Catchweight
Pool showdown
The Best Gas Pool Heaters of 2026 (Hayward vs Raypak vs Pentair vs Jandy)
Some links here are affiliate links — if you buy through them, we may earn a commission at no extra cost to you (sometimes with a discount for you). It never changes which products we recommend — and we name the SKIPs to prove it.
- contenders compared
- 5
- owner ratings · Amazon
- 637
- verified pull-quotes
- 4
- data last verified
- 2026-10-19
A gas heater is the muscle of the pool-heating world — the only kind that warms a pool in any weather, beats a cold snap, and runs a spa on demand. It’s also the one category where the big four brands — Hayward, Raypak, Pentair, and Jandy — genuinely dominate, so this is a real brand fight, not a white-label flood. But search “best gas pool heater” and every roundup skips the fact that actually decides your purchase: the multi-year warranty you think you’re buying evaporates the moment you buy online. So here’s the whole fight, sized by your pool — the brand pros default to, the durability story that matters for salt pools, and exactly where you have to buy to keep the coverage.
♨️ Not sure gas is even the right heater — or what size? Run your pool through the Pool Heater Finder first. It confirms gas vs heat pump vs solar and the BTU for your gallons, then points you back here to pick the model.
What will it cost to heat your pool?
Heat pump, gas, or solar — the purchase price is only half the story; the run cost is the other half. Set your pool and your rates, and see the estimated yearly cost of each. The math updates live.
Don't know your gallons? Work it out here →
Exact geometry at 7.48 gal/ft³. Kidney shapes, diving hoppers and salt/turnover figures live in the full Pool Volume Calculator.
Don't know your gallons? Estimate from your pool's size
Average depth = (shallow end + deep end) ÷ 2 — about 4–5 ft for a typical pool. Uses the standard pool-volume factors (rectangle ×7.5, oval ×6.7, round ×5.9 gallons per square-foot-foot). For a round pool, enter the diameter.
⚠ A heat pump shrinks in cool air. Its output falls to about two-thirds of its rating in 50°F (10°C) air (Pentair rates its UltraTemp 140 at about a third less heat at 50°F than at 80°F (27°C)), and below 50°F models differ — some defrost and carry on, some shut down until the air warms. The heat-pump figure above counts only the heat it can deliver in those months, so budget a gas top-up or a cover for them. Most calculators ignore this and quote a too-rosy heat-pump number.
Estimate only. Model: for each month of your season, what the pool loses through its surface on an average day at your target temperature — evaporation, air and sky, from the Florida Solar Energy Center's pool-loss equations run hour by hour on NOAA 1991–2020 hourly normals (your zone, or the station nearest your ZIP), with the wind at the water set by your yard — less the sun it absorbs (NASA POWER). A heat pump replaces that in the warmest hours first, at the makers' certified efficiency for each hour's air (a COP of about 5.6 at 80°F, 4.0 at 50°F, nothing counted below 50°F), because a pool holds its heat overnight. Gas is ~84% efficient regardless of weather. Solar's run cost is near zero because the filter pump is already running, but it only adds heat while the sun is out. Surface area comes from your gallons at an average depth unless the volume helper below sets your length and width. Energy prices start at U.S. EIA residential averages; your ZIP swaps in your state's.
The long-run picture: heat pump vs gas
Gas costs less to buy; a heat pump costs less to run. Here's where the heat pump's lower bills overtake gas's lower sticker price — built live from your run-cost numbers above.
Total cost = installed price + run cost × years, using your numbers above (installed prices are editable estimates — heat pumps run ~$4,000–7,000 installed, gas ~$2,500–4,000 plus a gas line). Solar is left off this chart on purpose: its run cost is near zero but it only partly heats and can't run on demand, so a pure total-cost line would crown it unfairly.
The short version — pick by your pool’s size:
🏆 Best overall (standard 15,000–25,000 gal): Hayward Universal H-Series 250K (W3H250FDN) — the gas heater pool pros name first, and the only one with a salt-tolerant cupro-nickel heat exchanger as STANDARD (Pentair charges extra for that). Deepest owner base in the field (4.0★/194), 84% thermal, Low-NOx — though read that 4.0 as bimodal, not mild: 66% leave five stars and 21% leave one. Buy it through a dealer for the real warranty. About $3,999.
💪 Most advanced brand + softest warranty channel: Raypak 266K Digital — the proven Raypak (4.0★/170), the brand pros rank a close second to Hayward, and the one major where buying through an authorized online dealer can still leave you fully covered. Its newest AVIA HD line adds a NiTek exchanger for salt pools. About $3,059.
