Do I Really Need a Swimming Pool Heater?

It’s a sunny day, your pool looks amazing… but the water is freezing. We’ve all been there. The sun might be blazing, but your pool still feels like an ice bath.

That’s where swimming pool heaters come in. Whether you're planning to swim in early spring, late fall, or just want more comfort on cooler days, a pool heater can make a huge difference.

But do you need one? How much do they cost? And what kind is best for your pool? Let’s break it all down.

What Are the Main Types of Swimming Pool Heaters?

There are three main types of heaters used for inground pools:

• Solar pool heaters
• Electric heat pumps
• Gas pool heaters (natural gas or propane)

Each works differently and comes with its own pros, cons, and price points. Let’s explore.

How Do Solar Pool Heaters Work?

Solar pool heaters use roof-mounted solar panels to absorb heat from the sun. Pool water is pumped through these panels, warmed, and returned to the pool.

To use one effectively, you’ll need:

• Plenty of direct sunlight
• Enough roof or ground space for the solar panels
  

As a general rule, solar panels need to cover between 50% and 100% of your pool's surface area. So, if you have a 16' x 40' pool (that’s 640 square feet), you may need anywhere from 320 to 640 square feet of solar panel space. That could look like an array of panels measuring 8' x 40' or more, depending on how much heating you want and how much sun your area gets.

This is why solar heaters work best in sunny climates with ample roof space—or open areas where panels can be installed on the ground nearby.

Cost to run:

About $80–$200/year, mostly for the pool pump electricity to circulate the water through the heater.

Cost to install:

Typically $2,500–$6,500+ with professional installation (recommended).

Pros:

• Eco-friendly and energy-efficient
• Long lifespan (15–20 years)
• Low operating cost
• May qualify for solar tax credits

Cons:

• High upfront cost
• Slower to heat
• Weather-dependent
• Takes up a lot of space
• May require permits and inspections
• You may need to get a bigger pool pump

What About Electric Pool Heat Pumps?

Electric pool heat pumps pull heat from the air and transfer it to your pool water, think of them as a pool’s version of a reverse A/C unit. They don’t generate heat like a gas heater; instead, they move existing heat from the outside air into your pool.

Because of that, they work best when air temperatures are above 55°F. In milder climates, electric heat pumps are an excellent, efficient way to maintain consistently warm water through much of the year. Some newer models, especially those with scroll compressors or inverter tech, can still perform well in cooler conditions, but they’re not made for freezing temps.

If you like the idea of “set it and forget it” heating and don’t need your water warmed up fast, a heat pump could be your pool’s best friend.

Cost to run:

$120–$200+/month, depending on location and usage.

Cost to install:

$3,000–$7,000+, including professional setup.

Pros:

• Energy-efficient
• Lower monthly costs than gas
• Environmentally friendly
• Long lifespan (10–20 years)
• Great for mild climates

Cons:

• Slower heating speed
• Doesn’t work well below 55°F
• Higher upfront cost than gas

How Do Gas Pool Heaters Work?

Gas pool heaters burn either natural gas or propane in a combustion chamber to quickly heat copper coils, and as water flows through these coils, it gets warmed fast. That water is then returned to your pool at a higher temperature.

Unlike solar or heat pump systems, gas heaters don’t rely on the sun or outside air temperatures. That means they work in just about any weather, day or night, which makes them especially popular in cooler climates or for pool owners who want to heat water on-demand.

Hosting a party this weekend? You can turn your gas heater on the day before and have warm water by the time your guests arrive. But that power and convenience come at a cost, gas heaters tend to be the most expensive option to run long-term, especially if you're using propane.

Cost to run:

$200–$850+/month, especially if used daily or with propane.

Cost to install:

$2,000–$6,000, depending on size and connection needs.

