Pentair Pool Heaters
Pentair builds three separate heating families: MasterTemp conventional gas heaters at 84% thermal efficiency, the same heaters in a cupro-nickel HD version at 82%, and the ETi high-efficiency line whose direct-fire titanium exchanger reaches 96%. On the electric side, UltraTemp heat pumps use a 100% titanium exchanger with a 10-year compressor and lifetime exchanger warranty. GulfStream is now a Pentair brand too. Almost everything is TradeGrade, which is Pentair's professional-channel line, and the warranty depends on that channel.
Pentair equipment shows up constantly on Florida equipment pads, and often as a complete system: pump, filter, salt cell, heater and automation from one manufacturer. That integration is the genuine advantage. A MasterTemp wired to an IntelliCenter over RS-485 is a networked device — the heater's own faults appear on the automation home screen rather than blinking on a panel behind the hedge — and no other gas heater in this comparison does that.
The gas range splits into two philosophies. MasterTemp is the conventional, induced-draft, atmospheric-pressure workhorse: Pentair's product page lists MasterTemp in 175, 200, 250, 300 and 400 sizes, while the 2025-2026 catalog ordering table starts at 200 and a separate MasterTemp 125 sits below the line. Efficiency is 84% with a copper heat exchanger, or 82% with cupro-nickel in the HD versions. It vents through a built-in stackless system outdoors, it drops onto 2 inch PVC with the unions supplied, and it is the gas heater our technicians open most often. The ETi line is the opposite bet: a condensing heater with a Titan-Tough direct-fire titanium heat exchanger, PVC venting, and 96% thermal efficiency on the ETi 400 measured to ANSI Z21.56:19/CSA 4.7:19. Pentair cites the Department of Energy's pool heater certification database for the claim that it is the highest in its class.
The electric side is the UltraTemp family — the UltraTemp 70 through the UltraTemp 140, 75,000 to 145,000 BTU/hr at the 80/80/80 test point, in heat-only, heat/cool (H/C) and three-phase commercial variants — all with a 100% titanium heat exchanger in a composite cabinet, a scroll compressor and a thermostatic expansion valve. Pentair's warranty on those two components is the strongest thing about them: 10 years parts and labor on the compressor and a lifetime term on the titanium exchanger. Above the standard heat pumps sits the UltraTemp ETi hybrid, which pairs a 93% efficient gas engine with a heat pump in one cabinet. Since Pentair acquired GulfStream, the Florida-built GulfStream HE Series heat pumps are also a Pentair line, sold and supported through Pentair's channels — see our GulfStream brand page.
One thing worth understanding before you shop on price: most of the Pentair pool range is TradeGrade, which Pentair describes as made for and sold by pool professionals. That is not just branding. Pentair's published warranty gives MasterTemp 2 years parts and labor, ETi 3 years parts and labor and UltraTemp 2 years plus the long compressor and exchanger terms — but only when the equipment is bought from a brick-and-mortar retailer, pool builder or pool service company and installed by a qualified professional who charges a fee. Bought from an internet retailer, the same heater is covered for 1 year parts only, with no labor at all. Pentair also publishes a bundle term: install a qualifying pump, filter and heater together and all three go to 3 years. Registration is required either way.
At a glance
- Headquarters
- Golden Valley, Minnesota
- Model pages here
- 6
- Lines
- MasterTemp, MasterTemp HD, ETi 400 and ETi 250, UltraTemp heat pumps, UltraTemp ETi hybrid, GulfStream by Pentair
What Pentair builds
MasterTemp
Gas heaterThe high-performance conventional gas line. Pentair's product page lists MasterTemp in 175, 200, 250, 300 and 400 sizes in natural gas and propane; the 2025-2026 catalog ordering table starts at 200, and the MasterTemp 125 is a separate, smaller model below the line. Copper heat exchanger, 84% thermal efficiency, certified for low NOx. Two-line LCD with a five-error fault history, RS-485 port for IntelliCenter and 2 inch PVC unions supplied. The most widely serviced Pentair heater in Florida.