💵 Best value (small pools & spas, up to 15,000 gal): Pentair MasterTemp 125K — the cheapest way into a name brand, compact (80 lb), and Swim University’s budget pick. Honest catch: the lowest owner base here (3.5★/84) and install-sensitive. About $2,249.
🫧 For the biggest pools (or fast heat): Hayward Universal H-Series 400K — same Hayward build, more burner, for a large or busy pool that a 250K can’t keep up with. About $5,099.
⚠️ Excellent, but dealer-only: Jandy JXi / JXiQ — the smallest and (in the JXiQ) smartest gas heater made. We don’t link an online buy for it, because Jandy’s warranty “does not apply to… products purchased through the Internet.” Buy it through a dealer or not at all.
Quick comparison: the gas contenders
| Model | Best for | BTU | Max pool size | Flow rate | Heat exchanger | Efficiency | Warranty (online) | Owner rating | Price |
|---|---|---|---|---|---|---|---|---|---|
| Best overall: the pros' default gas heater, salt-ready out of the box | 250,000 BTU | ~15,000–25,000 gal | 30–125 GPM | Cupro-nickel (standard) | 84% thermal, Low-NOx | ~1-yr parts, no labor | 4.0★ / 194 | ~$3,999typical at AmazonCheck price → | |
| Most advanced brand & the softest warranty channel — Hayward's closest rival | 266,000 BTU | ~15,000–25,000 gal | 25–100 GPM | Copper (cupro-nickel & NiTek on upgrade models) | ~82–84% thermal | Authorized online dealer stays covered (verify the seller) | 4.0★ / 170 | ~$3,059typical at AmazonCheck price → | |
| Best value: small pools, spas & above-ground | 125,000 BTU | up to ~15,000 gal / spa | 20–70 GPM | Copper (cupro-nickel = HD upgrade) | ~82% thermal | ~1-yr parts only (even via authorized online resellers) | 3.4★ / 88 | ~$2,249typical at AmazonCheck price → | |
| Best for the biggest pools & fast heat in any weather | 400,000 BTU | 25,000+ gal (or fast-heat / spa) | 30–125 GPM | Cupro-nickel (standard) | 84% thermal, Low-NOx | ~1-yr parts, no labor | 4.0★ / 185 | ~$5,099typical at AmazonCheck price → | |
 Jandy JXi / JXiQ Gas Pool & Spa Heater | Excellent — but dealer-only (an online buy = zero warranty) | 200K / 260K / 400K | ~10,000–25,000+ gal by BTU | 30–100 GPM | Cupro-nickel (Dura-Glas) | ~84% thermal | VOID — 'does not apply to… products purchased through the Internet' | Editorial — no rated online buy path | Soon |
Prices move constantly — any Amazon price shown is as of the date noted and subject to change; tap through for today's number.
Read the Heat exchanger and Warranty (online) columns down — those two are the whole story. The exchanger decides how long the heater survives your water (especially salt); the online-warranty column decides whether the brand’s coverage means anything when you buy the way most people actually buy.
The warranty trap (read this before you buy any brand)
Here’s the part every other gas-heater roundup skips. Hayward, Raypak, Pentair, and Jandy all make excellent gas heaters, and they all have live Amazon listings. But every one of them cuts or voids the real warranty when the unit is bought online. Full coverage applies only when you buy through an authorized dealer and pay for professional installation. Straight from each brand’s own current warranty document:
| Brand | Warranty via a dealer + pro install | Warranty bought online (Amazon) |
|---|---|---|
| Jandy JXi / JXiQ | 1-yr unit / 5-yr heat exchanger (with factory VersaFlo) | VOID — “does not apply to… products purchased through the Internet” (the sharpest) |
| Hayward Universal H-Series | Expert Line: 3-yr parts / 1-yr labor | ~1-yr parts, NO labor (the “W3 Open Line” SKUs), plus an unauthorized-seller reject clause |
| Pentair MasterTemp | 2-yr parts + labor (3-yr with the bundle) | “one (1) year (parts only)… even from Authorized Pentair Online Resellers” |
| Raypak Digital / AVIA | AVIA/HD: 3-yr parts + labor · Digital: 2-yr | may reject claims from “unauthorized… marketplace storefronts” — but an authorized online dealer stays fully covered |
So the honest decision is a fork, not a product. If you want the real multi-year warranty, buy a Hayward, Raypak, or Pentair through a dealer and have it professionally installed — you get the build quality, the local service, and coverage that means something. On Amazon, Jandy gives you zero coverage, Hayward and Pentair drop to about a year of parts, and Raypak is the one brand where buying online can still be fully covered — if it’s an authorized online dealer (Raypak invites you to verify the seller). It’s not a hypothetical, and it isn’t rare: we read the Hayward 250K’s critical reviews on 2026-08-14, and five of the first ten are a refused warranty — Hayward declining because the unit was bought online, In The Swim declining at 33 days, another seller blaming the installation, one owner unable to register the heater at all — “Do not purchase from The Swim Pool… they sold us a defective Pool Heater and poor customer service.” One detail nobody warns you about: a marketplace unit can be old stock. One owner’s heater carried a manufacture date three years before he bought it, so the one-year online warranty had already expired the day it arrived. Check the manufacture date on the unit before you install it. As Swimming Pool Steve says, the brand matters less than the install; a heater put in right and kept in balanced water lasts 10 years, and one that isn’t won’t, whatever the badge says.
