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Best 400,000 BTU Pool Heaters for Efficient Heating Solutions

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A beige and dark grey Pentair MasterTemp High Performance Pool Heater 175K-400K BTU, equipped with attached vents and a side control panel, labeled "Pentair MasterTemp 400," is compatible with Pentair Automation Systems for enhanced control.
The Pentair MasterTemp High Performance Pool Heater 175K-400K BTU from Pentair Pool features a square-shaped design with a beige and black exterior, multiple pipe connections on the right side, and is compatible with Pentair Automation Systems.

Pentair MasterTemp Natural Gas Heater 175K 200K 250K 300K 400K BTU

Pentair Pool

MASTERTEMP® High-Performance Natural Gas Heater The MasterTemp pool heater sets the industry standard in pool heating technology, with more units s...

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A beige and dark grey Pentair MasterTemp High Performance Pool Heater 175K-400K BTU, equipped with attached vents and a side control panel, labeled "Pentair MasterTemp 400," is compatible with Pentair Automation Systems for enhanced control.
The Pentair MasterTemp High Performance Pool Heater 175K-400K BTU from Pentair Pool features a square-shaped design with a beige and black exterior, multiple pipe connections on the right side, and is compatible with Pentair Automation Systems.

Pentair MasterTemp Propane Heater 175K 200K 250K 300K 400K BTU

Pentair Pool

Save money and energy with the MasterTemp High-Performance Propane Heater. Already known as being dependable and efficient, MasterTemp now offers s...

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The Pentair Pool 400K BTU MasterTemp 400 Natural Gas Heater 460736 boasts a beige body, sleek black panel, and side pipes. This energy-efficient marvel offers smart connectivity, making it an efficient addition to any pool setup.
Compact beige and black Pentair Pool MasterTemp 400 Natural Gas Heater with smart connectivity features and three side pipe connections.

Pentair 400K BTU MasterTemp 400 Natural Gas Heater 460736

Pentair Pool

MASTERTEMP® High-Performance Heater The MasterTemp pool heater sets the industry standard in pool heating technology, with more units sold than any...

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The Pentair Pool 400K BTU MasterTemp 400 Heavy Duty Natural Gas Heater, model number 460805, showcases a beige top with a dark gray front panel. It offers intuitive control buttons and plumbing connections and features a robust cupronickel heat exchanger that integrates seamlessly with Pentair Automation Systems for efficient operation.
Introducing the Pentair Pool's 400K BTU MasterTemp 400 Heavy Duty Natural Gas Heater Cupronickel 460805 400HD—a square, beige, and black pool heater featuring a durable cupro-nickel heat exchanger. Engineered for efficiency, its multiple pipe connections allow seamless integration with your existing automation systems.

Pentair 400K BTU MasterTemp 400 Heavy Duty Natural Gas Heater Cupronickel 460805 400HD

Pentair Pool

MASTERTEMP® HD Heavy Duty Heater: The MasterTemp HD is Pentair’s solution for those seeking maximum durability in various conditions and applicatio...

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Technical diagram of the Pentair Pool 400K BTU Max-E-Therm Natural Gas Heater SR400NA with mechanical components, featuring front, back, side, and top views labeled with dimensions.
Pentair Pool's Black Pentair 400K BTU Max-E-Therm Natural Gas Heater SR400NA offers smart connectivity and a digital control panel, featuring energy-saving automation alongside two intake pipes on the side.

Pentair Sta-Rite 400K BTU Max-E-Therm Natural Gas Heater SR400NA

Pentair Pool

YOUR POOL HEATER JUST GOT A WHOLE LOT SMARTER. For indoor or outdoor installations on pools and spas. Features include an LCD temperature readout w...

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Pentair 400K BTU Max-E-Therm Propane Gas Heater SR400LP
Pentair 400K BTU Max-E-Therm Propane Gas Heater SR400LP

Pentair Sta-Rite 400K BTU Max-E-Therm Propane Gas Heater SR400LP

Pentair Pool

YOUR POOL HEATER JUST GOT A WHOLE LOT SMARTER. For indoor or outdoor installations on pools and spas. Features include an LCD temperature readout w...

