Pool Heater Cost: Gas vs Heat Pump Pricing Compared
A gas pool heater costs $1,500 to $4,500 installed, with $250 to $400 a month to run. A heat pump costs more upfront, $2,000 to $6,000 installed, but runs $100 to $150 a month, often a fraction of that per hour compared to gas. Gas heats a pool in 3 to 6 hours; a heat pump takes 24 to 72 hours for the same temperature rise, but costs less every month it runs after that.
Which one makes sense depends less on the sticker price and more on how the pool actually gets used: heated occasionally for a weekend, or kept at temperature all season.
What does each heater type cost installed?
| Heater type | Typical size range | Unit cost | Installed cost | Monthly operating cost |
|---|---|---|---|---|
| Gas (natural gas or propane) | 125,000 to 400,000 BTU | $1,000 to $3,000 | $1,500 to $4,500 | $250 to $400 |
| Heat pump | Roughly 50,000 to 140,000 BTU | $1,500 to $5,000 | $2,000 to $6,000 | $100 to $150 |
(Ranges from Angi’s pool heater installation cost data and HomeGuide’s pool heater cost guide, 2026.) Heat pumps often add cost beyond the unit itself if the electrical panel needs a dedicated circuit or upgrade to handle the load, something a gas retrofit rarely requires if a gas line is already run to the equipment pad.
Why is gas so much more expensive to run, month to month?
Gas heaters burn fuel directly to heat water, roughly $4 to $9 an hour depending on local gas prices, while a heat pump pulls heat from the surrounding air using a small amount of electricity to run the compressor, closer to pennies per hour under normal conditions (Arctic Heat Pumps, gas vs. heat pump comparison). Over a full season, that gap compounds: heating a 20,000-gallon pool can run about $2,000 in gas versus roughly $600 with a high-efficiency heat pump, the same source reports.
Heat pumps are rated by Coefficient of Performance (COP) rather than the efficiency percentage gas heaters use. A COP of 5 to 6 in mild weather means the unit is moving 5 to 6 units of heat for every unit of electricity it consumes, which is why the operating cost drops so much even though the heat pump itself costs more to buy.
Which heater actually fits a given climate?
Gas heaters work at any ambient temperature, which is why they’re still the standard choice for pools that only get heated occasionally or that need to be ready fast for a specific weekend. Heat pump efficiency drops as the air cools: a unit rated at COP 4 around 50°F can fall to roughly COP 2.5 near 23°F, close to 50% more electricity for the same heat output, and most standard heat pumps stop heating effectively somewhere in the 45°F to 50°F range (Medallion Energy, heat pump low-temperature operation). In a warm climate that stays swim-season-mild for months, a heat pump’s slower heat-up time barely matters and the monthly savings add up fast. In a climate with real cold snaps, gas is often still the better fit for reliable heat when it’s needed.
What do real heater specs look like, by manufacturer?
- Pentair MasterTemp gas heaters range from 125,000 up to 400,000 BTU across the line, rated at 84% thermal efficiency with the standard copper heat exchanger, or 82% with the heavy-duty cupro-nickel heat exchanger built for higher salt or mineral content (Pentair MasterTemp product page, verified live).
- Raypak gas heaters span 105,000 to 399,000 BTU using copper fin-tube heat exchangers (VitaFilters heater comparison).
- Hayward HeatPro heat pumps carry an AHRI-certified COP of 6.4 on the 100,000 BTU model (W3HP31005T), with sizes running up to 140,000 BTU and a heat-and-cool variant for climates that also want a cooling mode in peak summer (Hayward HeatPro 100K BTU spec page).
How long does each type actually last?
Gas heaters typically last 5 to 10 years, sometimes stretching to 8 to 12 with careful maintenance; pool chemicals are hard on the heat exchanger, and a gas heater running on a poorly balanced saltwater pool can see its lifespan cut by roughly 40%. Heat pumps last longer on average, 10 to 15 years and sometimes beyond, because they have fewer parts directly exposed to pool water and combustion byproducts.
Whatever heater goes in, water chemistry is what protects it. Low pH corrodes a heat exchanger; high calcium hardness scales it. Run your fill or top-off numbers through the ClearCove Pools pool chemical calculator before the heater’s first run, since a brand-new heat exchanger is exactly the part a scaling or corrosive pool damages first.
The ClearCove Pools Pool Owner’s Handbook (free download) has a full equipment chapter with 2026 cost ranges for heaters, pumps, and filters side by side, useful for knowing what a fair quote looks like before a contractor shows up.
Frequently asked questions
Is a heat pump or gas heater cheaper overall? Gas costs less upfront but far more to run, $250 to $400 a month versus $100 to $150 for a heat pump. Over a full swim season, a heat pump usually costs less in total even accounting for the higher purchase price, unless the pool is only heated occasionally.
Can a heat pump heat a pool in cold weather? Not efficiently. Most standard heat pumps lose significant efficiency below 50°F and may not heat effectively at all below about 45°F. Gas heaters aren’t limited by ambient temperature and are the more reliable choice for cold-climate or off-season heating.
How long does it take to heat a pool with each type? Gas typically raises pool temperature in 3 to 6 hours. A heat pump takes 24 to 72 hours for the same rise, since it’s moving heat from the air rather than generating it directly.
Do pool heaters need regular maintenance? Yes. Both types need the water chemistry kept in range to protect the heat exchanger from scale and corrosion, plus periodic professional service: cleaning burners or coils, checking refrigerant on a heat pump, and inspecting for leaks.
Bottom line: gas costs less to install and heats faster, but a heat pump costs less to run in any climate mild enough to keep it efficient. Pick based on how often the pool actually gets heated, not just the sticker price.