The gas-specific thing nobody explains: the heat exchanger
Every gas heater burns fuel to warm water flowing through a heat exchanger, and the metal that exchanger is made of is the single biggest predictor of how long the heater lasts — especially on a salt pool, where the water is more aggressive. There are three tiers:
- Copper — the cheapest and the standard, but it corrodes fastest. Fine for a well-balanced fresh-water pool; the weak point on a salt or chemically hard one.
- Cupro-nickel — a copper-nickel alloy that resists salt and chemical erosion far better. This is what you want for a salt pool.
- NiTek — Raypak’s newest nickel coating (on the AVIA HD, Nov 2024), which Raypak claims is “300% more erosion resistant than copper.” The current top of the durability ladder.
The twist that decides our pick: Hayward puts cupro-nickel in the Universal H-Series as standard — so it’s salt-ready straight out of the box at no extra cost. Pentair’s cupro-nickel is a premium “HD” upgrade (the base MasterTemp is copper), and Raypak offers cupro-nickel and NiTek on its upgrade models. If you run salt, don’t buy a base copper heater to save a few hundred dollars — you’ll spend it back on an exchanger that dies early.
🏆 Best overall (standard pools): Hayward Universal H-Series 250K
Best overall: the pros' default gas heater, salt-ready out of the box · A 250,000 BTU natural-gas heater for standard in-ground pools, and the model pool pros name first. Its edge over the field: a cupro-nickel heat exchanger as STANDARD (salt-tolerant out of the box, where Pentair's cupro-nickel is a pricier HD upgrade), plus 84% thermal efficiency and Low-NOx compliance. It has the deepest owner base here (4.0★/194). The catch that decides the whole purchase: the real 3-year Hayward warranty applies only through an authorized dealer with professional install — buy this on Amazon and it drops to about one year, parts only, no labor.
Your pick if you have a standard 15,000–25,000-gallon in-ground pool, want the gas heater pool pros default to, and you're buying it through a dealer so the real warranty counts — Hayward puts a salt-tolerant cupro-nickel heat exchanger in the H-Series as standard, where Pentair charges extra for it.
Sold and shipped by US Parts Center · Non-returnable · read 2026-10-08
Picked before we checked what this link pays us.
“Really good heater. Super efficient at heating up our 40' x 25' in-ground pool. Works perfect. Was an easy install and super fast shipping. I received it two days after ordering! Recommended.”
Hayward Universal H-Series 250K BTU Gas Pool & Spa Heater (W3H250FDN)
Best overall: the pros' default gas heater, salt-ready out of the boxYour pick if you have a standard 15,000–25,000-gallon in-ground pool, want the gas heater pool pros default to, and you're buying it through a dealer so the real warranty counts — Hayward puts a salt-tolerant cupro-nickel heat exchanger in the H-Series as standard, where Pentair charges extra for it.
“Really good heater. Super efficient at heating up our 40' x 25' in-ground pool. Works perfect. Was an easy install and super fast shipping. I received it two days after ordering! Recommended.”— O.jay, Amazon · Verified owner
- Cupro-nickel heat exchanger STANDARD — salt-tolerant out of the box, no upgrade cost
- The pros' default gas pick (Swim University names the H-Series; INYO ranks Hayward #1)
- Deepest owner base in the field — 4.0★/194
- Heats fast in any weather and runs a spa; 84% thermal, Low-NOx (CA/TX compliant)
- Owners split hard — 21% of the base leaves one star, and the recurring story is a copper or heat-exchanger leak inside the first year; the standard cupro-nickel is a real advantage but it does not stop leaks at the joints
- A marketplace unit can be OLD STOCK — one owner's arrived with a manufacture date three years before the sale, so its one-year online warranty had already expired on arrival
- Highest running cost of any heater type — you're burning fuel, not moving free heat
- The branded warranty largely evaporates on an Amazon buy (~1-yr parts, no labor) — the real 3-yr coverage needs a dealer + professional install
- On 8 October 2026 the Amazon listing was sold by US Parts Center, LLC (84% positive over 56 ratings in a year), which does not appear in Hayward's own table of authorized online sellers. Hayward's warranty lets it refuse claims on units from sellers it has not authorized, so if the warranty matters, buy from a dealer
Warranty refused after an online purchase - Hayward and the marketplace seller each point at the other - usually after an early copper or heat-exchanger leak. One unit arrived with a manufacture date three years before the sale, so its one-year online cover had already run out.