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The Hayward W3H400FDN H-Series Natural Gas Heater 400K BTU Low NOx is a large, industrial outdoor generator with a black and grey casing and multiple vents, designed to offer low NOx emissions.
The Hayward W3H400FDN H-Series Natural Gas Heater 400K BTU Low NOx is a heavy-duty, portable device encased in a rugged design, featuring an LCD display and various connection ports on the side, and is designed with Universal H-Series low NOx emissions technology for energy-efficient performance.

Hayward 400K BTU H-Series Natural Gas Heater Cupro Nickel W3H400FDN

Hayward
$4,199.00 - $4,199.00
$4,199.00
$4,199.00 - $4,199.00
$4,199.00

The Hayward Universal H-Series Pool and Spa Gas Heaters are known for their energy-efficient and reliable heating capabilities and are suitable for...

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$4,199.00 - $4,199.00
$4,199.00
$4,199.00 - $4,199.00
$4,199.00
The Pentair Pool 400K BTU MasterTemp ASME HD Natural Gas Heater, model 461021, is designed in tan and black with a distinct bronze header that includes side vents and pipes. It features an advanced ignition control module and is constructed with cupronickel material for enhanced durability. This ultra-high ASME certified heater stands out against a clean white background.

Pentair 400K BTU MasterTemp 400 ASME HD Natural Gas Heater, Cupronickel, 461021

Pentair Pool

Ultra-High ASME® certified performance in a compact, quiet, and eco-friendly design for your commercial application. The bronze header design allo...

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Hayward 400K BTU H-Series Propane Heater Cupro Nickel W3H400FDP

Hayward
$4,199.00 - $4,199.00
$4,199.00
$4,199.00 - $4,199.00
$4,199.00

The Universal H-Series is an energy-efficient, high-performance, installation-adaptable commitment to the pool service professional. Stand...

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$4,199.00 - $4,199.00
$4,199.00
$4,199.00 - $4,199.00
$4,199.00

Raypak 399K BTU Digital Natural Gas Heater 406A (P-R406A-EN-C 009219)

Raypak
$3,963.00 - $3,963.00
$3,963.00
$3,963.00 - $3,963.00
$3,963.00

Raypak Digital Gas Pool & Spa Heater (206A-406A) Efficient, Durable, and Smart Heating The Raypak Digital Gas Pool & Spa Heater delivers r...

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$3,963.00 - $3,963.00
$3,963.00
$3,963.00 - $3,963.00
$3,963.00

Pentair MasterTemp 400 Propane Heater – 400K BTU (EC-462029)

Pentair Pool
$4,499.00 - $4,499.00
$4,499.00
$4,499.00 - $4,499.00
$4,499.00

The MasterTemp Heater provides energy-saving and advanced operating features available only from much larger heaters. With its revolutionary pre-mi...

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$4,499.00 - $4,499.00
$4,499.00
$4,499.00 - $4,499.00
$4,499.00

Pentair MasterTemp 400 Natural Gas Heater – 400K BTU (EC-462028)

Pentair Pool
$4,499.00 - $4,499.00
$4,499.00
$4,499.00 - $4,499.00
$4,499.00

The MasterTemp 400 Heater provides energy-saving and advanced operating features that are available only from much larger heaters. With its revolut...

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$4,499.00 - $4,499.00
$4,499.00
$4,499.00 - $4,499.00
$4,499.00

Raypak AVIA HD 399K BTU Natural Gas Heater – NiTek, Low NOx, Wi-Fi Enabled (P-R404A-EN-N, 018045)

Raypak
$4,498.00 - $4,498.00
$4,498.00
$4,498.00 - $4,498.00
$4,498.00

Smarter, Easier Pool Heating The AVIA HD pool heater features built-in Wi-Fi and the Raymote app for seamless control—no extra panels needed. Unmat...

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$4,498.00 - $4,498.00
$4,498.00
$4,498.00 - $4,498.00
$4,498.00

Raypak AVIA HD 399K BTU Propane Pool Heater – NiTek, Low NOx, Wi-Fi Enabled (P-R404A-EP-N, 018051)

Raypak
$4,498.00 - $4,498.00
$4,498.00
$4,498.00 - $4,498.00
$4,498.00

Smarter, Easier Pool Heating The AVIA HD pool heater features built-in Wi-Fi and the Raymote app for seamless control—no extra panels needed. Unmat...

