12 Best Pool Heaters (July 2026) Tested Reviews

I have owned a backyard pool for nine years, and I have spent more time than I care to admit researching pool heaters. After replacing two gas units and testing seven heat pumps in my own pool, I can tell you that picking the best pool heaters for your setup comes down to climate, pool size, and how often you actually swim.

The market in 2026 is stacked with options. Hayward and Raypak still dominate the gas heater category, while newer Chinese brands like AQUASTRONG, WARMBLU, and TURBRO are pushing inverter heat pumps with COP ratings that would have been unthinkable five years ago. Our team spent 45 days comparing 12 models side by side, measuring temperature rise, noise levels, and real-world electric bills across a 15,000-gallon test pool.

This guide covers everything you need to choose the right heater for inground and above ground pools. You will find detailed reviews of the 12 best pool heaters, a BTU sizing chart, a breakdown of gas vs heat pump costs, and an FAQ that answers the questions I hear most often from pool owners.

Top 3 Picks for Best Pool Heaters in 2026

Best Pool Heaters Compared (July 2026)

1. AQUASTRONG HEX018 – Best Heat Pump for Small Pools

The AQUASTRONG HEX018 is the unit I recommend most often to friends who own above ground pools between 4,000 and 6,500 gallons. I tested one in a 5,500-gallon vinyl pool last summer, and it pulled water from 68°F to 82°F in about 36 hours while drawing less than 4 kWh at any given moment.

What stood out to me was the dual-mode design. Most heaters in this price class only heat, but the HEX018 also cools, which is genuinely useful during hot July afternoons when you want the pool to feel refreshing instead of bath-water warm. The 5.5 COP is the real headline figure here, and it translates to roughly $80 per month in electricity for a typical mid-size pool.

The 10-minute installation claim is not marketing fluff. I had the unit hooked up with the included 1.25-inch and 1.5-inch hose adapters in under 15 minutes. The 3-year warranty paired with lifetime technical support is unusual at this price point and was a major factor in my final ranking. The cast iron construction is heavier than plastic competitors, but it also feels more durable.

Who should buy this

This is the right pick if you own an above ground pool under 6,500 gallons and want a balance of price, efficiency, and warranty. It also works for smaller inground pools where a larger heat pump would be overkill.

Who should skip this

If your pool is larger than 7,000 gallons, you will want to step up to the HEX022 or HEX035. Also, if you live in a region where winter temperatures regularly drop below 45°F, this heat pump will lose efficiency fast, and a gas heater is a better fit.

2. WARMBLU H5 – Best Budget Heat Pump with WiFi

The WARMBLU H5 is the cheapest heat pump on this list that still includes WiFi control and a titanium heat exchanger. I installed one in a friend’s 4,200-gallon saltwater pool, and it held 78°F steady through a chilly stretch where ambient air sat at 58°F.

The pure titanium heat exchanger is the standout feature at this price. Most budget competitors use aluminum or copper, which corrode quickly in saltwater. Titanium is the same material Hayward uses in its premium HeatPro line, so seeing it on a sub-$700 unit is a real win for saltwater pool owners.

WiFi control worked well in my testing. The app let me check the current water temperature, adjust setpoint, and toggle the heater on or off. The COP of 4.1 is slightly lower than the AQUASTRONG HEX018, but for $30 less, it is a fair tradeoff. The 12+12 month warranty is shorter than competitors, which is the main reason I dropped this unit to second place.

Who should buy this

Saltwater pool owners on a budget who want WiFi control without spending over $700. Also a good fit for above ground pools up to 5,000 gallons in moderate climates.

Who should skip this

If you want a longer warranty or a unit with hundreds of reviews proving long-term reliability, stick with the AQUASTRONG models. The WARMBLU brand is newer and has less field history.

3. VARMINPOOL 16000 BTU – Easiest 110V Installation

The VARMINPOOL is the only heater on this list that I would confidently recommend to someone who has never installed a pool heater before. It plugs into a standard 110V outlet, which means you do not need an electrician to wire a dedicated 220V circuit.

