Natural Gas Pool Heaters

If you want to heat your pool water regardless of the weather outside, this is the most suitable product to purchase. This is because they are designed to heat and keep the water temperature at whatever level you wish, even though there are high-winds outside. In addition to this, this item is much more convenient than the majority of its competitors. Due to the fact that they are made with corrosion-resistant materials that will last even in high temperatures and for many years to come.

This product uses gas as fuel to generate energy and transfer it to the combustion chamber. This means that they are highly energy efficient and it will not cost you thousands of dollars to maintain them. Another great thing about them is the fact that they are suitable for both inground and above-ground pools. Overall, this is a product you must have as it’s an investment rather than a meaningless purchase.

Top 4 Natural Gas Pool Heaters Comparison

1. Hayward H400FDN 2. Sta-Rite SR333NA 3. Pentair 460730 4. Hayward H100ID1
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General Info
Manufacturer Hayward H400FDN Sta-Rite SR333NA Pentair 460730 Hayward H100ID1
Width 36” 28” 28” 12.5
Depth 29.5” 35” 21” 22.5”
Height 24” 32” 28” 24”
Weight 160 Lbs 138 Lbs 128 Lbs 74.5 Lbs
Material Silicon and Stainless Steel Thermoplastic and PVC Thermoplastic and PVC Silicon and Stainless Steel

Technical Specifications

Power Source Electric Electric Electric Electric
Operating Voltage 110 – 220 240 110 – 220 120
Indoor Vent Pipe Diameter 6” 6” 5.6” 6”
Water Connections 2” x 2.5” 2” 2” 2” x 2.5”
Gas Connections 3/4” 3/4” 3/4” 3/8”
Performance Details
Thermal Efficiency 83% 84% 82% 81%
Heat Exchanger 100% 90% 100% 100%
Standard Air Flow Cupro Nickel Cupro Nickel Cupro Nickel Standard Copper
Heat Output 400,000 BTU/hr 333,000 BTU/hr 200,000 BTU/hr 100,000 BTU/hr


Compatible with existing systems
LED Panel
Other Features
CPVC plumbing connections Automatic gas shut-off Pre-mixed system with air and gas Cool-to-touch cabinet
Reduced circulation time Low Nox emissions Rotating digital display Switch to maintain consistent temperature
Access front-panel only Dura-Glas housing Water pressure switch Low Nox emissions


Product Warranty 1 Year 2 Years 2 Years 1 Year
User Manual
Costumer Support
Telephone Support 908-355-7995 800-831-7133 800-831-7133 908-355-7995
E-Mail Support

In-depth Analysis of Natural Gas Pool Heaters

1. Hayward H400FDN

If you are like most people, then you probably like swimming on a beautiful sunny day or relaxing around the swimming pool. We all know that swimming is an amazing way to beat the heat on a hot summer day. Now, if you want to extend your swimming season, you will need a pool heater. There are so many models available in the current market, that making the right choice can be a bit complicated. In terms of quality, performance and great features, the Hayward H400FDN could be exactly what you need. As you probably know, there are several types of heaters out there, including propane, electric resistance heaters, natural gas, solar heaters and pool heat pumps. This is a natural gas option that brings a lot of benefits.


Looking for a durable heater with a rust-proof construction? Take a look at this model as it could be exactly what you need. It is a compact product that comes with a lightweight design and a modern low-profile appearance. It measures 37.5 x 31.5 x 24 inches and weighs 197 lbs.. It is a bit heavy but has an easy and versatile professional installation. The heater is made from Cupronickel alloy which is specially used for marine applications due to its great resistance to saltwater corrosion. Built to last, it features silicone nitride hot surface igniters, insulated combustion chambers and stainless steel burners. All in all, it is a durable model designed for residential use only.


After reviewing more than 10 gas pool heaters, we can confirm that this incredible model provides an excellent performance. It is a quality pool heater that allows you to control your swim season and feel comfortable even when the outside temperature is around 20 degrees Fahrenheit. This is one of those models that provide the user with the most reliable, efficient solutions for any pool and spa. As its name itself suggest, this heater is rated at 400.000BTU which means the amount of energy required to increase the temperature of the water by one degree. You may wonder if this is what you need. The truth is that the bigger the BTU, the faster the water can be heated. For example, this unit is capable of raising the temperature of 300 gallons of water in 10 minutes. You should also know that it is up to 18% more efficient than its competitors.


What we really like about this unit is the fact that it combines advanced technology with impressive features and attractive design. It comes with a digital LED control panel that allows you to operate and maneuver it with ease. With this intuitive and easy-to-read display, you will be able to read the temperature as well as other information that it will provide you with. In addition to this, it also comes with a forced draft combustion system that has the main objective to move the air through its combustion chamber at a precise flow rate. This way, it eliminates the weather variables that can affect its performance. The fact that it comes with a polymer header design is a major perk as this will help you save energy. Also, this unique design that provides superior hydraulic performance will protect the unit against the damaging effects of corrosion. It is also worth mentioning that it is environmentally-friendly. Actually, this is one of the reasons why we were motivated to place it in the first position in our list. It is a low emissions Nox model that operates at optimal efficiency while complying with all the air quality standards.

