Product Overview

The Jandy JXi™ Natural Gas Heater | JXI400N is a compact, high-performance gas pool and spa heater built for fast heat-up, energy-efficient operation, and flexible installation. With a powerful 399,000 BTU input, this heater is ideal for residential pools, spas, and pool/spa combination systems that require dependable natural gas heating.

The JXi series is known for its ultra-compact 2' x 2' equipment pad footprint, lightweight cabinet, low-NOx burner design, and professional-friendly service access. Jandy lists the JXi platform as available in natural gas and propane models with 84% thermal efficiency, low-NOx design, and compact installation flexibility.

This model uses a copper heat exchanger for efficient heat transfer and supports high-flow pool applications when installed correctly. Distributor listings commonly identify JXI400N as a 399K BTU natural gas heater with copper exchanger, approximately 141 lb, and up to 100 GPM max flow, depending on listing source.

⚠️ 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.

Ideal For

• Residential inground pools
• Pool and spa combination systems
• Fast spa heat-up applications
• Natural gas pool heating systems
• Replacing older natural gas pool heaters
• Equipment pads with limited space
• Customers needing 400K BTU class heating
• Pool owners wanting digital heater controls
• Low-NOx heater replacement applications
• Professional pool heater installations

Key Features

• 399,000 BTU input — delivers powerful heating performance for pools and spas.
• Natural gas operation — designed for properties with compatible natural gas service.
• Low-NOx design — engineered for cleaner combustion and reduced emissions.
• Ultra-compact footprint — approximately 2' x 2' design helps save equipment pad space.
• Digital control interface — allows easy temperature adjustment and heater monitoring.
• Electronic ignition — provides reliable startup without a standing pilot.
• Copper heat exchanger — provides efficient heat transfer for fast water heating.
• 120/240V electrical compatibility — supports common pool heater electrical configurations.
• Flexible installation layout — JXi design supports easier replacement of many existing heater platforms.
• Professional service access — cabinet design supports easier installation and maintenance.
• Pool and spa compatible — suitable for properly sized pool, spa, and pool/spa applications.
• Automation compatible — works with compatible Jandy AquaLink automation systems when properly configured.

Benefits

The Jandy JXI400N provides high-output natural gas heating in a compact and service-friendly design. Its 399K BTU input helps reduce pool and spa heat-up time, making it a strong choice for pool owners who want fast, dependable heating performance.

The compact JXi footprint is especially useful on crowded equipment pads or retrofit installations. Its low-NOx burner design supports cleaner operation, while the digital controls make temperature management simple.

For pool professionals, the JXI400N offers a reliable natural gas heater option with flexible installation features, strong performance, and Jandy’s proven pool heating platform.

Specifications

Included Components

• 1 × Jandy JXi JXI400N natural gas pool and spa heater
• Integrated digital control panel
• Electronic ignition system
• Copper heat exchanger assembly
• 2" water connection components, depending on supplier packaging
• Manufacturer-supplied installation documentation

Natural gas line, gas regulator if required, shutoff valve, electrical wiring, bonding materials, venting components, plumbing valves, unions, check valves, equipment pad materials, 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 natural gas supply sizing, electrical wiring, bonding, grounding, plumbing layout, water flow verification, combustion air, and venting where required.

Before installation, confirm that the fuel type is natural gas, the gas supply can support a 399,000 BTU heater, and the electrical service is compatible with 120/240V, 60 Hz operation.

Water chemistry must be maintained within recommended ranges to protect the copper heat exchanger and preserve heater performance. Improper water balance, incorrect gas pressure, poor water flow, or improper installation can damage the heater and may void warranty coverage.

Customer-Facing Q&A

Q: What is the Jandy JXI400N?
A: It is a Jandy JXi natural gas Low-NOx pool and spa heater rated at 399,000 BTU input.

Q: What is the SKU?
A: The SKU is JXI400N.

Q: What is the UPC?
A: The UPC is 052337066495.

Q: What is the distributor product number?
A: The distributor product number is LAR-15-500.

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

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

Q: How many BTUs is this heater?
A: It is rated at 399,000 BTU input, commonly listed as a 400K BTU class heater.

Q: Does this heater have a copper or cupronickel exchanger?
A: This model is commonly listed with a copper heat exchanger.

Q: Is this a Low-NOx heater?
A: Yes. The JXi series is designed as a Low-NOx pool and spa heater platform.

Q: What voltage does it require?
A: It supports 120/240V electrical service.

Q: What size plumbing connections does it use?
A: It uses standard 2" water connections.

Q: Is this heater compact?
A: Yes. The JXi series is designed with an ultra-compact footprint of approximately 2' x 2'.

Q: Can this connect to Jandy automation?
A: Yes. It can connect to compatible Jandy AquaLink automation systems when properly installed and configured.

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.