5 of the first 10 critical cards (of 31) are a refused warranty and 4 an early leak or rust-through; the histogram is bimodal, 66% five-star against 21% one-star. All 10 are US verified purchases on the exact W3H250FDN, zero Vine. · critical reviews read August 2026
Sold and shipped by US Parts Center · Non-returnable · read 2026-10-08
The Hayward Universal H-Series 250K is the gas heater the pros reach for, and it earns it on the one spec that matters most for longevity: a cupro-nickel heat exchanger as standard, so it’s salt-tolerant out of the box where the Pentair charges extra for the same protection. Around that sits everything you’d expect from the category leader — 250,000 BTU that heats a standard 15,000–25,000-gallon pool fast in any weather, 84% thermal efficiency, Low-NOx compliance for California and Texas, and an easy-read digital control panel with onboard diagnostics. It also has the deepest owner base in this field at 4.0★ across 194 ratings, which for a gas heater — a category that draws more install and reseller complaints than any other — is as good as it gets.
The honest catch, and it’s the same one for the whole category: that Hayward warranty you’re picturing (three years of parts through Hayward’s Expert Line) only exists if you buy through an authorized dealer and have it professionally installed. Bought on Amazon, it drops to about a year of parts with no labor, and even that is not assured on this listing: on 8 and 11 October 2026 it was sold by US Parts Center, LLC (84% positive over 57 ratings in a year on the 11 October read), a seller that does not appear anywhere in Hayward’s own table of authorized online sellers, and Hayward’s online warranty lets it refuse claims on units from unauthorized sellers. The critical reviews show how that plays out, with Hayward and the seller each pointing at the other. So the buy-it-right move is a dealer; the buy-it-on-Amazon move is knowing you’re accepting thin coverage on an otherwise excellent machine. And gas is gas: it has the highest running cost of any heater type, so if you heat a warm-climate pool all season, price a heat pump against it first.
Not for you if: you have a small pool or spa and just want the cheapest name-brand entry (the Pentair MasterTemp 125 is half the price), or you live somewhere mild and heat all season long, where a heat pump’s running cost will beat gas badly over a few years.
💪 Most advanced brand & the softest warranty channel: Raypak 266K Digital
Raypak 266K BTU Digital Natural Gas Pool Heater (P-R266A-EN-C)
Most advanced brand & the softest warranty channel — Hayward's closest rivalYour pick if you want the gas heater pros rank right behind Hayward and you're buying online — Raypak is the one major whose warranty language leaves the door open: through an AUTHORIZED online dealer you can still be fully covered, where Hayward, Pentair and Jandy gut or void it.
“This is a nice heater. Requires a 3/4 inch gas line. All the heat is maintained in the heater, the outside doesn't get very hot and there is not a lot of gas fumes. It raises the temp of my pool around 3 degrees an hour and I have a inground 32×16 pool with a 2hp pump. Water flow matters. I love the electric ignition too. It's simple to operate.”— aaron, Amazon · Verified owner
- The proven Raypak (4.0★/170), the brand pros rank a close second to Hayward
- The only major where buying through an AUTHORIZED online dealer keeps you fully covered
- Digital control + high-flow automatic bypass (up to 125 GPM) for efficiency
- A real salt/durability upgrade path — the AVIA HD's NiTek exchanger
- Highest running cost of any heater type (gas)
- The base Digital exchanger is copper — for a heavy salt pool, step up to a cupro-nickel or NiTek Raypak
- Full warranty still only via an authorized dealer, not a random marketplace seller — confirm the seller before you buy
A minority electronics fault — a temperature-sensor or board problem at around the first year.
the dominant critical card rather than a broad pattern on a 169-rating base at the August 2026 read · critical reviews read August 2026
Raypak is the brand the pros rank right behind Hayward — INYO’s Charlie Ramirez calls it “a very close second” — and it has one edge no other major does: its warranty survives an online buy, as long as the seller is an authorized Raypak dealer. Where Hayward and Pentair drop to about a year and Jandy voids outright, Raypak only reserves the right to reject unauthorized marketplace sellers and invites you to verify — so with the right online dealer you can stay fully covered. The 266K Digital is the proven buy (4.0★/170), with digital control and a high-flow automatic bypass for efficiency.
