Gas Pool Heaters Buying Guide: Choosing the Best Models

Looking to buy a pool heater to heat the pool and extend the swimming season?

Gas pool heaters can be your best choice without a doubt. They are fast, efficient, affordable, and very easy to use – and still, they offer much more. Here are the important features to look for when buying a gas heating device for your swimming pool.

Even though gas pool heaters are the most common pool water heating device for pools, most people use them; it can still be tough to pick the right one.

But don't worry. If you are looking for a gas heater for either above ground or inground swimming pool, and you haven't found the perfect one yet– it means you need to take a look further into our buying guide. Come and learn more about gas swimming pool water heaters so you can end up with the best one!

In this article:

Gas pool heaters: Things to consider

You want the perfect device for your home – so what is more important than knowing what you're getting? Here are a few notions you should have before making your choice:

How does a gas pool heater work?

Hayward gas pool heaterHayward gas pool heater

Note: Professional installation and repairs are recommended.
Find out how on HomeAdvisor.com!

A gas heater may use natural gas or propane. Natural gas is widely used, and it is transferred to your home from the utility company through the gas lines. Propane gas is stored in the storage tank and, from there, moved to the device.

The gas/propane is used to fire up a flame that heats the combustion chamber. Meanwhile, a pump will make the pool water passing through a tube close to the chamber, heating the water in the tube that will eventually get pumped out again into the pool. At this moment, the water is already heated up and will stay like that until the heater is turned off.

The process of heating the water from gas heaters is fast and efficient. It is pretty simple as well and will maintain water at the desired temperature regardless of the outside climate or temperature fluctuation. Solar pool heaters, in contrast, won't work as efficiently when it is cloudy or at night, heat pumps are not good when it is cold, while electric does not have such power.

Initial price

A standard gas heater will cost from $600 up to $2,500 – a big difference from electric, heat pumps, or even solar heaters, which can cost up to $5000. The installation costs of a pool gas heater are also pretty affordable. It can cost up to $500 to install a gas heater, yet an electric one can cost up to $1000, while a solar panel may go over the $2000 for installation.

TIP: A gas heater may cost from $1000 to $3000 considering the cost of the device and installation. If you can afford a high-quality and energy-efficient heater, and professional installation, go for it. It will be costlier but much more reliable in the long run. Here is how to contact a professional installer.

Energy costs

Even though gas pool heaters are much more affordable than other versions, they may be costly in the long run, especially propane type.

Electric heaters may be as costly or even more than a gas heater in some cases, yet heat pumps and solar panels are often incredibly cheap to run in comparison.

Solar panels, for being renewable, may cost little to nothing to function as they take energy from the sun.

Heat pumps, on the other hand, reuse warm water to heat more water.

TIP: Consider the availability of fuel in your location. Sometimes, it's better to avoid going for gas heaters if fuel is not easy to find. This will not only make it harder to find fuel but also a lot more expensive, such as when using propane gas.


Despite being much more effective, natural gas heaters are not as long-lasting as other options. Typically, a gas water heating device lasts about five years but could go up to 20 years with luck, yet they require constant maintenance and service to work safely. Electric heaters may last up to 15 years, and solar panels last from 10 to 25 years in most cases.

TIP: Go for something that delivers effectiveness and quality at the same time. It's common to find more expensive devices much more quality-oriented than the cheapest ones. If you can afford a pricey heater, go for it.

Gas emission

Using natural fossil fuels is environmentally damaging. Natural gas heaters do precisely that; they emit CO2 that harms the environment. However, a few options come with a low NOx emission standard, which makes the water heating device environment-friendly. This standard was initially created to meet specific laws set in California and Texas, where low CO2 emissions are obligatory for heaters.

TIP: Make sure the heater you pick comes with a low NOx emission standard. This way, you will use an efficient and environmentally-friendly heating machine.

Best gas pool heaters to consider

Hayward H400FDN

The Hayward H400FDN comes with a Cupro-nickel heat exchanger, a polymer header, a bypass valve, and a low NOx build standard – making the device more reliable, efficient, and environmentally friendly. It provides a highly versatile performance, both for large pools and small spas. In addition, it is designed to deliver much more cost-efficient performance in the long run. It works with both natural gas and propane. You can choose from 100,000 up to 400,000 BTU.

Hayward H100ID1

Designed to deliver excellent performance in pools less than 450 sq. ft., the 100,000 BTU Hayward H100ID1 is the perfect choice for those who need a fast and capable device. It comes with electronic spark ignition, easy-to-use controls, and a straightforward design for easier installation. What's more, it is highly efficient and durable, thanks to excellent construction and outstanding engineering. It works with natural gas and propane, which generate low NOx emissions.

Pentair MasterTemp 

Offering a different power range in BTU, from 175,000 up to 400,000, the Pentair MasterTemp gas heater is a fantastic choice for anyone who wants efficiency and above-average performance. It comes with a Cupro nickel exchanger and tubing, digital control, electronic ignition, and a Low NOx certification for better environmental impact. It can operate with both 120 or 240 volts without problems and comes with a wide array of additional features for even more convenience. It works with natural gas only.

