Explore Raypak 399k BTU Pool Heater for Blissful Swimming

Nothing can be better than warm pool water. Getting warm pool water is really challenging if you do not have an efficient pool heater.

If you need an efficient solution you can dive into relaxation with the Raypak pool heater 399k BTU. With its electronic ignition and digital thermostat, controlling your water temperature has never been easier. The Raypak 399k BTU natural gas pool heater is crafted with Polymer headers for durability and efficiency. This gas-powered marvel delivers supreme performance for your aquatic oasis.

But that’s not all – no worries about harmful emissions with its low NOx technology. It ensures cleaner air and a greener footprint. With 399k BTUs of heating power, your water stays warm and inviting, perfect for year-round enjoyment.

Experience the pinnacle of pool heating innovation with Raypak – where comfort meets eco-consciousness, and every swim is a luxurious escape.

So, what are you waiting for? Let’s explore the Raypak 399K pool heater review.

Prominent Features of Raypak Pool Heater 399K BTU

Raypak pool heater 399k btu

1. 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.

2. 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.

3. 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.

4. 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.

5. Stainless Steel Tube Sheet

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

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

11. Fuel-Efficient

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

12. Low NOx Emissions

Equipped with low NOx technology, this heater produces significantly fewer harmful emissions compared to traditional models. It promotes cleaner air and environmental responsibility.

Benefits of Raypak Pool Heater 399k BTU

Raypak pool heater 399k btu
  • This Raypak is built to last. The Raypak 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 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 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. It’s 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 corrodible 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 399K BTU pool heater has 2 intakes and water discharges.
  • Unitherm governor removes condensation.


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


The Raypak pool heater 399k BTU stands as a testament to cutting-edge design, convenience, and environmental responsibility. Whether you’re soaking in the spa or splashing in the pool, this Raypak digital low Nox heater’s efficient performance ensures your enjoyment while minimizing your carbon footprint.