Extend your swim season, on top of a clean pool
Here's how the top-reviewed 2026 gas heaters and heat pumps compare on heating speed, running cost, and price.
Compare the top pool heatersQuick answer: Our top pick for pool heaters is the AQUASTRONG Inverter Pool Heat Pump (Best Value). If you're looking for best for mid-size pools, the Hayward W3H200FDN Universal H-Series 200,000 BTU Natural Gas Heater is a strong alternative.
A robotic cleaner keeps the water clear, but water temperature is a separate problem entirely — most unheated outdoor pools stay comfortably swimmable only a few months a year, and a single cool snap can end swim season well before summer is technically over. A dedicated pool heater adds real weeks or months of usable swim time on either side of peak summer.
Pool heaters split mainly into two types: gas heaters that heat fast regardless of outside air temperature but cost more per hour to run, and electric heat pumps that pull ambient heat from the air, cost far less to operate day to day, but heat more slowly and lose efficiency once air temperature drops. The right choice depends more on how many months a year you want to swim than on pool size alone.
| Product | Best For | Price | Rating |
|---|---|---|---|
| AQUASTRONG Inverter Pool Heat Pump | Best Value | $1,700 - $1,800 | 4.4/5 |
| Hayward W3H200FDN Universal H-Series 200,000 BTU Natural Gas Heater | Best for Mid-Size Pools | $3,400 - $3,600 | 4.5/5 |
| Hayward W3H400FDN Universal H-Series 400,000 BTU Natural Gas Heater | Best for Fast Heating | $5,000 - $5,200 | 4.6/5 |
| Hayward HeatPro 140,000 BTU Heat Pump | Best Energy-Efficient Premium | $6,500 - $7,000 | 4.6/5 |
An 80,000 BTU inverter heat pump for pools up to about 16,000 gallons, with smart WiFi control and both heating and cooling modes, priced well below most gas heaters of comparable capacity.
A 200,000 BTU natural gas heater with a low-NOx cupro-nickel heat exchanger, sized for mid-size in-ground pools that need faster heat-up than a heat pump can deliver.
The largest gas heater in this comparison at 400,000 BTU, built for large in-ground pools or anyone who wants to heat a full pool in the shortest possible time.
A 140,000 BTU electric heat pump with a titanium heat exchanger and digital controls, aimed at owners who want a premium, energy-efficient heating solution for a larger pool and don't mind the slower heat-up curve.
The AQUASTRONG Inverter Heat Pump (Best Value) is the most affordable way into a genuinely warmer pool.
The Hayward 400,000 BTU gas heater (Best for Fast Heating) heats the most water in the least time.