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If you want to make the most of your outdoor swimming pool, a pool heater is a must. They’re a worthwhile investment for making the most use of your pool while the season allows it, whether you like to make your pool as warm as bath water or just get it up to a comfortable temp for nighttime dips in late spring. Without a heater, mother nature is your thermostat—and even a long day of bright sun isn’t always enough to meaningfully change the temp of your pool.
There are several types of pool heaters that work in tandem with your in- or above-ground pool. They’re powered by solar, gas, or electric, and some models even have cooling abilities to take the temp down several notches during sweltering stretches of summer. If you’re concerned about your electric bill going up, there are solar-powered models (and you can save even more if you add an insulated pool cover).
No matter which type of pool heater you choose, we bet you’ll discover that it pays for itself, so to speak, in the value it offers.Read on for our top pool heater recommendations, plus advice to consider before you shop.
Looking for more great ways to upgrade your pool this summer? Check out our coverage of the best pool ladders, filters, and vacuums.
The Best Pool Heaters
1
Best Overall
Hayward W3H250FDN Universal H-Series Pool Heater
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2
3
4
5
6
Best for Above-Ground Pools
FibroPool FH120 Pool Heater Pump
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7
Best Heater-Chiller Combo
Raypak Crosswind Heat/Cool Electric Pool Heater Pump
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8
What to Consider
Pool Size
The size of your pool generally determines which type of pool heater is best for your needs. You can use low-power solar heaters to power small pools, while large pools benefit from powerful gas models.
Electric models can work well for both, but may get expensive to operate for big swimming pools compared to using natural gas. If you opt for a gas or electric heater, you’ll also need to select a model with an appropriate BTU rating for your pool’s size. More on that below.
BTU Output
BTU, or British Thermal Units, is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
To determine how many BTUs you need to heat your pool, calculate the pool’s surface area (multiply length by width), then divide the number by three. Then, take that number and multiply it by 1,000. If your pool is 15 by 30 feet, for instance, you’ll need a 150,000-BTU heater for optimal results.
Pool Compatibility
Most pool heaters are designed for compatibility with only in-ground or above-ground pools, though some can be used with both. Select the appropriate type for your pool—otherwise, you may have problems with installation and performance. If you have a saltwater pool, be sure to pick a heater that’s specifically approved for saltwater, as the salt can corrode internal components.
Solar, Gas, or Electric?
Traditional pool heaters are typically powered by propane or natural gas, like our best overall Hayward Universal H-Series pool heater. Gas heaters are generally the most powerful options and give you precise control over the water temperature compared to solar heaters.
Electricity is also usually more expensive than natural gas as a utility, so we only recommend a few electric options. Electric pool heaters are great if you don’t have a natural gas line at your house, you only need to heat the pool for certain periods of time, or you have a smaller pool. Generally speaking, electric heaters cap out around 100,000 BTUs, give or take.
Gas pool heaters can be quite pricey, though, generally costing several thousand dollars. Solar heater mats, on the other hand, have become increasingly popular as they’re significantly less expensive and way more eco-friendly. Just keep in mind that if it's cloudy or rains for too many days in a row, you'll need to brace for an invigorating dip.
How We Selected
To help you find the best pool heater, we selected a variety of options that are designed to heat both in-ground and above-ground pools of various sizes. We also searched for the best models for each fuel source, as well as heaters at various price points.
Plus, the pool heaters in this list are from reputable brands including Hayward, Raypak, and Pentair, known for quality products and customer service, so you can get the support you need if you have questions about the heater or if anything goes wrong.
Pros
- Multiple sizes
- LED control panel
- Compatible with saltwater pools
Cons
- Requires natural gas line
Depending on the size you choose, this pool heater delivers an output of 150,000 to 400,000 BTUs per hour. Hayward’s universal heater runs on natural gas, has low environmental impact, and meets clean air-quality standards.
It uses a cupronickel heat exchanger, which prevents corrosion, so it’s a great choice for saltwater and chemically treated in-ground pools.
There’s a digital LED control panel to control temperature, plus it can be installed on both new and existing pool systems. Also, service professionals appreciate the front-panel access for maintenance.
Key Specs
| Pool Type | In-ground |
|---|---|
| Power Source | Natural gas |
| BTUs | 250,000 |
Pros
- Cost-effective and reasonably priced
- Raises water temperature up to 10 degrees
- Can be roof-mounted
Cons
- No temperature control
- Requires lots of space
If you have the space to install them, these solar heaters are an eco-friendly and cost-effective method for warming your pool.
Each polypropylene panel is 20 feet long and four feet wide, and they come in a pack of two, providing 80 square feet of coverage. They hook up to the pool’s filter, and water absorbs the sun’s heat and flows through channels inside the panels.
This system can raise your pool’s temperature by as much as 10 degrees, though it only works well on sunny days. You’ll also need to make sure you have adequate installation space to roll them out on the ground or your roof.
Key Specs
| Pool Type | In-ground |
|---|---|
| Power Source | Solar |
| BTUs | N/A |
Pros
- LED control panel
- Corrosion-resistant
- Quiet operation with compressor cover
Cons
- Bulkier than many other electric models
We recommend this unit because of its versatility, as it can be installed in new and existing pool systems and doesn’t require a natural gas line.
