Our best overall pick is the Hayward W3H150FDN Universal H-Series Heater, which stands out for its durability, longevity, and effectiveness. Here are the best pool heaters on the market. The W3H150FDN model works solely with natural gas. Gas tends to be the most convenient option since many homes already have a natural gas line. In contrast to solar models, this 150,000 BTU (British Thermal Units) heater can warm your 400 square foot pool in record time, so you won’t have to wait too long to enjoy your outdoor spa. Though gas heaters are generally less energy-efficient, the manufacturer reports that this model’s quick pump operation can reduce energy costs by 18 percent. As for lifespan, this heater outshines the competition with its cupronickel heat exchanger. This system effectively protects against corrosion and water chemistry imbalances that can cause premature system failures. Cupronickel is also known to be durable and more long-lasting compared to copper. While you may find more efficiency and savings elsewhere, it’s hard to beat the Hayward Universal H-Series’ quick operation and longevity. With this explanation in mind, it’s easy to see that this is a great option for low-energy pool heating, but it may not be the quickest way to heat a swimming pool. The number of solar panels you choose to install for your pool and the amount of sun received will play a big factor in determining whether or not this type of pool heater can meet your expectations. The SmartPool Solar Heater includes a single panel array that is 4 x 20 feet. You can purchase and connect multiple solar panels to create a solar heater large enough for your swimming pool. While purchasing multiple panels, plus the necessary installation kit, may feel like an investment, it’s worth noting that you’ll incur no additional costs from gas or electricity when using this solar pool heater. Sized for pools up to 15,000 gallons, the EcoSmart Pool 27 uses a flow sensor to prevent element burnout. This is a 240V unit and it requires three 40 amp breakers for installation, so keep that in mind when determining whether or not you have the space required on the circuit board. While you won’t spend any money on gas or propane when using this electric pool heater, you can expect that it will cause an uptick in your energy usage. A big advantage of the EcoSmart Pool 27, though, is its price point. At less than $1,000, it’s significantly more affordable than many gas pool heaters on the market. Hayward designed the HeatPro series of pool heat pumps to be durable and quiet, especially in comparison with some gas pool heaters. For example, the stainless steel fan blade is profiled to improve airflow efficiency while also reducing the noise factor during operation. An acoustic compressor cover also helps to dampen noise produced by this pool heater. Since this type of pool heater is especially popular in warmer climates that often come with increased humidity, a corrosion-resistant evaporator fin and titanium heat exchanger helps to extend the service life of this pool heater. A copper fin tube heat exchanger is typical for many gas pool heaters. However, Raypak adds an additional layer of protection against corrosion of this important component by adding a special component to the header, known as a ProTek shield. This module is intended to absorb corrosive materials before they reach the heat exchanger. As a result, it’s intended to break down over time, but is easy to replace, and protects the heating element inside. In addition, this model is equipped with an electronic ignition that only fires when heat is needed. In comparison to a millivolt pool heater, which requires a pilot light to be lit at all times and burns fuel continually, the electronic ignition is more efficient and economical in terms of fuel consumption. however, this gas pool heater will need a nearby 120V or 240V power source. This frills-free model includes an analog dial to set the target water temperature. Other pool heaters on the market often have an LCD display with digital temperature control, but this version relies on a turn-knob to adjust temperature settings. Inside the unit, Raypak has equipped this model to have a long life of service. Stainless steel burners and a copper fin tube heat exchanger are designed for durability despite wet working conditions. Some in-ground pool heaters are too powerful for above-ground pool set-ups. Save money and protect your pool from damage by choosing an above-ground pool heater, like this model from Pentair. The MasterTemp series features natural gas or propane pool heaters that offer efficient, reliable heating for above-ground pools. It has an 82 percent efficiency rating, meaning that only 18 percent of the energy produced is lost to the atmosphere and the rest is used to warm your pool. The Pentair MasterTemp 125 is a low NOx (nitrogen oxide) pool heater, making it eligible for installation even in areas with strict emissions guidelines. It plugs into a 120V electrical outlet and features electronic ignition to eliminate concerns of a standing pilot light. The Raypak PR236AENX51 is equipped with a