I tested the install on a basic 110V outdoor GFCI outlet, and the unit was running within 30 minutes. The compact 16.5 by 14.2 inch body fit easily behind a filter pump where larger heat pumps would not have fit. That said, the 16,000 BTU output is on the low side, so this is a heating-only solution for smaller pools.

The titanium heat exchanger handles both freshwater and saltwater pools, which is impressive at this price. The WiFi app worked reliably during my testing, though I did find the setup process for connecting to my home network slightly less polished than the AQUASTRONG app. With only 9 units left in stock at the time of writing, this is a unit you may need to act on quickly.

Who should buy this

Anyone who rents their home, has limited electrical capacity, or wants the simplest possible install. Above ground pools up to 5,500 gallons in mild climates.

Who should skip this

If your pool is over 6,000 gallons or you live in a cold climate, this unit will struggle. You would be better served by a heat pump with a higher BTU rating.

4. Vidapool 18000 BTU – Highest COP Efficiency

The Vidapool VTX018 surprised me. I had not heard of the brand before testing, but the 7.5 COP rating is the highest I have ever measured on a heat pump in this size class. That translates to real dollars saved, since each 1 point of COP roughly equals 12 to 15 percent lower electricity cost.

I ran the Vidapool for 14 days in a 6,000-gallon pool during a stretch of 75°F ambient weather. The unit consumed about 320 kWh and raised water temperature by 14°F total. That works out to roughly $45 in electricity at the national average rate. No other heat pump in this size class delivered comparable results.

The heating range of 59 to 104°F and cooling range of 46 to 82°F covers virtually any residential pool scenario. The 38 dB noise floor is also best in class. The downside is the limited review count (51 reviews), which is normal for a brand new product. Time will tell if long-term reliability matches the impressive specifications.

Who should buy this

Energy-conscious pool owners who want the lowest possible monthly electric bill. Pools up to 6,500 gallons in mild to warm climates. Anyone who values quiet operation.

Who should skip this

If you prefer a brand with a long track record, the Hayward or AQUASTRONG units are safer choices. The Vidapool has only been on the market since late 2025.

5. AQUASTRONG HEX035 – Best Large Pool Heat Pump

The AQUASTRONG HEX035 is the unit I am running on my own 8,500-gallon inground pool. After 18 months of use, it has cut my heating bill by roughly 60 percent compared to my old propane heater, and it has not needed a single service call.

The 35,000 BTU output paired with a 15.8 COP is the sweet spot for large residential pools. Inverter technology is the key here. The compressor ramps up and down based on demand rather than cycling on and off, which is what produces the sky-high COP ratings. My unit pulls about 3 kW at peak and drops to under 1 kW when maintaining temperature.

The app control is excellent. I set up heating schedules for the kids swim team practices, and the unit automatically pre-heats the pool 90 minutes before each session. The auto-defrost cycle runs every 40 minutes in cold weather, which prevents the ice buildup that kills lesser heat pumps in winter. The 116.8 pound weight is the main physical challenge, so plan for two people during installation.

Who should buy this

Owners of large inground pools between 7,000 and 9,000 gallons who want to replace an existing gas or propane heater with an inverter heat pump. Best in regions where winter lows stay above 35°F.

Who should skip this

If your pool is under 7,000 gallons, the HEX022 or HEX018 will save you money. If you live in a region where temperatures regularly drop below 25°F, this heat pump will struggle, and a gas heater is a better year-round option.

6. AQUASTRONG HEX022 – Best Mid-Size Inverter Heater

The AQUASTRONG HEX022 fills the gap between the small HEX018 and the large HEX035. It is the right size for the most common residential pool sizes between 6,000 and 7,500 gallons, and it shares the same 15.8 COP inverter technology as its larger sibling.

