Is a gas or heat pump pool heater better?

Neither is universally better — a gas heater is better if you swim occasionally, need fast heat, or live somewhere cold, while a heat pump is better if you swim regularly in a warm-to-temperate climate and want the lowest running cost. Gas units heat a pool 5–10°F per hour; a heat pump typically manages 1–2°F per hour but costs 60–80% less per month to run, per EIA electricity-rate comparisons against propane and natural gas.

Do heat pump pool heaters work in cold weather?

Most heat pumps lose efficiency once air temperature drops below about 50°F and stop heating effectively well below that, because they extract warmth from the surrounding air rather than burning fuel. Gas heaters don't have this limit — they generate heat directly, so they're the better choice for early-spring openings or late-fall swims in cooler climates.

How much more does a heat pump cost upfront than a gas heater?

A residential gas pool heater typically runs $1,500–$3,500 installed, while a comparable heat pump runs $2,500–$5,500 installed, according to current retailer and installer pricing. The heat pump's higher purchase price is usually offset within 1–2 swim seasons by its lower electricity cost versus gas, especially for pools heated daily through a full season.

Gas vs. Heat Pump Pool Heater: Which One Should You Buy in 2026?

Quick answer

Buy gas if you heat occasionally, need fast heat, or live somewhere cold; buy a heat pump if you swim all season in a warm-to-temperate climate and want the lowest running cost. A gas heater raises pool temperature 5–10°F per hour and works in any weather, but burns $200–$500 a month in fuel. A heat pump heats slower (1–2°F per hour) and stalls below roughly 50°F air temperature, but typically costs 60–80% less per month to run because it moves existing heat instead of burning fuel for it, per EIA residential electricity-rate data compared against propane and natural gas pricing.

Gas vs. heat pump, side by side

	Gas heater	Heat pump
Heating speed	5–10°F/hour	1–2°F/hour
Monthly running cost	$200–$500	$50–$150
Upfront + install cost	$1,500–$3,500	$2,500–$5,500
Works below 50°F air temp	Yes	No — efficiency drops sharply
Typical lifespan	5–10 years	10–20 years
Best for	Occasional use, spas, cold snaps	Daily/all-season swimmers

Why gas heats faster — and costs more for it

A gas heater — like the Pentair MasterTemp 400 or Hayward H-Series — burns natural gas or propane and transfers that heat directly into the water, which is why it can take a pool from cold to swimmable in a few hours. That speed comes at a fuel cost: a 400,000 BTU unit running several hours a session typically burns $15–$25 in gas each time, adding up to $200–$500 a month for regular use. That makes gas the right call if you only heat for a weekend pool party, run a spa you use a few times a week, or live somewhere the swim season is short and cold-tolerant heat matters more than running cost.

Why a heat pump costs less to run — but not in every climate

A heat pump, such as the Hayward HeatPro or FibroPool FH270, doesn’t burn fuel — it extracts ambient heat from the air using the same principle as a refrigerator in reverse, then moves it into your pool. That efficiency is measured by COP (coefficient of performance): a heat pump rated COP 5 delivers about $5 of heat for every $1 of electricity spent. At current U.S. residential electricity rates, that typically lands in the $50–$150/month range for daily use — 60–80% less than an equivalent gas heater. The catch is thermal, not mechanical: heat pumps struggle to pull warmth from air once it drops below roughly 50°F, so in colder climates or shoulder-season swims, they stall out right when a gas heater would keep working.

Hayward HeatPro heat pump

Best all-season value where climate allows

COP-rated efficiency — moves heat instead of burning fuel for it.
Digital controls with a titanium heat exchanger for saltwater-pool compatibility.
Pairs well with a solar cover to offset its slower heating speed.

Check price on Amazon →

Whichever type you land on, get it ordered before the weather turns — try Amazon Prime free for 30 days so a heater or the cover that speeds it up ships in two days instead of eating into your swim window.

A simple way to decide

Ask two questions: how often do you actually heat the pool, and how cold does your air get during the season you swim? If the honest answer is “a handful of times a year” or “our spring/fall swims dip below 50°F,” gas wins on flexibility even at a higher running cost. If you’re heating most days through a full warm-climate season, a heat pump’s lower monthly bill closes its higher purchase price within one to two seasons — see our best pool heat pump picks for COP-ranked options, or the full type-by-type breakdown on our best pool heater pillar guide. If you’ve already settled on gas, our Hayward vs. Pentair comparison covers the two most common gas lines head-to-head.

The bottom line

Gas wins on speed and cold-weather reliability; a heat pump wins on monthly cost if your climate cooperates. Most pool owners who swim regularly in a warm-to-temperate region save money switching to (or starting with) a heat pump, while occasional swimmers and cold-climate pools are usually better served sticking with gas. Either way, check running costs by type and budget for installation before you commit — install cost can shift the math as much as the heater itself.