The Best Pool Heaters of 2020 – Comprehensive Guide

Having trouble with your freezing cold pool? Maybe it’s crying out for a heater and you are just not paying attention!

pool heaterA pool heater is a wise investment. It’s a tremendous partner for your pool. Aside from being able to splash around and swim on warm pool water at night, it also allows you to take a dip whenever you want.

Pool heaters burn fuel and convert it to heat. The heat then passes through a heat exchanger which heats up the water drawn from your pool. To avoid any problems, buy a heat that’s large enough to heat your pool faster than the rate at which the heat is lost on the surface.

Hayward H400FDN Universal H-Series Low Nox
Hayward H400FDN Universal H-Series Low Nox
36.5 x 29.3 inches
245 pounds

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Smartpool WWS601P Sunheater

Smartpool WWS601P Sunheater
48 x 1 x 240 inches
29 pounds
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Hayward H100ID1 H-Series Low NOx
Hayward H100ID1 H-Series Low NOx
26.5 x 21.8 x 31 inches
74.5 pounds
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Hayward CSPAXI11
Hayward CSPAXI11
8.3 x 12 inches
14 pounds
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Smartpool WWS421P Sunheater
Smartpool WWS421P Sunheater
48 x 1 x 240 inches
29 pounds
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Top Pool Heaters Reviewed

If you’re wondering about the best pool heater, don’t worry. We’ve done the research for you and we’ll present pool heater reviews in a while. We will also include solar pool heater reviews in the buying guide. Ready? read on!

#1 Hayward H400FDN Universal H-Series Low NOx

Hayward H400FDN Universal H-Series Low NOxType: Natural Gas Pool Heater

The Hayward H400FDN is the best pool heater for the money and that’s because of its standard Cupro Nickel heat exchanger, patented polymer header and bypass valve design, environmentally responsible low NOx emissions, and the famous Hayward Universal design. It’s also reasonably priced at $2,260.

Its highly resilient Cupro Nickel heat exchanger allows it to be even more durable even in salt-based, high flow or aggressive water chemistry conditions. The polymer header design, on the other hand, provides expert hydraulic performance that saves energy and protects against erosion from high flow conditions. It sure is one reliable pool heater!

What’s more, the forced draft combustion system which constantly moves air through the combustion chamber at a precise flow rate eliminates all outside weather elements that may affect its heating performance. You don’t need to worry about high wind conditions with this one. It also features a LED digital control panel that’s easy to read. This panel provides digital temperature readout, diagnostics, and electronic lock-out of temperature set-point. It’s accurate, saves time, saves money, and convenient!No wonder it’s also called the best gas pool heater.
What you may not like, however, is the noise it makes. The Hayward H400FDN is also not weatherproof. Nonetheless, it’s energy efficient, acts fast, and easy to set up. There’s absolutely nothing more to ask for from the best pool heater on the market.

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#2 Hayward H100ID1 H-Series Low NOx

Hayward H100ID1 H-Series Low NOxType: Natural Gas Pool Heater

Hayward is surely an expert at natural gas pool heaters and its H100ID1 is an evidence. Equipped with an electronic direct spark ignition for easy automatic control, this above ground pool heater takes pool heating a piece of cake. Couple that with a simple plug-in 120V electric cord and you get one pool heater that’s so easy to install.

The Hayward H100ID1 also features revolutionary induced draft technology, ensuring you top performance regardless of weather and wind conditions. This product is recommended for use on pools less than 450 square feet and is not for installation at an elevation greater than 2,000 feet above sea-level. It’s tailored for smaller pools and operates at 81% thermal efficiency. It can heat up a 450-square foot pool in just a few hours.

It is inexpensive, energy efficient, and has an induced draft technology. Despite all that, it has limited abilities and has no LED control panel, which makes the monitoring of temperature somehow vexing.

At the end of the day, it’s still one of the best above ground pool heaters on the market and its price tag allows you to enjoy your swimming pool at the comfort of your home and in a temperature you prefer.

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#3 Hayward CSPAXI11

Hayward CSPAXI11Type: Electric Resistance Heater

Electric spa heaters from Hayward have all the up-to-the-minute features and capabilities of heaters twice their size. They’re the new definition of the phrase small but terrible. The Hayward CSPAXI11, though compact, is undeniably powerful. It’s easy to install and customer service is always available.