If you run a salt pool, this is also where the durability story points: Raypak’s newest AVIA HD line adds a NiTek nickel-coated exchanger (“300% more erosion resistant than copper”), the toughest exchanger in the category. Its Amazon owner base is still too thin to wire as a pick, so buy the proven 266K Digital today — but know that the base Digital’s exchanger is copper, so for heavy salt, step up to a cupro-nickel or NiTek Raypak through a dealer.
Not for you if: you’re on a base copper budget and don’t run salt (the Hayward 250K’s standard cupro-nickel is the better value), or you want the single deepest-proven owner base (Hayward’s 194 edges Raypak’s 170).
💵 Best value (small pools & spas): Pentair MasterTemp 125K
Pentair MasterTemp 125K BTU Natural Gas Pool & Spa Heater (EC-462024)
Best value: small pools, spas & above-groundYour pick if your pool or spa is 15,000 gallons or under and you want the cheapest way into a name-brand gas heater — the compact 80-lb MasterTemp 125 is Swim University's budget pick, as long as you accept the lowest owner base here and an install that has to be done right.
“Have had zero issues with this heater. Works well for my 18'x54" above ground pool. Easy to install, would recommend for anyone with a smaller pool. This is our second season using this heater, and haven't had any issues.”— Aj, Amazon · Verified owner
Pro review “The MasterTemp 125 is Pentair's smallest gas heater, and it punches way above its weight.”— Justin D., The Pool Nerd
- Cheapest way into a name-brand gas heater
- Compact (~80 lb) — fits a tight equipment pad; the budget pick per Swim University
- Heats a small pool or spa fast, on demand, in any weather
- Lowest owner base in the field (3.4★/88) — the 1★ reviews cluster on dead-on-arrival startup failures and a third-party reseller that shipped damaged units with missing parts, so buy the cleanest listing and test it the day it's installed
- Base heat exchanger is copper (cupro-nickel is the pricier HD model) — not ideal for a heavy salt pool
- Even from an authorized online reseller, Pentair's own terms drop it to ~1-year parts only
The complaints are about the CHANNEL, not the machine. Owners describe warranty registration falling between Amazon, the reseller and Pentair; units arriving with the high-temp unions missing; and a heat exchanger that failed at five months and was refused under warranty. Two separate owners report electrical faults found at install. Buy a dealer-warranted gas heater from an authorised dealer, not a marketplace.
35 of 86 ratings were critical (41%) at the August 2026 read; 6 of the 10 read are warranty, registration or missing-parts failures that trace to the purchase channel rather than the unit · critical reviews read September 2026
If your pool or spa is 15,000 gallons or under, the Pentair MasterTemp 125 is the cheapest way into a name-brand gas heater — Swim University’s budget pick, and at about 80 pounds, compact enough to squeeze onto a tight equipment pad. It heats a small pool or spa fast, on demand, in any weather, which is the whole point of gas.
Be clear-eyed about the trade, though: it carries the lowest owner base in this field (3.5★/84), and it’s install-sensitive — a lot of the complaints trace back to installation rather than the unit. Two more honest notes: the base MasterTemp’s exchanger is copper (Pentair’s salt-tolerant cupro-nickel is the pricier “HD” model), so it’s not the pick for a heavy salt pool; and the MasterTemp is automation-compatible, not Wi-Fi-native — pair it with a Pentair automation system and you get app control, but the heater itself isn’t a smart heater. For a small fresh-water pool or a spa on a budget, though, it’s the name-brand entry point.
Not for you if: you have a standard or large pool (step up to the Hayward 250K or 400K), or you run salt (buy cupro-nickel, not this base copper unit).
🫧 For the biggest pools: Hayward Universal H-Series 400K
Recall notice, September 2026: CPSC recall 26777 covers Hayward’s HDFS400 Universal-HC, a 400,000 BTU dual-fuel heater sold through pool pros from March to July 2026, for a carbon monoxide hazard. It is not the Universal H-Series heater below. If the name plate on yours reads HDFS400, stop using it and call Hayward at 855-500-5288 for the free repair.
Hayward Universal H-Series 400K BTU Gas Pool & Spa Heater (W3H400FDN)
Best for the biggest pools & fast heat in any weatherSold in 4 capacities on this listing (150K–400K BTU) — this card is the 400,000 BTU. Check the size before you add to cart.
Your pick if you need heat fast, in any weather, or you run a spa — 400K BTU of gas warms in an afternoon where a heat pump can't; you'll just pay the most to run it.
