The Best Pool Heater of 2023: Reviews and Buying Guide

• Best overall: Hayward W3H150FDN H-Series 150,000 BTU Pool Heater
• Best natural gas: Raypak 336,000 BTU Pool Heater
• Best solar-powered: Smart Pool S601 Pool Solar Heaters
• Best electric: EcoSmart SMART POOL 27 Electric Tankless Pool Heater
• Best heat pump: Hayward W3HP21004T 95,000 BTU Pool Heat Pump
• Best for saltwater pools: Hayward W3H400FDN H-Series 400,000 BTU Pool Heater
• Best for cold climate: Raypak 406,000 BTU Pool Heater
• Best budget: Fafco Solar Bear Economy Heating System

Types of Products

• The pool size: You first should measure your pool's size to determine the suitable BTU (British Thermal Unit) output. BTU refers to the amount of energy it takes to increase the temperature of one pound of water by one degree F at sea level. It would help if you looked for the specs to see whether that heater is right-sized for your pool.
• BTU output: Most pool heaters have a BTU output of 150,000 to 400,000. You can approximate the BTU you need by multiplying the total water capacity in gallons by the weight of a gallon of water (8.3 pounds). The answer is how many BTUs you need to raise the pool's water by 1 degree (I will mark it as X).
  Then determine the difference between the target temperature and the coldest ambient air temperature. For example, you want to reach 80°F, and the coldest ambient air temperature is 60°F, the temperature difference will be 20°F.
  Multiply X by the temperature difference; you will get the approximate BTUs you expect to raise your pool temperature.
  Of course, you also have to calculate some objective factors like rainfall, evaporation, or sunlight, and the process will be complicated. Fortunately, you will see this information in the product's description.
• Solar, electricity, or gas: Gas pool heaters deliver outstanding performance but take a big expense to operate. Besides, this type of heater requires maintenance frequently and is harmful to the environment.
  Solar pool heaters use energy from sunlight to warm the water up, so they eliminate fuel usage. However, they take longer to heat your pool, and the performance depends on the amount of sunlight received. As a result, solar pool heaters are preferred in geographic areas where there're many sunny days.
  Electric pool heaters use electricity to heat the pools. They offer high performance and do not emit any pollutants. However, these machines eat much energy and extend your electricity bills.
• Pool compatibility: Some pool heaters are for inground pools, some are for above-ground pools. It's essential to choose the right one to avoid equipment malfunction and pool structure damage.
  Some swimming pools use salt water, which can damage unprotected inside components of the heaters. Fortunately, some models specialized for saltwater pools, like the Hayward W3H400FDN we're going to review below.

How we tested

Since each machine has a different BTU output, we divided these machines into appropriately sized pools. We tested for a period of 4 hours on each device and measured the water temperature every hour. We apply the approximate BTU calculation formula as mentioned in the buying guide section to see if the manufacturer's specifications are correct.

Besides, we also tried to test these machines in all weather conditions possible to assess the impact of external factors on the heaters' performance. As the engine ran, we measured fuel/power usage with electric and gas-powered machines and the sunlight absorption efficiency with solar-powered machines.

In addition, we also tested the hardware quality to predict durability and resistance.

Here are the 8 best pool heaters reviews for Your Pool at the Perfect Temperature.

1. Hayward W3H150FDN H-Series 150,000 BTU Pool Heater

Best pool heater overall

Today's best deal: Check Price on Amazon

Specification

• Power source: natural gas
• BTU: 150,000
• Pool type: inground
• Pool size: 400 sq.ft

Reasons to buy

• Easy-to-use control panel
• Consistent heating for every weather condition
• Performance: suitable for small and medium swimming pools

Reasons to avoid

• Must have access to propane and suitable plumbing

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Natural gas pool heaters are usually most suitable for those who set up a natural gas line in their house. With this Hayward W3H150FDN, you can extend the swimming season and enjoy the warm water.

This 150,000 BTU heater is sized right for 400 square feet pools, equalling about 13,000 gallons of water. If your swimming pool is larger, you can opt for other Hayward products that deliver better BTU output.

