JXi™ Pool & Spa Heater

The JXi offers a Space-Saving and Energy-Efficient Design that’s Easy to Install


The JXi™ heater sets the standard in pool and spa heating with its ultra-compact size, lightweight design and durable construction that protects against rodents. Boasting an 84% thermal efficiency rating* and a low-NOx design, the JXi is available in both natural and propane gas models.

An ideal heater for any circumstance, new build or as a drop-in replacement, the JXi is easy to install with ample plumbing flexibility to accommodate a quick swap for Mastertemp® and Max-E Therm® with no unnecessary adjustments.

The JXi also features advanced automation compatibility with AquaLink® systems and iAquaLink® control, for anytime, anywhere convenience—making it a top choice for pool professionals and pool owners everywhere.

JXi™ Pool & Spa Heater Specifications

JXi™ Pool & Spa Heater Features

JXi™ Pool & Spa Heater Related Products

JXi™ Pool & Spa Heater Accessories

JXi™ Pool & Spa Heater Frequently asked questions

For the last 20 years, Jandy has been using a patented technology associating polyamides and titanium, both of which are totally free from the effects of corrosion. Today over 120,000 appliances have been installed without any corrosion defects. If a salt water chlorination method is being used, it is important to install a check valve between the heater outlet and the salt water chlorinator, to prevent high concentrations of chlorinated water from back siphoning into the heater.
No, it is perfectly possible to heat an "open air" pool without a cover or a shelter. The power and fuel requirements is similar to heating a house with the windows open! This is why we recommend the use of an insulating cover to limit heat loss to the open air when the pool is being heated. A covered or sheltered pool will reduce the amount of fuel needed and reduce the operating cost. Example: A 400 square foot pool in Tampa, heated to 82F year round could save 50% on the heating bill just by keeping the pool covered for 20 hours a day. Interested in getting a cover for your pool to save money? Check out our Coverpool products www.coverpools.com
  1. Look for obstruction or closed valve in system.
  2. Check for damaged internal bypass.
  3. Variable-speed pump set too low.
  4. Dirty filter or baskets.
  1. Flip the switch to “on” position.
  2. Cycle ignition sequence until air is out of the gas line.
  3. Replace gas valve.
  4. Check controls for proper operation.
  5. Check supply pressure.
  1. Heater is condensing. Flue product moisture will condense at the start-up until the heater water temperature reaches the normal operating conditions.
  2. Faulty or broken Thermal Flow Regulator.
  3. Correct the plumbing.
  4. TRV failure.
  1. Gas meter too small.
  2. Gas line from meter to heater too small.
  3. Correct gas supply pressure to 4.0" W.C.
  4. Replace with heater of higher input.
  5. Check blower inlet grill for obstruction.
  1. Check circuit breakers and power source.
  2. Replace the pump.
  3. Recheck wiring.
  4. Check time clock setting.
  1. Make sure the gas supply matches the gas type indicated on the rating plate.
  2. Correct gas supply pressure to 4.0" W.C.
  3. Increase offset gas pressure. Rotate adjustment screw clockwise.
  4. Correct gas supply pressure to 4.0" W.C
  5. Decrease offset gas pressure. Rotate adjustment screw counter-clockwise.
  6. Check offset pressure is set to —0.2” W.C. If this is set properly, connect manometer to blower throat and gas valve port to obtain differential. Make sure the differential value falls within the specified range for the heater size (see Table TBD in the owner's manual).