Raypak AVIA 404A
The best rounded in-ground pool heater here for most owners: efficient, low NOx and app controlled with a longer warranty, if bought from an authorized dealer.
Amazon $4,420.27$4,420.27
A gas pool heater burns natural gas or propane to heat pool water fast, in any weather, which makes it the choice for heating a pool for a weekend, extending the season into cold months, or bringing a spa up to temperature in half an hour. These rankings compare what the makers publish on the same terms: how much heating input you get for the money, how much input there is, how efficiently it turns gas into heat, and how long it’s covered.
Heating input sets how fast the water warms. As a rough guide, a 400,000 BTU/h heater raises a 20,000 gallon pool about 2 °F an hour, and a 200,000 BTU/h heater half that. Bigger is faster and costs barely more to run per degree, since the gas burned per degree is about the same.
Most gas heaters are about 82 to 84% efficient; condensing models reach about 95%. Where gas is cheap or the pool is heated only now and then, gas wins; for a pool kept warm all season in a mild climate, a pool heat pump costs far less to run.
Top Picks
Shop by Size
Under 250,000 BTU
8 rankedHeaters for above-ground pools, spas and small in-ground pools, up to about 15,000 gallons.
Top rated: Raypak Digital 206A $3,023
250,000 BTU and up
12 rankedHeaters for typical and large in-ground pools, and for heating a spa fast.
Top rated: Raypak AVIA 404A $4,420.27
Narrow It Down
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Best Small Gas Pool Heaters (Under 250,000 BTU)
- Raypak Digital 206A#1 of 8Full review
Good value for spas and small pools outside low NOx areas, provided it comes from an authorized dealer so the warranty holds.
Amazon $3,023$3,023199,000 BTU/h82%2 years - Sta-Rite Max-E-Therm 200#2 of 8Full review
A Pentair built heater for owners on Pentair automation who want low NOx and high efficiency; compare prices with the MasterTemp first.
Amazon $3,650$3,650200,000 BTU/h84%1 year - Raypak 156A#3 of 8Full review
A low cost heater for above-ground pools and spas outside low NOx areas.
Amazon $2,290.44$2,290.44150,000 BTU/h82%2 years - Hayward H-Series H200FD#4 of 8Full review
A low NOx, salt tolerant spa or small pool heater for owners who buy online and can live with a short warranty.
Amazon $3,699$3,699199,900 BTU/h83%1 year - Pentair MasterTemp 125#5 of 8Full review
A compact, light heater for spas and above-ground pools, best for owners with Pentair automation.
Amazon $2,098$2,098125,000 BTU/h82%1 year
Best Gas Pool Heaters for In-Ground Pools (250,000 BTU and Up)
- Raypak AVIA 404A#1 of 12Full review
The best rounded in-ground pool heater here for most owners: efficient, low NOx and app controlled with a longer warranty, if bought from an authorized dealer.
Amazon $4,420.27$4,420.27399,000 BTU/h84%3 years - Raypak AVIA HD NiTek 404A#2 of 12Full review
For salt pool owners who want the AVIA features with a tougher heat exchanger and will pay extra for it.
Amazon $4,923$4,923399,000 BTU/h84%3 years - Pentair MasterTemp 400#3 of 12Full review
A strong pick for in-ground pools already on Pentair automation, though online buyers get only a short warranty.
Amazon $4,079$4,079400,000 BTU/h84%1 year - Raypak Digital 406A#4 of 12Full review
Good value for in-ground pools outside low NOx areas, provided it comes from an authorized dealer so the warranty holds.
Amazon $4,421.17$4,421.17399,000 BTU/h82%2 years - Sta-Rite Max-E-Therm 400#5 of 12Full review
A Pentair built heater for owners on Pentair automation who want low NOx and high efficiency; compare prices with the MasterTemp first.
Amazon $4,499$4,499400,000 BTU/h84%1 year
How We Rank
Each heater is ranked against others of similar size, and scored on its price per 1,000 BTU, its heating input, its thermal efficiency and its warranty.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per 1,000 BTU/h of input | 35% |
| Heating input | gas input, BTU/h | 25% |
| Efficiency | thermal efficiency | 20% |
| Warranty | residential warranty | 20% |
How we rank explains each factor in full.