Pentair MasterTemp 250HD Heavy Duty Gas Pool Heater
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.
Gas heater
SKU MasterTemp 250HD
- BTU input
- 250,000 BTU/hr
- Fuel / power
- Natural gas
- Thermal efficiency
- 82% thermal efficiency (input rated; 250,000 BTU/hr input)
- Heat exchanger
- Cupro-nickel
- Warranty
- 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.
Modern Pool Heating Equipment Score
Our score for the equipment itself. It is not a Google or customer review rating.
How we rate heatersFull specifications
Every row below is taken from a manufacturer document. Anything the manufacturer does not publish is left out rather than estimated.
| Manufacturer model | MasterTemp 250HD, natural gas, P/N 460806 |
|---|---|
| BTU input | 250,000 BTU/hr input — Pentair defines MasterTemp model size as BTU input in thousands of BTU/hr |
| Thermal efficiency | 82% (tested per ANSI Z21.56:19/CSA 4.7:19 2019, section 5.10) |
| Heat exchanger | Cupro-nickel — this is what the HD designation means |
| Fuel | Natural gas only; Pentair publishes no propane part number for any HD variant |
| Emissions | MasterTemp High Performance Heater is certified for low NOx emissions per Pentair's catalog; CSA certified to CSA/ANSI Z21.56:19/CSA 4.7:19 |
| Water connections | 2" PVC slip unions, supplied with the heater |
| Water flow | 25 GPM minimum, 120 GPM maximum (bypass valve required above 120 GPM) |
| Gas connection and supply pressure | 3/4" pipe to the gas valve; 4" w.c. minimum and 14" w.c. maximum inlet; manifold factory set at -0.2" ±0.1" w.c.; sediment trap and manual shut-off required outside the cabinet |
| Gas pipe sizing (natural gas) | 3/4" to 20 equivalent ft, 1" to 70 ft, 1-1/4" to 250 ft (add 3 ft per elbow) |
| Electrical | 120 or 240 VAC, 60 Hz, single phase; 15 A circuit, 14 gauge field wiring; about 5 A at 120 VAC or 2.5 A at 240 VAC. Ships with the 240 VAC plug fitted. Not rated for 208 VAC. |
| Clearances | 6" from combustible surfaces on the top, exhaust side, header side and door panels; 3 ft between the top of the exhaust vent and any roof overhang; 36" from an air conditioner or heat pump |
| Dimensions and weight | 23.02" W x 21.0" D x 28.15" H; 136 lb carton weight |
| Minimum water temperature | Do not run continuously below 68°F water — condensation damage voids the warranty |
| Controls and automation | RS-485 COM port connects directly to an IntelliCenter Control System (up to 16 heaters, addresses 1-16; the heater's own buttons go inactive and its alarms appear on the IntelliCenter home screen). IntelliTouch and EasyTouch use the 2-wire fireman's switch terminals; Pentair's IntelliConnect guide wires a heater through its low-voltage dry contacts to the heater's external switch connection. Optional Smart Heater Bypass Kit P/N 462048. |
| Florida anchoring | Bolt Down Bracket Kit P/N 460738; Pentair states anchor clamps are required in Florida |
Why homeowners consider it
- It is the smallest cupro-nickel heater Pentair builds in the MasterTemp line, which makes it the cheapest route into a corrosion-resistant gas exchanger on this brand.
- The install is far easier than a 400HD: 25 GPM minimum flow instead of 40, and 3/4 inch gas pipe is allowed to 20 equivalent feet with 1 inch good to 70 feet.
- Same LCD diagnostics, same five-error history, same RS-485 port to IntelliCenter as every other MasterTemp — the HD changes the exchanger, not the brain.
- For a salt pool that is heated occasionally or that sits behind solar or a heat pump, it is a sensible amount of gas heater rather than an expensive one.
- Parts availability is identical to the rest of the line, which in Florida is the practical difference between a one-visit repair and a two-week wait.
What to know before buying
- Natural gas only — Pentair publishes no propane part number for any HD model. On propane you are looking at the copper MasterTemp 250 (P/N 460733) instead.
- 82% thermal efficiency rather than 84%. That is the price of the cupro-nickel exchanger and it is a permanent, if small, operating cost.
- 250,000 BTU/hr is not a fast spa heater. If you have an attached spa you want hot in half an hour, this is the wrong size.
- Pentair's manual warns that running the heater continuously below 68°F water causes condensation damage and voids the warranty. Do not use it as freeze protection.
- Cupro-nickel does not excuse bad plumbing. Chlorine tablets in the skimmer or a chemical feeder upstream of the heater will still attack the exchanger.
- The warranty is 2 years parts and labor, and only when the heater is bought through the professional channel and installed by a paid professional. Online purchase drops it to 1 year parts only.
Warranty, term by term
The warranty only matters on the parts that actually fail. Here is how this one splits up.
- Parts
- 2 years
- Labor
- 2 years
Pentair's published warranty table gives MasterTemp 2 years parts and labor when the heater is bought through a brick-and-mortar retailer, pool builder or pool service company AND installed by a qualified professional who charges a fee. A heater bought from an internet retailer is covered for 1 year parts only, with no labor. Pentair also publishes a bundle: install a qualifying pump, filter and heater together and all three go to 3 years. Registration is required. MasterTemp is a TradeGrade product, which is Pentair's professional-channel line. Professional installation and authorized-channel requirements apply.
Why the heat exchanger matters
The heat exchanger is the part of a pool heater that actually moves heat into the water, and what it is made of decides how long the heater survives Florida water chemistry. Here is what the four materials mean in practice.
- Copper
- The traditional material and the cheapest to build. It transfers heat well and is fine on a well-balanced chlorine pool, but it is the least forgiving of low pH, high chlorine and salt. On the Gulf Coast it is usually the first component to fail.