The electric heat pump delivers an output of 90,000 or 140,000 BTUs per hour, depending on the model you choose. It requires a 240-volt connection and works as a heat exchanger, drawing warmth from the air to heat pool water.
Other highlights include the digital LED control panel to adjust water temperature, and we appreciate the acoustic compressor cover that keeps noise level to a minimum.
Key Specs
| Pool Type | In-ground |
|---|---|
| Power Source | Electric |
| BTUs | 90,000 |
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Pros
- Multiple sizes
- Electric pilot ignition
Cons
- Vent top sold separately
Natural gas pool heaters are a convenient and efficient option if your home already has a natural gas line, and this model comes in several sizes ranging from 206,000 to 406,000 BTUs—perfect for big pools.
The heater features an extremely durable corrosion-resistant galvanized metal cabinet with a wind-resistant design, providing uninterrupted performance in nearly all weather.
It also features a reliable electronic pilot ignition that’s controlled digitally, and the ignition is compatible with most major pool control and remote systems. Just keep in mind that a vent top, which isn’t included, is required for indoor installation.
Key Specs
| Pool Type | In-ground |
|---|---|
| Power Source | Natural gas |
| BTUs | 206,000 |
Pros
- Compact
- Digital thermostat
Cons
- Limited heating power
Most pool heaters are large and cumbersome, but the EcoSmart tankless pool heater has a compact design that isn’t as much of an eyesore in your yard.
This electric pool heater can raise the temperature in pools by 1 to 1.5 degrees per hour, and it has a digital thermostat that you can set to your desired temperature in one-degree increments.
This heater uses flow activation technology instead of a traditional pressure switch, which increases its reliability and reduces the risk of burnt-out switches. It’s compatible with the brand’s remote control (sold separately) that lets you warm up the pool from across your yard, and you can even use it as an alternative to a booster pump.
Key Specs
| Pool Type | Above- or in-ground |
|---|---|
| Power Source | Electric |
| BTUs | Not listed |
Pros
- Electric
- Easy to install
- Slim design
Cons
- Performance varies
This pool heat pump can be used with either in- or above-ground pools, but it’s ideal for circular above-ground pools 18 feet wide or bigger.
The unit plugs into a 120-volt outlet (ideal if you don’t have a gas line in your home) and you can set up without professional installation. It features a slim profile, easy-set digital controls, and 20,ooo BTUs of power.
While it can heat up to 7,500 gallons of water, its performance does vary depending on the ambient temperature outside—it operates most efficiently at 80 degrees with 80 percent air humidity. If you live somewhere with a colder or less humid temperature, it may not work as well.
Key Specs
| Pool Type | Above- or in-ground |
|---|---|
| Power Source | Electric |
| BTUs | 20,000 |
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Pros
- Compact size
- Heats and cools
- Quiet operation
Cons
This energy-efficient, compact pool heater automatically shifts into maintenance mode once the water reaches the desired temperature, and rather than shutting off, it switches to low capacity to maintain the temperature. It also has chilling capabilities for extremely hot days to bring down water temperature.
The heater-cooler combo runs on a 230-volt electrical connection, making it easy to install, and provides an output of 61,000 BTUs per hour. It features an inverter compressor and a low-speed fan motor for extremely quiet operation. There’s also a conveniently placed digital control panel.
Key Specs
| Pool Type | Above- or in-ground |
|---|---|
| Power Source | Electric |
| BTUs | 61,000 |
Pros
- Durable design
- Wind-resistant
- Digital controls
Cons
- Can be expensive to operate
For homes without a natural gas line, this pool heater from Raypak conveniently runs on liquid propane tanks. It has a 150,000-BTU output, and the brand recommends it for both above- and in-ground pools up to 15,000 gallons.
This model is quite similar to the brand’s natural gas heater, featuring a polyester-coated, non-corrosive cabinet, stainless steel burners, and digital controls, but the design is more compact—and less expensive.
It also features an electronic ignition, as well as a wind-resistant design that’s ideal for outdoor installation. Plus, the heater is compatible with any two- to three-wire remote and can be integrated into your pool control system.
Key Specs
| Pool Type | Above- or in-ground |
|---|---|
| Power Source | Propane |
| BTUs | 150,000 |
Camryn Rabideau
Camryn Rabideau is a freelance writer and product reviewer specializing in home, kitchen, and pet products. In her four years as a product tester, she's tested hundreds of items firsthand, and her work appears in publications such as Forbes, USA Today, The Spruce, Food52, and more.
Rachel Klein
Senior Commerce Editor
Rachel Klein is a Senior Commerce Editor for Popular Mechanics, where she writes about everything from garden hose reels and patio furniture to mesh wifi systems and robot vacuums. She started her career as a daily newspaper reporter and was a travel editor for more than a decade before she started testing and reviewing luggage, noise-cancelling headphones, and other travel-related products. Fast-forward another five years and her area of expertise includes home decor, appliances, tech, and outdoor adventure gear. In her spare time, you'll find her planning her next trip, reading historical fiction, and seeing as much art as she can squeeze into a weekend.