Ideal for hot tubs and spas, this heater features 304 stainless steel tank, a threaded head, a safety sensor electric heating element, and a heater on indicator light. It’s highly efficient, inexpensive compare to gas heaters, compact, easy to install, and more importantly, it works great for spas and small above ground pools.

However, it works well with small pools and spas only, which limits its capabilities. The heat isn’t instant as well; it heats at a rate of 5 degrees Fahrenheit per hour in a 1,000-gallon spa. You have to be patient with it. To make you feel better, at least a lot of customers reviewed the product positively. They were pleased with it. They say it’s small enough to be easily kept or hidden and it’s one well-built heater. Aside from that, this product comes from one of the best brands that offer pool heaters, so that puts it in a fortunate position in this comprehensive guide.

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#4 Smartpool WWS601P Sunheater

smartpool-wws601p-sunheaterType: Solar Pool Heater

If you’re on a tight budget and you’re in dire need of a pool heater, the Smartpool WWS601P is the heater for the job. It keeps your pool warm with a polypropylene heat collector and works very well.

Featuring 80 square feet of solar panels and a panel array that measures 4 feet wide by 20 feet long, it’s a pool accessory that’s perfect for heating any in-ground swimming pool. It’s the budget buy you’ve been looking for.

Aside from its extremely affordable price, it’s also known as the best solar pool heater. That’s because it uses renewable energy, energy efficient, and requires no maintenance at all. And because it uses the heat of the sun, you don’t have to spend for fuel for it to operate successfully. Other solar pool heaters cost $4,000 but this cheap product isn’t cheap with its quality at all. It lasts long and saves you a large amount of money.

However, some customers complained about it springing a leak during a fill. The installation kit, which is sold separately, is also a waste according to some.

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#5 Smartpool WWS421P Sunheater

Smartpool WWS421P SunheaterType: Solar Pool Heater

Looking for another solar pool heater? Then this is a great second choice. Just like the previous one, it also uses a polypropylene heat collector, features 80 square feet of solar panels, and measures 4 feet wide by 20 feet long. The difference is that the Smartpool WWS421P is designed for above ground pools.

You may be skeptical but I’m telling you, a lot of satisfied customers were. But after testing this durable heater and finding out that it works well, they decided to keep it. You can be one of them, too! After all, this is the best above ground pool heater on the market. If you want to save fuel, energy, and money, this is the best investment you can get for your above ground pool. Don’t hesitate; doubting is time-consuming. As long as you have the sun by your side, you can get your pool heated up the way you want to.

One customer, however, mentioned it only lasted as long as the warranty. After six years, 50% of the panels weren’t working already. Another customer also said that he could hear a high pitched wine when it runs, which makes the heater a bit annoying.

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Pool Heater Buying Guide

Which Type of Pool Heater Should I Get?

There are four types of pool heaters to choose from: Electric Resistance Heaters, Gas Heaters, Heat Pumps, and Solar Heaters.

1. Electric Resistance Heaters

  • These heaters usually used to heat small pools for therapy and portable spas, generate heat through electric currents.
  • In order to pay twice for operating costs, purchase a thermal cover with this one. Without a thermal cover, you will need a larger heater aside from spending more money.


  • Most electric resistance heaters are inexpensive and cost less than $2,000.
  • They are independent of air temperature and doesn’t need the latter to work well.
  • They can maintain temperatures between 80 to 90 degrees Fahrenheit even if the temperatures outside are low.
  • They do not emit gasses into the environment, making them environmentally friendly.
  • They are a great alternative if your home is not compatible with solar power.


  • They require a significant amount of electricity even though they are small. They need circuit breakers that have large amperage and heavy-duty wiring, which means installing them would be expensive.
  • They have a COP of 1.0, which means they are costly to operate and are not energy efficient heaters.

2. Gas Heaters

  • These heaters, formerly used widely and considered the best pool heater type, use propane or natural gas to heat pool water.
  • They are expensive to use especially if you want to maintain your pool at a consistent temperature.
  • Just like the first type, it works best with a thermal cover.


  • They heat water regardless of air temperature.
  • Most of them have price tags attached to them which are less than $1,500.
  • They have the capacity to heat the pool rapidly.
  • They have a portable fuel source.


