Jandy JXi malfunction

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socalagua

socalagua

Member
Apr 14, 2022
10
Los Angeles, CA
Hi there,

I have a Jandy JXi heater that is malfunctioning. I have done comprehensive reading of past posts here on the LXi and JXi, as well as additional reading up on the Fenwal controller that the heater is outfitted with. The issue I am having is ignition. When I turn on the heater, the heater will attempt ignition 3 times, and then goes into fault mode, with the Fenwal unit led flashing three times. I can smell gas being purged through the vent during each subsequent attempt the heater makes to complete the ignition process, so I know the heater is getting gas flow. I pulled the ignitor to inspect and clean it. It showed obvious wear that would be expected with a 7 year old heater. Upon lightly cleaning it the carbon build up of of the ignitor coil, it instantly crumbled at the point where it looked the most worn. I replaced the ignitor with a new one, but I am still getting the same results with the ignition process, and the three flash code from the Fenwal unit. On top of the original issue, the JXi is now repeatedly turning on and off with the Fenwal unit making a clicking noise every time the Aqualink turns on and initiates the filter pump. I am attaching a Youtube link to a brief video, showing this:

VIDEO HERE

Any further knowledge about the JXi and assistance would be greatly appreciated. I would very much like to avoid a costly repair bill.

Thanks
 

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Rule #1 - never touch the igniter surface. If you touched the heating surface of the new igniter, it could have instantly burned out due to the oils that are on your fingers (even if you just washed your hands). Check the continuity with an ohm meter. Should be around 50 - 75 ohms. If out of range or 0 igniter is damaged
 
Welcome to TFP.

Smelling gas does not confirm you have proper gas pressures. You need to measure gas pressures using a manometer both static and when the gas valve opens.

You can have gas but not the proper pressures and thus not having the proper gas/air mixture to light.

@setsailsoon has lots of experience inside that heater.

@swamprat69 may also be helpful.
 
Thanks for the responses. The issue occurring in the video has ceased, but the ignition lock out fault persists. The ignitor is brand new and has continuity. I don't know the external gas pressure to the JXi, but there is a Bosch flash heater for the house right next to the JXi. It is working fine. I would assume the demand for gas pressure would be at least equivalent, if not higher, for the Bosch. If gas pressure was too low, it would most likely caused by an internal issue. Possibly a faulty gas valve? Not sure how to assess that. I will look into getting a manometer. I will check the voltage going to the ignitor tomorrow to ensure it's receiving 24 volts, but I don't know what else to to do to troubleshoot. Any expert guidance would be greatly appreciated.
 
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What size is your JXI heater? A pool heater will have much more gas demand then a flash water heater.
 
I really think you need to find a qualified pool heater technician who knows his way around the heater.

Workbook JXi Pool&Spa Heater is a training manual for pool repairmen and may help you find your way around the heater.
 
Thanks for the link. I was just reading a post by @setsailsoon about his issue with the heater. Like him, I suspect I am having a ground interference issue. I have been having some electrical issues in my house recently that I have yet to get to the bottom of and think it could be related. Sounds like it may be worth running an isolated ground to the heater circuit may help. He also added a ground wire directly from the burner to the ground gang on the raceway.
 
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socalagua said:
Thanks for the link. I was just reading a post by @setsailsoon about is issue with the heater. Like him, I suspect I am having a ground interference issue. I have been having some electrical issues in my house recently that I have yet to get to the bottom of and think it could be related. Sounds like it may be worth running an isolated ground to the heater may help.
Click to expand...

If you are having a flame sense problem you will feel a burst of heat out the exhaust as it lights and then the heater will shutdown because it does not sense the flame. If you don't get the burst of heat then you are not getting the initial light off and it is probably not a flame sense problem that a ground would fix.

Heater Flame Sensing - Further Reading

www.troublefreepool.com www.troublefreepool.com
 
Your fan is cycling pretty fast and never really stops plus the red indicator light is showing a continuous red light. When the problem is with failure to ignite the cycling takes longer then the Fenwal stops the fan completely after 3 tries. The "red on" condition indicates an internal control problem. There are a couple of situations that I can think of that may cause this:
  • Connection failure. Try to wiggle wires connecting to the fan or sensors to see if this changes the fan running time. I found a lot of connection problems with the wiring on this heater. I ended up taking all the sensor connectors off, cleaning, then spraying with Corrosion Block to solve this issue.
  • Call for heat is intermittent because of a connection failure or temp sensor problem. Narrow this by adding a jumper to artificially "call for heat". Only do this temporarily and only enough time to check the function. Leaving this jumper in place is extremely dangerous. Do not do this.
  • Control board relay failure. There is a thread that shows how to jumper this to test it and a board level repair by replacing the relay. I would not repair as he did but replace the board.
  • Fenwal failure.
I hope this is helpful.

