The 5 Best Pool Heaters of 2021

Change the temperature of your pool without the hassle

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Our Top Picks
"Quickly raises pool temperatures and to extend the swimming season."
"A solar-powered pool heater that utilizes the sun's energy to warm your pool."
"The induced draft technology enables the unit to stay lit and operational."
"The manufacturer reports that it can raise water temperature by 10 degrees."
"Energy efficient and doesn't require the use of a fuel source."

Best Overall: Hayward HeatPro W3HP21104T Pool Heat Pump

Warm your pool with the powerful and popular Hayward HeatPro Heat Pump. This pool heater is engineered for quiet, powerful performance and features titanium heat exchangers for superior resistance to rust and corrosion.

The Hayward HeatPro stands out for its quiet operation—thanks to an acoustic compressor cover and a scroll compressor with profiled fan blades for reduced wind resistance and noise. Pool owners who prefer a serene setting or to enjoy lively conversation with friends and family will appreciate the fact that this pool heater doesn’t steal the show with noisy operation.

With 140,000 BTU of heating power, the Hayward HeatPro earns plenty of praise for its ability to quickly raise pool temperatures and extend swimming seasons. It’s not uncommon for this pool heater to raise pool temperatures by 15 degrees in a day or two at most. The Hayward HeatPro is more expensive than some other types of pool heaters, but it pays off in reliable, efficient heating and quiet operation.

Best Budget: SmartPool S601P SunHeater Solar Heating System

If you want to raise your pool’s temperature without springing a major leak in your finances, consider a budget pool heater. The SmartPool SunHeater system is a solar-powered pool heater that utilizes the sun’s energy to warm your pool gradually.

Using 80 square feet of solar panels with collector tubes fed by the pool pump, this solar panel pool heater works well to raise pool temperatures by at least several degrees—depending on sun exposure and weather conditions. The biggest downsides frequently noted are that the system doesn’t come with much instruction and is highly dependent on solar exposure.

Something to keep in mind when setting up the system is that users warn against diverting the full flow from your pool pump through these solar panels, since the water pressure can dislodge the solar panels if the flow is too strong. The system works well for both in-ground and above-ground pools.

Best for Above Ground Pools: Hayward H-Series 100,000 BTU Propane Above Ground Pool Heater


If you want to take the chill off your above ground pool, consider a pool heater specially made for this purpose. The Hayward H100ID1 Above Ground Pool Heater is available in either natural gas or propane configurations and can raise the temperature of your pool water in just a few hours.

The slim unit measures just over two feet long and has a slim profile of only 21 inches. A 120V electrical cord plugs into a standard outlet and set up is simple according to users. The induced draft technology enables the unit to stay lit and operational even under fairly windy conditions.

People are satisfied with the performance of this above ground pool heater, though some warn that the unit experienced malfunction after the initial 1-year warranty ended. The Hayward H100ID1 is recommended for above ground pools that are 450 square feet or less in size.

Best Electric: Ecosmart US SMART POOL 27 Electric Tankless Pool Heater

Electric pool heaters are a popular choice if you lack a natural gas line or want to skip the hassle of keeping propane on hand for your pool heater. Also called tankless pool heaters, the other advantage of these units is their space-saving design—making them good for large or small pools. The Smart Pool series by EcoSmart offers fast and efficient heating of pools up to 15,000 gallons.

If you opt for an electric pool heater, keep in mind the required voltage to properly and safely install the heater. The Smart Pool heater requires service from a 200 amp electrical panel, and you’ll need to connect it to two or three 50 amp breakers (depending on the model you choose). All that power means it can heat fast—with the manufacturer reporting that it can raise water temperature by 10 degrees in a 15,000 gallon pool in as few as 13.5 hours.

Satisfied users of the Smart Pool electric pool heater frequently describe the unit as small and silent. It stands out for being so compact and it’s also easy to operate, thanks to a digital control panel that lets you set precise target temperatures for your pool. While some people complain about long-term reliability after the initial few years of use, others are quick to point out that, this is an affordable option for an electric pool heater that will be around just as long as many heat pumps that cost three times as much.

Best Heat Pump: Pentair UltraTemp High Performance Heat Pump


Heat pumps are a popular type of pool heater since they are energy efficient and don’t require the use of a fuel source—like natural gas or propane. The UltraTemp Heat Pump from Pentair is a practical choice if you’re looking for a swimming pool heat pump.

This pool heater is one of Pentair’s EcoSelect pool heaters, meaning that it’s engineered to conserve energy and also uses an eco-friendly refrigerant (R410A) that doesn’t deplete ozone. It’s also economical to operate, with well-engineered parts to maximize efficiency—like a titanium heat exchanger and scroll compressor.

A unique feature of the Pentair UltraTemp is its ability to maintain target pool temperatures with both a heating and cooling function. In especially hot climates, it’s convenient to have a unit that does double duty to cool your pool down a few degrees when intense sun might make your pool anything but refreshing.

Just know that the condensation that routinely occurs with a pool heat pump may lead to some water runoff. One user noted this as a potential con, but it’s commonly seen with all heat pumps and is a tradeoff for the lack of fuel required from a compressor-powered heat pump.

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