Best Pool Heater

The 7 Best Pool Heaters (Exclusive from Each Category)

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If you are interested in seeing a list of the best pool heater, from each category, this article will provide you with precisely what you need.

Whimsical people own various types of pools, and all pool heaters don’t fulfill their criteria. 

So I’ll help you with an easy approach shorting out the best inground, above ground, propane, natural gas, heat pump, and solar pool heater to match your exact requirement.

Which one will warm your pool faster, or which one will save a lot of electric or gas bills? Let’s reveal all curious answers from the experience of real pool owners!!!

A Quick Overview Of Best Swimming Pool Heater

Just in case if you want to skip the lengthy review of the best pool heaters for different pool types, here’s our quick list.

  • Best Inground Pool Heater – Hayward W3HP21404T Read Review
  • Best Aboveground Pool Heater – FibroPool FH120 Read Review
  • Best Natural Gas Pool Heater – Hayward W3H400FDN Read Review
  • Best Solar Pool Heater – Smart Pool S601 Read Review
  • Best Heat Pump Pool Heater – Hayward W3HP21104T Read Review
  • Best Propane Pool Heater – Hayward W3H400FDP Read Review
  • Best Electric Pool Heater – EcoSmart SMART POOL Read Review

My Humble Submission

I have researched and analyzed my best to present you with an in-depth guide recommending top pool heaters of each category. As far as possible, I have explained to the point.

I have provided my own brief review, functionality overview, and whatever else is required to make your decision easier.

So, if you have any questions about pool heaters, confusion, or are unsure about choosing one, please go through my detailed guideline here.

Are you ready to begin?…

7 Best Pool Heater Reviews – Propane, Natural Gas, Heat Pump, and Solar Pool Heater

1. Best Inground Pool Heater – Hayward HeatPro

Best Inground Pool Heater - Hayward HeatPro

There’s no other best choice but Hayward HeatPRO to warm your inground Pool, ensuring the most energy efficiency. Inground pools have a massive water holding capacity & demand vast power to warm it up.

Hayward HeatPRO contains a heavy-duty ultra-quiet scroll compressor to produce an extensive 140,000 BTU/hr heat energy, sufficient to warm a standard 20′ x 40′ pool or 20,000-30,000 Gallons of water by 15 degrees a day.

An acoustic compressor cover & profiled fan blade has made the operation whisper quiet!!! While relaxing & gossiping with family and sipping your drink, you’ll never be able to notice this bad boy is running on full throttle.

Hayward has integrated a counter flow titanium heat exchanger to prevent any energy loss by its higher heat transmission rate so that you get the most energy efficiency with ultra-reliability. Uses of R-410A refrigerants ensure the lowest impact on the ozone layer.  

HeatPRO has an industry-leading 5.7 Coefficient of performance (C.O.P) rating, meaning that for spending every $1, you will get 5.7X heat energy.

Neighbors from the coastal area can now remain tension-free. Thanks to the ultra gold corrosion-resistant evaporator fins & injection molded UV resistant body panels, which are entirely inaccessible to rust and deterioration.

All the single internal hardware is made of stainless steel & the insider evaporator coil is protected by a polyethylene screen that maintains peak efficiency accordingly.

Some Important Facts to Know

  • Its 7.2 KW unit and input is 240V & consumes 30A Current. So a 40 amp breaker will be required.
  • If your Pool holds below 10,000 Gallon of water, you may choose the 90,000 BTU variant. 
  • The 140,000 Variant works excellent for a 20,000+ Gallon pool and can raise the temperature by 15 degrees within 10 hours. If your pool size is twice then the duration will be longer, or you may install multiple units.
  • Must try to install this unit at least a feet above the ground or on concrete to protect it from muds & moisture.
  • Ensure 6 feet clearance above & 4 feet clearance around it for the best performance.
  • Don’t tip over during carrying the unit or taking it to the place.
  • Installation might require professionals.
  • I think it’s a bit overpriced.

You may also read our expert opinions on Inground Pool Heater here.

2. Best Above Ground Pool Heater – FibroPool FH-120

Best above ground pool heater - FibroPool FH-120

You’ll love to have FibroPool FH-120 as a permanent, straightforward, and efficient solution for your aboveground pool without any massive expense. Definitely, it will make the pool session more pleasurable and extended for you and the kids.

You will enjoy the surprisingly effortless installation. FibroPool FH-120 requires only 10 amp and 120V input voltage, so no necessity for additional electric wirings or hiring an electrician. 