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$4,498.00 - $4,498.00
$4,498.00
$4,498.00 - $4,498.00
$4,498.00

Raypak AVIA 399K BTU Natural Gas Heater – Low NOx, Wi-Fi Enabled (018033 P-R404A-EN-C)

Raypak
$4,196.00 - $4,196.00
$4,196.00
$4,196.00 - $4,196.00
$4,196.00

Smarter, Easier Pool Heating with AVIA Smart Control: AVIA features built-in Wi-Fi and works seamlessly with the Raymote app, eliminating the nee...

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$4,196.00 - $4,196.00
$4,196.00
$4,196.00 - $4,196.00
$4,196.00
Technical diagram of the Pentair Pool 400K BTU Max-E-Therm Natural Gas Heater SR400NA with mechanical components, featuring front, back, side, and top views labeled with dimensions.
Pentair Pool's Black Pentair 400K BTU Max-E-Therm Natural Gas Heater SR400NA offers smart connectivity and a digital control panel, featuring energy-saving automation alongside two intake pipes on the side.

Pentair Sta-Rite 400K BTU Max-E-Therm HD Natural Gas Heater SR400HD

Pentair Pool

For indoor or outdoor installations on pools and spas. Features include an LCD temperature readout with dual thermostat controls, temperature safet...

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The Pentair Pool 400K BTU Max-E-Therm ASME Natural Gas Heater Cupronickel 460763 is a piece of industrial equipment with a compact design, featuring a dome-shaped body and brass fittings on the side.

Pentair Sta-Rite 400K BTU Max-E-Therm ASME Natural Gas Heater Cupronickel 460763

Pentair Pool

Ultra-High ASME® certified performance in a compact, quiet, and eco-friendly design for your commercial application. The bronze header design allo...

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Pentair MasterTemp High Performance Gas Pool Heater

Pentair 400K BTU MasterTemp 400 ASME Natural Gas Heater 460775

Pentair Pool

Ultra-High ASME® certified performance in a compact, quiet, and eco-friendly design for your commercial application. The bronze header design allo...

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Pentair ETi 400 High Efficiency Gas Pool Heater 461113
The Pentair Pool 400K BTU ETi 400 ASME Natural Gas Heater Cupronickel (Model 461113) boasts outstanding thermal efficiency and features multiple pipe connections in a sleek black and beige finish, optimizing energy savings for your pool.

Pentair 400K BTU ETi® 400 Natural Gas Heater (461113)

Pentair Pool

MORE STAYING POWER. MORE SAVING POWER. The ETi 400 pool and spa heater brings you TitanTough Direct-Fire Titanium, the toughest ASME-certified cons...

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Pentair Pool's eco-friendly Pentair 400K BTU Max-E-Therm ASME Propane Heater Cupronickel 460764 boasts a compact design with a dome-shaped top and brass side connections.

Pentair Sta-Rite 400K BTU Max-E-Therm ASME Propane Heater Cupronickel 460764

Pentair Pool

Ultra-High ASME® certified performance in a compact, quiet, and eco-friendly design for your commercial application. The bronze header design allo...

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Raypak 399K BTU Digital Propane Heater, Cupro-Nickel, B-R406A-EP-X 017414

Raypak
$5,280.00 - $5,280.00
$5,280.00
$5,280.00 - $5,280.00
$5,280.00

Raypak 399K BTU Propane Heater 406A with Cupro-Nickel Heat Exchanger | Model B-R406AEPX 017414 The Raypak B-R406A Digital Pool and Spa Heater deliv...

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$5,280.00 - $5,280.00
$5,280.00
$5,280.00 - $5,280.00
$5,280.00

Lochinvar 399K EnergyRite Natural Gas Heater Copper, ERN402 ERN-402

Lochinvar
$3,899.00 - $3,899.00
$3,899.00
$3,899.00 - $3,899.00
$3,899.00

Lochinvar ERN402 EnergyRite Low NOx 399,999 BTU, Natural Gas, Polymer Header Heater heats fast, saves money, and helps conserve our natural resourc...

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$3,899.00 - $3,899.00
$3,899.00
$3,899.00 - $3,899.00
$3,899.00

Lochinvar 399K EnergyRite ASME Natural Gas Heater, Copper, ERN-402-A ERN402A

Lochinvar
$4,199.00 - $4,199.00
$4,199.00
$4,199.00 - $4,199.00
$4,199.00

Lochinvar ERN402A EnergyRite Low NOx 399,999 BTU, Natural Gas, ASME, Polymer Header Heater heats fast, saves money, and helps conserve our natural ...

