Gas vs. Electric Pool Heater: Which Is Right for Your Backyard?

An electric heat pump costs less to run year after year, but a gas pool heater heats faster and works better in colder weather. The gas vs electric pool heater question comes down to how often you swim, how cold your winters get, and how quickly you want warm water.

Every homeowner wants warm water for more of the year without spending a fortune to keep it there. A gas heater gets you swimming faster and later into the cold months, since it heats quickly and works in any weather. An electric heat pump keeps the water warm for far less. Because a fiberglass pool shell holds heat so well, the cheaper-to-run electric heat pump comes out ahead for many families.

Key Takeaways

• A gas pool heater installs for $1,500 to $4,500 and heats fast in any weather, while an electric heat pump installs for $2,000 to $5,000 and up.
• An electric heat pump costs far less to run, around $50 to $150 a month against $200 to $400 or more for gas.
• Heat pumps lose efficiency below about 50°F, while a gas heater warms your pool no matter how cold the air gets.
• A fiberglass pool shell holds heat well, so your heater runs less and you can often size it down.
• Gas or a dual-fuel setup suits fast heat and cold-month swimming, and a heat pump suits season-long swimming at the lowest cost.

Gas vs. Electric Pool Heater at a Glance

Feature	Gas Pool Heater	Electric Heat Pump
How it heats	Burns natural gas or propane to warm the water directly	Pulls warmth from the surrounding air and moves it into the water
Upfront cost (installed)	$1,500 to $4,500	$2,000 to $5,000+
Monthly running cost	$200 to $400+ (propane runs higher)	$50 to $150
Heating speed	Fast, heats on demand	Slower, works best once the air warms up
Climate fit	Works at any outdoor temperature	Efficient above about 50°F, falls off below
Lifespan	About 5 to 10 years	About 10 to 15 years or more
Best for	Fast heat, spas, cold-month swimming	Season-long swimming at the lowest running cost

How Each Type Heats Your Pool

A gas heater makes heat. A heat pump moves heat that already exists in the air. Because one creates warmth and the other relocates it, gas works in any weather while a heat pump needs warmth to draw from, and their running costs sit far apart.

Gas Pool Heaters

A gas pool heater works like a furnace. Pool water flows through a copper coil above a burner, the burner ignites natural gas or propane, and the flame heats the water as it passes through. The heat goes straight into the water, which is why gas warms a pool so fast. A gas heater can handle its task whether it’s 70°F or 30°F outside, and it can take a cold pool to swimmable in hours rather than days.

That speed is the main reason homeowners still choose gas. It handles on-demand heating better than anything else, warming the pool for a weekend and then resting.

Fuel type changes the running cost more than most homeowners expect. A gas heater runs on natural gas piped from the street or propane stored in a tank, and modern units convert roughly 82 to 95 percent of their fuel into usable heat. (The older “55 percent” figure you may see online is a conservative Department of Energy baseline, not what a current heater delivers.) Many homes across the Southeast and mid-Atlantic have no gas line, so their only option is propane, which costs roughly 1.7 to 2.3 times more per unit of heat than natural gas.

Gas heaters also have the shortest lifespan here, around 5 to 10 years, and they need regular servicing plus professional installation and venting. Our guide to heating your pool covers every heater type side by side.

Electric Heat Pumps

An electric heat pump doesn’t burn anything. It captures warmth from the outside air and moves it into your pool water, the way an air conditioner moves heat, only in reverse. Because it moves existing heat instead of creating it, a heat pump produces far more warmth than the electricity it uses. That’s the root of its low running cost. When this guide says electric, it means a heat pump, not an electric resistance heater, which warms water with metal elements and costs far more to run on a full pool.

A heat pump warms a pool over a day or two, and it works best when the air is warm enough to draw heat from. Efficiency stays strong above about 50°F and tapers off below, with a practical floor near 45°F.

If you want the full breakdown of how a heat pump works, including efficiency ratings and sizing, read our complete guide to inground pool heat pumps. Electric heat pumps also last longer than gas units, typically 10 to 15 years or more, which softens their higher upfront price over time.

What Each Costs, Upfront and Every Month

Gas costs less to buy and more to run. A heat pump costs more to buy and far less to run.

Gas runs $200 to $400 or more during active heating, and propane lands higher still. A heat pump usually runs $50 to $150. Over a full season, the heat pump’s lower running cost can erase its higher purchase price and keep saving you money every year after.

A gas heater delivers less than one unit of heat for every unit of fuel it burns. A heat pump returns about five units of heat for every unit of electricity it draws, because it moves warmth rather than making it. That efficiency gap is why electric wins the long game on running cost.

Pool Brokers USA serves states including North Carolina, South Carolina, Tennessee, Georgia, and Virginia. Electricity in those states runs roughly 12 to 16 cents per kilowatt-hour, below the national average of about 17 to 18 cents, according to the EIA. Cheaper local power makes a heat pump look even better here than the national averages suggest. If the upfront number is the hurdle, our pool financing options include flexible terms through partners like VistaFi and HFS Financial.

Why Fiberglass Changes the Decision

The material your pool is made of changes how hard your heater works, which changes which heater makes sense.

A fiberglass pool shell holds heat far better than concrete. The shell conducts heat outward to the surrounding ground at a fraction of concrete’s rate, with a thermal conductivity around 0.04 watts per meter-kelvin. Concrete sits between 1.0 and 1.8, dozens of times higher. The smooth, non-porous gel coat surface also loses less water to evaporation, and evaporation is the single largest way a pool sheds heat.