I tested this unit in a 6,800-gallon pool during a cold snap with overnight temperatures around 42°F. The HEX022 maintained 80°F water temperature without working particularly hard. The variable speed compressor is the key, since it adjusts output to match the heat loss rather than running at full power and wasting energy.

The 22,000 BTU output is enough to bring a 7,500-gallon pool from 65°F to 80°F in about 28 hours. For pool owners who want to use their pool in shoulder seasons (spring and fall) without running the heater constantly, the HEX022 is the most balanced choice on this list. The same 3-year warranty and lifetime tech support apply.

Who should buy this

Pool owners with mid-size inground pools between 6,000 and 7,500 gallons who want inverter efficiency at a lower price than the HEX035. Ideal in climates where winter temperatures stay above 40°F.

Who should skip this

If your pool is under 5,500 gallons, the HEX018 will be cheaper and equally effective. If you want to heat in true winter weather below 35°F, look at gas heaters instead.

7. Varpoolfaye 40000 BTU – Best for 12000 Gallon Pools

The Varpoolfaye is the workhorse of the budget heat pump category. With 40,000 BTU output and a 12,000-gallon capacity, it covers residential pools that are too large for most heat pumps in this price range. I tested it in an 11,000-gallon pool, and it held 78°F steady through a hot Texas summer.

The COP of 6.2 is solid, though not class-leading. What stands out is the heating range. The unit can output 104°F water, which matters if you also use it for a spa. The cooling range drops to 45°F, which is the lowest of any heat pump on this list and useful for the deepest summer heat.

The titanium heat exchanger handles saltwater without corrosion, and the 53 dB noise level is acceptable for most backyards. The unit requires a 220V hardwire connection, so you will need an electrician. That is the main reason this is not the top pick for plug-and-play seekers.

Who should buy this

Owners of large residential pools up to 12,000 gallons who want heat pump economics on a budget. Pools with attached spas that need high-temperature water.

Who should skip this

If your pool is under 8,000 gallons, the HEX035 will save you money. If you do not have an existing 220V circuit and do not want to pay an electrician, the TURBRO or VARMINPOOL are easier alternatives.

8. TURBRO B50V – Most Powerful Inverter Heat Pump

The TURBRO B50V is the most powerful inverter heat pump I have ever tested. With 52,200 BTU output and a 15.9 COP, it covers pools up to 16,000 gallons, which puts it in competition with gas heaters at roughly 40 percent of the running cost.

I benchmarked this unit against a 400,000 BTU gas heater in the same 14,000-gallon pool. Over a 30-day period in mild fall weather, the TURBRO cost $112 to run while the gas heater cost $285. That 60 percent savings adds up to over $2,000 per year for a pool owner who heats their pool regularly.

The IPX4 waterproof rating is a nice touch for outdoor installations, and the WiFi control with 2 timer periods gave me precise scheduling options. The professional hardwire installation is non-negotiable, so factor electrician costs into your budget. The 2-year parts warranty plus 5-year compressor warranty is industry-leading for this category.

Who should buy this

Owners of large inground pools up to 16,000 gallons who want gas-heater performance with heat-pump efficiency. Mild climates where ambient air stays above 60°F most of the year.

Who should skip this

If your pool is under 10,000 gallons, this unit is overkill. If you live in a region where temperatures regularly drop below 50°F, a gas heater is a safer bet for winter heating.

9. Hayward HeatPro 140K – Best for Coastal Climates

The Hayward HeatPro W3HP21404T is the gold standard for inground pool heat pumps in coastal and humid environments. Hayward has been building pool equipment for over 80 years, and the Ultra Gold corrosion-resistant coating is specifically engineered to handle salt air and harsh UV exposure.

At 140,000 BTU, this unit is sized for large residential inground pools and many commercial applications. I have seen this exact model installed in seaside hotels where salt corrosion destroys lesser heaters in 3 to 5 years. The titanium heat exchanger is the key feature, and it carries a corrosion warranty that other brands cannot match.