MasterTemp HD
Gas heaterThe same heater with a cupro-nickel heat exchanger instead of copper, at 82% thermal efficiency. Pentair positions it for low pH, high flow and heavy use — which describes most salt pools on the Gulf Coast. Natural gas only: Pentair publishes no propane part number for any HD variant.
ETi 400 and ETi 250
Gas heaterHigh-efficiency condensing heaters with a Titan-Tough direct-fire titanium heat exchanger and PVC or CPVC venting. The ETi 400 (400,000 BTU/hr) is rated at 96% thermal efficiency; the ETi 250 is 94% on natural gas and 96% on propane with the conversion kit. Both carry 3 years parts and labor, against 2 years parts and labor on MasterTemp.
UltraTemp heat pumps
Electric heat pumpElectric heat pumps from the UltraTemp 70 to the 140 class, in heat-only, heat/cool (H/C) and three-phase versions. 100% titanium heat exchanger, composite cabinet, R-410A, scroll compressor and a plain-English LCD that reports faults in words rather than codes. Compressor is covered for 10 years parts and labor and the titanium exchanger for life.
UltraTemp ETi hybrid
Electric heat pumpA dual-fuel unit that combines a 93% efficient direct-fire titanium gas engine with a heat pump in one cabinet, so the gas side can give a fast boost and the heat pump side carries the everyday load. Available in natural gas and propane, 3 years parts and labor.
GulfStream by Pentair
Electric heat pumpGulfStream's HE Series heat pumps, built in North Fort Myers, Florida, are now a Pentair line — product information, warranty, service and technical support run through Pentair. Titanium exchanger, ABS cabinet, heat-only (RA) and heat/cool (TA) models. We cover them separately on our GulfStream brand page.
Pentair models we have researched
Every figure below is verified against the manufacturer's own documents, with the sources listed on each model page.
| Model | Type | BTU rating | Heat / cool |
|---|---|---|---|
| Pentair MasterTemp 400 NG Gas Pool HeaterMasterTemp 400 NG | Gas heater | 400,000 BTU/hr gas input | Heat Only |
| Pentair MasterTemp 250 NG Gas Pool HeaterMasterTemp 250 NG | Gas heater | 250,000 BTU/hr gas input | Heat Only |
| Pentair MasterTemp 400HD Heavy Duty Gas Pool HeaterMasterTemp 400HD | Gas heater | 400,000 BTU/hr gas input | Heat Only |
| Pentair MasterTemp 250HD Heavy Duty Gas Pool HeaterMasterTemp 250HD | Gas heater | 250,000 BTU/hr gas input | Heat Only |
| Pentair ETi 400 High-Efficiency Gas Pool HeaterETi 400 | Gas heater | 400,000 BTU/hr gas input | Heat Only |
| Pentair UltraTemp 140 H/C Heat and Cool Pool Heat PumpUltraTemp 140 H/C | Electric heat pump | 140,000 BTU/hr heat output | Heat + Cool |
Scroll the table sideways to see every column.
Pentair · MasterTemp
Pentair MasterTemp 400 NG Gas Pool Heater
Model MasterTemp 400 NG
- BTU input
- 400,000 BTU/hr
- Thermal efficiency
- 84%
- Heat exchanger
- Copper
- Warranty
- 2-Year Parts & Labor
- Wi-Fi / automation
- Automation Compatible
A large pool, or a pool and spa combination, on a pad that is already Pentair and an owner who wants heat on demand rather than an everyday running cost.
Pentair · MasterTemp
Pentair MasterTemp 250 NG Gas Pool Heater
Model MasterTemp 250 NG
- BTU input
- 250,000 BTU/hr
- Thermal efficiency
- 84%
- Heat exchanger
- Copper
- Warranty
- 2-Year Parts & Labor
- Wi-Fi / automation
- Automation Compatible
An average-sized Florida pool with no spa, or a pool where gas is the backup to solar or a heat pump rather than the everyday heat source.