“Turned heater on and had it up to 88 degrees in 4 hours for a pool 18x38 inground — absolutely thrilled.”— verified buyer, INYO Pools · Verified owner
- Heats fastest and works in any weather — the only type that can warm a pool in a cold snap or extend the season into the shoulder months
- 400,000 BTU plus a standard cupro-nickel heat exchanger suits large pools, spa duty, and frequent cold-starts
- 84% thermal efficiency, Low-NOx (California/Texas compliant); natural-gas or propane versions
- Ideal for a pool-and-spa combo where you want hot water fast on demand
- Highest running cost of the three by far — you're burning fuel, not moving free heat
- Needs a gas line (or a propane tank) sized for 400,000 BTU/hr — a real install consideration
- Overkill for a small pool in a warm climate, where a heat pump runs for a fraction of the cost
- On 19 October 2026 the featured offer on the Amazon listing was US Parts Center, LLC, a seller missing from Hayward's own table of authorized online sellers; the offer list also carried Pool Supplies Superstore (a Doheny's storefront) at $5,099, but Hayward's table contradicts itself on that seller — its poolsuppliessuperstore.com row is marked for Amazon while its doheny.com row carries no marketplace mark — so an authorized dealer remains the safe way to buy if the warranty matters
Units that would not fire or failed early: ignition and flame faults, control-board error codes (one owner traced a CE code to a wet board under a control panel that is not rainproof), a manifold leak inside two years, and one that blew up on first light after sitting four years as old stock. Owners who bought online also found the warranty pays for the part and not the labor.
36 written critical reviews against a base of 185 at the 2026-10-19 pass · critical reviews read 2026-10-19
Stock note, 11 October 2026: The Hayward 400K’s Amazon listing was sold by US Parts Center, LLC, a seller that does not appear in Hayward’s own table of authorized online sellers. The second seller on the listing is Doheny’s (trading as Pool Supply Super Store), and that table contradicts itself on Doheny’s: one of its domains is marked for Amazon and the other is not. Hayward’s online warranty lets it refuse claims on units from unauthorized sellers, so an authorized dealer remains the safe way to buy this heater.
Everything that makes the 250K our overall pick — the standard cupro-nickel exchanger, 84% efficiency, Low-NOx, the digital control — but with 400,000 BTU for a big pool, a busy pool-and-spa combo, or anyone who wants the fastest possible heat-up. It’s the same Hayward build and the same warranty math: buy it through a dealer for the real coverage. For a large in-ground pool that a 250K would fight to keep warm on a cold night, this is the muscle pick.
Not for you if: your pool is a standard 25,000 gallons or under — you’d just be buying (and running) more burner than you need; the 250K is the right size and a lot less to buy.
⚠️ Excellent, but buy it through a dealer: Jandy JXi / JXiQ
Jandy JXi / JXiQ Gas Pool & Spa Heater
Excellent — but dealer-only (an online buy = zero warranty)Your pick if you want the smallest, smartest gas heater made and you're buying it the RIGHT way — through a Jandy dealer with professional install. Do NOT buy this one online: Jandy voids the warranty on any internet purchase outright, so an Amazon JXi is an excellent heater with zero coverage.
- Smallest footprint of any gas heater — a 2'×2' unit that fits where others can't
- JXiQ adds built-in iAquaLink automation + Bluetooth diagnostics — the smartest gas heater
- Up to a 5-year heat-exchanger warranty (through a dealer, with factory VersaFlo)
- Warranty is VOID on ANY online purchase — the sharpest channel trap in the category
- Worth buying only through an authorized Jandy dealer with professional install
- No owner-rated online buy path we can responsibly recommend
The Jandy JXi is a genuinely brilliant heater — the smallest footprint in the category (a 2’×2’ unit that fits where nothing else will), and the JXiQ adds built-in iAquaLink automation and Bluetooth diagnostics, making it the smartest gas heater you can buy. On the hardware, it’s a contender for best in class.
We still won’t link an online buy for it, and it’s the sharpest example of this entire post’s thesis: Jandy’s warranty flatly “does not apply to… products purchased through the Internet.” Buy a JXi on Amazon and you own an excellent heater with exactly zero coverage — on a $3,000-plus appliance that lives outdoors and runs a gas burner, that’s not a risk worth taking to save a few dollars. So the JXi is the pick you buy through an authorized Jandy dealer with professional installation, where it comes with real coverage (up to a 5-year heat exchanger with factory VersaFlo) — or you don’t buy it at all. That’s why there’s no buy button on this card. It’s not a knock on the heater; it’s the one place in this category where the channel completely decides the value.
How to buy the right gas heater
Size to your pool, and don’t overthink it. Gas heaters are sized generously — a bigger burner just heats faster and cycles less, so there’s little penalty to going up a size. A pool or spa up to ~15,000 gallons is happy on 125,000–250,000 BTU; a standard 15,000–25,000-gallon pool wants 250,000–266,000; a big or busy pool wants 400,000. The real constraint is the gas line, which has to be sized to feed the heater’s full BTU/hr — confirm that with your installer before you buy, because an underfed heater starves and short-cycles.