This favors the heat pump in particular. A heat pump is strongest at holding a temperature it has already reached and weakest at recovering big losses fast. A fiberglass shell loses heat slowly, making the heat pump’s job easier. That lets you size the heater down and run it less, widening electric’s running-cost lead over gas.

How much you actually save depends on your cover, climate, and habits, which is why we skip hard “cut your bill by 30 percent” claims.

Climate, Speed, and How You Swim

Gas wins for heat on demand, cold-month swims, and warming a spa or hot tub fast, while a heat pump wins for low-cost season-long swimming. Whichever you choose, two add-ons cut how hard the heater works and what it costs to run.

A chiller helps at the hot end. In the Southeast, a pool can overheat to bath-water temperatures by midsummer. Pool Brokers USA offers an electric heater-chiller combination that warms the water in the shoulder seasons and cools it during peak summer, so it stays comfortable on both ends of the calendar.

A cover is the bigger lever. A solar, thermal, or automatic cover cuts evaporative heat loss by roughly 70 to 80 percent, so your heater runs less and your bills drop. A mesh safety cover is different. It’s built for winter protection and does little to hold heat. Our pool cover options handle both jobs.

So Which Pool Heater Should You Choose?

Pick an electric heat pump if you swim mostly in mild weather and want the lowest running cost. This fits most fiberglass pool owners in Pool Brokers USA territory, where a heat-holding shell makes the savings even better. Pick a gas heater if you want heat fast, swim in cold months, heat a spa, or run the heater only for the occasional weekend. A tight upfront budget points to gas too, since it costs less to buy.

Choose a dual-fuel setup if you swim year-round and want both, letting the heat pump hold temperature day to day and calling on gas for quick recovery or cold-weather swims.

The right answer also depends on your pool size, climate, and how your shell is installed. Our team compares gas and electric heaters with you, recommends the right size for your fiberglass pool shell, and supplies it manufacturer-direct. We are not your installer. We are the guide and source that makes the choice clear and the equipment affordable. Shopping off-season? Our roundup of winter pool heater deals can help you save on the unit you choose.

Ready to match a heater to your pool and climate? Request a quote and we’ll help you size it for your fiberglass pool shell. No pressure, no pushy sales tactics, just a straightforward quote.

Frequently Asked Questions

Is a Gas or Electric Pool Heater Cheaper to Run?

An electric heat pump is much cheaper to run, around $50 to $150 a month against $200 to $400 or more for gas. A heat pump moves existing heat and delivers about five units of warmth per unit of electricity, while a gas heater makes heat and delivers less than one. Gas costs less to buy, but the heat pump usually costs less over the life of the equipment.

Which Pool Heater Is Best for a Fiberglass Pool?

An electric heat pump suits most fiberglass pools in mild-to-variable climates. A fiberglass shell holds heat well thanks to its low thermal conductivity and non-porous surface, so the heater mostly maintains temperature rather than recovering it. That plays to a heat pump’s strengths and lowers your cost. Gas remains the better pick for fast heat, cold-weather swimming, or quick spa heating.

Does a Fiberglass Pool Need a Smaller Heater?

Often it does. A fiberglass shell loses heat slowly thanks to its low thermal conductivity and non-porous surface, so it holds temperature with less work than a concrete or vinyl pool of the same size. That lets many owners choose a smaller heater, which trims both the upfront price and the monthly run cost. Exact sizing depends on your pool, climate, and cover, which is where matching the heater to your shell pays off.

Do Electric Heat Pumps Work in Cold Weather?

Pool heat pumps work well in cool weather but lose efficiency once the air drops below about 50°F, with a practical floor near 45°F. They pull warmth from the air, so colder air gives them less to work with. A pool heat pump isn’t the same as a cold-climate home heat pump, so gas or a dual-fuel setup is more reliable for genuinely cold-month swimming.

Can You Use Both a Gas Heater and a Heat Pump?

You can, and serious year-round swimmers often do. A dual-fuel setup uses the heat pump for low-cost everyday temperature maintenance and the gas heater for fast recovery or cold-weather swims. You pay for two units upfront, but you gain cheap daily operation plus all-weather power whenever you need it.

Do You Need a Gas Line for a Gas Pool Heater?

Not necessarily. A gas heater runs on either natural gas piped from the street or propane stored in a tank, so a home without a gas line can still run one on propane. The catch is cost. Propane runs roughly 1.7 to 2.3 times more per unit of heat than natural gas, which is why many homeowners without a gas line look at an electric heat pump instead.

Making the Right Call for Your Backyard

The gas vs electric pool heater choice settles on three questions. How fast do you want warm water, how cold does it get when you swim, and what do you want to spend each month? Gas heats fast, works in any weather, and costs less to buy, while an electric heat pump costs far less to run and lasts longer. A fiberglass pool shell holds heat so well that it makes the heat pump the everyday winner for many families, with gas and dual-fuel setups ready when you need speed or cold-weather power. Whatever you pick, add a thermal or automatic cover and you’ll heat less and save more.

Dreaming of your perfect pool? Let’s turn it into reality! Contact Pool Brokers USA today and get your pool process started with one of our fiberglass inground pools. Our team of experts is here to help you find your perfect pool. Check out our pool ordering process to see how simple it is to get started and browse our pool gallery for design inspiration.

Pool Brokers USA provides affordable fiberglass inground pools for any size backyard! We help families bring people together and create memories that will last a lifetime. To learn more, visit our frequently asked questions or request a quote today!