10 Best Pool Heaters 2026 in the United States

The Aquastrong Inverter Swimming Pool Heat Pump is a powerful and versatile choice for both above ground and inground pools up to 26,000 gallons. With a strong heating capacity of 100,000 BTU, it can quickly raise your pool temperature, making it a great option for larger pools or cooler climates. One standout feature is its dual-mode system, which not only heats but also cools the pool water, allowing you to enjoy comfortable swimming conditions across different seasons. The WiFi-enabled app control adds convenience, letting you adjust settings and schedule heating from anywhere.

Energy efficiency is a major plus here. The inverter technology means it uses less electricity than traditional heaters, boasting about 70% energy savings compared to electric resistance heaters and better efficiency than gas systems. This can save you money on energy bills over time. The unit also runs quietly at 55 decibels, which is roughly the noise level of a normal conversation, and includes an automatic defrost feature that keeps it working smoothly in cold weather.

Installation is designed to be user-friendly with multiple hose and pipe adapters included, fitting a variety of pool setups. The cast iron build suggests durability, and a 3-year warranty offers some peace of mind. On the downside, the unit weighs nearly 200 pounds, so installation might require professional help or extra effort. Also, it operates on 220 volts, meaning it needs the right electrical setup, which could add to installation complexity or costs. This heat pump is ideal for pool owners looking to extend their swim season with efficient, reliable heating and cooling, especially those with larger pools or who want smart control features, though they should be prepared for a somewhat involved initial setup due to size and electrical requirements.

The Hayward W3HP21405T HeatPro is a heat pump designed for heating pools with a strong 140,000 BTU capacity, which means it can warm a medium to large pool effectively. It uses a titanium heat exchanger, which stands out because it resists corrosion from saltwater and pool chemicals, making it a durable choice, especially if you have a saltwater pool or live near the coast. This model is also designed to operate quietly, so it won’t disturb your outdoor relaxation.

Energy efficiency is a key advantage here—this heat pump uses less electricity compared to traditional pool heaters, helping reduce your energy bills and environmental impact. It also uses less refrigerant, which is better for the environment. These features make it a smart option if you want to keep operating costs and your carbon footprint low.

The unit is fairly large and heavy (weighing 281 pounds), which might make installation a bit more involved, but it’s built to last with low-maintenance materials. It may not be the best fit if you live in very cold climates, as heat pumps generally work best in moderate to warm weather. While not the cheapest pool heater on the market, the energy savings over time can offset the initial investment. This model is a solid choice if you want a reliable, energy-efficient pool heater with quiet operation and good resistance to harsh conditions, but if you’re in a colder area or on a tight budget, you might want to explore other options.

The Hayward W3H400FDN Universal H-Series 400,000 BTU Natural Gas Pool and Spa Heater is a robust option for heating in-ground pools and spas. With a significant heating capacity of 400,000 BTU, it is well-suited for larger pools and spas, providing efficient and fast heating. The heater features a durable cupro-nickel heat exchanger that offers excellent protection against corrosion, which is essential for maintaining longevity and reliability, especially in areas with unbalanced water chemistry.

Its industry-leading hydraulic design is notable for reducing the circulation pump run time, leading to major energy savings and improved efficiency. Additionally, low NOx emissions ensure it meets air quality standards, making it an environmentally friendly choice. The heater's front-panel-only access and intuitive control pad design simplify operation, servicing, and maintenance, which is a plus for ease of use.

It is essential to consider that natural gas heaters can have higher operational costs due to fuel expenses compared to electric or solar options. The initial installation may also require professional help, adding to the cost. Weighing 195 pounds and measuring 39.6 x 32.8 x 30.6 inches, it requires adequate space and planning for installation. This heater is ideal for users needing a powerful, efficient, and reliable solution for heating large pools and spas, with the trade-off being higher operational costs and potentially higher initial setup complexity.