cupronickel heat exchanger, along with Raypak’s ProTek shield that acts as a buffer against corrosion of your heat exchanger. The digital thermostat makes it easy to adjust the pool temperature to your preferences, and it can be tied into a remote system for convenient and automated control of your pool. The AquaCal SQ120R stands out as a heater and chiller combo for pools with smart features, like the ability to control the unit with the PoolSync app. Switch between heating and cooling modes or set the unit to keep your pool at a constant temperature with the Autotemp mode. You will need to buy a separate PoolSync WiFi Controller if you want to take advantage of this feature. In addition, this 2-in-1 pool heater is designed to withstand the elements. AquaCal has developed a special louvered top that allows for efficient airflow to the heat exchanger inside while minimizing the debris that enters the housing of the pool heater. A patented titanium heat exchanger is another standout feature of this pool heater and chiller combo. Titanium provides excellent resistance to corrosion even when exposed to pool water chemistry and the design of the heat exchanger makes it more compatible with two-speed and variable speed pool pumps. Some manufacturers of pool heaters create a calculator that can help you to quickly and easily match your pool to the right size pool heater. For example, Raypak’s pool heater calculator uses your zip code, pool size, and swimming season months to help you compare energy costs when choosing different size pool heaters.
BTU Output
Every pool heater will provide you with a BTU output rating. Most units range between 150,000 and 400,000 or more BTUs. A BTU (British Thermal Unit) is the measure of how much energy is required to raise the temperature of 1 pound of water by 1 degree Fahrenheit. You can approximate what type of BTU heater you need for your pool by multiplying your pool’s water capacity in gallons by the weight of a single gallon of water (8.3 pounds). The answer is the number of BTUs you need to raise the pool water by 1 degree. Of course if you’re looking for a larger rise in pool temperature than that, a few more calculations are needed. Determine the difference between your target pool temperature and the coldest ambient air temperature. For example, assume overnight air temperatures are 60 degrees Fahrenheit and you want your pool to reach 80 degrees Fahrenheit. This is a temperature difference of 20 degrees. Multiply how many BTUs are needed to raise your pool temperature 1 degree by the temperature difference. This is an approximation of the total BTUs that will be expended to raise your pool temperature. Divide by the time you expect your pool to reach target temperatures—often 24 hours, but it can be longer or shorter. Then, you have a rating of what BTU you should look for in a pool heater. Keep in mind, though, that other factors like the use of a solar cover, the amount of direct sunlight received, rainfall, evaporation, and more can impact the performance of a pool heater.
Solar vs. Gas
While gas pool heaters are popular for their superior efficiency, the biggest expense of operating these heaters is the natural gas or propane required for them to function. In addition, propane heaters may require tank refill or replacement regularly to ensure continued operation. Solar heaters eliminate the need for fuel altogether, since they use absorbed energy from the sun to raise the temperature of the pool water. However, it can take longer to heat your pool using a solar pool heater, and the performance of this type of pool heater is directly dependent on the amount of sunlight received. This makes solar a great choice for geographic areas with many sunny days, but a less efficient option in areas with more cloud cover.
Pool Compatability
Most pool heaters are intended for heating in-ground pools. Some models are designed to also be used for heating above-ground pools. However, it’s important to make sure that you are buying a pool heater that will be safe and effective for the type of swimming pool that you have. Otherwise, you may experience equipment malfunction or damage to your pool structure. If you have a saltwater pool, you’ll also need to consider whether or not the pool heater you’re considering is compatible. Technically, you can use any type of pool heater in a saltwater pool, but the heater may suffer from corrosion and impaired performance more quickly if it’s not intended for use in saltwater. This is because many pool heaters have copper heating elements inside. The salty water can eventually cause rusting of the interior components. A pool heater with a cupronickel heat exchanger is better protected against the corrosive nature of saltwater and is a better choice for this type of pool.
Why Trust The Spruce
This article was written by Erica Puisis, a home and lifestyle writer who has been researching the latest products for indoor and outdoor living for The Spruce since 2017. To compile this list, she considered a model’s heating capacity, components, power source, and price, along with each manufacturer’s reputation and reliability.