- Cupro-nickelThis heater
- Copper alloyed with nickel. It gives up a little heat transfer in exchange for much better resistance to unbalanced water chemistry and salt. On gas heaters this is the upgrade worth having in Florida, and some manufacturers now ship it as standard.
- NiTek (nickel alloy)
- A nickel-alloy exchanger used on some gas heaters as a corrosion-resistant alternative to copper. Positioned between cupro-nickel and titanium in both durability and price.
- Titanium
- Effectively immune to pool water chemistry, including salt. It is the standard on quality pool heat pumps and the reason a heat pump can sit on a salt pool for years without exchanger trouble. It is expensive, which is why you rarely see it on gas heaters.
Whatever the material, plumbing order matters just as much: a chlorinator or salt cell belongs downstream of the heater, never upstream.
How we scored it
- Warranty matches the rest of the MasterTemp line at 2 years parts and labor through the professional channel, with the online-purchase penalty intact.
- The cupro-nickel exchanger earns the durability score; on a salt pool or a coastal lot it is the reason to buy this SKU over the copper 250.
- Performance is the lowest score on the card and fairly so: 82% efficiency and 250,000 BTU/hr input make this a steady heater rather than a fast one, and it will not serve an attached spa well.
- Serviceability is a full 5 — shared parts with every other MasterTemp, stocked regionally, and an LCD that stores the last five faults.
- Controls are identical to the larger models: RS-485 direct to IntelliCenter, fireman's switch for IntelliTouch, EasyTouch, IntelliConnect or a timer.
- Value is strong because the install is cheaper than a 400HD in every direction — smaller gas line, lower flow requirement, less fuel — while keeping the exchanger that actually matters here.
- The computed score sits below the owner's 4.5 starter score for the MasterTemp line. The exchanger and controls score well; it is the combination of 82% efficiency and 250,000 BTU/hr input that costs it, and that is a fair description of what this SKU is.
Real Modern Pool Heating installations
Installed locally, researched for everyone
Affordable Solar & Pool Heating, LLC installs and services pool heating in Sarasota, Manatee, Charlotte & Pinellas County, Florida. If you are outside that area this page is still yours to use — take the questions on it to your local contractor. Pool heater installation in Sarasota.
Other heaters worth putting beside it
Same job, different tradeoffs. Every one of these has its own verified spec page.
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.
Hayward · Universal H-Series
Hayward Universal H-Series H250FDN Gas Pool Heater
Model H250FDN
- BTU input
- 250,000 BTU/hr
- Thermal efficiency
- 84%
- Heat exchanger
- Cupro-nickel
- Warranty
- 3-Year Parts / 1-Year Labor
- Wi-Fi / automation
- App Control via AutomationAutomation Compatible (Relay)
An average-sized Florida pool, or a pool with a small spa, where you want gas-speed heat without paying for 400,000 BTU you will never use.
Raypak · AVIA HD with NiTek
Raypak AVIA HD 404A with NiTek Gas Pool & Spa Heater
Model P-R404A-EN-N
- BTU input
- 399,000 BTU/hr
- Thermal efficiency
- 84%
- Heat exchanger
- NiTek (nickel alloy)
- Warranty
- 3-Year Parts & Labor
- Wi-Fi / automation
- Wi-Fi Built InAutomation Compatible (Relay)
A salt pool, a coastal lot, or any Florida pool whose chemistry does not get watched closely — the version of the AVIA to buy when the heat exchanger is the part you are worried about.
MasterTemp 250HD questions
Is the 250HD worth the premium over the standard MasterTemp 250?
On a salt pool, a coastal lot or a pool whose chemistry drifts, yes — you are buying a cupro-nickel exchanger instead of a copper one for a modest price difference. On a chlorine pool inland with disciplined chemistry, the standard 250 at 84% efficiency is the better value.
Will a 250,000 BTU heater run my spa?
It will heat a spa, but slowly by gas-heater standards. If fast spa heat is the reason you are buying gas, size up to a 400. If the spa is occasional and you do not mind waiting, the 250 is adequate.
Is the 250HD available on propane?
No. Pentair lists a natural gas part number (460806) and no propane equivalent for the 250HD or any other HD variant. Propane buyers get the copper MasterTemp 250, P/N 460733.
What flow rate does it need?
25 GPM minimum through the heater and 120 GPM maximum before a bypass valve is required. On a variable-speed pump, program a heating speed that clears 25 GPM or the water pressure switch will keep the burner off.
How long is the warranty?
Two years parts and labor, when the heater 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 online, Pentair's warranty page gives 1 year parts only with no labor. Registration is required.
Do you install Pentair heaters in my area?
We install and service Pentair gas heaters throughout Sarasota, Manatee, Charlotte & Pinellas County, Florida. This page is written for pool owners anywhere; the installation offer is local.
Is the MasterTemp 250HD right for your pool?
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 (models, part numbers, efficiency)
- Pentair — MasterTemp 250HD SKU page (P/N 460806)
- Pentair — MasterTemp Pool and Spa Heater Installation and User's Guide (BTU input, gas pressure, flow, clearances, electrical, error codes)
- Pentair — 2025-2026 Pool Product Catalog, Heaters & Heat Pumps section (June 2025)
- Pentair — High-Performance Pool & Spa Gas Heaters brochure (efficiency, exchanger, dimensions, heat-up times)
- Pentair — Pool product warranty information (parts, labor, compressor, exchanger terms and channel conditions)
- Pentair — IntelliConnect Control and Monitoring System Installation Guide (how a heater is wired to IntelliConnect)
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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Mon-Sat, 8am-6pm · Licensed & insured · Florida Certified Pool/Spa Contractor CPC1460367