heater reviews
  • This Raypak ASME Digital Copper Heat Exchanger Natural Gas Heater is built to last. The Raypak ASME heaters are intended for use in commercial facilities such as flats, condominiums, and public pools and spas, where local rules necessitate the use of ASME-certified equipment.
  • The Raypak commercial digital heater comes with ASME-approved waterways and comes with microprocessor-based thermostat control for commercial application. Using the up or down button, the user may control the pool or spa temperature at a precise setting. The digital monitor continuously displays the water temperature of the pool.
  • The “pagoda design” on the Raypak Digital Natural Gas Heater gives the heater more resistance to downdrafts and strong wind speeds while also enabling it to stay effective. Galvanized metal and powder coating is used to make the heater cabinet, which can outlast the elements and rust. The Raypak 399 btu pool heater’s copper fin tube is especially strong when exposed to harsh pool chemicals, which stand up to consistent use.
  • This Raypak digital low nox natural gas heater 399k BTU is widely compatible with nearly all popular swimming pool automation and remote control systems today. Raypak digital controls can accept any two- or three-wire remote, which means you can connect the remote and control the pool from a different location.
  • This pool is small and so perfect for above-ground and in-ground pools. The Raypak digital low nox pool heater BTU 399k has a digital thermostat dial that turns digitally.
  • An easily operated soft-opening gas valve provides safe and reliable lighting of the pilot flame, and the system offers fast and steady heat. The wall-mounted copper heat exchanger is corrodable and has an integrated bypass valve that balances the flow and adapts to a broad variety of pump sizes and flow rates. There is a one-year warranty with it.


  • Liquid crystal display (LCD) digital control for temperature selection and heater configuration.
  • Plumb immediately from the 2″ PVC threaded union provided.
  • The smart microprocessor handles diagnostic reading and checks operating status continually.
  • The Raypak 399 btu pool heater has 2 intakes and water discharges.
  • Unitherm governor removes condensation.


  • It is quite expensive.
  • It needs direct sunlight.

How does a gas pool heater work?

A gas heater can use natural gas or propane

The gas is utilized to kindle a fire that heats the combustion chamber. In the meantime, a pump will make the pool water flow through a tube near the chamber to heat the tube, which will eventually be emptied into the pool. The water is already hot and remains like this until the heater is turned off.

The water heating process with gas heaters is rapid and efficient. It is also quite simple and keeps the water at the required temperature regardless of the external climate or temperature fluctuations.

In contrast, solar pool heaters won’t operate so efficiently when it’s cloudy or when it’s very chilly in the evening while electricity hasn’t that power.

Accessories that come with the Raypak digital low NOx pool heater BTU 399k

Digital Controls Monitor

Equipped with a sophisticated control system that can be simply linked to an existing remote system, our heater also contains a thermostat that is micro-processed to establish the right heat for your pool or spa. Raypak Digital monitors the electricity supply at low voltage. This ensures that the heater is properly wired during the installation. The heater will also let you know if the tension is too low to work correctly.

Microprocessor-Based Thermostat

Raypak 399k BTU natural gas heater is fitted with a thermostat control based on a microprocessor. This control allows you to set your swimming pool or spa temperature to your desired location by pressing the button above or below the temperature control. The digital display provides you with the constant reading of the water temperature of your pool.

Board Diagonostic Control

Raypak digital low NOx pool heater BTU 399k contains onboard controls that let you and the service provider know at all times what happens to the heater. If you have a problem with the heater, the digital display displays where the problem is in the control system.

Copper Fin Tube

The Raypak digital low NOx pool heater BTU 399k is built to last with the integrated copper fin tube of the finest quality. Copper is known for the capability to transmit heat efficiently and is the top choice for the building of the swimming pool and spa heat exchanger. The time test as the industry benchmark for efficiency, quality, and product life was pure copper.


At the end of the Raypak Natural Gas pool heater reviews, I would say that if you reside in a chilly area, even a little one, and want to keep your pool open all year round or longer, then they are worth every single penny. It doesn’t just mean that the weather gets cooler that you must close your pool during the season. With the right pool heater, you can swim comfortably and enjoy your pool regardless of the temperature outside.

In this guide, I have tried my best to explain every criterion about this Raypak 9243 Gas pool heater. I hope by reading this guide, you would be able to make the right buying decision for this gas pool heater.

See also:

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  2. 6 Giant Performing Pool Heat Pump Heater For In-ground Pool!
  3. 10 Best Gas Pool Heater That Provides Optimum Performance!
  4. 10 Best Solar Pool Heater For Above Ground Pool And In Ground Pool!