Additionally, the unit comes with an 8 feet long power cable with a US-type plug, and you are allowed to connect the waterlines with flexible garden hoses. 

Not only that!!! The easy operations are like a charm. With the digital display and easily accessible buttons, you can hassle freely maintain your desired temperature.

It’s very slim and slick. Enamel-coated external chassis protects the unit from any corrosion or weather damage. Never get worried about saltwater pools. All internal components are engineered to be used in critical locations.

With a high-pressure scroll compressor and titanium heat exchanger, FibroPool has maximized the energy efficiency to achieve a 4.81 COP, and you will be surprised that the unit runs by only a ~16 cents hourly cost.

Important Facts to Know

  • In most cases, the unit doesn’t require a breaker, but you should connect it to a GFCI protected outlet.

3. Best Natural Gas Pool Heater Hayward H Series Natural Gas (FDN)

Best Natural Gas Pool Heater - Hayward H Series Natural Gas (FDN)

Large pool owners love fast heating solutions. If you are somebody like them and have easy access to natural gas, then the Hayward H Series natural gas pool heater can handle your entire situation.

H series is available in a wide range of 150K to 400K BTU. 

No matter how large your pool is, Hayward will make it warm within less than 10 hours. 

Their patented cupro-nickel Finn plate heat exchanger ensures a long-lasting lifespan even in salty water or aggressive mineral chemistry. 

Innovative polymer water inlet/outlet header design provides superior hydraulic execution while saving energy, protects the unit from damaging corrosion effects from high flow conditions, and enhances durability.

Hayward has introduced a forced draft combustion system to enhance the heating performance eliminating any outside weather variables like heavy air, rains, or everything else to get a constant hot water flow rate. This system sucks air using a strong blower, mixes it with gas, and then passes inside the combustion chamber by igniting with an electric sparker.

LED digital control panel offers you the most effortless operation to maintain your desired water temperature. Additionally, the electronic circuit operates the thermostat to ensure accuracy.

Hayward H series natural gas pool heater is pretty much environment friendly as it emits a meager amount of NOx comparing others.


  • It’s Loud!!! Very Loud!!! It feels like running a blower & a pressure gas stove simultaneously.
  • Operation is expensive. In colder months, your gas bill only for the 400K BTU unit will around $350.  

4. Best Solar Pool HeaterSmart Pool S601

Best solar pool heater - Smart Pool S601

Gradually the world is turning into green energy to reduce cost along with save the environment, and the Smart Pool S601 solar pool heater could be a great symbol of that. Such an astonishing system that has the ability to heat your pool water without costing a penny.

The system is made of polypropylene that contains individual fed collectors to ensure superior water flow, easier draining for winterization, and reduce back pressure on the pool pump. Also, the threaded header provides you the flexibility to use it for both inground & above-ground pools.

Each box contains 80 square feet (4′ x 20′) of water heating panel. You should consider installing not less than 60% of your pool surface to enjoy the most impressive performance. Depending on sunlight and the climate, this solar pool heater can raise the pool water temperature up to 6-10 degrees F by a day. 

There are TWO drawbacks of this unit, explained by all users. Firstly, there is no installation instruction. Secondly, you can’t allow the pump to pass water with full force inside the fed collector. Must use a pressure reducer valve, otherways excessive water pressure will damage the collector or make a leakage.

It would be best if you don’t think of using this unit as the primary heating source for your pool. Cause you have no control over the sun!!! 

Installing this with any core pool heater would be the intelligent choice to enhance efficiency & reduce costs.

Fact to remind

You will require additional installation kits which are not included.

5. Best Heat Pump Pool Heater Hayward HeatPump 110,000 BTU

Best heat pump pool heater - Hayward W3HP21104T

If you own a mid-size pool that contains 10,000 to 20,000 gallons of water, and you want to heat that up in the most efficient way, then Hayward HeatPRO 110,000 BTU is an unbeatable choice.

Most importantly, it’s not overpriced like the 140K BTU variant, and you will get more than value for money.

The 110K BTU variant contains the haywards patented acoustic compressor with a profiled fan blade to ensure the whisper-quiet operation and boost energy efficiency by reducing all mechanical friction.

Ultra gold corrosion-resistant evaporator fins and injection-molded UV-resistant body panels help the unit to survive any critical climate and face any crucial chemical imbalance of water.

The titanium heat exchanger’s high heat-transmitting capability has raised the energy efficiency level to achieve a 5.7 COP. So you never will need to worry about massive electric bills at the end of the month. Hayward offers a 4X cheaper operational cost than any gas pool heaters.

