Sta-Rite is a Pentair-owned brand best known for pumps and filters, but its Max-E-Therm line is a legitimate gas pool heater option — engineered on the same platform as Pentair’s own MasterTemp, just sold through a different dealer channel. Here’s how the three sizes compare and where the brand fits if you’re already comparing MasterTemp or Hayward.

Quick answer

The Sta-Rite SR333NA (333,000 BTU, 84% thermal efficiency, ~$5,297 installed) is the best all-around choice for a typical in-ground pool. Downsize to the SR200NA (200,000 BTU, ~$4,268 installed) for a spa or smaller pool, or step up to the SR400NA (400,000 BTU) for the fastest heat-up on a large pool — though most retailers hide that model’s price behind an in-store “call for price” policy. Every size is also available as an HD version with a cupro-nickel exchanger for salt-chlorinated or harsh-water pools.

Sta-Rite Max-E-Therm lineup at a glance

ModelBTUEfficiencyExchangerPrice
Sta-Rite SR200NA200,00084% thermalCopper~$4,268 installed
Sta-Rite SR333NA333,00084% thermalCopper~$5,297 installed
Sta-Rite SR400NA400,00084% thermalCopperCall for price
Sta-Rite HD versionsSame BTU tiers82% thermalCupro-nickel~$150–$250 more

Installed prices include delivery and local flat-rate installation per retailer bundle pricing; unit-only street prices typically run lower — get an exact quote from your installer.

1. Sta-Rite SR333NA — Best Overall

Sta-Rite SR333NA Max-E-Therm (333,000 BTU)

Best overall · Natural gas · 84% thermal efficiency · ~$5,297 installed
  • Rated 84% thermal efficiency with a Dura-Glas rustproof cabinet and copper heat exchanger.
  • Right-sized for most 15,000–25,000-gallon in-ground pools — enough BTU for fast heat-up without paying for capacity a mid-size pool won't use.
  • LED temperature readout with dual thermostat controls and low-NOx design.
Check price on Amazon →

Warm up your pool sooner — try Amazon Prime free for 30 days and get your pool heater delivered in two days. The SR333NA sits in the same 84%-efficiency tier as Pentair’s own MasterTemp 250, which makes it a reasonable alternative any time the MasterTemp is backordered or priced higher at your local dealer.

2. Sta-Rite SR200NA — Best Value

Sta-Rite SR200NA Max-E-Therm (200,000 BTU)

Best value · Natural gas · 84% thermal efficiency · ~$4,268 installed
  • Same 84% efficiency rating and Dura-Glas construction as the larger SR333NA, sized down for spas and smaller pools.
  • Lightweight, compact design suited to retrofit installs where an older heater is being swapped in place.
  • 2-year manufacturer's warranty plus a typical 1-year installation warranty from most dealers.
Check price on Amazon →

For a pool under roughly 15,000 gallons, the SR200NA heats just as effectively as the 333NA at a lower price and with a smaller gas-line requirement — right-sizing down is the better call unless you need the fastest possible warm-up.

3. Sta-Rite SR400NA — Best for Large Pools

Sta-Rite SR400NA Max-E-Therm (400,000 BTU)

Best for large pools · Natural gas · 84% thermal efficiency · Call for price
  • Fastest heat-up in the Max-E-Therm lineup, built for large in-ground pools or frequent cold-start heating.
  • Compatible with Pentair's IntelliCenter control system and an optional Smart Heater Bypass valve rated for up to 35% savings in yearly operational cost, per the manufacturer's spec sheet.
  • Most retailers list this size "too low to advertise" under Pentair's minimum-advertised-price policy — expect to call or visit a local dealer for an exact number.
Check price on Amazon →

The 400NA is the right call for anything above 25,000 gallons, but budget a phone call into your shopping process — MAP pricing rules keep the number off most retailer websites, the same hidden-pricing pattern we ran into with Jandy’s heat pump line.

Is Sta-Rite the same as Pentair MasterTemp?

Sta-Rite has been a Pentair-owned brand for years, and the Max-E-Therm line shares its core engineering with Pentair’s own MasterTemp: both rate their standard copper exchanger at 84% thermal efficiency and offer a cupro-nickel HD version at 82% efficiency for pools with salt systems or harsh water chemistry. The real difference is distribution — MasterTemp is Pentair’s retail-facing line, stocked widely on Amazon and at big-box stores, while Max-E-Therm sells mostly through wholesale pool-supply dealers. That narrower distribution is also why Sta-Rite pricing is harder to find online than MasterTemp pricing for an equivalent BTU size.

The bottom line

The Sta-Rite SR333NA is the best overall pick for a typical in-ground pool, with the SR200NA a smart downsize for spas and smaller pools and the SR400NA reserved for large pools willing to call a dealer for pricing. If you run a salt system or fight low pH, step up to the HD cupro-nickel version of whichever size fits your pool. And if Sta-Rite pricing proves hard to track down locally, the functionally identical Pentair MasterTemp is worth cross-shopping since it’s stocked more widely.