7 Best Pool Heaters Worth Trying in 2024 + Reviews

What can be better than relaxing in a warm pool after a long and tiring day? But, how confusing is the process of choosing the best pool heater when there are countless options available in the market? With so many technical specifications and details, customers can be left in a fix as to what really matters. This is where we come in and help. Our review will help you pick the right pool heater for your needs.

In this review, we’ll provide you with:

• The top 7 best-swimming pool heaters in each category: gas heaters, heat pumps, electric heater, and solar heaters
• Information on our research process
• Little known perks of pool heaters
• Information on how to finance the pool heater
• Guide on pool heater types
• Information on problems you can face and how to prevent them
• Accessories which will prolong the lifespan and increase heater efficiency
• Usually, you’ll also need a pool pump – check out our take on the pool pumps available

Our final winner

	



	
Hayward H-Series natural gas heater

The quickest to heat the water in any weather condition


	
Benefits:
✔ Easy L.E.D. control panel; 

✔ Low emissions; 

✔ Easy-to-install;  
✔ Suitable for all pool sizes; 

✔ Wind resistant design; 

✔ Cupro-nickel heat exchanger;


	
Heater type:
Natural gas;


	
Pool type:
in ground/ above ground;


	
BTU Rating*BTU is a unit of measurement of energy (such as calories). 1 BTU is the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit. BTU/ hr is the measure of the power of your heater; the higher BTU/ hr the quicker your pool will heat up: 
150,000 - 400,000;


	
Efficiency**The natural gas thermal energy that will be transformed into heat. As a result of our research, the indicator 83% is the highest among other gas heaters on the market:
83% (great);


	
Warranty:
1 year;


	
Price:
Show price

🤷‍♂️ Who we recommend this heater for:

The Hayward H-Series natural gas heater isn’t dependent on temperature conditions, so even if you want to swim when it is chilly (e.g. temperature drops below 50°F), it won’t be a problem.

If you don’t want to wait a long time to swim in the pool, the Hayward heater will be perfect. It is the quickest heater among those on our list. The Hayward heater will increase the temperature by 2-4°F in an hour. It is 2 times quicker than any other heat pump that we have reviewed.

The heater is the best option for those who have a connection to natural gas.

🤔 What we like the most about this heater:

• The heater has an intuitive L.E.D. panel. It is simple to use for even those who are not tech-savvy. 
• Low emissions. The problem with gas heaters is the increased amount of emissions as compared to other types of heaters. Due to this reason, there were restrictions put in place in California and Texas; the Hayward heater has low emission technology, making it more eco-friendly and suitable to use in any state. 
• The Hayward H-Series natural gas heater is durable; the heat exchanger is made of the material used in building propellers and hulls of ships (cupro-nickel). It is more corrosion- resistant than any other heater.
• Thanks to the high efficiency (the percentage of gas thermal energy which will be transformed to heat your pool) the monthly bill will be lower than with any other natural gas heater on the market. This heater operates on natural gas that makes the monthly costs 1.5 times lower compared with a propane heater.

For more information, jump to the detailed review

If you want to see more options available on the market, see our list with the best pool heaters below.

Here are our best pool heaters:

	
Model
Characteristics
Best heater if


	


Hayward H-Series Natural gas

Show price

Show price
Heater type: Natural gas;

Pool type: inground/above ground;

BTU Rating: 150,000 - 400,000;

Efficiency: 83% (great);

Warranty: 1 year;

What makes it a winner: The quickest heating;



Benefits:

✔ Easy L. E. D. control panel;

✔ Suitable for all pool sizes;

✔ Wind-resistant design;

✔ Easy-to-install;

✔ Silent operation;

✔ Low emissions;

✔ Cupro-nickel heat exchanger;

...You have a natural gas connection;

...Live in an area with a cold climate (temperature drops below 50-55°F);

...You want your pool to heat water extremely quickly (the quickest heater, increases temperature by 2-4°F per hour);

jump to the detailed review


	


Hayward H-Series Propane

Show price

Show price
Heater type: Propane;

Pool type: in ground/ above ground;

BTU Rating: 150,000 - 400,000;

Efficiency: 83% (great);

Warranty:  1 year;

What makes it a winner: Quickest propane heater;



Benefits:

✔ Low emissions: meets California and Texas regulations;

✔ Suitable for all pool sizes;

✔ Easy to set-up;

✔ Easy-to-use;

✔ Cupro-nickel heat exchanger;
...You have propane connection;

...You live in the region where the temperature falls below 50-55°F;

jump to the detailed review


	


Hayward HeatPro Series

Show price
Heater type: Heat pump;

Pool type: in-ground;

BTU Rating:  90,000; 140,000;

COP: 5.7 (great);

Warranty: 1 year;

What makes it a winner: The best in maintaining temperature;



Benefits:

✔ Low operating costs;

✔ Durable body panels;

✔ Heats water quickly*;

✔ Titanium heat exchanger;

✔ Easy installation;

✔ Quiet operation;

✔ Easy-to-use.

…You are the owner of an above ground pool;

… The temperature in your area doesn’t fall below 50°F;

…You don’t mind if the water heats a little slowly;

...You appreciate quiet operation;

jump to the detailed review


	


SmartPool S601P

Show price
Heater type: Solar;

Pool type:  inground;

Size:  4 ft. x 20 ft.;

Panel area:  80 square feet;

Warranty:  5 years;

What makes it a winner: The most eco-friendly heater type; The most silent operation; No monthly operating costs;



Benefits:

✔ No monthly operating costs;

✔ Raises temperature 6-10°F (4-6°C) per day*;

✔ Wide panels area;

✔ Fiberglass reinforced over-molded header;

✔ Can be installed anywhere.
…You are the owner of an inground pool;

...You live in a sunny region;

...You have concerns about ecology;

...You want to have the quietest heater;

jump to the detailed review


	


Fafco Solar Bea

Show price
Heater type: Solar;

Pool type:  above ground;

