Help! I think I might have fried my Jandy Jxi heater

[jpage4500]

When I turned my pool heater (Jandy Jxi) on this year it turned on for maybe 10 seconds and then turned off and would repeat this over and over. There wasn't any error messages displayed.

I searched and made a list of a couple of things it could be and figured I'd try testing them 1 by 1..

- water pressure switch
- high limit switch
- thermal regulator

Anyway, I started with the pressure switch and tried using a jumper cable to connect the 2 wires together.. that worked fine but when I put the wires down to turn the heater on I noticed a small spark. Now the display panel is black.

Obviously I forgot to turn the power off.. I wasn't sure it was necessary for this little switch but am now kicking myself for not doing it. I did turn the power to the heater off and on a few times but still the display is off.

Any ideas? Could I have fried the control board? Or the power board? I've got a multimeter but not sure how to test anything.. just really hoping I don't need a new heater...

control board: Jandy Heater Controller Power Interface R0458200
power board: Jandy JXi/LXi Power Distribution PCB Kit | R0458100

the picture below is just something I found online - not the exact model.. these are the 2 wires I connected together to test

 

[ajw22]

Welcome to TFP.

@setsailsoon @swamprat69 knows their way around the JXI.

Workbook JXi Pool&Spa Heater is a training manual for pool repairmen. Troubleshooting Guide begins on page 24. It mentions checking a fuse.

BP Electronics has repaired Jandy heater boards. Check with them if it ends up your board needs replacement.

 

[Poolbreh]

There is a fuse coming out of the transformer I would check. If it’s the first start up of the year you may need to cycle a few times before it fires up. If the blower is coming on and the gas valve opens it means all sensors are working. Is it natural or propane?

 

[setsailsoon]

Almost certainly you popped the transformer fuse by accidentally grounding the LV power. Check the fuse and replace if needed. Make sure to replace it with the proper amperage. The secondary windings on the transformer won't take much amperage so it easy to fry this also and it's very expensive. On some units the fuse is actually over-sized and so you could have fried the transformer. You can check the transformer at the secondary windings to be sure it's working or just replace the fuse (cheap and easy) and see if your screen powers up.

I hope this is helpful.

Chris

 

[jpage4500]

Almost certainly you popped the transformer fuse by accidentally grounding the LV power. Check the fuse and replace if needed. Make sure to replace it with the proper amperage. The secondary windings on the transformer won't take much amperage so it easy to fry this also and it's very expensive. On some units the fuse is actually over-sized and so you could have fried the transformer. You can check the transformer at the secondary windings to be sure it's working or just replace the fuse (cheap and easy) and see if your screen powers up.

I'm praying that's the case as I'm really mad at myself for possibly making a semi-easy repair MUCH harder. I was already trying to figure out if I should take a stab at buying a new control board ($400+) just to 'see' if that gets the display back on. It's very difficult to get a pool tech out and my fear is they'd just tell me I need a new $3,000+ heater.

I'm going to try and get the fuse out.. check if it's blown and hopefully can get a new one at a local Home Depot. At this point I just want to get back to my original issue lol! (everything would turn on and work great for maybe 10 seconds or so before turning off..)

 

[jpage4500]

@setsailsoon @swamprat69 knows their way around the JXI.

Workbook JXi Pool&Spa Heater is a training manual for pool repairmen. Troubleshooting Guide begins on page 24. It mentions checking a fuse.

BP Electronics has repaired Jandy heater boards. Check with them if it ends up your board needs replacement

Thanks for that manual link!! It's a lot more detailed than anything else I've seen to-date

 

[jpage4500]

There is a fuse coming out of the transformer I would check. If it’s the first start up of the year you may need to cycle a few times before it fires up. If the blower is coming on and the gas valve opens it means all sensors are working. Is it natural or propane?

It's natural gas. I had turned it on earlier and noticed the temperature sensor wasn't working and had just replaced it. I had replaced that temp sensor a year or so ago previously as well. That one was pretty easy to spot as the spa temp was listed a lot higher than the actual temp and the system would work fine if I just manually increased the temp as high as it could go.

Now, the system turns on (hot water coming out of the jets) but the heat turns off after about 10 seconds (blower still runs for a bit). It then tries again with the same result.

It seemed like something I might be able to troubleshoot myself before having to get a pool tech out.. at least these 3 things below:
- water pressure switch
- high limit switch
- thermal regulator

 

[Poolbreh]

It could be a a flame rectification problem. If you aren’t getting any sensor errors and it’s happening exactly at 5-7 seconds after it fires.

 

[jpage4500]

It could be a a flame rectification problem. If you aren’t getting any sensor errors and it’s happening exactly at 5-7 seconds after it fires.

Would that be caused by something like a gas line pressure issue? That's probably not something I can figure out myself.. but wondering if there was something I could test before calling in help.

