A larger pool or a pool-and-spa combination that needs fast heat-up in any weather.
★★★★★ 230+ Google Reviews · CPO C-105377 · 40+ years of combined founder experience
Sizing comes first.The right heater is set by your pool's surface area and the temperature rise you want, and by the flow your pump and plumbing deliver. Start with the heater size calculator; we confirm it on site before quoting.
This model hasn't been through our rating yet.
MasterTemp 400 NG
Pending
From the manufacturer's documents listed under Sources. Where the documents disagree, the table says so.
| Manufacturer model | MasterTemp 400, natural gas, P/N 460736 |
|---|---|
| BTU input | 400,000 BTU/hr input — the MasterTemp manual defines model size as BTU input in thousands of BTU/hr, so output is input times efficiency |
| Thermal efficiency | 84% (tested per ANSI Z21.56:19/CSA 4.7:19 2019, section 5.10) |
| Heat exchanger | Copper (cupro-nickel on the HD models) |
| Fuel | Natural gas (P/N 460737 is the propane version) |
| Emissions | Certified for low NOx emissions; CSA certified to CSA/ANSI Z21.56:19/CSA 4.7:19 |
| Water connections | 2" PVC slip unions, supplied with the heater |
| Water flow | 40 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) | 1" to 20 equivalent ft, 1-1/4" to 100 ft, 1-1/2" to 200 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 |
Parts
2 years
Labor
2 years
Heat exchanger
Under the parts term
| Parts | 2 years |
|---|---|
| Labor | 2 years |
These are the manufacturer's published terms. Terms can depend on the installer, the dealer program and where the heater was bought, and they change without notice, so we confirm the exact term for your install on the written quote.
The traditional material and the cheapest to build. It transfers heat well and does fine on well-balanced chlorine water, but it's the least forgiving of low pH, high chlorine and salt. Water chemistry has to stay in range for a copper exchanger to reach its full life.
See every material side by side on the comparison page, or read the Pentair MasterTemp error codes guide for what the display is telling you.
Most to least forgiving of salt and unbalanced water.
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Built-in Wi-Fi
Every figure on this page comes from these manufacturer documents. We re-open each one and match the model number, capacity and efficiency before the date moves. How we verify.
Manufacturers revise terms without notice. Treat this page as a starting point and confirm the current terms before you buy. If something here is out of date, tell us and we'll fix it.
Parts: 2 years. Labor: 2 years. These are the manufacturer's terms as published; warranty terms change and can depend on the installer and the channel, so we confirm the exact term for your install on the written quote.
The MasterTemp 400 NG is rated at 400,000 BTU/hr input. Heater size comes from your pool's surface area and the temperature rise you want, not from gallons, and the pump and plumbing have to deliver the flow the heater needs. Use our heater size calculator for a starting number, and we confirm it on site before quoting.
Not directly. The MasterTemp 400 NG connects to pool automation through a relay, and the heater has no app of its own.
The traditional material and the cheapest to build. It transfers heat well and does fine on well-balanced chlorine water, but it's the least forgiving of low pH, high chlorine and salt. Water chemistry has to stay in range for a copper exchanger to reach its full life.
Every figure on this page comes from the manufacturer's own documents, listed under Sources with the date we last checked them. Manufacturers revise terms without notice, so treat the page as a starting point and confirm the current terms on your quote.
We quote, install and service Pentair heaters across Palm Beach and Broward, managed by us under our Florida Certified Pool/Spa Contractor license (CPC1461731). You get a free on-site sizing visit and one written price. Gas lines, new circuits and refrigerant work are done by licensed contractors we manage.
We call back within 30 minutes during business hours.