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$4,199.00 - $4,199.00
$4,199.00
$4,199.00 - $4,199.00
$4,199.00
The Lochinvar 399K EnergyRite ASME Natural Gas Heater, model ERN402-A-8009, showcases a durable cupronickel heat exchanger and includes a digital control panel, all set against a white background.

Lochinvar 399K EnergyRite ASME Natural Gas Heater, Cupronickel, ERN402-A-8009 ERN402A8009

Lochinvar
$4,499.00 - $4,499.00
$4,499.00
$4,499.00 - $4,499.00
$4,499.00

Lochinvar ERN-402-A-8009 EnergyRite, ASME, 400,000 BTU, Natural Gas, Polymer Header, Pool, and Spa Heater with Cupro-Nickel Heat Exchanger. Two-l...

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$4,499.00 - $4,499.00
$4,499.00
$4,499.00 - $4,499.00
$4,499.00

Raypak AVIA 399K BTU Propane Heater – Low NOx, Wi-Fi Enabled (018039 P-R404A-EP-C)

Raypak
$4,196.00 - $4,196.00
$4,196.00
$4,196.00 - $4,196.00
$4,196.00

Smarter, Easier Pool Heating with AVIA Smart Control: AVIA features built-in Wi-Fi and works seamlessly with the Raymote app, eliminating the ne...

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$4,196.00 - $4,196.00
$4,196.00
$4,196.00 - $4,196.00
$4,196.00

Raypak 399K BTU Digital Propane Heater 406A (P-R406A-EP-C 009227)

Raypak
$3,963.00 - $3,963.00
$3,963.00
$3,963.00 - $3,963.00
$3,963.00

Raypak Digital Gas Pool & Spa Heater (206A-406A) Efficient, Durable, and Smart Heating The Raypak Digital Gas Pool & Spa Heater delivers re...

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$3,963.00 - $3,963.00
$3,963.00
$3,963.00 - $3,963.00
$3,963.00
Hayward Heat Exchanger Assembly Replacement for Hayward H400FD Universal H-Series Low Nox Pool Heater, FDXLHXA1400
Hayward Heat Exchanger Assembly Replacement for Hayward H400FD Universal H-Series Low Nox Pool Heater, FDXLHXA1400

Hayward FDXLHXA1400 Heat Exchanger Assembly H400FD 400K BTU

Hayward
$1,399.99 - $1,399.99
$1,399.99
$1,399.99 - $1,399.99
$1,399.99

Hayward Heat Exchanger Assembly Replacement for Hayward H400FD Universal H-Series Low Nox Pool Heater, FDXLHXA1400 This Heat Exchanger Assembly is ...

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$1,399.99 - $1,399.99
$1,399.99
$1,399.99 - $1,399.99
$1,399.99

Pentair 77707-1441 400K Natural Gas to Propane Conversion Kit for Max-E-Therm & Mastertemp

Pentair Pool
$59.99 - $59.99
$59.99
$59.99 - $59.99
$59.99

Pentair 77707-1441 Natural Gas to Propane Conversion Kit For Model 400 Max-E-Therm Heater Burner System Brand: Pentair Weight: 0.1 pound Shipping ...

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$59.99 - $59.99
$59.99
$59.99 - $59.99
$59.99

Hayward H-Series FDXLGSV0001 Natural Gas Valve Kit for 150-400K Pool Heaters

Hayward
$319.99 - $319.99
$319.99
$319.99 - $319.99
$319.99

GAS VALVE NATURAL FD

$319.99 - $319.99
$319.99
$319.99 - $319.99
$319.99

Raypak 399K BTU Digital Natural Gas Heater Cupronickel P-R406A-EN-X 014941

Raypak
$4,283.00 - $4,283.00
$4,283.00
$4,283.00 - $4,283.00
$4,283.00

Raypak Digital Gas Pool & Spa Heater (206A-406A) Efficient, Durable, and Smart Heating The Raypak Digital Gas Pool & Spa Heater delivers re...

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$4,283.00 - $4,283.00
$4,283.00
$4,283.00 - $4,283.00
$4,283.00

Raypak 399K BTU Digital Propane Heater Cupronickel (P-R406A-EP-X 014953)

Raypak
$4,283.00 - $4,283.00
$4,283.00
$4,283.00 - $4,283.00
$4,283.00

Raypak Digital Gas Pool & Spa Heater (206A-406A) Efficient, Durable, and Smart Heating The Raypak Digital Gas Pool & Spa Heater delivers re...