Pentair · MasterTemp HD
Pentair MasterTemp 400HD Heavy Duty Gas Pool Heater
Model MasterTemp 400HD
- BTU input
- 400,000 BTU/hr
- Thermal efficiency
- 82%
- Heat exchanger
- Cupro-nickel
- Warranty
- 2-Year Parts & Labor
- Wi-Fi / automation
- Automation Compatible
A large salt-water or coastal pool, or a pool and spa that gets used hard, where the exchanger material matters more than the last two points of efficiency.
Pentair · MasterTemp HD
Pentair MasterTemp 250HD Heavy Duty Gas Pool Heater
Model MasterTemp 250HD
- BTU input
- 250,000 BTU/hr
- Thermal efficiency
- 82%
- Heat exchanger
- Cupro-nickel
- Warranty
- 2-Year Parts & Labor
- Wi-Fi / automation
- Automation Compatible
An average-sized salt-water or coastal pool that wants a corrosion-resistant exchanger without the gas line, flow rate and fuel bill of a 400,000 BTU heater.
Pentair · ETi
Pentair ETi 400 High-Efficiency Gas Pool Heater
Model ETi 400
- BTU input
- 400,000 BTU/hr
- Thermal efficiency
- 96%
- Heat exchanger
- Titanium
- Warranty
- 3-Year Parts & Labor
- Wi-Fi / automation
- Automation Compatible (Relay)
A high-use pool or pool-and-spa where the fuel bill is the deciding factor, and an owner willing to pay premium money up front and manage a condensing heater's condensate.
Pentair · UltraTemp
Pentair UltraTemp 140 H/C Heat and Cool Pool Heat Pump
Model UltraTemp 140 H/C
- Heating capacity
- 140,000 BTU/hr
- Efficiency (COP)
- COP 5.6
- Heat exchanger
- Titanium
- Warranty
- 2-Year Parts & LaborLifetime Heat Exchanger
- Wi-Fi / automation
- Automation Compatible
A large Gulf Coast pool that gets swum in most of the year, on a pad that is already Pentair, where the owner also wants the option to chill the water in late summer.
Pentair models side by side
| Specification | Pentair MasterTemp 400 NG Gas Pool HeaterMasterTemp 400 NG | Pentair MasterTemp 250 NG Gas Pool HeaterMasterTemp 250 NG | Pentair MasterTemp 400HD Heavy Duty Gas Pool HeaterMasterTemp 400HD | Pentair MasterTemp 250HD Heavy Duty Gas Pool HeaterMasterTemp 250HD |
|---|---|---|---|---|
| BTU input | 400,000 BTU/hr | 250,000 BTU/hr | 400,000 BTU/hr | 250,000 BTU/hr |
| Fuel / power | Natural gas | Natural gas | Natural gas | Natural gas |
| Heat or heat + cool | Heat Only | Heat Only | Heat Only | Heat Only |
| Heat exchanger | Copper is standard on the non-HD MasterTemp; the HD models swap it for cupro-nickel | Copper is standard on the non-HD MasterTemp; the 250HD swaps it for cupro-nickel | Cupro-nickel is what the HD designation buys; Pentair positions it for low pH, high flow and heavy use | Cupro-nickel is what the HD designation buys; Pentair positions it for low pH, high flow and heavy use |
| Thermal efficiency | 84% thermal efficiency (input rated; 400,000 BTU/hr input) | 84% thermal efficiency (input rated; 250,000 BTU/hr input) | 82% thermal efficiency (input rated; 400,000 BTU/hr input) | 82% thermal efficiency (input rated; 250,000 BTU/hr input) |
| Warranty | Parts: 2 years · Labor: 2 years | Parts: 2 years · Labor: 2 years | Parts: 2 years · Labor: 2 years | Parts: 2 years · Labor: 2 years |
| Controls & automation | Two-line LCD with separate pool and spa setpoints, fault history for the last five errors, runtime, cycles, stack flue temperature and flame status; RS-485 COM port for direct IntelliCenter control, 2-wire fireman's switch for IntelliTouch, EasyTouch, IntelliConnect or a time clock. | Two-line LCD with separate pool and spa setpoints, fault history for the last five errors, runtime, cycles, stack flue temperature and flame status; RS-485 COM port for direct IntelliCenter control, 2-wire fireman's switch for IntelliTouch, EasyTouch, IntelliConnect or a time clock. | Two-line LCD with separate pool and spa setpoints, fault history for the last five errors, runtime, cycles, stack flue temperature and flame status; RS-485 COM port for direct IntelliCenter control, 2-wire fireman's switch for IntelliTouch, EasyTouch, IntelliConnect or a time clock. | Two-line LCD with separate pool and spa setpoints, fault history for the last five errors, runtime, cycles, stack flue temperature and flame status; RS-485 COM port for direct IntelliCenter control, 2-wire fireman's switch for IntelliTouch, EasyTouch, IntelliConnect or a time clock. |
| Relative price | $$$ — Upper mid-range | $$ — Mid-range | $$$ — Upper mid-range | $$$ — Upper mid-range |
| MPH Equipment ScoreHow we rate heaters | 4.2 / 5 | 4.1 / 5 | 4.3 / 5 | 4.2 / 5 |
Scroll the table sideways to see every column. Every row is derived from the same fields on each product, so the comparison is like for like. Showing the first 4 of 6 models — a side-by-side table stops being readable past that. Every other model has its own page in the list above.