Warranty and Customer support

This Hayward model is covered by a 1-year warranty. To benefit from this warranty, it is recommended to follow all the instructions according to the manual guide. Also, the device should be installed by someone who is qualified in pool heater installation as improper installation can cause serious damage. In order to find out more about this product, you can contact the customer service. It will gladly provide or assist you with any further help or information needed in this matter.



Designed to keep constant temperature Not intended for storable pools
It automatically produces diagnostics
Created for modern plumbing systems
Environmentally friendly


This is a popular choice because it’s very effective by trapping the heat and maintaining it. As well as, the LED control panel makes this model convenient and easy to use. So, even if you are a newbie, you will know exactly what to do.

2. Sta-Rite SR333NA

The high-efficiency model is extremely economical. It only uses 240V so you will be able to keep it on to function for as long as you want without worrying about your electricity bill. This item has been specially designed to allow fast warming of your pool or spa. The conveniently placed control panel is simple to maneuver and you don’t have to be a professional to know how to program it. As well as, the cabinet is made out of a special material named Dura-Glas which doesn’t corrode over a large period of time and it stands strong in harsh weather conditions.

In addition to this, you will like the fact that it has been certified with NOx emissions. This means that you can use it for a long period of time without ruining our environment. You can easily install it with existing systems or new ones. Whatever systems you choose, this heater will still be able to keep the temperature at a constant level.



Corrosion resistant material Some say customer service should be better
One-touch buttons
Low operation costs
Energy efficient


This product is another bestseller because it’s one of the safest models to use. In case something is wrong, you will be able to see the diagnostic lights flashing. Depending on what color it shows, you will be able to tell whether there’s problems with the pump or the filter.

3. Pentair 460730

This model is special because it has a pre-mixed system. It’s able to use air and gas as a way to create heat for your precious pool. As well as, this innovative system will be able to heat up faster than many of its competitors. The hot surface ignition has been designed with push-button, digital controls, and conveniently placed buttons, in order to provide you with supreme comfort when handling it. The majority of people that have purchased this product argue that when they compare it with other energy efficiency ratings, this product is at top of the list. It simply is the only and best energy efficient product.

On top of the compact design, the item has a rotating digital display which is easy-to-view and understand. As well as, it will rotate depending on how you position the cabinet. Thus, you don’t have to move your head or neck awkwardly to read it. The greatest thing about it is that it has a quiet operation. This is great news if you don’t want it to intrude with your leisure time around the pool.



Eay-to-read display Vertical plumbing fixtures make it difficult for water connections
User-friendly controls You can only set the temperature if the pump is running
It doesn’t make loud noises
Designed to heat up fast


The reason why this product is so popular is because it has a rust-proof exterior which handles the weather very well. As well as, the heat. In additionto this, if you purchase this model, you will also take care of the environment. This item has been certified with Low NOx emmissions.

4. Hayward H100ID1

This model is suitable for above-ground swimming pools. It features an electric ignition system and an energy efficient chamber. It will provide you with 100,000 BTU/hr and 81% thermal efficiency. This is more than enough if you have an average sized pool. You will definitely find that the water is warm as soon as you step inside. Just like the top models in this niche, you will find that this model is also designed with a draft system. This means that it’s immune to high winds or cold weather outside. In addition to this, this product has a large number of positive reviews which claim that this item is leak-proof. You can rely on this model for many years to come.

Additionally, this item has been designed with FireTile combustion that allows quick heating. Therefore, you do not have to wait a long time before you can enjoy your precious pool. This is another enery efficient model as it only uses 120-volts.



Cord length is 3 ft Only suitable for above-ground pools
Weather-proof The bolts should be more heavy-duty

Designed with electronic ignition
Energy efficient


The reason why this item sells so well is because it’s very safe to use. Therefore, even if you have pets or children that love to wonder, you can have ease of mind as the cabinet will remain cool-to-touch no matter how high the temperature gets. Therefore, you will be worry-free.

5. Raypak 266,000 BTU Digital Electronic Ignition

Looking for an energy-efficient natural gas heater for your swimming pool? Then, take a closer look at this model. This 266.000 BTU heater comes with a microprocessor-controlled thermostat that can easily be set to your liking. It has a stainless-steel tube sheet and 2-inch CPVC water connections. In addition to this, it comes with a PolyTuf powder coating and polymer headers. Also, it should be mentioned that there is an all copper-fin-tube heat exchanger, burner tray and fire tile. All in all, it comes with all it needs to do a great job.