Size: 4 ft. x 20 ft.;

Panel area: 80 square feet;

Warranty:  10 years

What makes it a winner: The most eco-friendly heater type; The most silent operation; No monthly operating costs;



Benefits:

✔ Increases temperature 7-10°F per day *;

✔ Easy-to-install;

✔ Easy to regulate;

✔ Can be installed anywhere
…You are the owner of an above ground pool;

...You live in a sunny region;

...You have concerns about ecology;

...You want to have the quietest heater;

jump to the detailed review


	


Hayward CSPAXI

Show price
Heater type: Electric;

Pool type: above ground/inground;

BTU:  17, 000; 37,500;

Warranty: 1 year;

What makes it a winner: The quickest to heat the water for small pools;



Benefits:

✔ Maintains desirable temperature;

✔ Compact design;

✔ Durable materials
...You are the owner of a small pool or hot tub;

...The temperature drops below 50°F;

...You want to heat the water in the shortest time;

jump to the detailed review


	


Hayward HP50HA

Show price
Heater type: Heat pump;

Pool type: in ground/ above ground;

BTU Rating: 45,000;

COP: 5.4 (good);

Warranty:  2 years;

What makes it a winner: Quiet operation;



Benefits:

✔ Maintains constant temperature;

✔ Low operating costs;

✔ Eco-friendly;

✔ Heats water quickly*;

✔ Titanium heat exchanger;

✔ Easy-to-install;

✔ Includes cooling mode to lower the temperature;
...You live in the area where air temperature doesn’t drop below 50°F;

…You don’t mind if the water heats a little slowly;

...You look for a quite operated heater;

jump to the detailed review

How did we decide?

To provide you with up-to-date information and the list of the best, top-rated pool heaters, we conducted research which included:

• Analysis of 18 heater models (5 gas and 3 electric heaters, 5 heat pumps, 5 solar heaters);
• Studied over 720 customer reviews;
• Picked the most important parameters for pool heater owners;
• Ranked all heater models according to the parameters and came up with a list of the best pool heaters.

Our review distinguishes among dozens of others you can find on the Internet. We carried out unbiased research, it wasn’t sponsored by any brands, even though 70% of all heaters are from one manufacturer, we haven’t received a dollar from Hayward. You can check and challenge our thinking below.

As a result of our research, we figure out the most important criteria for pool heaters and ranked the units accordingly:

• Quick to heat the water;
• Easy-to-install;
• No need to replace the heater parts frequently (e.g. heat exchanger, control board);
• Silent operation;
• Warranty and service (easy to solve replacement problems/ warranty assistance);

We have created a table below to compare all the available pool heaters. Here is how we rated the pool heaters:

Choosing the best pool heater

The process of choosing the right pool heater may seem challenging. But it is not that difficult to pick the perfect pool heater for your needs. You should take into account several factors.

• You have to understand what goals you want to achieve while using a pool heater. For example, if you want to heat the pool water in the shortest time, the best option for you will be a gas heater.
• Decide how much you can spend on the operating costs per month. The most expensive will be gas and electric heaters. While heat pumps will be cheaper, and solar heaters are the cheapest.
• The type of pool you need: inground or above ground. The same size inground and above pools in the same climate conditions will need different heaters. Above ground pools require a more powerful heater since while heating the water, a lot of the heat escapes through the sides and the top of the pool. It will be indicated on the pool heater whether it is for inground or above ground pool.
• Climate features. This is extremely important if you would like to heat water with a heat pump or solar heater since both are highly dependent on air temperature and the amount of sunlight.
• Law regulations in your area. In California and Texas, there is a law that establishes some emission limits. If you live in these states and want to heat your pool with natural gas or propane, you should take the regulations into account.

To find more information about choosing the best heater, read our article on how to choose the best pool heater.

Top gas heaters

Gas heaters are universal and can be used in any type of climate, these heaters lead in their ability to heat the water quickly. Read details in the section with the gas heater.

1. Hayward Universal H-Series Natural Gas — best natural gas heater

	
Model/Specs
400
350
300
250
200
150


	
Fuel type
Natural gas 


	
BTU/hr *BTU is a unit of measurement of energy (such as calories). 1 BTU is the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit. BTU/ hr is the measure of the power of your heater; the higher BTU/ hr the quicker your pool will heat up
400,000
350,000
300,000
250,000
200,000
150,000


	
Pool type
Inground/above ground


	
Efficiency**The natural gas thermal energy which will be transformed into heat. 82%-83% is the highest indicator
83%
83%
82.7%
83%
83%
82.7%


	
Width
36"
33"
30"
28"
25"
21"


	
Weight (Ibs.)
160
158
145
134
123
110


	
Heat exchanger
Cupro Nickel


	
Warranty
1 year

Established in 1925, Hayward is the most popular manufacturer in the pool industry. Besides heaters, this company also produces filters, automatic pool cleaners, and other equipment for pools.

🏆 What makes it a winner?

The quickest to heat the water in any weather condition. This gas heater is the best choice if you want to heat the water within the shortest time. It will heat the water 2 times quicker than any heat pump. This model can increase the temperature by 2-4°F to the average pool size per hour.

Unlike heat pumps and solar heaters, the performance of the gas heater is not dependent on outside conditions (such as air temperature or amount of sunlight), it will work despite the changeable weather and low temperature.