What we like
- Automation integration is the best in the gas category. The MasterTemp's RS-485 COM port connects directly to an IntelliCenter Control System — up to 16 heaters, addressed 1 to 16 — and the heater's alarms are displayed on the automation home screen rather than only on the heater.
- Three genuinely different gas answers instead of one. If efficiency is the priority you buy the 96% ETi 400; if corrosion resistance is, you buy a cupro-nickel MasterTemp HD; if service simplicity and price matter most, you buy a standard MasterTemp. Few manufacturers cover that spread within one brand.
- On the heat pump side, Pentair's published coverage on the two components that end a heat pump's life is 10 years parts and labor on the compressor and lifetime on the titanium heat exchanger.
- Diagnostics are practical rather than decorative. A MasterTemp's LCD stores the last five errors along with total runtime, on/off cycles, live stack flue temperature and flame sensor status, and the UltraTemp reports faults in full words instead of numeric codes.
- Documentation is thorough and public. Pentair publishes full installation manuals, quick reference guides, submittal data and a plain warranty table on its own site, which is why almost every figure on these pages could be checked against a manufacturer source rather than a retailer listing.
- Parts and service depth in Florida is excellent. MasterTemp boards, igniters, thermistors, pressure switches and blowers are stocked regionally, and most pool technicians in this market have worked on one.
What to know before buying
- The channel conditions are real and they catch people out. Pentair's warranty page gives MasterTemp 2 years parts and labor and ETi 3 years parts and labor through a brick-and-mortar retailer, pool builder or pool service company with professional installation — but a heater bought from an internet retailer is covered for 1 year parts only with no labor. Registration is required in every case.
- MasterTemp's base warranty is 2 years parts and labor. Raypak publishes 3 years parts and labor on AVIA, and Pentair's own ETi line gets 3 years, so the heater most people actually buy carries a year less than either.
- The standard MasterTemp uses a copper heat exchanger. That is the category baseline, not a coastal specification, and on a salt pool the HD version is the model you should be quoted.
- MasterTemp HD is natural gas only. Every HD part number Pentair publishes — 250HD, 400HD and the HD ASME variants — is a natural gas SKU, so propane customers cannot have a cupro-nickel MasterTemp.
- Automation compatibility is uneven across the range. The MasterTemp gets a true RS-485 connection to IntelliCenter; the ETi 400 manual documents only a 2-wire dry contact; the UltraTemp manual documents RS-485 with IntelliTouch and EasyTouch on software 1.11 or higher and sends everything else, including IntelliConnect, to dry-contact relay terminals. Check what your specific controller will actually do with your specific heater.
Pentair installations
Real jobs from our installation library. A model number appears only where it was readable on the unit.
Pentair questions
Is a MasterTemp 400 rated at 400,000 BTU of output?
No — that is the input. Pentair's MasterTemp manual states directly that the model size is the BTU input in thousands of BTU per hour, so a MasterTemp 400 burns 400,000 BTU/hr of gas and delivers 84% of it to the water. When you compare it against a heater advertised by output, you are not comparing the same number.