The outstanding feature that makes Hayward W3H150FDN different is the cupronickel heat exchangers. Cupronickel offers longer life and better durability than copper heating elements, which are more subject to corrosion.

2. Raypak 336,000 BTU Pool Heater

Best natural gas pool heater

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Specification

• Power source: natural gas
• BTU: 336,000
• Pool type: inground
• Pool size: not mentioned

Reasons to buy

• Powerful heater capacity
• Automatically turn on when the temperature is below the pre-set level
• Copper fin tube heat exchanger: better heat transfer
• LCD digital display

Reasons to avoid

• Must have access to natural gas and suitable plumbing

Check Price on Amazon

The Raypak 336,000 BTU Pool Heater has an electronic ignition that automatically turns the heater on when the temperature falls below the preferred temperature. You can set this feature on the microprocessor-controlled thermostat.

You can quickly keep track of the settings through an LCD digital display and make changes if necessary. The Raypak heater is compatible with most sizeable inground swimming pools and delivers 336,000 BTU.

The copper fin tube heat exchanger maximizes heat transfer, so the process of warming water will happen more quickly. That's the reason why it is best suitable for large pools.

3. Smart Pool S601 Pool Solar Heaters

Best solar pool heater

Today's best deal: Check Price on Amazon

Specification

• Power source: solar
• BTU: not applicable
• Pool type: inground
• Pool size: 288 sq. ft.

Reasons to buy

• Saving-energy solar heater
• Simple installation
• Affordable price
• Ability to increase the temperature by up to 15°F

Reasons to avoid

• Installation kit required and sold separately
• Requires 80 sq. ft. for solar panels

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Smart Pool S601 is a saving-energy solution for those who have a large roof or yard where you can install 80 square feet of solar panels. Those panels are made of durable polypropylene and have individually fed collector tubes.

It's pretty simple to install this solar heating system, and it can raise the temperature by up to 15°F. The solar panels have fiberglass reinforced headers and wind vents to protect them from windy weather. However, you have to pay an extra amount of money to buy the separate installation kit.

4. EcoSmart SMART POOL 27 Electric Tankless Pool Heater

Best electric pool heater

Today’s best deal: Check Price on Amazon

Specification

• Power source: electricity
• BTU: not applicable
• Pool type: inground and above-ground
• Pool size: 15,000 gallons

Reasons to buy

• Lower price than gas pool heaters
• Do not use gas or propane
• Simple installation

Reasons to avoid

• Increase the energy consumption
• The performance is not as high as gas heaters

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If natural gas resources are unavailable in your area and you don't want to get into trouble while monitoring the propane tank levels, you can opt for electronic options. EcoSmart SMART POOL 27 Electric Tankless Pool Heater can raise the temperature in the pool up to 1.5°F every hour.

The temperature management is simple, thanks to the digital thermostat control. You can keep track of and adjust the temperature as your preference.

This 240V unit requires three 40 amp breakers, so that you may need a large circuit board. Although you will not spend money on gas or propane, your electricity bill may be much higher as it consumes quite a lot of power.

5. Hayward W3HP21004T 95,000 BTU Pool Heat Pump

Best heat pump

Today’s best deal: Check Price on Amazon

Specification

• Power source: electricity
• BTU: 95,000
• Pool type: inground
• Pool size: small pools

Reasons to buy

• Quiet technology: reduce the noises
• Stainless steel hardware
• Durable, injection-molded, UV-resistant body panels
• High performance

Reasons to avoid

• High cost

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A heat pump uses ambient air to heat up swimming pool water. Because it uses the surrounding air to increase the water temperature, it's more economical than gas, propane, and electric heaters. This 95,000 BTU heat pump is suitable for small pools. There are also solutions for larger pools, which deliver up to 140,000 BTU.

The Hayward HeatPro series products are made of durable materials like the Ultra Gold corrosion-resistant evaporator fin (which works well in coastal environments), polyethylene screen, and stainless steel hardware. Furthermore, the fan blade is designed to optimize the airflow and reduce the noise rate during its operation.