By a day, the unit can raise a mid-size pool temperature up to 10-15 degrees quickly, depending on your pool size. 

Hayward 110K BTU unit consumes 5.7-kilowatt electricity, and you will require a 240V wiring and 30 amp circuit breaker for hassle-free operation.

Some crucial facts

  • I don’t like their packaging and customer services. But that wouldn’t be a big issue.

6. Best Propane Pool HeaterHayward H Series Propane (FDP)

Best propane pool heater - Hayward W3H400FDP

If you are a large pool owner and prefer to install a propane pool heater, then the Hayward H series propane heater is my straight recommendation. Cause they are excessively powerful, durable, efficient & offer you the value for money.

Hayward’s cupro-nickel heat exchanger is inaccessible to any correction due to boiling saltwater and imbalanced mineral chemistry. The impressive hydraulic water inlet/outlet design reduces water pump runtime to save a significant amount of energy.

Obviously, you will enjoy the powerful forced draft combustion system that ensures the constant performance level eliminating any surrounding destruction of heavy wind or storm!! 

The digital control panel is very straightforward to access. Simply it needs a few clicks to operate the unit. The unit holds the water temperature on a constant level very accurately due to the electronically controlled thermostat mechanism.

Hayward H series propane heater is also available on a wide range of 150K, 200K, 250K, 300K, 350K & 400K BTU variants so that you can pick your suitable variant according to your pool size.

Our recommendation is, choose the unit 10X of your pool’s water holding capacity for a faster heating experience. Example:

If your pool size is 15K Gallon, go for 150K BTU similarly,

For 20K Gallon pool, go for 200K BTU

For 25K Gallon pool, go for 250K BTU

For 30K Gallon pool, go for 300K BTU

For 35K Gallon pool, go for 350K BTU

For 40K Gallon pool, go for 400K BTU

Thus you will be able to raise your pool temperature in a faster way.

All gas pool heaters emit NOx, so the Hayward isn’t the difference. But the emission quantity is impressively low. So it doesn’t impact the environment too much.

Some drawbacks

  • The running cost is massive. Hourly it will consume 5~20 Ibs propane depending on BTU until it reaches your desired water temperature.
  • Very loud!!!

Customer service isn’t that satisfying.

7. Best Electric Pool HeaterEcoSmart Instant

Best electric pool heater - EcoSmart SMART POOL

If you are unwilling to pay a couple of thousand dollars to buy a pool water heater, then EcoSmart is here to pick with a few hundred bugs.

Despite being cheap, the performance of EcoSmart is really crazy!!! It’s available in 18KW and 27 KW variants which can easily heat an 11,000 gallon & 20,000-gallon pool on the sequence.

Instead of using an activation valve, this unit has a flow detecting sensor to automatically detect water flow and turn the heater ON so that you get warm water on demand.

With the digital thermostat and easy rotateable thermal regulator, you can set up your desired water temperature within a second. The internal elements are wisely engineered to protect the unit from unwanted damages.

Please Keep in Mind

  • The 18KW & 27 KW unit consumes 75amp & 112.2 amp current on sequence, so you must require a 100 amp breaker for an 18KW unit or 120 amp breaker for a 27 KW unit for trouble-free operation.
  • Must ensure the water input flow is around 6-12 GPM to keep your unit alive.

Only and Only choose this unit if you don’t afford a heat pump or don’t want to expend too much currently cause this unit will skyrocket your electric bills.

Which Pool Heater Should I Pick among Gas, Electric, or Solar?

You may choose the best type of pool heater by considering a few facts. Those are

  • Your Pool Size
  • The climate of your location
  • The way you use your Pool (Commercial or noncommercial)

Let me describe all types of pool heaters and their suitable scenario or purpose of use so that you can easily decide which one you should go for.

Electric Heatpump Pool Heater (Best household solution): 

Heatpumps are expensive, but it’s the best solution for warming your household pools. These are available from 20K BTU to 140K BTU, sufficient to heat the pool water with 5000 to 30,000 gallons capacity.

Most importantly, heat pumps are the only type of pool heater that offers minimal operation cost. So investing in an expensive heat pump is a wise choice. Cause every month, along with every season, it will save you thousands of dollars of the electric bill. So at the end of the day, you will win the deal!!!

