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- Jandy JXI400NS JXi Heater | 400 BTU | Pool & Spa | Natural ASME CUNI
Jandy JXI400NS JXi Heater | 400 BTU | Pool & Spa | Natural ASME CUNI
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- OEM Jandy JXi 400NS ASME Cupronickel Natural Gas Pool & Spa Heater | 399K BTU | Ultra-Compact & Durable
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Designed for commercial and residential applications, the Jandy JXi 400NS ASME Cupronickel Pool & Spa Heater combines commercial-grade construction with compact, installation-friendly design. Delivering 399,000 BTUs at 84% thermal efficiency, it features a cupronickel heat exchanger for superior resistance to corrosion and demanding water conditions.
At approximately 168 pounds, this lightweight yet rugged heater simplifies installation and retrofitting. The JXi 400NS is automation-ready, integrating with AquaLink® systems for convenient remote operation through the iAquaLink® app. Installation is streamlined with a 180° rotatable top and flip-up electrical panel for easy access in tight spaces.

Energy-Efficient Heating
84% thermal efficiency rating and low-NOX design surpasses strict DOE Energy Efficiency requirements
Commercial Grade Models
Small but strong enough to handle the rigors of non-residential use, ASME compliant JXiQ heaters feature burly bronze headers and 30%1 thicker-walled, robust cupronickel heat exchanger tubes and corrosion-resistant bronze headers to meet the high stresses of commercial installations. Plumbing flexibility for quick MasterTemp® and Max-E Therm® replacement that requires no plumbing adjustments


Ultra-Compact Lightweight Design
Fits on a 2’ x 2’ pad and is 38% lighter with a 28% smaller footprint. Easy to install. Top easily removed and rotated 180 degrees for increased accessibility; includes flip up electrical panel.
Automation-Ready
Compatible with AquaLink® automation systems for anytime, anywhere control from your mobile device using the iAquaLink™ app.

The JXiQ™ ASME Compliant Gas Pool & Spa Heater for Commercial use takes the guess work out of pool heating making it easy to use, install and service.
Built with the brawn to withstand the high-use demands of commercial properties, ASME compliant JXiQ heaters are ultra-compact and constructed with bronze headers and thicker-walled cupronickel fin tubes.
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Commercial Grade Models
Small but strong enough to handle the rigors of non-residential use, ASME compliant JXiQ heaters feature burly bronze headers and 30%1 thicker-walled, robust cupronickel or cupronickel heat exchanger tubes and corrosion-resistant bronze headers to meet the high stresses of commercial installations
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Energy-Efficient Heating
84% thermal efficiency rating2 and low-NOX design surpasses strict DOE Energy Efficiency requirements -
Low Gas Pressure Sensor
Ensures there’s enough gas pressure to safely ignite
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Optimize Flow
Measures temperature rise between the inlet and outlet
to optimize flow and avoid heat exchanger failures
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Auto-Sensing Power Input
Automatically adjusts to supplied power when installed — no cards to flip and no wires to change -
Largest Display in the Industry
Digital display is 50% larger than before and
capable of showing 80 characters -
Best Drop-In Option
Plumbing flexibility for quick MasterTemp® and Max-E Therm®
replacement that requires no plumbing adjustments -
Flexible Installation. Easy Servicing.
Top easily removed and rotated 180 degrees for increased accessibility; includes flip up electrical panel -
Keeps Critters Out
No more chewed up wires. The JXiQ is made with a fully encased shell to protect against rodent intrusion and damage -
Ultra-Compact Lightweight Design
Fits on a 2’ x 2’ pad and is 38% lighter with a 28% smaller footprint
Specification
- Includes Versaflo Bypass - No
- Depth - 22.1"
- Efficiency - 0.84
- Exchanger - Cupronickel
- Fuel Type - Natural Gas
- Headers - Bronze
- Height - 26.5"
- Input Rate BTUH - 399K BTUH
- Max. GPM - 100
- Min. GPM - 30
- Pool Surface Area - up to 600 sqft
- Vent Diameter - 8"
- Weight - 168 lbs
- Width - 23.3"
Highlights
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Commercial-Ready: ASME certification with durable bronze and heavy-duty components
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Energy Efficient: 84% thermal efficiency meets stringent energy codes
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Ultra-Compact: Easy to install and ideal for retrofits in tight spaces
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Automation Integration: Compatible with Jandy AquaLink® systems for remote management
- Optional Hydraulic Boost: VersaFlo™ Integrated Bypass available for greater energy efficiency
OEM Jandy JXi 400N ASME CUNI Pool & Spa Heater | 399,000 BTUs | Cupronickel Grade
The Jandy JXi 400N ASME Natural Gas Pool & Spa Heater is engineered for high-use commercial environments, offering robust 399,000 BTU heating performance, superior durability, and energy efficiency in an ultra-compact, easy-to-install design.
Commercial-Grade Construction
ASME-Certified Durability
Built with bronze headers and 30% thicker-walled cupronickel heat exchanger tubes to withstand high-stress commercial applications.
Corrosion-Resistant Build
Engineered for long-lasting performance, even in harsh, high-demand settings.
Energy-Efficient Heating
84% Thermal Efficiency
Exceeds strict DOE energy efficiency standards for lower operational costs.
Low-NOx Design
Environmentally friendly combustion reduces harmful emissions.
Ultra-Compact, Lightweight Design
Space-Saving Footprint
Fits on a 2’ x 2’ pad, 28% smaller footprint, and approximately 38% lighter than similar models.
Easy Handling
Top panel easily rotates 180° and includes a flip-up electrical panel for faster setup and servicing.
Seamless Automation Integration
AquaLink® Compatible
Control heating remotely via the iAquaLink® app for ultimate convenience.
Auto-Sensing Power Input
Automatically detects and adjusts to supplied voltage — no rewiring needed.
Optimized for Commercial Retrofits
MasterTemp® and Max-E-Therm® Replacement
Designed to simplify retrofitting without requiring plumbing changes.
Critter-Proof Shell
Fully enclosed shell prevents rodent damage for added reliability.
Performance Enhancements
Optional VersaFlo™ Integrated Bypass
Boosts hydraulic performance and further increases energy savings when installed.
Flow Optimization Technology
Built-in sensors measure inlet/outlet temperature to optimize flow rates and protect the heat exchanger.
Specifications
Fuel Type
Natural Gas
Input Rate
399K BTUH
Efficiency
84% Thermal Efficiency
Heat Exchanger
Cupronickel (ASME-grade thickness)
Headers
Bronze
Flow Rate
30 to 100 GPM
Dimensions
22.1" Depth × 23.3" Width × 26.5" Height
Vent Diameter
8"
Weight
168 lbs
Installation
Professional installation required; automation compatible
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