What is TradeGrade, and does buying a Pentair heater online affect the warranty?
TradeGrade is Pentair's professional-channel product family, described by Pentair as exclusively made for and sold by pool professionals; MasterTemp and every UltraTemp model are TradeGrade. It matters because of the warranty: Pentair's own page gives full parts and labor coverage only when the equipment is bought from a brick-and-mortar retailer, pool builder or pool service company and installed by a qualified professional who charges a fee. Bought from an internet retailer, the same product gets 1 year parts only with no labor.
What is the difference between MasterTemp, MasterTemp HD and ETi 400?
The heat exchanger and the efficiency. MasterTemp uses copper at 84% thermal efficiency. MasterTemp HD swaps in cupro-nickel at 82% and is natural gas only. The ETi 400 uses a direct-fire titanium exchanger at 96% and carries 3 years parts and labor instead of 2 — but it is a condensing heater that produces 2 to 4 gallons of condensate an hour, it is physically much larger, and it sits in a premium price tier.
Is GulfStream the same company as Pentair now?
GulfStream is now a Pentair brand. Pentair states that GulfStream heat pumps are sold and supported through Pentair and normal distribution channels, that warranty, service and technical support are managed by Pentair, and that GulfStream continues as a product line in Pentair's heat pump portfolio. The units are still built in North Fort Myers, Florida. We cover them on our GulfStream brand page.
Will a Pentair heater work with automation from another brand?
For basic on/off control, usually yes. Every Pentair heater and heat pump here accepts a dry contact — the fireman's switch terminals on the gas heaters, the relay remote terminals on the UltraTemp — which is what a third-party controller or a time clock uses. The deeper integration, where the automation reads the heater's faults and sets its temperature over RS-485, is Pentair-to-Pentair only, and even then it depends on the model and the controller's software version.
Pentair on the Gulf Coast
Pentair equipment shows up regularly on our own job sites — two of the installs in our gallery are Pentair heaters, one of them a gas heater squeezed into a narrow side yard and one on a fully re-plumbed equipment pad — and we install and service Pentair heaters and heat pumps throughout Sarasota, Manatee, Charlotte & Pinellas County, Florida. We are not claiming authorized-dealer status for any manufacturer on this site. What we can tell you is how this equipment behaves on a Gulf Coast pad, and which of the three gas families is the right answer for your pool. The comparison content on this page is written for pool owners anywhere; the installation offer is local.
Thinking about Pentair? Ask us first.
We install and service pool heating in Sarasota, Manatee, Charlotte & Pinellas County, Florida. If you are outside that area, the comparison above is still yours to use — ask your local contractor the same questions.
Licensed & insured · Florida Certified Pool/Spa Contractor #CPC1460367 · Mon-Sat, 8am-6pm
Last verified September 17, 2026
Specifications and warranty terms are taken from the manufacturer documents below. Manufacturers revise these without notice, so confirm the current terms before you buy. If you spot something out of date, email us and we will fix it.
Sources
- Pentair — MasterTemp High Performance Heater product page
- Pentair — 2025-2026 Pool Product Catalog, Heaters & Heat Pumps section (June 2025)
- Pentair — High-Performance Pool & Spa Gas Heaters brochure (MasterTemp, MasterTemp HD, ETi 400, ETi 250)
- Pentair — UltraTemp High Performance Pool Heat Pump product page
- Pentair — UltraTemp High-Performance Heat Pump brochure (capacity and COP table, warranty, TradeGrade)
- Pentair — Pool product warranty information (MasterTemp, ETi, UltraTemp, GulfStream terms and channel conditions)
- Pentair — MasterTemp Pool and Spa Heater Installation and User's Guide (model table, automation, error codes)
- Pentair — GulfStream brand landing page (GulfStream is now part of Pentair)
- Raypak — pool warranty page (3-year parts and labor on all AVIA residential gas pool heater models)
Ratings on this site are the editorial opinion of Affordable Solar & Pool Heating, LLC, trading as Modern Pool Heating. How we rate heaters. Corrections: modernpoolheating@icloud.com.
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