Benefits:

1. Easy L. E. D. control panel. It provides digital temperature readings and makes controlling water temperature much easier.
2. Low NOx emissions. NOx is produced when nitrogen and oxygen gases are mixed during combustion. You experience these in everyday life. They are the same emissions produced by vehicles.  
   The low emissions technology presented in Hayward Universal H-Series heaters makes gas heaters less harmful for the environment. In states like California and Texas, a law was established in 1998 stating emission limits. Hayward heaters will be good for pool owners who live in these states.
3. High efficiency. Gas heaters are the most expensive to operate among other types of heaters, but this model has high efficiency (83%) which means that most of the energy used to heat the water will be transformed into heat; it will save your money. Also, this heater operates on natural gas which is 1.5 times cheaper than propane.
4. Easy to set-up. 80% of buyers said it was easy-to-install due to clear instructions. It takes just 5-6 hours to install the heater and get it to start heating. Another feature that makes setting up easier is the universal wiring and dual voltage system (both 110V and 220V). You will not need to buy adapters or other equipment to install the heater.
5. Suits any pool size. Hayward gas-powered Universal H-Series heaters offer models for different pool sizes. To pick the right heater size, use our calculator.
6. Wind-resistant design. The wind may chill the heater and therefore reduce its efficiency. You don’t need to install a high-wind stack, thanks to its design the impact of the wind will be eliminated.
7. Cupro-nickel heat exchanger. Cupro-nickel alloys are frequently used in marine applications (for propellers and hulls) since they are highly resistant to seawater corrosion, making this heater suitable for saltwater pools. 

❗ Warning: In the review section of this pool heater (and every other), you will find comments of disappointed buyers who faced a leaking heat exchanger. Why does it happen and how can you prevent it? Jump to the section with common heater problems.

Customer reviews

Here are some reviews of Hayward Universal H-Series owners. Some people bought this heater for the second time since they were so pleased with its performance.

Mike, Georgia

Tiny, California

Brian, New Jersey

Verdict

Pros:

Pros

• Heats water very quickly. This heater will raise the temperature 2 times quicker than any other heat pump. It is a total winner in terms of fast heating capability;
• Works in any weather conditions. Unlike other types of heaters (such as heat pumps and solar heaters), it will not be affected by the weather since it doesn’t take any energy to heat the pool from the outside;
• Low emission technology makes it more eco-friendly than other natural gas heaters on the market and suits California and Texas regulations;
• High efficiency. Gas heaters are the most expensive among other types of heaters, but this model will save most of the energy and hence your money;
• Easy-to-use control panel which will be understandable by even a 5-year old;

Cons

• Loud operation. This heater is 4 times louder than other heat pumps from our list. But it will not cause problems if it is placed outside (as most of the heaters);

🤔 We recommend the Hayward H-Series Natural gas heater for:

People who have a natural gas connection and don’t want to be dependent on weather conditions. This heater is ideal for those who are looking for the best option to heat the pool and be able to swim in instantly. If you are concerned about the environment, this heater produces fewer emissions than any other natural gas-operated heater available on the market. It also complies with the California and Texas regulations.

2. Hayward Universal H-Series Propane — best propane heater

	
Model/Specs
400
350
300
250
200
150


	
Fuel type
Propane


	
BTU/ hr *BTU is a unit of measurement of energy (such as calories). 1 BTU is the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit. BTU/ hr is the measure of the power of your heater; the higher BTU/ hr the quicker your pool will heat up
400,000
350,000
300,000
250,000
200,000
150,000


	
Pool type
Inground/above ground


	
Efficiency **The propane thermal energy which will be transformed into heat. 82-83% is the highest indicator
83%
83%
82.7%
83%
83%
82.7%


	
Width
36"
33"
30"
28"
25"
21"


	
Weight (Ibs.)
160
158
145
134
123
110


	
Heat exchanger
Cupro Nickel


	
Warranty
1 year

Propane is not a popular source of energy in the USA, so the choice of propane heaters is less than natural gas. To heat water with a propane heater, you should also have a large propane tank, it needs to be filled up regularly. It is also worth mentioning that operating costs will be 1.5 times more than natural gas.

🏆 What makes it a winner?

The quickest propane heater that is not dependent on the weather. The Hayward H-Series Propane heater is the fastest model on the market to run on propane; it will raise the temperature by 2-4°F per hour which is 2 times faster than any heat pump.

Weather conditions don’t have any impact on this heater and it can operate under any circumstances. Unlike heat pumps and solar heaters, it doesn’t take any energy to transfer it into heat from the outside.

Benefits

1. Low emissions. Besides the fact that gas heaters are the least eco-friendly type, its amount of emissions in the atmosphere may break a law in states like California and Texas. Hayward gas heaters include Low NOx emissions technology and meet all the air quality standards. NOx is produced when nitrogen and oxygen gases are mixed during combustion. It is similar to emissions from cars in traffic jams.
2. Easy-to-use. The Hayward H-Series Propane heater will start working once sensing a drop in water temperature. It goes on standby mode once the water is heated. There is no need to control the water temperature every time, this heater works quite independently.
3. Suitable for all pool sizes. The Hayward H-Series Propane heaters are made for any pool size. You just need to calculate the heater size (BTU/ hr) required for your pool and then pick the right model. To find the heater size that you need — use our calculator.
4. Easy to set-up. Owners of the Hayward H-Series Propane heaters claim that the unit was straightforward to install and the instructions were clear. On average it takes approximately 5-6 hours to set up this heater.
5. Cupro Nickel heat exchanger. Cupro-nickel is a durable, corrosion-resistant metal that is compatible with saltwater pools since it is often used in marine applications to build propellers and hulls of ships.

❗ Warning: You may find comments about the poor quality of this heat exchanger, but we figured out that the problem can be due to improper maintenance. To find more information on how to avoid this problem and save money, jump to the section with common heater problems.

Customer reviews

Mike, Alabama

John, Maryland

Ben, Connecticut

Verdict

Pros

• Quickest heating on propane. The water will be heated 2 times quicker than with any heat pump;
• Not dependent on the weather. The propane heater can operate in any weather condition since it doesn’t take any energy from the outside, unlike heat pumps and solar heaters.
• Low emissions. This heater is environment-friendly and meets the California and Texas regulations;

Cons

• High operational costs. The operating costs will be 1.5 times higher than heaters that run on natural gas.

🤔 We recommend Hayward Universal H-Series Propane heater for:

Those people who use propane as a source of energy. it is perfect for people who need to heat the pool in the shortest time (adds 2-4°F per hour). This heater is also more eco-friendly and produces fewer emissions (meets California and Texas regulations).