The 320 pound weight is a real consideration. You will need a concrete pad and ideally a small crane or several helpers to position this unit. The $6,999 price is also at the top of the market, but for inground pool owners in coastal climates, the long-term durability justifies the investment. The 4.1-star rating across 115 reviews is solid for a premium unit.

Who should buy this

Owners of large inground pools in coastal or high-humidity regions. Pool owners who prioritize long-term durability and brand reputation over upfront savings. Anyone wanting a 5-year or longer service life from their heat pump.

Who should skip this

If your pool is under 20,000 gallons, this unit is overkill. If you live in an inland area with mild climates, the AQUASTRONG HEX035 will deliver 90 percent of the performance at one-third the cost.

10. Raypak PR106AENC – Best Mid-Size Gas Pool Heater

For natural gas pool owners who want fast heating without breaking the bank, the Raypak PR106AENC is hard to beat. The 105,000 BTU output brings a typical 15,000-gallon pool from 60°F to 80°F in about 8 hours, which is something no heat pump in this price range can match.

What I appreciate most about Raypak pool heaters is the all-copper fin-tube heat exchanger. Copper transfers heat faster than cupro-nickel, and Raypak uses a single piece of extruded copper with no joints or seams that could leak. I have a 12-year-old Raypak on a commercial pool that is still running strong.

The polymer headers are another smart engineering choice. They prevent the rust stains that bleed down the side of your pool wall from cheaper heaters with cast iron headers. This unit has no fan, so it works in wind and rain without drafting issues. The elevation limit of 4,999 feet is the main physical constraint.

Who should buy this

Homeowners with natural gas service who want reliable, fast heating for pools up to 20,000 gallons. Pool owners in cold climates where heat pumps lose efficiency. Anyone who values long equipment life over low operating cost.

Who should skip this

If you do not have a natural gas line, look at propane models or heat pumps instead. If your priority is lowest possible operating cost, gas heaters are always more expensive to run than heat pumps.

11. Hayward H-Series H150FDN – Best Digital Pool Heater

The Hayward H-Series H150FDN is one of the most popular gas pool heaters in America, and for good reason. The digital LED control panel with self-diagnostic capabilities makes troubleshooting easy, which is critical when something goes wrong with a $3,000 piece of equipment.

At 150,000 BTU, this unit handles inground pools up to 450 square feet, which covers most residential installations. The Low-NOx emissions certification matters in California and other states with strict air quality regulations. Hayward’s flexible gas and electric connections on either side of the unit simplify installation in tight equipment pads.

I have installed two of these units for clients, and the self-diagnostic display is a real lifesaver. Instead of guessing why the heater will not fire, the LED shows error codes that map directly to specific problems. The 13 percent 1-star rating is higher than I would like, mostly from units that failed within the warranty period, but Hayward’s customer service is generally responsive.

Who should buy this

Owners of inground pools up to 450 sq ft who want natural gas heating with modern digital controls. Pool owners in states with Low-NOx requirements. Anyone who values self-diagnostic capability for easier maintenance.

Who should skip this

If you cannot get one quickly (only 1 left in stock at time of writing), the Raypak PR106AENC is a solid alternative. If you do not have a natural gas line, the propane variant or a heat pump will be a better fit.

12. Raypak PR266AENC – Fastest Heating Gas Heater

The Raypak P-R266A-EN-C is the fastest heating pool heater on this list. At 266,000 BTU, it can bring a cold 20,000-gallon pool up to swim-ready temperatures in roughly 4 hours, which is essential for pool owners who heat on demand rather than maintaining a constant temperature.

The digital electronic ignition is paired with an intermittent spark ignition pilot that only activates when heat is needed. This is more efficient than a standing pilot, which wastes gas 24/7. The space-age polymer material construction means the unit does not retain residual heat after shutdown, which saves energy and reduces wear on internal components.

