Best Pool Heaters of 2021

Why are you interested in a pool heater? Do you dislike swimming in a cold pool? Perhaps to make the pool season last longer. Whatever your motivation, you have a variety of options to pick from. Knowing how they work, determining the correct size for your pool, and understanding the benefits and drawbacks of each is crucial to making the best decision. You should also consider how much money you will spend or save.

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What options are available?

Pool heat pumps, solar heat pumps, and gas heat pumps are the three basic forms of these systems.

Heat Pumps

A heat pump pool heater is still considered electric because it runs on electricity. The distinction is that it doesn’t use electricity to generate heat; instead, warm air is used to heat the water as it goes through the pump.

Solar Heaters

Pumping the pool water through the filter and then through the solar collector is how solar heaters function. The water is heated there before being poured back into the pool. There are two types of solar heaters: glazed and unglazed. Unglazed heaters are typically used in pools where the temperature never drops below freezing, while glazed heaters are preferred in colder areas because they are more durable.

Gas Heaters

A gas pool heater uses gas or propane to heat the copper coils by running water through a combustion chamber that burns the gas. Before returning to the pool, the water passes through these warm copper coils.

When it comes to picking a pool heater, there are more factors to consider than just the upfront expenditures, because each one has its own set of maintenance costs.

Cheapest Type of Pool Heater to Operate

A gas model is normally the least expensive to purchase, but if natural gas or propane prices are high in your area, it may wind up costing you more every month.

Low NOx

NOx (or nitrogen oxides) is a byproduct of combustion when nitrogen is present (as it is in the air we breathe) and high temperatures are present. Low NOx indicates that the emission created is limited when looking for heaters. For commercial uses, some portions of the country, such as most of Southern California counties and some counties in Texas, mandate Low NOx emission heaters. Select brands, such as Raypak, make some Low NOx versions, while others, such as Pentair, make all of their heaters Low NOx.


When buying a heater for a commercial property, the heater must pass a set of tests in order to be suitable for commercial use. The approach and design through which we determine if the heater is suitable for commercial usage is ASME (American Society of Mechanical Engineers). These heaters usually have a more powerful heat exchanger as well as glass-lined metal headers.


Copper heat exchangers are used in all gas heaters. Although copper is an excellent heat conductor, it is extremely prone to abrasion due to its soft nature. The Cupro-Nickel heat exchanger was designed with salt pools and pools with tough water in mind. These heat exchangers are made of copper that has been nickel plated to make them more resistant to the salt’s abrasiveness. These sorts of heaters are highly suggested for warranty purposes if you have a salt pool. It’s also an excellent overall investment for a heavier-duty heat exchanger.

Compatibility with Automation

Regardless of brand, most heaters are compatible with most automation systems. The temperature is set at the heater when it is installed (typically 100-104 F for spas and 75-85 F for pools). Once the heater is connected to automation, the system will use a sensor to instruct the heater to switch on. The functionality will vary depending on your heater, pool setup, and automation system, but the key benefit is being able to set the temperature using the automation system.

To assist you in finding the ideal heater for your pool, we’ve compiled a list of some of our top pool heaters.

Best Propane Pool Heater: Editor’s Pick

Hayward H400FDN

This heater is extremely durable and dependable. Unbalanced water chemistry causes corrosion, which the cupro nickel heat exchanger guards against. It also saves a lot of energy and emits very little NOx, allowing it to meet air quality criteria.

The Hayward H400FDN, with 400,000 BTUs of heating output, can heat just about any pool of any size. While your gas bills may go up, they will still be lower than alternative heating systems because the system is built for very low emissions and efficient operation.

Best Natural Gas Pool Heater: Editor’s Pick

Raypak 206,000 BTU Digital Electronic Ignition Natural Gas Pool Heater

For temperature selection and heater settings, this heater has a digital control panel (LCD). It’s a space-saving pool heater with outstanding efficiency.

Because of its small size, it is suitable for both inground and above ground pools. A digital thermostat dial is included with the Raypak.

Lighting the pilot is simple and safe thanks to a soft-opening gas valve, and the system provides consistent and quick heat. The corrosion-resistant thick-walled copper heat exchanger has an integrated bypass valve that balances the flow and adjusts for a wide range of pump sizes and flow rates. A one-year warranty is included.

Best Pool Heat Pump: Editor’s Pick

Hayward W3HP21404T HeatPro 140,000 BTU Pool Heat Pump for In-Ground Pools

A contoured fan blade and an ultra quiet acoustic compressor cover provide efficient performance. Furthermore, the titanium heat exchanger is built for optimal heat transfer, efficiency, and dependability.

This Hayward pool heat pump produces 140,000 BTU for consistent, uniform heating and is designed for optimal heat transmission, efficiency, and reliability. It has titanium counter-flow heat exchangers for optimum performance, even in the harshest of environments. It also boasts stainless steel hardware and heavy-duty, whisper-quiet scroll compressors.

Its UV-resistant injection-molded body panels are resistant to rust and degradation. The evaporator fin is also resistant to corrosion. Its spherical shape allows it to pass through gats with ease and takes up less room on an equipment pad.

Best Solar Pool Heater: Editor’s Pick

This solar pool heater has 80 square feet of solar panels that boost pool water temperature. This pool heater system may be put on a roof with just 80 square feet of solar panels. The polypropylene heat collector boosts the pool water temperature by 6 to 10 degrees Fahrenheit (4 to 6 degrees Celsius). An installation kit is required for this system, which is supplied separately.

Best Pool Heat Pumps in 2021

Best Overall: 

FibroPool FH055 Inground Swimming Pool Heat Pump
“Clean electricity, weather-proof case, easy set digital display.”

Best Budget: 

AquaCal Tropical T90 Pool Heat Pump
“Eco-friendly refrigerant, microprocessor-controlled automatic defrost.”

Quietest Pool Heat Pump:

Puri Tech Quiet 127k BTU Pool Heat Pump
“QZ Quiet Technology saves up to 2,000 dollars a year.”

Best for Above Ground Pools: 

AquaPro VIGOH77 Pool Heat Pump
“Heat an above-ground pool to 24,000 gallons, easy installation.”

Best for Inground Pools: 

Hayward TRANE Pool Heat Pump
“Self-diagnostic codes monitor, easy installation, convenient drop-in replacement.”

Best for the Money: 

FibroPool FH120 Above Ground Pool Heat Pump
“Most energy-efficient, easy-set digital panel, enamel-coated steel chassis.”

Best for Cold Climates: 

Pentair 460932 UltraTemp Heat Pump
“Automatic defrost feature, 60-Hertz frequency, 50-ampere breaker size.”

Best Electric Pool Heat Pump: 

Zodiac EE2500T EE-Ti Digital Titanium Pool Heat Pump
“Built-in by-pass flow assembly, programmable features for pool and spa.”

Most Efficient: 

Hayward HP50HA Fan Pool Heat Pump
“Built-in thermostat, equipped with a water pressure safety switch.”

Best Warranty: 

AquaCal TropiCal T115 Pool Heat Pump
“AquaCal’s extraordinary 7-year warranty, hybrid functionality.”

Best Rated: 

Hayward W3HP HeatPro BTU Pool Heat Pump
“Heavy-duty, super-quiet scroll compressors, titanium heat exchanger.”

Best for Small Pools: 

FibroPool FH220 Swimming Pool Heat Pump
“Lightweight, compact for small pools and spas with 20,000 BTU, 4.85 COP.”

Best Pool Heaters in 2021