I did see this chart in the service manual.. not sure I'm able to test many of these things though

 

[Poolbreh]

I believe it’s the hsi that switches to flame rectification. Testing it is beyond me. But the sequence would be pretty consistent firing and shutting off within 5-7 seconds every time.

 

[Poolbreh]

and yes your symptoms could be a gas pressure related issue as well.

 

[setsailsoon]

Turning on for about 10 seconds then switching off is a common problem but it most likely has nothing to do with your display being blank. Cycling of the heater 3 times then shutting down can be caused by a number of failures including sensors, connections, grounds etc. The display is needed so you can see the error code and you'll need it to operate the pool. So I would focus on getting the display back first. Also, try to resist the temptation to "trial and error" replace parts. This is expensive and rarely works. Check to see if you have 14 vac at the transformer secondary, then passed through the fuse and at the panel. If you have power to it check the connections at both ends of the connector and if it's completely blank it's most likely toast. This is pretty rare though. I've only seen this once on the Jandy heaters. While you work on the fuse/transformer issue do you remember how many times the red light on the Fenwal ignition control blinked after the unit shut down? This is the Fenwal and notice the red light on the top connectors:



Don't beat yourself up. We all make mistakes and so far you haven't done anything near as bad as I did when I accidentally dumped about a cup of rainwater on the electrical tray with power on. And this was after a lightning strike fried a lot of components! It was very frustrating and took a couple weekends but I got it back up running and it was a fraction of the cost of a replacement of the heater.

Chris

 

[jpage4500]

So I would focus on getting the display back first

It's back!! I replaced the 2 amp fuse with a cheap one from an AutoZone and voila - back to where I was originally (turning on and off)! That's a huge relief since I thought I had cost myself big time.

I also took a video this time of the heater turning on and off and just happened to notice an error on the display which only lasted a second or 2. It said: "FAULT FUSELINK / FIELD". I'm guessing this was always displayed before but I just never noticed it since I was looking at other areas when it happened



I searched around and found lots of different suggestions for this specific error.. the service manual mentions "or replace Vent Limit" but I'm not sure what part to order and don't see it listed.


There's several other threads that mention this same error.. the second link shows a picture of this fuse but I don't see it on my heater unless I'm not looking in the right place. Is there anything I can try to test or is it time to call in a pro?

Jandy LXi - Fuse Link Fault

Ran my Heater for a good 15-20 hours this year. Recently getting the 'Fuse Link Fault' Error'. When I turn the heater on, the fan starts. A little while later it ignites and I can feel heat being exhausted off the top. 20-30s later it stops with that error. It then retries a number of times...

www.troublefreepool.com

Pool heater Fault

Yesterday got this code from our pool heater. Fuse Link Fault/Field. It's a Jandy Legacy LRZ 399,000 BTU,. Did some googling and didn't find much. I found this in the troubleshooting guide FAULTFUSELINK/FIELD 1. Fusible link fault. 1. Identify and correct loose connections or replace Fusible...

www.troublefreepool.com

Thanks to everyone by the way for all of the help!

 

[Poolbreh]

I don’t see a fusible link on the jxi diagram, I wonder if the board is an earlier generation right before changing Lxi to jxi. A lot of the parts seem to be the same and explain the fusible link error instead of a stack flue error. The vent limit switch is probably the stack flue sensor.

 

[setsailsoon]

It's back!! I replaced the 2 amp fuse with a cheap one from an AutoZone and voila - back to where I was originally (turning on and off)! That's a huge relief since I thought I had cost myself big time.

I also took a video this time of the heater turning on and off and just happened to notice an error on the display which only lasted a second or 2. It said: "FAULT FUSELINK / FIELD". I'm guessing this was always displayed before but I just never noticed it since I was looking at other areas when it happened

View attachment 407018

I searched around and found lots of different suggestions for this specific error.. the service manual mentions "or replace Vent Limit" but I'm not sure what part to order and don't see it listed.
View attachment 407019

There's several other threads that mention this same error.. the second link shows a picture of this fuse but I don't see it on my heater unless I'm not looking in the right place. Is there anything I can try to test or is it time to call in a pro?

Jandy LXi - Fuse Link Fault

Ran my Heater for a good 15-20 hours this year. Recently getting the 'Fuse Link Fault' Error'. When I turn the heater on, the fan starts. A little while later it ignites and I can feel heat being exhausted off the top. 20-30s later it stops with that error. It then retries a number of times...

www.troublefreepool.com

Pool heater Fault

Yesterday got this code from our pool heater. Fuse Link Fault/Field. It's a Jandy Legacy LRZ 399,000 BTU,. Did some googling and didn't find much. I found this in the troubleshooting guide FAULTFUSELINK/FIELD 1. Fusible link fault. 1. Identify and correct loose connections or replace Fusible...

www.troublefreepool.com

View attachment 407020

Thanks to everyone by the way for all of the help!

Congrats on the progress! I believe the fusible link the error refers to is the sensor located in the flue and as I recall it's a one-time sensor that actually burns. I'll check later tonight when I have time.

Chris