Top heat pumps

The heating pool with heat humps is a more eco-friendly way to heat water than gas heaters but it requires some conditions to work properly e.g. constantly high temperature (50°F). Heat pumps are the leaders in maintaining a constant temperature but take more time to heat the pool. If you still doubt whether you should buy a heat pump, jump to the section with heat pumps best for and read more.

3. Hayward HeatPro Series — best heat pump for above ground pools

	
Model/ Specs
W3HP21004T
W3HP21254T
W3HP21404T


	
BTU *BTU is a unit of measurement of energy (such as calories). 1 BTU is the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit.
90,000
125,000
140,000


	
Pool type
Above ground


	
Coefficient of performance (COP) **Tooltip content
5.7 (great)


	
Net Weight (Ibs.)
190
200
250


	
Heat exchanger
Titanium


	
Warranty
1 year

🏆 What makes it a winner?

The best in maintaining temperature. To maintain the desired temperature, you will need to turn on the heat pump just for several hours per day. It will not increase your electricity costs as with gas heaters; you will pay just $1.60 per day. Its high coefficient of performance will not allow the heat to escape and it will make the process of maintaining temperature more efficient.
If you want the pool to retain heat, keep it covered with a pool cover.

Benefits:

1. Low operating costs. You’re not in for a nasty surprise when it comes to your electricity bills. This pump hardly consumes energy, it only needs energy to operate the circle. Also, the coefficient of performance is higher than other heat pumps on the market (5.7), which means the heat will not be “lost” on its way to the pool. You will pay approximately 80 cents per hour, which is 7 times less than a gas heater.
2. Durable body panels. Highly detailed body panels (injection-molded) are UV-resistant and will serve for a long time. It will perform and look good even after 20 years of use.
3. Heats water quickly. This criterion to a huge extent depends on air temperature; on warm days it can add 2°F per hour to a medium pool size (24,000-gallon pool) which is a good speed for a heat pump. It is 2 times less than heating with a gas heater.
4. Easy-to-use. In the event of a decreased flow of water, the heater will shut down automatically. Decreased flow of water is also a common reason why heat pumps often break down. Turning off automatically will prolong the heat pump’s lifespan. You just need to set the desired temperature and the heat pump will do everything by itself.
5. Titanium heat exchanger. This type of metal has high thermal conductivity and is not affected by the impact of saltwater. Titanium is also known for its corrosion-resistance.
6. Easy-to-install. You will not need to buy additional equipment to install this unit. General plumbing connections (2in x 2 1/2in CPVC) will suffice. Customers say that the process of installation is quick and takes approximately 3-4 hours.
7. Quiet operation. Due to the acoustic compressor cover and profiled fan blade, this model doesn’t produce loud noises while operating. It will be much quieter than any gas heater.

Customer reviews

Mike, Indiana

Melanie, Pennsylvania

Ernie, North Carolina

Harry, New York

Verdict

Pros

• Maintains desirable temperature. To maintain the temperature you will need to turn on the heat pump for a few hours per day, it will not use a lot of electricity unlike gas heaters;
• Low monthly cost. On average the monthly operating costs for a heat pump is 7 times less than gas heaters;
• Heats water quickly. This unit will add 2°F per hour on average. It is 2 times slower than a gas heater but much quicker than solar heaters.

Cons

• Heavy. You will certainly need help to transfer it to your home;
• Will not heat the water if the environment temperature is below 50°F. This is common in all heat pumps, so if you don’t want to be dependent on weather conditions, consider gas or electric heaters;

🤔 We recommend Hayward HeatPro Series heat pump for:

Owners of above ground pools of any size. It is an ideal choice for people who live in a warm climate, where the temperature doesn’t drop below 50°F. If you can wait longer to heat the pool and want to save money on operating costs, this unit will be perfect for you.

4. Hayward HP50HA — our best heat pump for above and inground pools

	
Model/Specs

HP50HA


	
BTU*BTU is a unit of measurement of energy (such as calories). 1 BTU is the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit.
50,000


	
Pool type
Inground/above ground


	
Coefficient of performance (COP) **COP is a ratio between work (or energy) output and energy input. COP of 5.4 means that for every 1 BTU used by the heat pump, 5.4 BTU will be produced (heat energy will be taken from the outside air)
5.4 (good)


	
Dimensions
44.5" x 18.5" x 26.8"


	
Heat exchanger
Titanium


	
Warranty
2 years

🏆 What makes it a winner?

Quiet operation. The Hayward HP50HA is the winner in this category. This heat pump doesn’t disturb with annoying noises and stays on almost unnoticed while operating. It is 4 times quieter than any gas or electric heater.

Benefits:

1. Maintains constant temperature. To maintain the desired temperature, you need to run the heat pump just 2-3 hours per day. That’s enough to maintain a comfortable swimming temperature at all times.
2. Low operating costs. A heat pump doesn’t need much electricity since it only consumes electricity to operate the circle. According to owners’ reviews, it adds to your electric bill approximately 80 cents per hour which is 7 times cheaper than a heater running on natural gas.
3. Eco-friendly. The heat pump takes just a little electricity to operate the circle. It also doesn’t produce emissions making it more eco-friendly than gas heaters.
4. Includes cooling mode. A little known feature of the heat pump. Sounds weird — Why do I need to COOL the water if I buy a pool HEATER? This function can be useful for people in areas with a hot climate.
5. Heats water quickly. The speed of heating the water with a heat pump depends on the air temperature since it doesn’t generate the heat but utilizes it from the environment and moves this heat in the pool water. So, how quickly the water heats up, will depend on weather conditions, but on average this heat pump can raise the water temperature 1-2°F per hour. It is 2 times slower than heating with a gas heater but quicker than using a solar heater.
6. Easy-to-install. Setting up this model doesn’t require extra materials, just standard plumbing materials. It won’t take a lot of time to install this heat pump, just around 4-6 hours.
7. Titanium heat exchanger. Titanium is a highly efficient metal, it will not allow your pump to lose heat while transferring it to your pool. Titanium is also corrosion-resistant and can be used in saltwater pools. Titanium is widely used in the aerospace industry due to its extreme robustness and ability to withstand high-stress temperatures and pressures. Rackets, engines, and airframes are made of this material.