Natural gas or propane — match your fuel. Every model comes in both. Natural gas is piped in and cheaper to run; propane comes from a tank and heats the same pool for noticeably more, but it’s your option with no gas line. Order the version that matches your fuel — the model number changes (Hayward’s W3H250FDN is natural gas, W3H250FDP is propane).
Buy for the exchanger if you run salt. Copper is the cheap standard; cupro-nickel and NiTek are the salt- tolerant upgrades. Hayward’s H-Series gives you cupro-nickel standard; on Pentair and Raypak it’s an upgrade model. On a salt pool, pay for it.
Buy through a dealer for the warranty. This is the whole point of the post. Every one of these brands guts or voids the real warranty on an online purchase. If the coverage matters to you — and on a gas appliance that lives outside, it should — buy through an authorized dealer with professional installation. Raypak is the one brand where an authorized online dealer can also keep you covered; verify the seller before you click buy.
FAQ
What size gas pool heater do I need?
Match the BTU to your pool. A rough guide: a pool or spa up to ~15,000 gallons wants 125,000–250,000 BTU (the Pentair MasterTemp 125 for a small pool or spa, a Hayward H150–H250 for an average one); a standard 15,000–25,000-gallon pool wants 250,000–266,000 BTU (the Hayward Universal H-Series 250K or the Raypak 266K Digital); and a big, busy, or fast-heat pool wants 400,000 BTU (the Hayward 400K, or Raypak's 406K). Gas heaters are usually sized generously — a bigger burner just heats faster and cycles less. Undersize it and it struggles to hold temperature on a cold night; the bigger risk is the gas line, which has to be sized for the heater's full BTU/hr, so confirm that with your installer.
Do Hayward, Raypak, Pentair, or Jandy gas heaters have a warranty if I buy on Amazon?
Mostly no, and this is the fact that should decide your purchase. The headline multi-year warranties apply only through an authorized dealer with professional installation. Bought online: Hayward's 'W3 Open Line' SKUs drop to about one year, parts only, no labor; Pentair's own terms say 'one (1) year (parts only)… even from Authorized Pentair Online Resellers'; Jandy's warranty flatly 'does not apply to… products purchased through the Internet' — zero coverage. Raypak is the one exception worth knowing: it reserves the right to reject claims from 'unauthorized… marketplace storefronts,' but an AUTHORIZED online dealer stays fully covered, and Raypak invites you to verify the seller. So on a gas heater, where you buy matters as much as what you buy.
Gas heater or heat pump — which should I get?
Gas if you need heat fast, in any weather, or you run a spa; a heat pump if you want the lowest running cost and you live somewhere mild. Swim University puts it plainly: 'A gas pool heater will heat your water faster and work better in colder temperatures. But the heat pump is more energy-efficient and you'll spend less money running it.' Gas is the only type that beats a cold snap, warms a pool for a single weekend, or runs a spa on demand — it just costs the most per hour to run. A heat pump moves heat instead of burning fuel, so it's far cheaper to run, but its output shrinks as the air cools, and below about 50°F some models shut down until it warms. If you heat only a handful of days a year, or you swim through cold weather, gas wins; if you hold a pool warm all season in a warm climate, a heat pump usually wins on total cost.
What's the best gas pool heater for a salt water pool?
Look at the heat exchanger material, because saltier, more aggressive water eats a cheap one. Copper is the standard (and cheapest), cupro-nickel resists salt and chemical erosion far better, and Raypak's newest NiTek nickel coating claims '300% more erosion resistant than copper.' The important twist: Hayward puts cupro-nickel in the Universal H-Series as STANDARD, so it's salt-ready out of the box — which is a big reason it's our overall pick. Pentair's cupro-nickel is a pricier 'HD' upgrade (the base MasterTemp is copper), and Raypak offers cupro-nickel and NiTek on its upgrade models. For a salt pool, buy cupro-nickel or better, not a base copper unit.
Natural gas or propane?
Every model here comes in both a natural-gas and a propane version — you pick the one that matches the fuel you already have. Natural gas is piped in and cheaper per unit of heat; propane comes from a tank and runs noticeably pricier to heat the same pool, but it's the option when you have no gas line. The heaters are otherwise identical; just make sure you order the version that matches your fuel (the model number changes — Hayward's W3H250FDN is natural gas, W3H250FDP is propane).
How much does it cost to run a gas pool heater?