6. Hayward W3H400FDN H-Series 400,000 BTU Pool Heater

Best for saltwater pools

Today’s best deal: Check Price on Amazon

Specification

• Power source: natural gas
• BTU: 400,000
• Pool type: inground
• Pool size: 1,200 sq. ft.

Reasons to buy

• High performance
• Corrosion protection
• Simple operation, service, and maintenance
• Low environmental impact

Reasons to avoid

• High cost

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Saltwater pools take a toll on mechanical devices because they cause corrosion. You can reduce this risk by choosing the components and equipment that are specially designed for saltwater.

This Hayward W3H400FDN pool heater has a cupronickel heat exchanger that is resistant to corrosion. Although it may cost higher than a copper heat exchanger, it offers durability and service life.

Moreover, you can easily adjust the pool's temperature through a digital thermostat, which can be tied in a remote system for convenient operation and control. The machine is also optimized for emitting low-NOx emissions, minimizing the environmental impact.

7. Raypak 406,000 BTU Pool Heater

Best pool heater for cold climate

Today’s best deal: Check Price on Amazon

Specification

• Power source: natural gas
• BTU: 406,000
• Pool type: inground
• Pool size: 1,200 sq. ft.

Reasons to buy

• Corrosion-resistant Polyester-coated cabinet
• Automatically turn on when the pool's temperature goes down below the pre-set
• High performance

Reasons to avoid

• Must have access to natural gas and suitable plumbing

Check Price on Amazon

You need a powerful pool heater in cold weather to supply enough energy to heat the water. Raypak 406,000 BTU Pool Heater is one of the most bright candidates as it has an excellent heating output of 406,000 BTUs. An electronic ignition system will automatically turn on the machine when the water falls below the pre-set temperature.

The LCD digital display shows the current temperature and allows you to adjust to your favorite level. The internal components are protected from water and moisture through a polyester-coated cabinet.

8. Fafco Solar Bear Economy Heating System

Best budget pool heater

Today's best deal: Check Price on Amazon

Specification

• Power source: solar
• BTU: not applicable
• Pool type: above-ground
• Pool size: small pools

Reasons to buy

• Affordable price
• Energy-efficient solar heating
• Simple installation

Reasons to avoid

• Only get the highest performance under strong sunshine (from 10 am to 4 pm)
• Not as strong as gas or electric pool heaters

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Above-ground pools require less energy to warm the water up. Hence, people usually use solar pool heaters like Fafco Solar Bear Economy Heating System. This machine comes with a single solar panel measuring 4 feet x 20 feet.

Fafco Solar heating system can be installed everywhere there is sunlight. The manufacturer suggests you position it on an angle of 10 to 30 degrees and face towards the South to optimize the heat collection.

1. Can I install the pool heater by myself?

It depends on your technical skills and knowledge. An experienced person can quickly install some heaters like solar pool heaters. However, things are never such that simple. You have to consider many factors like the type of pool heater, your house setup (such as whether your house has natural gas lines), the type of swimming pool, and so on.

Therefore, the best solution is to hire a professional to install the pool heating system to ensure it operates accurately.

2. Should I leave my pool heater working overnight?

You should turn off your pool heater at night if you don't want your gas or electricity bills longer. At night, the low temperature may drop the pool's temperature down, so the heater must work harder.

In case you want to swim in the morning, you can set the alarm and wake up early to turn on the heater. If you don't want to get up early, you must accept the higher cost you must pay for gas or power the machine consumes.

3. How long do I expect the pool heater to last?

Pool heaters typically have proper life spans from 5 to 10 years. You can extend this amount of time by appropriate installation and maintenance.

Final Thoughts

Swimming is one kind of entertainment that helps you release stress and do exercises. With the support of pool heaters, swimming in cold weather is no longer impossible. We always keep updating the latest information and reviews regarding garden and outdoor devices. We also give you multiple tips to take care of every part of your house. Keep following us to get the latest news!