Customer reviews

Brian, Indiana

Chris, Illinois

Michel, Kentucky

Verdict

Pros:

Maintains desirable temperature. To keep the required temperature, you will need to run it 2-3 hours per day, which will not affect your monthly bill as with gas heaters. To retain the heat in your pool, we recommend using a pool cover.

Quiet operation. This unit will be 4 times quieter than a gas heater, but it will not be completely silent as a solar heater;

Low operating costs. The running costs will be 7 times less than a gas heater;

Heats water quickly. This heater will raise the water temperature 1-2°F per hour which is quicker than solar panels but slower than a gas heater;

Cons:

Will not heat if the environment temperature is below 50°F. This is a common feature for all heat pumps. If you want your heater to heat the water temperature in any condition, we advise looking at gas or electric heaters;

Good for medium-sized pools only (up to 13,000 gallons);

🤔 We recommend the Hayward HP50HA for:

Those that have a medium pool size (up to 13,000 gallons) and for those who appreciate quiet operation — this heater will be 4 times quieter than any gas heater. It is a highly efficient heater for areas where the temperature doesn’t fall below 50°F. The heater is also much cheaper to run (just 80 cents per hour) and more eco-friendly than any gas heater.

Top electric heater

The electric heater is a good choice for owners of small pools and hot tubs. It heats up the water quickly and works in any environment. But the operating costs are more than heat pumps and solar heaters. To read more information on this heater type, jump to the section with electric heaters, and see whether this type suits your needs.

5. Hayward CSPAXI — best electric heater for small pools

	
Model/Specs
CSPAXI55
CSPAXI11


	
BTU/hr*BTU/ hr is the measure of the power of your heater; the higher BTU/ hr the quicker your pool will heat up
17,000
37,500


	
Pool type
Inground/above ground


	
Construction material
304 stainless steel


	
Warranty
1 year

🏆 What makes it a winner?

The quickest to heat small pools. According to owner reviews, on average, a small 1,000-gallon pool will increase the temperature by 2-3°F per hour. Electric heaters along with gas heaters can raise the water temperature very fast since they are independent of ambient temperature.

Benefits:

1. Maintains constant temperature. Once the desired temperature has been achieved, this electric heater will effectively maintain it while running at low speed, which will not harm your electricity bill. To retain the heat in your pool, we recommend using a pool cover.
2. Compact design. This electric heater is so small that it can fit in any compact space. This heater is the most compact in our list.
3. Durable materials. The tank, threaded head, and electronic heating element are made from 304 stainless steel. This material offers good corrosion resistance and durability.

Customer reviews

Jacob, Minnesota

Mike, New York

Richard, Florida

Verdict

Pros:

Quick to heat small pools or hot tubs. Along with gas heaters, this heater is the quickest and will raise the water temperature 3 times quicker than any heat pump;

Maintains temperature. As with heat pumps, this heater is great in maintaining temperature;

Compact design. The smallest heater in our list making it compact for pools;

Cons:

Good for small pools (less than 5,00 gallons) or hot tubs;

A timer to control the increase in temperature is not included;

🤔 We recommend Hayward CSPAXI for:

Owners of a small pool (less than 5,00 gallons). If you live in a chilly area where the temperature drops below 50°F, this heater will be perfect since it isn’t dependent on weather conditions. It also heats up quickly.

Top solar heaters

Solar heaters are the most eco-friendly type among others. But they need a lot of sunlight to operate. Solar heaters are often used as an additional source of energy to cut down on the heating expenses, to read more jump to the section with solar heaters.

6. SmartPool S601P — our best solar heater for inground pools

	
Model /Specs
S601P 


	
Pool type
Inground


	
Size
4 ft. x 20 ft.


	
Panel area
80 square feet;


	
Mounting
On the roof/yard


	
Warranty
5 years

SmartPool offers a remarkable option for owners of inground pools. It will be a good choice if you live in a hot climate and have frequent sunny spells. Solar panels can be used as the sole heating source or additional to your primary heater (gas, electric, or heat pump).

🏆 What makes it a winner?

The most eco-friendly heater type. The solar heater doesn’t produce any emissions while operating, unlike gas heaters. Furthermore, it doesn’t need electricity to operate the circle as with heat pumps. It utilizes sunlight to generate heat.

The most silent operation. With gas heaters you may notice loud noise while they are operating, heat pumps are 4 times quieter, this solar heater will not make any noise while running.

No monthly operating costs. The solar heater utilizes the sunlight to generate electricity, thereby saving on costs, unlike gas or heat pumps. 

Benefits:

1. Raises water temperature quickly. In the case of solar heaters, efficiency depends on the amount of solar energy received, but on average you will get 6-10°F (4-6°C) per DAY which is less in comparison to gas heaters (2-4°F per HOUR) and heat pumps (1-2°F per HOUR).
2. Fiberglass reinforced over-molded header. Fiberglass will provide a long lifespan since it is much stronger than sheet metal used in other heaters. Fiberglass also has better thermal performance than other materials such as metal, plastic, and wood.
3. Wide panels area. Wide panels are an important feature in solar heaters, since the wider the area of the panels, the more solar thermal energy will be received, and the higher the water temperature.
4. Can be installed anywhere. This heater can be installed on the ground in your yard, on the roof, or in any other place where it suits. We recommend mounting it on the roof since in this way solar panels will provide the highest efficiency and heat transfer.

Customer reviews

Vickie, Indiana

Sarah, Michigan

Kelly, Florida

Richard, South Carolina

Verdict

Pros:

Eco-friendliness. This is the most eco-friendly type of heater; it doesn’t produce emissions like gas heaters and it doesn’t need electricity to operate the circle as with heat pumps;

No monthly operating costs. Since it needs sunlight to operate, you will be saving on monthly operating costs.