  • Propane is more expensive than natural gas.
  • They cost pool owners about $300-$500 per month because of the price increase of gas.
  • Most of them have a Coefficiency of Performance (COP) of 0.80 to 0.85 which means they aren’t energy efficient. COP is the measure of energy output divided by energy input.
  • They emit air pollution and are not environmentally friendly, unlike solar pool heaters.

3. Heat Pumps

  • These heaters extract heat from the air, compress it, then transfers it to your pool water.
  • Heat pumps are composed of few separate parts and take up more space in your pool area than self-contained heaters.
  • The heat pump unit contains the compressor, condensing coil, fan, and motor. The air handler, on the other hand, consists of the blower motor, electric heat pack, and evaporator coil. The air handler keeps the system balanced and efficient. The line set contains the copper tubing which connects the heat pump and the air handler. It also includes the black rubber insulation for the copper tubing.


  • They efficiently use electricity, which means they are inexpensive to operate and will cost you about $50-$150 a month only.
  • They are good alternatives for locations which are non-solar feasible.
  • Water-source heat pumps do not need the air temperature to operate.
  • They use renewable energy and have no emissions, making them environmentally friendly.


  • They have more expensive price tags compared to the first two types I mentioned. The usual price won’t be less than $2,000.
  • Air-source heat pumps are not effective in colder temperatures because they depend on air temperature to effectively operate.
  • The exchanger requires pool deck space and 220V outlet.
  • They take a while to heat your average or large-sized pool.

4. Solar Heaters

  • These heaters use solar panels to gather heat from the sun and transfer that heat directly to your swimming pool.
  • They transfer the heat to your pool water while it is pumped through the circulation system and solar panels.


  • They are perfect for locations which usually have warm and sunny climates.
  • They won’t make you spend any additional cost for it to operate because the energy source is free and unlimited.
  • They are energy efficient because they only work with your pool pump.
  • They use renewable energy and do not release harmful gasses.
  • They can last up to 20 years thanks to their durability and most of them offer a 10-year warranty.
  • They also require no maintenance.


  • They are the most expensive pool heaters you’ll ever encounter, having at least a $4,000 price tag attached to one.
  • They depend on the heat of the sun and can only operate efficiently if you’re in a place that comes in contact with direct sunlight.
  • They heat your pool water slowly.
  • They will require you to have a backup heater in cool climates or at night.
  • Repaying one solar heater, if you’re not extremely wealthy, may take several years.

Things to Consider:

1. Price and Brand

  • Quality pool heaters usually cost $1,000 to $3,000 for the unit alone.
  • You also have to add an extra $150 to $1,500 to the overall cost of the installation fee.
  • The prices, of course, depend on the type, model, and brand.
  • The best brands in the industry are Blue Wave, Hayward, Horizon, Pentair, Smartpool, and Zodiac.

2. Size

  • Usually, a pool heater will specify on the packaging the pool size they are able to heat.
  • If you select a pool heater that’s too small, it will exert much effort and may not give sufficient heat to your pool water.
  • A pool heater can never be too large for a pool.

3. Control Panel

  • In order to control the temperature of your pool water, a control panel is needed.
  • It helps you adjust without having to guess the temperature.
  • A pool heater may have a digital or analog control panel.
  • Some heaters, however, offer a temperature monitor only.
  • Some do not even have a control panel so you have to monitor the temperature of your pool water with an external thermometer, which is inconvenient.


Pools are perfect for those who aim to stay in shape and take a break. They serve as inspiriting getaways from the exhausting outside world.

However, a pool that’s always cold may not be useful in a cold weather. Plus, you cannot swim in a pool that’s ice-cold especially if you wish to take a dip at night. This is where a pool heater comes in handy. They allow you to swim any time of the day. There are additional benefits from a pool heater as well, depending on the type you’re willing to purchase. Having a heater will allow you to fully enjoy your pool.

The overwhelming number of models and prices to choose from may cause you to worry, on the other hand. But with proper guidance and knowledge, you can get the right pool heater. The best thing to do is to narrow down your choices to three or four. Weigh the pros and cons and also read customers reviews about the products. It’s wise to check the ratings they have received, too.

Don’t forget to settle with the correct size that fits your budget and suits your location. I hope I helped you make up your mind with this guide.