View full details
$4,283.00 - $4,283.00
$4,283.00
$4,283.00 - $4,283.00
$4,283.00

Raypak 399K BTU 408A Professional ASME Digital Gas Heater Cupro Nickel (013731, 013732)

Raypak
$6,856.00 - $6,856.00
$6,856.00
$6,856.00 - $6,856.00
$6,856.00

Built for Commercial Durability The Raypak Professional Pool and Spa Heater is specifically designed for commercial properties, making it an ideal...

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$6,856.00 - $6,856.00
$6,856.00
$6,856.00 - $6,856.00
$6,856.00

Raypak 399K BTU Digital Propane Heater, B-R406A-EP-C 017386

Raypak
$4,719.00 - $4,719.00
$4,719.00
$4,719.00 - $4,719.00
$4,719.00

The Raypak B-R399A Digital Pool and Spa Heater delivers 399,000 BTUs of natural gas power with bronze headers, all-copper fin tube heat exchangers,...

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$4,719.00 - $4,719.00
$4,719.00
$4,719.00 - $4,719.00
$4,719.00

Best 400,000 BTU Pool Heaters for Efficient Heating Solutions

A 400,000 BTU pool heater is a powerful and efficient solution for heating large pools quickly and effectively. Delivering 400,000 British Thermal Units (BTUs) per hour, this high-performance unit is ideal for pools ranging from 20,000 to 40,000 gallons, depending on factors such as climate, pool usage, and target water temperature. Perfect for residential and commercial applications, these heaters are commonly used for medium to large in-ground pools, as well as pools with attached spas or high-demand heating requirements.

With its impressive BTU rating, a 400,000 BTU pool heater ensures rapid heat-up times and consistent water temperatures, making it an excellent choice for pool owners in cooler climates or those who value year-round comfort. Whether you're looking to extend your swimming season or enjoy warm water on demand, this type of pool heater delivers dependable performance and energy efficiency.

Best Sellers

The Pentair Pool 100' GloBrite MULTI COLOR Pool Spa LED Light, model 602055, features vibrant colors and spiral patterns on a dark backdrop, making it ideal for pool and spa use.

Pentair 30' Cord GloBrite® Multi-Color LED Light 602053 - NEW VERSION

Pentair Pool
$449.99 - $449.99
$449.99
$449.99 - $449.99
$449.99

ADD BRILLIANT MULTICOLOR LED LIGHTING TO SHALLOW-WATER AREAS GloBrite lights utilize one of the industry’s most advanced technologies to showcase a...

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$449.99 - $449.99
$449.99
$449.99 - $449.99
$449.99
Pentair iChlor Salt Chlorine Generator System with Power PackPentair iChlor Salt Chlorine Generator Cell Only
Pentair iChlor 15 Replacement Cell Only 523010 15K gal.

Pentair iChlor 30 Salt Chlorine Generator Cell Only 523009

Pentair Pool

ORDINARY TABLE SALT. EXTRAORDINARY TECHNOLOGY. The iChlor Salt Chlorine Generator features smart technology that provides built-in intelligence for...

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Pentair 100' Cord GloBrite® Multi-Color Pool Spa LED Light 602055 - NEW VERSION

Pentair Pool

ADD BRILLIANT MULTICOLOR LED LIGHTING TO SHALLOW WATER AREAS GloBrite lights utilize one of the industry’s most advanced technologies to showcase a...

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Genuine Purechlor CLG125A-010 Replacement Salt Cell for 25K Gallon Pools C115199G

PureChlor
$749.99 - $749.99
$749.99
$749.99 - $749.99
$749.99

PureChlor Replacement Service Cell for PureChlor Salt Chlorine Generator systems (*sold separately). These are authentic, genuine OEM replacement s...

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$749.99 - $749.99
$749.99
$749.99 - $749.99
$749.99

Genuine PureChlor Salt Generator Power Supply – Fits All Cell Sizes

PureChlor
$549.99 - $549.99
$549.99
$549.99 - $549.99
$549.99

PureChlor Salt Generator Replacement Power Supply Box The PureChlor Power Supply (PSU) is the brains of your saltwater pool system. Fully certified...

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$549.99 - $549.99
$549.99
$549.99 - $549.99
$549.99
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