Silent operation. It’s not loud in operation, unlike gas heaters and heat pumps.

5 years warranty. This solar heater has a longer warranty period than any of the gas heaters or heat pumps (their average warranty period is 1 or 2 years).

Cons:

Difficult to install on your own. The panels are big and heavy, it will be a problem to install them on the roof;

Need to buy an installation kit separately;

Not efficient in areas not exposed to sunlight. The solar heater is dependent on outside conditions such as a good amount of sunlight.

🤔 We recommend the SmartPool S601P for:

Owners of inground pools who live in areas exposed to good sunlight. If you are concerned about the environment, you will appreciate this. You’ll also be saving a lot of money on energy costs. Fafco Solar Bear — the best solar choice for above ground pools;

7. Fafco Solar Bear — the best solar choice for above ground pools

	
Model/Specs
Solar Bear


	
Pool type
Above ground


	
Size
4 ft. x 20 ft.


	
Panel area
80 square feet 


	
Mounting
On the ground/on a rack/nearby roof


	
Warranty
10 years

Established in 1969, Fafco is one of the first manufacturers of solar heating systems in the USA. Today, Fafco is among the largest distributors of solar heaters in the United States.

🏆 What makes it a winner?

The most eco-friendly heater type. This heater needs sunlight to operate, so it doesn’t produce any emissions as gas heaters do. This heater doesn’t need electricity to start working as with heat pumps. This makes it the most eco-friendly heater among others.

The most silent operation. This solar heater doesn’t produce any noise while operating unlike gas heaters (which are the noisiest) and heat pumps (4 times quieter than gas heaters).

No monthly operating costs. Since the solar heater doesn’t consume energy (gas or electricity) to operate, you will not pay running costs.

Benefits:

1. Increases water temperature quickly. After a sunny day, your pool temperature will increase up to 7-10°F on average which is slower than any other type of heater, e.g. a gas heater will add 2-4°F per HOUR and a heat pump will add 1-2°F per HOUR. But heating up the water with a solar heater will save on electricity costs.
2. Easy-to-install. Buyers claim that setting up this solar heater takes an hour and doesn’t require any technical skills.
3. Easy to regulate. The solar system includes an integral bypass valve, which will make pool heating much easier — you can turn it on and off as needed.
4. Can be mounted anywhere. Fafco Solar Bear panels can be mounted on the ground, on a rack, or a roof. We recommend mounting the solar panels on the roof to collect solar thermal energy and maximize efficiency.

❗ Note: The set doesn’t include a hose, it is sold separately.

Customer reviews

Ben, Florida

Diane, Arizona

Jason, California

Verdict

Pros:

Eco-friendliness. This heater doesn’t produce any emissions and doesn’t need gas or electricity (as gas heaters and heat pumps) to operate making it eco-friendly;

No operating costs. Since it consumes free solar energy, you will not pay for operating costs; 

Silent operation. This unit doesn’t produce any noise while operating unlike gas heaters and heat pumps;

10 years warranty. The warranty period of this heater is the longest amongst other heaters in our list;

Cons:

A hose is not included;

Not efficient in areas not exposed to sunlight. This heater is highly dependent on the weather (amount of sunlight), it will not work in any condition like gas heaters and electric heaters do.

🤔 We recommend Fafco Solar Bear Economy Heating System for:

Owners of above ground pools, who live in areas that get a good amount of sunlight. It is perfect for people who are concerned about the environment and require a very quiet heater. 

Calculating the size of the pool heater

Calculating the right size of the pool heater is crucial when buying the unit. Choosing the right size is essential as it will determine the effectiveness of the heater. 

Sizing a pool heater includes a lot of factors such as:

• The pool area;
• The difference between pool and average air temperatures;
• Climate features (wind exposure, humidity levels, night temperature);

The higher indicators listed above — the bigger pool heater you need.

So now let’s figure out what heater size you need according to the heater type.

Gas heaters & Heat pumps & Electric heaters

Gas heaters are rated by BTU output (British thermal units). And heat pumps along with electric heaters are rated by both BTU and horsepower (hp). 

The following steps will help you come up with the right pool heater size:

1. Define the desired water temperature for your pool;
2. Define the average temperature during the coldest month of using the pool;
3. Define the temperature raise needed (subtract the average temperature for the coldest month from the desired pool temperature);
4. Define the pool surface area (in square feet);
5. Use the formula below to determine the BTU/ hour output requirement of the heater.

We placed all the pool heaters in one place and ranked them by BTU. So now, when you have BTU needed for heating the pool water, you can pick the best heater according to the type.

	
BTU/Heater type
Electric
Heat Pump


	
17, 000
Show heater
+



	
37, 500
Show heater
+



	
45, 000
Show heater
+


	
90, 000
Show heater
+


	
140, 000
Show heater
+

	
BTU/Heater type
17, 000
37, 500
45, 000
90, 000
140, 000


	
Show heater
Show heater
Show heater
Show heater
Show heater


	
Electric
+
+



	
Heat pump
+
+
+

	
 BTU/Heater type

Natural gas
Propane


	
150,000
Show heater
+



	
200,000

Show heater
+



	
250,000
Show heater
+



	
400,000
Show heater
+



	
200,000
Show heater
+


	
250,000
Show heater
+


	
400,000
Show heater
+

Once you know the BTU required for your pool, check the heaters that are the best choices according to the BTU and type of heater.

Solar heaters

There are some common rules in sizing solar panels. 

The surface area of the solar panel should be equal to 50%–100% of the surface area of your pool. The bigger surface of solar panels, the more solar energy will be collected and the quicker you will achieve perfect water temperature. If you live in a cooler or cloudier area, you may need to increase the ratio between the panels and the pool’s surface area.