It is made of high-quality materials, so rest assured that it is a long-lasting investment. It features a wind-resistant design, not to mention about its parts: the cabinet and the internals which are rust resistant and non-corrosive. As compared to many other similar pool heaters, it comes with a digital display which will allow you to see all the needed information about the water temperature.



Great heater for pools and spas It is designed for residential use only
Rust resistant and non-corrosive
Self-diagnostic controls
It has the most reliable spark-to-pilot ignition system


The Raypak 266,000 BTU Digital Electronic Ignition is one of the most efficient pool heaters on the market. It is very simple to use and extremely durable. It is made of high-quality materials and has all the needed features in order to function properly. Also, it comes with a very reasonable price and with a long warranty as well.

6. Hayward H250FDN

The Hayward H250FDN is a great option to consider when looking to purchase a natural gas heater for your swimming pool. First of all, it is important to know that it has a strong construction with a patented polymer header and bypass valve design. Compared to many other similar models, it comes equipped with a Curpo nickel plate exchanger. This is a big plus as you can use it even in salt-based swimming pools. It is extremely resistant and durable. Also, it is important to know that it has a forced draft combustion system that makes the air circulate through the combustion chamber at a normal flow rate.

The main purpose of this system is to eliminate outside all those weather variables that will normally affect its performance. Since we are talking about a new version, it is important to mention that it comes with a LED digital control panel. It has an easy to read panel that provides accurate results and displays temperature diagnostics in a short time. We guarantee that his 250,000 BTU natural gas heater is ideal for your existing installation. It is energy-efficient and very easy to install. Also, it is covered by a 1-year warranty.



It comes equipped with a LED digital control panel
It has a combustion system to move air through the combustion chamber at a normal rate
Durable construction
Easy installation


With an easy installation and a strong construction, we are proud to include this model on our list. It is an efficient unit that comes at a reasonable price. It is not the most affordable unit, but considering its features and settings, it is a great value for money.

How To Calculate The Right One For You

In order to know which model is suitable for your needs, you must know which one is suitable for your pool. The only way to know is to make a quick calculation. Of course, you must also consider things such as the volume of water the pool can hold. Now let’s start from the beginning. The first calculation you must do is find out how many BTUs are needed to heat the volume of water in the pool. Let’s find out the calculations of a pool of 10,000 gallons of water:

1 gallon of water equals 8.83 lbs. Now, multiply the volume of your pool by 8.83 in order to find out how many lbs of water it holds. Therefore, 10,000 x 8.83 =88,300 lbs.

Next step is to divide the lbs of water by 24 (24 hours in a day) as you need to find out how many BTUs are needed per hour to heat the pool by 1 degree in 24 hours. So, 88,300 divided by 24 = 3,680 BTUs per hour. This will help you to get the right temperature. Now let’s calculate how much is needed to maintain the temperature you want.

The calculation we are about to take is based on a pool that holds 10,000 gallons and is 15 x 20. The first calculation to do is multiply the length and the width of the area of the pool. For example, 15 x 20 = 300 sq. ft. It’s a general rule that there are 10 BTUs required per sq. ft. to maintain 1 degree of difference between the water temperature and the air temperature.

It was highlighted that we need 3,000 BTUs for the 1-degree temperature difference between the pool water and the air temperature. Now let’s say the pool is heated at 80 degrees and the air outside is 60 degrees. There is 20 degrees difference between them. What you need to do now is multiply how many BTUs are needed per hour times the difference. So, 3,000 x 20 = 60,000 BTUs to maintain the right temperature for this pool.

Types Of Heaters

There are different types of heaters on the market. Whatever one you choose, depends on your needs. Nonetheless, it doesn’t matter which one is your choice if you don’t maintain it properly by checking on it once in a while. As well as, you must understand that even though they are low-maintenance, you must clean them and check up on the troubleshooting if there are any problems with it. Below you will find the different types that are on the market today.

  • Heat Pumps – Just like gas heaters, they use electricity to function. Some companies design them with mixed systems so they function on either an air-source or water-source. The majority of people that go for this type, purchase them because they are energy efficient. It won’t cost a lot to keep them functioning. In addition to this, they last for many years as they are too created from corrosion-resistant materials.
  • Gas Heaters – There are two types of gas heaters. The one that uses natural gas to form energy which in turn will heat up the water in the pool. As well as, the ones that use propane to warm up the water. Whatever one you choose depends on how much money you are willing to spend. This is because natural gas is energy efficient. Whereas, propane is more on the expensive scale.
  • Electric Resistance – This model is suitable if you have a small above-ground pool. It solely depends on electricity and it’s very small in size compared to its competitors. Don’t worry, even if its small, it will work just as efficiently as the bigger ones. Please do note that they can be more expensive to install compared to the others.

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