Meet the JXi Natural Gas Low-NOx Pool & Spa Heater, a high‑output solution engineered for rapid heat-up, consistent comfort, and cleaner operation. With a robust 400,000 BTU heating capacity and a Cupronickel exchanger, this unit is built to heat large in‑ground pools and attached spas quickly while standing up to the demands of outdoor installation. Model JXI400NN pairs powerful performance with a modern digital control interface and built‑in diagnostics for straightforward service.
Fast, reliable heat for big pools and spa combos
- 400,000 BTU heating capacity delivers rapid water warming, making your pool ready when you are—even after cooler nights or busy weekends.
- Max flow 100 GPM supports larger volumes and spa integration without sacrificing temperature stability.
- Cupronickel exchanger provides exceptional corrosion resistance in chlorinated environments, delivering longer life and fewer maintenance headaches.
- Low-NOx emissions design reduces airborne pollutants, helping you meet local air-quality requirements without compromising performance.
- User-friendly digital interface with built-in diagnostics simplifies temperature control and troubleshooting, so you can spend more time enjoying the water and less time maintaining it.
- Service-friendly design emphasizes easy access during maintenance and routine servicing.
Why this JXi heater stands apart
- Dedicated low‑emission operation paired with high output means you get fast heat without the environmental impact typical of older 400K heaters.
- The copper-nickel (Cupronickel) exchanger is engineered for durability in pool environments, reducing the risk of corrosion and extending service intervals.
- Built-in diagnostics and a modern digital control provide clearer insight into performance and easier, faster service calls.
- Designed for practical installation and long‑term reliability on outdoor equipment pads, supporting steady operation across seasons.
Ideal installations and use cases
- Larger in-ground pools that require quick heat-up and reliable temperature rise.
- Attached spas where fast temperature recovery matters for weekdays and weekends alike.
- Natural gas homes seeking high‑output heating with cleaner operation.
- Upgrading from an older 400K heater to a Low‑NOx, more efficient model.
- Applications that benefit from straightforward control and diagnostic capabilities to reduce downtime.
Specifications
- Heater Type: Pool & spa gas heater
- Fuel: Natural Gas
- Heating Capacity: 400,000 BTU
- Emissions: Low-NOx
- Application: In-ground pool / spa systems
- Exchanger: Cupronickel
- Weight: 141 lbs
- Model: JXI400NN
What’s included
One JXi Natural Gas Low-NOx Pool and Spa Heater, 400K BTU. Note: Plumbing, gas line components, electrical whip, venting, and pad materials are not included.
Replacement and installation considerations
In many cases, this unit can replace an existing 400K gas heater. Replacement suitability depends on proper gas line sizing, plumbing alignment, electrical connections, ventilation/clearances, and local code requirements. If you’re upgrading to a cleaner, higher‑output option, this Low‑NOx model provides a straightforward upgrade path with long‑term value.