Chris
 
setsailsoon said:
Your fan is cycling pretty fast and never really stops plus the red indicator light is showing a continuous red light. When the problem is with failure to ignite the cycling takes longer then the Fenwal stops the fan completely after 3 tries. The "red on" condition indicates an internal control problem. There are a couple of situations that I can think of that may cause this:
  • Connection failure. Try to wiggle wires connecting to the fan or sensors to see if this changes the fan running time. I found a lot of connection problems with the wiring on this heater. I ended up taking all the sensor connectors off, cleaning, then spraying with Corrosion Block to solve this issue.
  • Call for heat is intermittent because of a connection failure or temp sensor problem. Narrow this by adding a jumper to artificially "call for heat". Only do this temporarily and only enough time to check the function. Leaving this jumper in place is extremely dangerous. Do not do this.
  • Control board relay failure. There is a thread that shows how to jumper this to test it and a board level repair by replacing the relay. I would not repair as he did but replace the board.
  • Fenwal failure.
I hope this is helpful.

Chris
Click to expand...
Thanks for your response, and for all your previous posts that have well documented your issues with the JXi. I followed the flow chart in the JXi repair handbook and took some readings. I received zero voltage on the feeds going to the ignitor. The flow chart then said to measure between L1 and L2 on the ignition control module. I received zero voltage on there as well. According to the flow chart, it says to replace the ignition control module. I have ordered a new module, and will report back after I replace it. I'm hopeful that this will fix the heater, but at least I can eliminate it as the issue if it doesn't resolve the problem.
 

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Something didn't make sense to me about Jandy's flow chart in the JXi repair handbook, and made me doubt that the ignition control module is my issue. Since I received zero voltage on L1 and L2 when I should have measured 120 VAC, that would point to a power issue. L1 and L2 supply 120 VAC to the Fenwal from the transformer, by way of the power distribution board. So today I took a closer look at the power distribution board, and found at least part of my problem. It is fried. I believe a power surge could have made this occur. The fact that the Fenwal is still receiving 24 VAC, and the blower is operating tells me that the transformer is still operating, and the power distribution board is still partially working. It just isn't putting out the 120 VAC current necessary to supply power to the ignitor. I have ordered a new power distribution board, and now will replace this first. I will report back after replacing it.
 

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socalagua said:
Something didn't make sense to me about Jandy's flow chart in the JXi repair handbook, and made me doubt that the ignition control module is my issue. Since I received zero voltage on L1 and L2 when I should have measured 120 VAC, that would point to a power issue. L1 and L2 supply 120 VAC to the Fenwal from the transformer, by way of the power distribution board. So today I took a closer look at the power distribution board, and found at least part of my problem. It is fried. I believe a power surge could have made this occur. The fact that the Fenwal is still receiving 24 VAC, and the blower is operating tells me that the transformer is still operating, and the power distribution board is still partially working. It just isn't putting out the 120 VAC current necessary to supply power to the ignitor. I have ordered a new power distribution board, and now will replace this first. I will report back after replacing it.
Click to expand...
That makes a lot of sense and yours looks like mine did after I accidentally drenched it with rain water while powered up after a heavy shower... I think I documented this also. At least the power distribution board is one of the cheaper ones. If you still have this issue I would try to work your way back from the fan power supply to see what is causing it to cycle so quickly. I've never observed that. Do you know what could have shorted the power supply? A burn mark on the voltage switching board indicates a dead short occurred.

Chris
 
I replaced the power distribution board and I'm happy to report that the JXi is fully operational again. The board was partially shorted out. I don't know exactly what caused the short or when it occurred. Last week, when I replaced the ignitor and restarted the heater, it was early morning. This time of year, there is quite of bit of condensation in the mornings here. While I was waiting for the ignitor to arrive, I had the heater wrapped in a tarp, but high winds the night before I replaced the ignitor, blew the tarp off. I suspect this series of events could have caused the board to short out when I powered up the heater after replacing the ignitor. Regardless of how and when the board fried, there was quite a bit of corrosion on the conductive contact points on the old power distribution board, and I am glad I replaced it. I was able to get an open box power distribution board on eBay for $100. This includes a 3 year Square Trade warranty I was able to add to the purchase for an additional $7. A new part that is not installed by a licensed Jandy tech carries no warranty. I was able to get an open box ignitor on eBay for $30. That brings the total for this repair to $130.
 

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