Product Overview

The Jandy JXi Natural Gas Heater | JXI400NN is a compact, high-performance pool and spa heater designed to deliver fast heat-up times, efficient operation, and professional-grade reliability. With a powerful 399,000 BTU input, this heater is ideal for medium to large pools, spas, pool/spa combinations, and systems where quick temperature recovery is important.

This model includes a durable cupronickel heat exchanger, making it a strong choice for demanding water conditions, saltwater pools, high-flow systems, and applications where added corrosion resistance is preferred. The JXi platform is known for its space-saving footprint, lightweight design, low-NOx operation, and installer-friendly layout.

With natural gas fuel, electronic ignition, digital controls, 2" water connections, and included Versa Plumb® connection components, the JXI400NN is built for professional pool heating installations.

⚠️ Important Purchase Notice

This product is intended to be purchased and installed by pool professionals. Product support is not provided to homeowners.

Returns are not accepted on this or any electronic equipment.

Damages to product from shipping will be covered and must be reported promptly.

To prevent possible damage during transit, we strongly recommend selecting Freight.

By purchasing this item, you agree to the terms above.

Ideal For

• Medium to large residential pools
• Pool and spa combination systems
• Fast spa heat-up applications
• Saltwater pools and demanding water conditions
• Natural gas pool heating systems
• Equipment pads with limited space
• Replacing older gas pool heaters
• Pool owners wanting fast temperature recovery
• Professional pool heater installations
• Systems requiring a corrosion-resistant cupronickel exchanger

Key Features

• 399,000 BTU input — delivers powerful heating performance for pools and spas.
• Natural gas operation — reliable heating fuel source for compatible gas systems.
• Cupronickel heat exchanger — offers enhanced resistance to corrosion and demanding pool water conditions.
• Low-NOx design — designed to meet modern emissions requirements in many regions.
• Compact JXi footprint — approx. 2' x 2' equipment pad footprint helps save space.
• Lightweight heater design — easier to handle and position compared with many traditional heaters.
• Electronic ignition — reliable startup without a standing pilot.
• Digital control interface — simplifies temperature adjustment and system operation.
• 2" water connections — standard pool plumbing connections for professional installation.
• Versa Plumb® compatible components included — supports efficient Jandy equipment pad layouts.
• Indoor/outdoor application — suitable for approved indoor or outdoor installations when properly vented and installed.
• CSA and ANSI certified — built to recognized heater safety and performance standards.

Benefits

The Jandy JXI400NN provides the heating power needed for fast pool and spa temperature recovery while maintaining a compact, efficient design. Its 399K BTU rating makes it a strong choice for larger pools and spa systems where quick heat-up is a priority.

The cupronickel heat exchanger is a major advantage for pools with salt systems, aggressive water chemistry, or higher mineral content. Compared with standard copper exchanger models, cupronickel provides added durability in tougher water environments when water chemistry is properly maintained.

For installers, the JXi’s compact footprint, included union components, lightweight cabinet, and digital controls help make installation and service more convenient.

Specifications

Included Components

• 1 × Jandy JXi JXI400NN natural gas heater
• Cupronickel heat exchanger assembly
• Digital control interface
• Versa Plumb® sweep elbow
• 2" universal union tailpiece
• 2" universal union cap
• 2" universal union O-ring
• 2" universal union nut
• Manufacturer-supplied installation documentation

Gas line materials, shutoff valve, electrical wiring, venting components, bonding materials, automation wiring, plumbing valves, check valves, and installation labor are sold separately unless specifically included by the supplier.

Installation Notes

This heater must be installed by a qualified pool professional, licensed gas technician, or licensed contractor as required by local code. Proper installation requires correct gas supply sizing, venting, combustion air, electrical wiring, bonding, grounding, water flow, plumbing layout, and startup testing.

Before installation, confirm that the fuel type is natural gas, the pool system can provide the required 40–120 GPM flow range, and the gas supply can support a 399,000 BTU heater. Indoor installations require approved venting and combustion air provisions.

Water chemistry must be maintained within recommended ranges to protect the heat exchanger and preserve heater performance.

Customer-Facing Q&A

Q: What is the Jandy JXI400NN?
A: It is a Jandy JXi natural gas pool and spa heater with 399,000 BTU input and a cupronickel heat exchanger.

Q: What is the SKU?
A: The SKU is JXI400NN.

Q: What is the UPC?
A: The UPC is 052337068673.

Q: What is the distributor product number?
A: The distributor product number is LAR-15-836.

Q: What fuel type does this heater use?
A: This model uses natural gas.

Q: How many BTUs is this heater?
A: It is rated at 399,000 BTU input.

Q: Does this model have a cupronickel heat exchanger?
A: Yes. The JXI400NN includes a cupronickel heat exchanger for added corrosion resistance.

Q: Is this good for saltwater pools?
A: Yes. Cupronickel is commonly preferred for saltwater pools and demanding water conditions, provided water chemistry is properly maintained.

Q: What size water connections does it use?
A: This heater uses 2" water connections.

Q: What is the flow range?
A: The listed flow range is approximately 40–120 GPM.

Q: Can this heater be installed indoors?
A: It may be installed indoors only when properly vented and installed according to code and manufacturer requirements.

Q: Is this a propane heater?
A: No. This model is natural gas. Propane versions use different model numbers.

Q: Can a homeowner install this heater?
A: No. This product is intended to be purchased and installed by pool professionals.

Q: Are returns accepted on this item?
A: No. Returns are not accepted on this or any electronic equipment.