Here is a slight hint about the electric efficiency of the heat pump. The 140K BTU heat pump is only 7.2 Kilowatt. But the same capacity-on-demand basic electric pool heater consumes 27 kilowatts!!! Almost 4X, right?

Again, here is the yearly operation cost of several types of pool heaters 

  1. Heat pump annual cost, $1676.15
  2. Natural gas pool heater’s annual cost $5265
  3. Propane pool heater’s annual cost $6852
  4. Standard electric pool heater’s annual cost $8551

So you can imagine how massive the difference is between the operational costs of heat pumps and other types of heaters!!!

You may ask me why a heat pump can be driven with this bit of cost? 

Well, to explain this, I need to describe a bit about the mechanism of a heat pump.  

The heat pump works in a very similar way to an air conditioner, but the mechanism works on the reversed procedure. By compressing the refrigerant, the heat pump compressor sucks the environmental temperature and releases it into the pool water. 

As a result, there are no high wattage heating elements. So, you get a long-lasting, cost-minimal device to warm your pool water!!!

Solar Pool heater (The Energy Saver): 

The solar pool heater is something that everybody should install additionally with their primary pool heater. But this should not be your only heating solution, as we have no control over the sunlight or the cloud. 

Are they entirely cost-free? The answer is NO. You have to run a water pump to circulate water through it that requires electricity, so it’s not wholly cost-free. 

The best setup is connecting this unit on series with a heat pump or gas pool heater to boost the performance. 

Solar pool heaters can be placed on the roof, ground, or mounted on the fence and useable for both inground and aboveground pools. But the system can’t perform on the chilled area. 

Cause at the cold locations, the system will raise water temperature by 4-5 degrees on whole days, and the water will become cold again at night!!! 

Again, in winters, the solar pool heating system needs to be winterized. Otherways the unit will get damaged!!! 

Propane/Natural Gas Pool Heater (Best for Large & Commercial Pools)

Large pools require massive energy to heat that a heat pump can’t generate, and commercial pools require high-speed heating functionality. Installing multiple units of a heat pump is too costly. So gas pool water heater is the solution.

Gas pool water heater’s heating capacity starts from 150K BTU, and they are available up to 400K BTU. So you can pick one from this wide range according to your pool size.

Choosing the natural gas or propane variant is up to your availability. Running on natural gas is a bit less costly than Propane. 

People ask me, Can I use Propane on a natural gas pool heater? or vice versa?

The answer is NO. It will damage the unit. 

Natural gas contains a low amount of carbon molecule while propane includes 3. So the amount of gas that needs to be injected inside the combustion unit is constant. So there is no way to do this.

Standard Electric Pool Heater (Cheapest Solution):  

This device is entirely similar to your household electric tankless water heater. These shorts of water heater works in a faster way but consumes too much electricity. So I would like to avoid them as much as I can.

Difference between an Electric Pool heater & a Heat Pump?

Heat pumps are similar to air conditioners, while standard pool water heaters are similar to tankless water heaters.

Heat pumps use refrigerants to raise the water temperature, while electric water heaters raise the temperature using an electric coil.

That’s the fundamental difference between them.

What size pool heater do I need?

This is arguably the best question to ask.

BTU/hr or British Thermal Unit explains the pool heater’s capacity. The amount of energy is required to raise 1 gm of water temperature by 1 degree is called 1 BTU.

You should decide your pool heater’s required heating capacity based on two different facts. 

  • Your Pool’s water holding capacity
  • Average Environment Temperature

To calculate the pool’s water holding capacity, firstly calculate the pool’s volume. Example:

12′ length x 24′ width x 5′ avg depth = 1,440 cubic feet.

Now do it 7.48052 times to find the gallon.

So, 1,440 x 7.48052 = 10,771 gallons

For household pools, you may choose 5X more BTU than the pool’s capacity. For example, your pool holds 20,000 gallons of water, so you may select 20,000 x 5 = 75,000 BTU.

For commercial purposes, or if your home location’s average environment temperature remains too cold, you should go for 10X BTU than the pool’s water holding capacity. For example, if your pool contains 20,000 gallons of water, you should pick a 200,000 BTU water heater.

What to consider before buying a pool heater?