You should also take into account the desired length of the swimming season. For instance, people in sunny states like Florida often use the pool all year round, for this purpose, it will be better to choose a collector that covers 100% of the pool area to provide the desired temperature even on less sunny days. For people who would like to use the pool for 6-8 months per year, the surface of the collector can be 60% – 70% of the pool area.

To provide the coverage necessary for heating, you should consider buying several panels.

After picking the right amount of panels, the temperature rise will depend on factors such as the amount of sunlight, type of your pool, the model of solar panels, but on average it will raise the water temperature to 7-10°F per day.

Check out our best solar heaters

Little known perks of pool heaters

Besides the most common reasons for buying pool heaters such as the need to add some degrees to achieve comfortable water temperature and willingness to extend the swimming season for a few more months every year, there are also some little known benefits of pool heaters:

• Heat pumps (remove heat from the surrounding pool water and transfer this heat into the environment) can also be used for cooling the pool water (if you live in an area with extremely high temperature);
• If you live in an area with constantly high temperatures, you can install solar panels, produce energy, and earn Solar Renewable Energy Certificates (SRECs) for every 1000 kilowatt-hours (kWh. You can sell these certificates (energy) to the utility.

How to finance the pool heater?

A pool heater is an expensive purchase, wouldn’t it be great to find financing options which would cover the expenses of the unit? Thankfully, some programs can cover some qualified expenses if you choose to install a solar heater.

Residential Renewable Energy Tax Credit. That’s the federal program, according to which, you can claim up to 26% of qualified expenses for investing in the solar heater. Eligible costs include labor, assembling, and installing and expenses related to piping and wiring.

Investment Tax Credit. This program is available for Vermont citizens. With investment tax credit, you can cover up to 30% of the eligible costs.

At the level of states, you can also find a lot of rebates on solar systems, to find more programs visit a DSIRE site, and pick your state to see the available offers.

Where to purchase a pool heater?

There are a lot of places to buy a pool heater (numerous online and offline stores) but we highly recommend choosing the biggest online retailer — Amazon.com.

You may have read complaints regarding damaged units delivered from online stores. For this reason, you can count on the A-to-Z guarantee which ensures the quality and delivery of an item, you can easily return or change the pool heater if needed. With Amazon, this procedure is much easier than with any other known online store.

Also, buying a heater on Amazon is very beneficial and can save you a lot of money, as the buyers of pool heaters prove:

“I was being charged a whopping $1,000 more by a pool repair company for a low-brand pool heater that had the same specs. I bought the pool heater online and saved so much money.”

Heater performance in the saltwater pool

Owners of a saltwater pool may have some concerns about the heater performance. This is because saltwater along with poorly balanced water (too high or too low pH, total alkalinity, chlorine/bromine levels) can cause corrosion of metal parts in the heater. 

Of course, manufacturers take these factors into account and use stainless steel in their construction, titanium, or cupro-nickel for heat exchangers which are durable and can resist rust. Remember, no one is safe from damages, so it’s better to prevent problems than deal with consequences. Better to be safe than sorry. 

To extend the service of your pool heater and eliminate the impact of saltwater, we recommend using the zink node. It can be installed anywhere in the plumbing system of the pool as long as it has contact with the water (e.g. between filter and pump) and the bonding grid wire is connected to it.

How it works

The metal parts are immersed in the saltwater pool and they produce an electrical voltage. When the metal is submerged into the saltwater, this current passes through it and leads to corrosion.

Electric current will be passed onto the zinc anode instead of it flowing through the pool water to the metal parts resulting in corrosion. Over time, the zinc anode will break down and sacrifice itself, in this way no metal parts in your pool heater will be affected by corrosion.

Typical problems with pool heaters and how to avoid them

Regardless of the heater type, owners of pool heaters encounter some common problems such as a short lifespan of the heat exchanger (it leaks after several months of use) and problems with the warranty. Here we will delve into the root of these problems and help you minimize their risks.

Heat exchanger leaks

The heat exchanger is one of the essential components in the pool heater. It helps to transfer the heat from a hot fluid to cold, heating the water in this way.

In the comment section under each pool heater, you will find customers’ complaints about a low quality heat exchanger and how quickly it started to leak. In most cases, the reason is because of improper water care and it has nothing to do with the heater’s quality. It is negligence from the customer’s end. We can assure you that if you care about the water properly, you won’t face any problem.

The lifespan of the heat exchanger depends mainly on two factors: its material and the water quality in your pool. The most durable materials for heat exchanger are titanium and cupro-nickel since they are corrosion resistant. 

Poorly balanced water can also affect the heat exchanger’s lifespan, it leads to corrosion. Keep the water perfectly balanced all the time is difficult, so it is better to have a “safety bag” — check valve (jump to the section check valve to read more) and a zinc anode in case you are an owner of a saltwater pool (jump to the section heater performance in the saltwater pool to find more information).

A manufacturer doesn’t honor the warranty

On average the gas/ electric/ heat pump warranty is 1 year and for solar heaters, it is 5 years. People often claim that the manufacturer will not honor the warranty if something happens. Here the terms of warranty come into force. Most of the manufacturers will not cover the expenses in case of damage if you installed the heater on your own. Some manufacturers will not replace the parts or pay for labor if the damages are caused by poorly balanced water. These points are worth keeping in mind.

Types of pool heaters

If you still struggle with the type of heater to choose, we will help you to make a final decision. There are four main types of heaters (gas, electric, heat pump, and solar heaters) each of them has their pros and cons and will be perfect to achieve certain aims; some of them will be more effective in one climate conditions and the others will be less effective. It depends on the conditions and your requirements. Let’s figure out who each type of heater will be ideal for.

1. Natural gas & propane heaters

A gas heater is the most popular type since it can be used in any climate, its performance isn’t dependent on the air temperature. Unlike heat pumps or solar collectors, gas heaters don’t take the energy from the surroundings, they produce it. Gas heaters produce energy by burning gas in the heating chamber and then this energy is transferred to the water.

Gas heaters were extremely popular in the past, but with the increase in gas prices and a high number of emissions in the environment, people are looking for more efficient and eco-friendly alternatives.