More than any other type — you're buying fuel by the hour. A gas heater's running cost tracks the price of natural gas or propane and how many degrees you're raising the water, with no efficiency multiplier the way a heat pump gets (a heat pump delivers roughly five units of heat per unit of energy; gas gives you a little over three-quarters of the fuel's energy as heat). Use the calculator on this page to estimate your yearly cost from your gallons and climate. The single biggest saving, on any heater, is a solar cover — it roughly halves the heat you lose overnight, which is most of what you're paying to replace.
Is the Jandy JXi a good pool heater?
It's excellent — the smallest footprint of any gas heater (a 2'×2' unit), and the JXiQ adds built-in iAquaLink automation and Bluetooth diagnostics. We still list it as editorial-only, and only for one reason: Jandy's warranty 'does not apply to… products purchased through the Internet,' so buying it online leaves you with a great heater and zero coverage. If you want a Jandy, buy it through an authorized dealer with professional installation — that's the only way it makes sense, which is exactly why we don't link an online buy for it.
Update history
- October 2026 (2026-10-14) — Search title tightened for the results page: added a short metaTitle ("Best Gas Pool Heaters of 2026: Hayward vs Raypak vs Pentair") so the searched phrase and the year show before Google cuts the title off. The headline on the page is unchanged. Search Console 3-month export of 2026-10-14: 21 impressions at position 18.4 (10.8 on 10-03); full title 73 characters.
- October 2026 (2026-10-11) — Seller read: the Hayward 400K's Amazon seller (US Parts Center) is not in Hayward's authorized-seller table; a stock note under the pick says so.
- October 2026 (2026-10-08, later) — The Hayward H250's Amazon seller changed: Doheny's on 14 September, US Parts Center, LLC on 8 October. The catch paragraph named Doheny's; it now names the seller we read, which is not in Hayward's authorized-seller table either.
- October 2026 (2026-10-08) — Added a "start here" box at the top for readers whose equipment just failed or whose closing date is close: the free or cheap check from our own guide first, then the fastest buy, which is the crown below.
- October 2026 (2026-10-08) — Raypak Digital 266 price re-read on Amazon (2026-10-08): $3,179 -> $3,059.
- September 2026 — Added a notice beside the Hayward H-Series card: CPSC recall 26777 (2026-09-17) covers the HDFS400 Universal-HC dual-fuel heater, a different model, for carbon monoxide.
- September 2026 — Corrected the FAQ's cold-air line: a heat pump's output shrinks as the air cools and some models shut down in cold air; it does not stop at a fixed temperature. The embedded calculator now starts at EIA's 2026 U.S. residential energy prices.
- September 2026 — Re-read the Hayward 250K listing: it is now sold by Doheny's, and Hayward's own table of sellers authorized on Amazon does not mark Doheny's for Amazon, so the one-year online warranty is not assured on that buy path; the card and the warranty section now say so. Price $3,679 → $3,999, rating 4.0★/194 unchanged.
- August 2026 — First published. Gas pool heaters compared BY POOL SIZE (Catchweight): Hayward Universal H-Series 250K (W3H250FDN) best overall — cupro-nickel exchanger standard, the pros' default, 4.0★/192; Raypak 266K Digital = the proven Raypak + the one softest online-warranty channel; Pentair MasterTemp 125K = cheapest name-brand for small pools/spas (3.5★/84); Hayward 400K for the biggest pools; Jandy JXi/JXiQ = editorial, dealer-only (online buy voids the warranty outright). The warranty-channel moat: every major guts or voids coverage on an online buy. Ratings from signed-in reads 2026-08-02. Owner quotes for Raypak/Pentair are _reviewTodo (paced/Brad-paste). Hero reuses inground-pool-diving-board.jpg (swap-TODO).
Every Pool Heating showdown, by division
Same fight, different budgets. The head rulings first, then each weight class as the price climbs.
- Pound-for-poundThe Best Pool Heaters of 2026: Heat Pump vs Gas vs Solar
CatchweightThe Best Pool Water Levelers of 2026, and Why Every One Can Stick Open
Five portable pool water levelers compared in October 2026 on their owner record, what each mak…
Heavyweight · $1,400–$1,600The Best Self-Docking Pool Robots (2026): WYBOT S2 Solar vs S2 Solar Vision vs Aiper Scuba X1 Pro Max
The Heavyweight class, $1,500–$2,000 at list price, read signed in on Amazon and on each maker'…
CatchweightThe Best Pool Basketball Hoops of 2026: Matched to Your Pool and Deck
Nine pool basketball hoops read one listing at a time, with every recent critical review. The D…
Lightweight · $16–$69The Best Halloween Pool Floats of 2026: Float a Pumpkin, Not a Coffin
Halloween pool floats, read one listing at a time with every recent critical review. FUNBOY's l…