Jandy JXI not working


New member
Nov 5, 2021
South Florida
Almost new JXI 600,000 natural gas heater comes on ignites and shuts off x3 . Error code Ign comes up. it was working one day and not the next. No power. Pool guys came out and discovered the PCB had melted. They replaced that board and the unit power up But would not fire up. They then replaced the entire electrical component tray including the transformer . Unit comes on ignites and shuts off. Had gas plumber out ,replaced the regulator. He says gas supply is not the problem. Is there a separate flame sensor on this unit,or is it part of the igniter? I noticed (and I’m not positive) when they put a new igniter in it looked like the one listed for an LXi heater. The one for a JXI looks different on parts lists I have looked at. It’s been going on a year now and no one seems to be able to help. any guidance would be most appreciated.


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Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Welcome to TFP.

@setsailsoon wrestled with flame sense problems in his JXI heater in this thread...

You can read more about testing the flame sense in the Fenwal box in...



TFP Expert
Mar 2, 2011
JXI 600,000 natural gas heater
There's no such thing as a 600,000 btu/hr JXi heater.

What model number do you have?

Do you have pictures of everything?

Do you have video of what is happening?

Is the heater indoors or outdoors?

If it is indoors, does it have an adequate intake air supply?

Last edited:


TFP Expert
Mar 2, 2011
The combustion happens in a sealed chamber.

So, if a circuit board is burning up, then you have a serious problem.

Are you using the VersaFlo bypass?



What is the inlet gas pressure before the heater fires and after the heater tries to fire?

What is the manifold pressure?

Can you feel good airflow coming from the heater as soon as the blower starts?


Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
Palm City/FL
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-30 Plus

Welcome to TFP and sorry we have to meet like this! But the way a lot of new members find us is from a pool store disaster or an equipment problem like yours. Good news is we almost always get these things resolved working together with you.

As James indicates you've had a major failure. I went through this after a lightning strike and then a self-inflicted issue during repairs with intermittent thunderstorms fried some components again. Is this unit still being covered under warranty? So can you please provide some more details. What happened that led up to this situation.n When boards melt something major went wrong in the circuit. Did the unit ever work right or was this the situation at installation? Who did the install? I installed my unit myself and it worked flawlessly for a year. Then a connection issue caused intermittent failure. I located and fixed this and it worked flawlessly until my major direct hit lightning strike to the house. Took weeks to diagnose and a LOT of help from @JamesW @ajw22 @swamprat69 plus several others here. But I did get it fixed and working flawlessly for waaaay less than the cost of a new unit. It was still working great a couple more years when I sold the house. I dealt with completely melted boards, and even fried wires but I got it working using diagnostic testing not trial and error replacement like it appears your tech's have done so far.

So let's start at the beginning:
  • What unit do you have? It's likely a 400 or 260 Kbtu. It's not 600 if it's a Jandy Jxi.
  • What level of DIY skills would you say you can do? OK with 240 vac electrical, do you have a good quality VOM? If not, you really do need a skilled, certified Jandy tech. Not all tech's are created equal and diagnosing flame sensing issues is simple for a skilled tech or DIYer. It's a waste of time and money for anybody else.
  • When did this first happen and what were the circumstances? These units are usually supplied for 240v ac. Did it get initially installed with incorrect power accidentally, lightning strike, accidental short during hookup, unit left open with power on and electrical tray exposed to rain? Or did it work one time and melt? This information will get you to a solution much quicker.
  • After your unit shuts down how many times does the red light on the Fenwal control module flash?
We have a 100% volunteer organization that provides you experts (like a few you've already gotten on this). It would help immensely if you could provide a signature. Here's how. This helps our volunteers be most effective with their time.

I hope this helps you get on the path to enjoying your pool instead of dealing with equipment frustration!

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