The Best type for:

• People who live in a cooler environment. If your pool isn’t exposed to a lot of sunlight, you cannot get a comfortable water temperature even on sunny days and you would like to extend the swimming season regardless of the environment temperature, a gas heater will prove to be the best solution. It doesn’t need a constantly high air temperature (over 50°F) to operate as heat pumps or sunlight (as solar heaters), it will work even in a cooler environment.
• People who want to heat water extremely quickly. Gas heaters are leaders in their speed of heating the water. They are 2 times faster than any heat pump. You can just turn on the heater several hours before the planned swimming session and you will get a comfortable temperature.
• People who need a pool occasionally or can pay high operating costs. Gas heaters are the cheapest option to buy but the most expensive to operate. Natural gas heaters are 7 times more expensive to operate than heat pumps. An hour of operating with a natural gas heater will cost approximately $7. And for a propane heater, it will raise 1.5 times (around $18 per hour). As you see, both natural gas and propane are expensive sources of energy, so get ready for an increase in bills, particularly if you plan to use a gas heater often.

2. Pool heat pumps

A heat pump is an innovative type of heater since it needs little electricity to push the process of circulating energy. Why does it circulate and not produce energy? Because a heat pump takes the heat from the surroundings and moves it to your pool water. This principle of operation makes them extremely efficient.

The Best type for:

• People who live in areas with consistently high temperatures. Unlike gas heaters or electric heaters, the heat pump moves the heat from the surroundings and this is what makes it more dependent on the environment; for high efficiency, the outside temperature should be consistently high — approximately 50°F.
• People who like to plan. Heat pumps compared to gas and electric heaters raise the water temperature slowly. This is due to the principle of operation — moving energy, not producing it. So, if you are more likely to plan your swimming sessions, a heat pump will be perfect for you.
• People who want to maintain constant water temperature. As a result of our research, we can safely say that heat pumps are the best choice if your goal is to maintain a set temperature. Heat pumps can work on low revs, this will maintain the perfect temperature and will not affect your electricity bill.

People who look for an alternative heating system. The heat pump is a very eco-friendly heater type, it can also be used in areas where solar heaters do not work well (e.g. due to shadow), but the air temperature is high.

3. Electric heaters

Both electric heaters and heat pumps need electricity to operate, but the difference is in the amount of energy that is required. Unlike a heat pump, electric heaters rely exclusively on electricity, they don’t take the heat from the surrounding. Here there is a common feature for electric heaters and gas heaters — both can operate effectively in any temperature and weather.

The Best type for:

• People who live in a cooler environment. Unlike heat pumps and solar heaters, electric heaters can raise the water temperature in any climate conditions, it just needs electricity to operate efficiently.
• Owners of small pools or hot tubs. Currently available on the market, models of electric heaters are made for small pools (less than 5,00 gallons) or hot tubs. A good example of an electric heater for small pools is the Hayward CSPAXI.
• People who want to heat water quickly. Perfect for an unplanned swimming session, an electric heater will raise the temperature to a comfortable temperature in the shortest time.
• People who can afford to pay higher electricity bills. Electric heaters consume a lot of energy to heat the pool, so be ready for high electricity bills if you plan to heat your pool frequently.

4. Solar pool heaters

The solar heater is the most eco-friendly type of heater. Solar heaters don’t have any monthly expenses, however, the initial cost can be high.

Solar heaters capture energy from the sun and transfer it to your pool, so the efficiency of the solar heater is highly dependent on climate features.

The Best type for:

• People who live in a sunny area. Solar heaters are more dependent on weather conditions than gas or electric heaters. Since solar panels should collect solar energy to heat the water, you should place the panels in the area most exposed to the sun; the best place will often be the roof.
• People who care about the environment. Solar heaters are the most eco-friendly type of heaters since they don’t need gas or electric energy to operate. They consume renewable energy (sunlight). As a result of running the heater, you won’t also have to deal with emissions in contrast to the use of gas heaters.
• People who look for an alternative to cut down on their operating expenses. Solar panels can serve as an additional source of energy to heat your pool’s water. For instance, you live in an area where there are a few sunny months, you can heat the water using solar panels, and at other times when you don’t get much sunshine, you can use another type of pool heater. This way, you can significantly cut down on the operating costs.

Accessories to prolong the lifespan and achieve maximum efficiency

The accessories listed below will enhance your pool heater experience, they will help to prolong the heater’s lifespan and save your money in the long run.

Pool cover

A pool cover is one of the best investments you can make for your pool.

The pool cover will extend the swimming season; it will increase the water temperature by 6-8°F. Also, the pool cover will reduce the heating expenses since it creates an insulation layer between the water and the air which doesn’t let the heat evaporate.

Using a pool cover has a lot of advantages, which don’t relate to the heating pool:

• Reduce evaporation. On average a pool loses 5 mm of water every day; if you use a pool cover regularly, you can reduce the loss of water up to 95%.
• Keep water clear. Debris such as leaves and insects will be kept out of your pool water thanks to a pool cover.
• Reduce the usage of chemicals. Chlorine is often used as a sanitizer for the pool. It evaporates under the sun’s UV rays. A pool cover will minimize the impact of UV rays on chlorine and this way you can use fewer chemicals.

Check valve

Every heater manufacturer includes a note in the user manual about the importance of a check valve to avoid corrosion of metal parts in the pool heater.

A check valve is essential if you use chlorine as a sanitizer since chlorine can damage the heater. A check valve is installed between a chemical feeder and the outlet of the heater. Without a check valve, the heater will be exposed to a dose of concentrated chlorine, and highly chlorinated water will damage your heater.

Programmable timer

This is a great tool to program the timing of your pool. The timer will help to achieve the desired temperature and maintain it automatically. Also, the programmable timer will save you a few dollars by turning the heater off when it isn’t required or when the desired temperature has been achieved.

The timer will also be useful if you live in an area with frequent power outages, it will make heating the water much easier.

FAQ