Pros:

• Fast heating
• Works any time of day and in colder climates
• Lower upfront cost than solar or heat pumps

Cons:

• Shorter lifespan (~5 years)
• Less energy-efficient
• More expensive to run long-term
• Not eco-friendly

With multiple sizes and features to choose from, pricing can vary. Want a clearer idea of what your pool might cost? Try our Design and Price tool below.

What Size Pool Heater Do I Need?

Pool heaters are sized in BTUs (British Thermal Units). A good rule of thumb is:

50,000 BTUs per 10,000 gallons of water

For example, a 20,000-gallon pool needs at least 100,000 BTUs.

Larger heaters warm water faster, but also cost more. Your ideal size depends on pool volume, how quickly you want heat, and how often you plan to use the heater.

Are Swimming Pool Heaters Worth It?

That depends on how and when you want to swim.

You probably need a heater if:

• You live in a colder climate
• You want to swim in spring and fall
• Your pool is indoors or enclosed
• You prefer warm water year-round
• People sensitive to cold will be using the pool

You might not need one if:

• You live in a warm climate
• You’re okay with seasonal swimming
• You don’t mind cooler water

Still unsure? You can always install a heater later, many pool owners do.

Are There Any Budget-Friendly Ways to Heat a Pool?

If you're not ready to commit to a full heater, there are a few DIY or low-cost ways to warm your water:

• Use a solar pool cover (it traps heat and reduces evaporation)
• Try solar rings (like floating mini-covers)
• Remove nearby shade (trees, umbrellas, etc.)
• Shield your pool from wind (with fences or landscaping)
• Use solar heating mats (best for small pools)

And no, boiling water from the stove won’t help. Please don’t try it.

Solar pool cover

How Much Should I Expect to Spend on Swimming Pool Heaters?

Here’s a quick comparison:

Final Takeaway

Swimming pool heaters can stretch your swim season, increase comfort, and make spontaneous swims way more enjoyable. Whether you go solar, electric, or gas depends on your budget, climate, and preferences, but the good news is, there’s a great option for just about every pool owner.

Still on the fence? Reach out to your installer or local pool pro to chat through what makes sense for your backyard setup.

Frequently Asked Questions

How much does it cost to install a swimming pool heater?

• Gas heater: $2,000–$6,000
• Electric heat pump: $3,000–$7,000+
• Solar pool heater: $2,500–$6,500+

Keep in mind that professional installation is recommended for safety and performance.

What size swimming pool heater do I need?

A general rule is 50,000 BTUs for every 10,000 gallons of water.
Example: a 20,000-gallon pool needs at least a 100,000 BTU heater. Bigger heaters warm water faster, but cost more upfront.

Can I install a pool heater later?

Yes, many pool owners wait until after their first season to decide. Just let your builder know you’re considering one so they can prep the plumbing in advance. Adding a heater later is common and totally doable.

Which swimming pool heater lasts the longest?

• Solar heaters: 15–20 years
• Electric heat pumps: 10–20 years
• Gas heaters: Around 5 years

Lifespan depends on usage, maintenance, and local conditions. 

From the Author

I’m Cristian Shirilla, Director of Marketing at River Pools and co-owner of a fiberglass pool installation company in Virginia. I wrote this article because over the years, I’ve seen how much a swimming pool heater can change the overall experience of owning a pool. For some families, it’s the difference between a short swim season and months of extra enjoyment. My goal here is to help you understand the real costs, trade-offs, and benefits so you can decide whether a heater makes sense for your backyard.

From the Manufacturer  

At River Pools, we manufacture fiberglass pools for homeowners across a wide range of climates, from warm southern regions to places with shorter swim seasons. Because of that we realize there’s no one-size-fits-all answer, but there is a right answer for your climate, usage, and budget.

If you’re considering a swimming pool heater as part of your project, the best next step is to talk with an independently owned and operated installer in your area. They can evaluate your yard, energy options, and local climate to help you choose the system that fits your goals, not just your pool.

Ready to start the conversation?