Benefits of buying a gas pool heater

When looking for a water heater, you must consider a few features that will undoubtedly matter the most in the long run. Here are the benefits you will get from getting a gas heater:


Gas heaters heat the water much faster and effectively than any other type of heater. These heaters also run anywhere at any time and will heat the water nonetheless, without problems.

Small & compact

Most gas-driven pool heaters are small and compact, so they take less space and will fit practically anywhere.

Versatile fuel options

Even though natural gas is easy to find in most places, it may be a tough job in other areas. That's why these heaters are often ready to work with propane as well. This makes them much more versatile for different situations.

Easy to install & use

A gas heater won't be a problem in any way. It is straightforward to install, doesn't cost too much, and lasts longer without much maintenance. The same happens with use; a gas heater needs slight settings configured, and then it will work all year-round without problems.

Selecting tips for gas pool heaters

Picking the right size

The first and most important part you should consider when buying a gas heater is the size. The power in gas pool heaters is measured in BTUs (British Thermal Unit), and it means the total energy need to heat one pound of water in Fahrenheit. So, the more water your pool has, the larger it is, and the coldest it is, the more BTU it will need to heat it up.

Here is a chart of the amount of BTU needed to heat different pool surface areas.

Pool Surface Area (sq. ft.)




This chart, however, is not entirely accurate as there are many other factors you may need to consider. To measure it up accurately, here are a few steps you should follow:

  1. Determine the temperature you want for your pool.
  2. Find out the yearly coldest temperature in your location.
  3. Subtract the desired pool temperature with the yearly coldest one (from step 2). You will end up with the temperature rise measure.
  4. Then calculate the total sq. ft. of your pool surface area (i.e., rectangle shape: length X width; round shape: radius X radius X 3.14).
  5. Make some additional calculations with the following equation:

Temperature Rise x Pool Area x 12

If the temperature rise is 50, for example, and your pool area is 500 sq. ft., then the formula should be:

50 x 500 x 12 = 300,000

If you have a 500 sq. ft. pool and the temperature rise is 50, you will need a 300,000 BTU gas heater.


If you search for a product that delivers quality, make sure it is made of tough and long-lasting materials. For this, make sure the device comes with a Cupro nickel tubing and heat exchanger. Also, it should come with polymer or resin headers for better performance and much more reliability in different conditions.


There are two main choices for ignition, Millivolt and Electronic.

A millivolt is a typical pilot light that stays on all the time, reliable yet not as efficient as the electronic ignition. On the other hand, this one ignites the burners only when needed, avoiding gas leaks and using less fuel in the long run.


The controls of a heater need to be convenient to use and straightforward. Most heaters just come with a knob to turn it on and a thermostat to set the desired temperature. Other options may even come with an LCD screen and a wide array of features, including process monitoring, an efficiency display, and even a timer or clock.


When you pick a gas heater, you must consider how efficient it is regarding fuel use. The best choice you can make is selecting a device that offers over 90% efficiency; this way, you will have only 10% energy waste, meaning that you get better value for your money and eventually waste less fuel in the long run.

Natural gas or liquid propane?

One of the most critical questions you need to consider when buying a water heating device for your pool is the type of gas you want to use.

The most important things to consider here are availability and cost. If your home comes with a natural gas line, it is better than buying propane which is usually harder to find and more expensive, and requires frequent deliveries. However, additional considerations should be made:

Environmental damage

We all know that fossil fuels damage the environment. Natural gas has a damaging nature regarding the emission of greenhouse gases into the atmosphere. Even when the device comes with a low NOx standard, a natural gas heater will be a lot more damaging in the long term. That's why propane is a better choice if you can afford it, as it has a lower impact on the environment.


The density of the fuel will tell you how efficient it will be in the long run. The more density the fuel has, the longer it lasts and the more powerful it is. Propane, in this case, is always the best choice, as it is denser and much more long-lasting. A pound of propane produces more than double the energy that a natural gas pound does but is more expensive.


Swimming pool water heaters using propane are 60% costlier than natural gas pool heaters. When you consider availability, the price will go even higher in places where propane is not easy to find. However, due to density and efficiency, it may be almost as efficient in the long run.

Gas pool heaters vs. Electric type

Gas heaters

More energy efficient in the long run ($5000 a year)

Cheaper - Initial price $300 to $2500

Lifespan from 5 to 15 years (low maintenance)

Works all year in every temperature - works without electricity

Electric heaters

Less energy efficiency ($6000 a year)

Expensive - Initial price $600 to $3000

Lifespan from 5 to 15 years (high maintenance)

Works all year in every temperature - doesn't work without electricity

What's the best gas water heating device for your pool?

When searching for the best gas pool heaters, you will find many options out there – so you should pick wisely, or else you may get higher energy bills than expected. That's why you should always consider your needs first. Make sure the device meets all of your expectations and fits your budget by examining every one of our recommendations.

TIP: Reduce the heating costs by choosing an energy-efficient gas pool heater and covering the pool when not in use.

Get Help from a Local Plumber. FREE Estimates!

You might like these articles about pool heaters