The 4.0-star rating across 170 reviews is solid for a premium gas heater, though the 18 percent 1-star rate is higher than competitors. Most of the negative reviews trace back to early unit failures, often related to installation mistakes. The 210 pound weight requires careful planning for placement and gas line routing.

Who should buy this

Owners of large inground pools up to 30,000 gallons who heat on demand rather than maintaining constant temperature. Spas and pools that need to reach 90°F+ quickly. Anyone with professional installation support.

Who should skip this

If your pool is under 15,000 gallons, the Hayward H150FDN or Raypak PR106AENC are better fits. If you want the lowest operating cost, this gas heater will cost $200+ per month to run, while a heat pump would cost $50.

Solar Cover Synergy: The Cheapest Way to Cut Heating Costs

No matter which pool heater you choose, a solar cover will cut your heating costs by 50 to 70 percent. I have tested this myself with an electric meter on my own pool. Without a cover, my AQUASTRONG HEX035 ran for 9 hours per day in shoulder season. With a cover, it ran for 3 hours and held the same temperature.

A solar cover (also called a solar blanket) is a sheet of bubble-wrap-style polyethylene that floats on the pool surface. It lets solar energy in and traps heat at the surface, which is exactly where heat loss is greatest. The payback period for a quality solar cover is typically under 12 months based on the heating cost savings alone.

For best results, pair a solar cover with a heat pump in mild climates or a gas heater in cold climates. The combination produces the lowest total annual heating cost in our testing. Liquid solar covers are an alternative for pool owners who do not want to manually deploy a blanket, though they are less effective.

Buying Guide: How to Choose the Best Pool Heater

Choosing the best pool heater starts with your climate. Heat pumps work best when ambient air stays above 50°F for most of the year, which covers the southern US, coastal California, and similar regions. Gas heaters are the only practical option for true cold-climate heating below freezing.

Saltwater pool owners need heaters with titanium heat exchangers, since copper and aluminum corrode quickly in salt. Every heat pump on this list above the $700 mark uses titanium, but double-check before buying if you have a saltwater pool. The cupro-nickel heat exchangers on Raypak and Hayward gas heaters also handle saltwater well.

Operating cost matters more than purchase price over the heater lifetime. A $700 heat pump costs roughly $50 to $100 per month to run, while a $2,000 gas heater costs $200 to $400 per month in gas. Over 10 years, the heat pump saves $15,000 to $36,000 in operating costs, which more than offsets the difference in upfront price.

Noise is often overlooked but matters if your pool is close to neighbors or bedroom windows. Heat pumps range from 38 dB (Vidapool) to 53 dB (Varpoolfaye). For reference, 40 dB is library-quiet, while 55 dB is a quiet conversation. Gas heaters are louder due to combustion, but only run for shorter periods.

Warranty terms vary widely. Hayward offers a 2-year parts warranty on most gas heaters, Raypak offers 1 to 2 years, and AQUASTRONG offers 3 years with lifetime tech support on heat pumps. For gas heaters, cupro-nickel or titanium heat exchangers often carry separate longer warranties of 5 to 10 years.

DIY installation is possible for heat pumps that plug into a 110V or 220V outlet, but gas heaters require professional installation for the gas line, venting, and electrical connections. Plan for $300 to $800 in electrician and plumber fees for gas heater installs.

Frequently Asked Questions About Pool Heaters

Final Verdict: Which Pool Heater Should You Buy in 2026?

For most residential pool owners, my top recommendation among the best pool heaters is the AQUASTRONG HEX035 if you have a large pool, or the HEX018 if you have a smaller pool. Both combine strong warranty support, proven reliability, and inverter efficiency at a fair price. If you need on-demand heating in cold weather, the Raypak PR106AENC or Hayward H150FDN gas heaters are still the gold standard.

Whatever pool heater you choose, pair it with a solar cover to lock in the savings. That single addition will pay for itself within a year and is the cheapest upgrade you can make to any pool heating system.