  • Heat Conservation:  How much temperature can your pool reserve while you are not running the water heater? It’s something more essential facts than you think. There should be a heat reflector layer at the pool’s surface for both the inground and above ground pool so that the earth or the environment can’t suck the temperature from the pool surface. Otherwise, you would require a more capacity pool heater to warm the pool.
  • Heater Casing: Ensure your preferred pool heater has an enamel coated exterior to survive in crucial weather. Otherways salty water or acid rain will quickly make it rusty.
  • Flow Rate Calibration:  Most of the pool heaters require an exact amount of flow rate for hassle-free operation. Ensure your water pump can pass that amount of flow through the water inlet.
  • Winterizing: Almost every single water heater needs to winterize during icy cold weather. Make sure whether your preferred pool heater requires it or not. Using a blower or vacuum sucker, you may winterize the unit easily. Simply blow through the inlet valve using a blower, and ensure there is no rest water inside the unit.
  • Ease of Installation: In most cases, users suffer because of unprofessional installation. Firstly, think twice if you can install it yourself. Read the manual multiple time before attempt to install. Then if you get it complicated, call some professionals. Give more concern on electric wirings especially when it remains beside salty water.  
  • Maintenance: If you ask me which pool heater is almost maintenance-free? The answer should be heat pumps. Otherways the standard electric water heater requires very frequent maintenance, and gas pool water heaters require minimum maintenance depending on how you are using it.
  • Water Temperature in Season: It’s something basic requirement for choosing the best pool heater. If you are from a colder area, be aware of the heating capacity.   Better is to select something more extensive. Alternatively, if you are from a warmer place, you should not waste energy selecting a gigantic pool water heater at all. 

How much does the pool heater installation cost? Which one is cheaper?

Pool heaters require multiple angles of installation. For heat pumps and standard electric pool water heater, its required electric wiring installation & water line setup. In most cases, you are able to do both of them by following provided instructions. Otherwise, if you require to hire professionals and have to build new electrical wirings & outlet, the cost may vary from $200 to $1000 including material prices.

For gas pool heaters, you need a Gas line, water line & Electric line installation at a time. So it’s the most tricky & difficult task. To higher professional plumbers and electricians, this setup may require up to $1500 for installation.

The solar pool heater is the easiest unit to install. You can do it yourself with some handy installation kits, so it’s ultimately cost-free.

What’s the monthly operation cost for a pool heater?

This term varies on the fuel type and heating capacity of the pool heater. 

Solar pool heaters are cost-free. Once you install it, there is no monthly bill to count for solar pool heaters.

Heat pump pool heaters are the most energy-efficient option to go. Depending on the heating capacity, weather, and pool size, the monthly operational cost remains $60 to $150 on average. 

Gas pool heaters contain tremendous heating capacity, so it costs much. The monthly maintaining fee is around $350 to $650 for the gas water heater.

Standard water heaters are hulk. They are not energy-efficient, and the monthly cost remains between $950 to $1200 depending on how long you need to use them.

Which Pool heaters last longer?

The first place should go for a solar pool heater. They last for almost a lifetime; if not happens any accidental leakage.

Secondly, the heat pumps. They last for decades and need very little maintenance or refrigerant refills. 

The gas pool water heater generally lasts longer than 7-8 years but depends on how carefully you use them.

Then the last sequence goes towards a standard tankless water heater. These items require very frequent maintenance due to their working procedure.

Frequently Asked Question about Pool Heaters

1. Is it possible to install the pool heater myself?

Yes, you can, but you have to have some technical skills. In terms of solar pool heaters, those are very easy to install, and anybody can do that.
Heat pumps require some basic plumbing and electrician skills. Be aware of maintaining all safety precautions.
Gas heaters installation is tricky, so you should not attempt to install them on your own if you are not a higher professional.

2. Is it required to winterize the pool heater, and how to do that?

Yes, all the pool heaters require winterizing in chilled weather. To do that, take a blower and open both the water inlet and outlet. Then pass the air using the blower through the water inlet and make sure there is no water remaining inside it anymore.

3. Is there any noise-free pool heater? 

Yes. Solar pool heaters are 100% noise-free. Then all-electric pool heaters, including the heat pumps, are almost noise-free.

4. Is a damaged pool heater repairable?

It depends on the type of damages. If the damaged parts are sparely available, like the compressor for the heat pump, or a heat exchanger for the gas water heater, they are repairable.
If your pool water heater has any leakage issue, that is repairable too. 
Some significant defects like breaking or burning the unit might not be fixable or too costly to repair. But this case is rare.

5. Should I turn ON the pool heater overnight?

Yes, you can. Pool water heaters contain an integrated thermostat with them, and most of them are electronically controlled. So if you turn it ON overnight, the system will automatically get turned OFF once it reaches the preset temperature. So there is no issue with turning it ON overnight.