Jandy LXi heater shuts down

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gazerbeam

gazerbeam

Member
May 20, 2020
22
Simsbury, CT
Hi I just tried the heater first time this season - CT location. Jandi LXi400. Heater fires up 3 times for about 15 sec each and then shuts down with FAULT- CHECK IGN CONTROL error. The burner does light, I can see the flames and feel the blower and the heat. The flame sensor and air flow sensor seem to work as well. Any ideas?
 
Welcome to TFP.

I think your flame sensor may not be working. Read Heater Flame Sensing - Further Reading

Find the Fenwal box inside and see if the LED is flashing when it shuts down.

@setsailsoon another one for you to help if you choose to accept it.
 
ajw22 said:
Welcome to TFP.

I think your flame sensor may not be working. Read Heater Flame Sensing - Further Reading

Find the Fenwal box inside and see if the LED is flashing when it shuts down.

@setsailsoon another one for you to help if you choose to accept it.
Click to expand...

I put a clamp on amp meter on the black wire from the flame sensor - I could read a significent change when the heat started so it seems to be doing something.

I also checked the LED - it never flashed once in multiple test runs.

I'll review the post you recommended.

Thanks
 
Gazer,

Almost certain you have a ground issue or less likely a bad Fenwal ignition module. Luckily the cheap solution is the most common. Can you please provide any additional background like when did it work last, anything else done lately to the heater, or did you have a lightning storm since you last ran it? I would start first by checking the ground wires from the burner and the ground wire gang (yellow wires) near the Fenwal. If this doesn't work add the ground wire that is described in the article. Do you have a voltmeter or true rms ammeter that can read millionths of an amp?

Chris
 
I have not checked fan speed but I did check that the air flow switch is working and activating. And the air flow feels the same as it did last season. Also made sure the mice did not block anything.

I found the table you pasted was also in my Jandy manual. I think i'm good on all those points.

The Heater Flame Sense link you gave me is awesome. I was clueless how the flame sensor worked. Thank you so much.

I'm beginning to suspect a ground issue. Sure smells like one. I had issues last year with corrosion on the contacts for the water temp sensor. Once i cleaned them it worked great.

Thanks
 
setsailsoon said:
Gazer,

Almost certain you have a ground issue or less likely a bad Fenwal ignition module. Luckily the cheap solution is the most common. Can you please provide any additional background like when did it work last, anything else done lately to the heater, or did you have a lightning storm since you last ran it? I would start first by checking the ground wires from the burner and the ground wire gang (yellow wires) near the Fenwal. If this doesn't work add the ground wire that is described in the article. Do you have a voltmeter or true rms ammeter that can read millionths of an amp?

Chris
Click to expand...


yes I was coming to that conclusion as well. Thanks
 
I think your unit has a separate flame sense rod. Check the connection to the Ignition module. What is your serial number?
 
Sorry for the multiple questions but a couple more. Can you tell me if the flame while lit is blue and defined shape or if it's yellow and somewhat flickering? Also is the flame sense rod in the blue part of the flame? Also please check the gas supply line all the way back to the meter to make sure there's no partially open valves. It's surprising how many people find somebody partially closed a gas valve during the off season. Recommended practice #1 for heaters: try the simple stuff first.

Thanks,

Chris
 

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setsailsoon said:
I think your unit has a separate flame sense rod. Check the connection to the Ignition module. What is your serial number?
Click to expand...


SN is D09LL0417
Flame is blue.
I can see the hot surface igniter glowing before the gas opens. Hard to tell the shape of the flame through the view port, but the exhaust kicks out a healthy amount of heat and on par with prior years function.
I can't see the flame sense rod, but don't really know what i'm looking for. This is my deepest dive into this thing so far.

Two things i'm not sure of.
1) looking at the grounding issue fix - where are the blower flange bolts? It's dark and i'm not going back there till tomorrow.
2) I've never seen any flashes from the LED - none.

Thanks
 
Gazer,

OK, when you get to this situation you either have a flame that's too small which is usually gas supply or blower related. Please do check the gas supply from the heater to the house just because it's so simple to do. Look for any valve that appears less than fully open. Or you have a good flame and the flame sense rectification signal is being interfered with or the signal is present at the Fenwal and the board inside is defective and it needs to be replaced. The Fenwal is expensive and doesn't really fail all that often so it's worth checking it out a little more carefully before you replace it. Your heater model doesn't use the flame tube so the grounding wire addition isn't applicable (my bad, sorry). It is worth checking out the integrity of the ground wires. Please check the yellow wire connection to the Fenwal and the transformer. Also check the any connections to the frame from yellow wires. Lastly check the flame sense rod black wire to the ignition control board. When you mention the fact there are no flashes of the LED are you talking about the red LED on the ignition control module? This indicates you could have a bad module. Best way to check it is to rig up wires to the terminal connectors (2 mm) right below the red LED and run them out to a meter that can measure millionths of an amp and measure the current. Or you can use insulated micro connectors (the ones with a little hook at the end). You must have a true RMS ammeter that will measure millionth's of an amp. Micro amps not milli amps. An alternative is to measure voltage that will infer amperage. Should read greater than 1.5 micro amps or at least 4 volts. I found the voltage measurement to be pretty reliable. If the reading is good then you're getting the flame sense signal to the module but it's not being recognized. There are only 2 things that can cause this:
  • Bad module
  • Interference in the ground circuit
Usually it's the module. The second item is not documented anywhere but I tried it as a last resort before replacing the expensive module again (original had been fried by the lightning strike). Turns out my power supply wires had damaged insulation that were allowing a tiny leakage to ground that made the power supply look good but were interfering with the flame sense signal. When I bypassed the original power supply with a new jumper made from scrap Romex cable my heater worked perfectly. Saved me a $300+ unnecessary expense! But this is pretty rare. As far as I can tell it's only happened to me as a result of lightning strike. This could also happen from poor power connections at the heater or breaker. Since they're easy to check it's worth doing before you replace the module. I've also included a trouble shooting guide for the LXI. It's a little more informative than the user manual.

I hope this helps.

Chris
 

Attachments

  • LXiTS.pdf
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You're on propane so you really need to first check if you have a full tank or not. If it's full then you need to check the pressure coming to the heater. Then check the pressure when the unit is in operation. If you see a drop in pressure and you have a full tank, you would have a stuck float n the tank and not allowing the gas to flow correctly. Also, if you have a clogged vent line on the regulator, it can cause issues with units lighting and running. Also a bad regulator at the heater or on the tank can cause issues. I would get someone who works with propane to check all of that out. You're thinking it's a heater related issue when it could all be gas related.
 
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Wow, I missed that you have propane. Check Paul's recommendations above first. Even though you seem to have a good flame it's hard to see through the window.
 
setsailsoon said:
Wow, I missed that you have propane. Check Paul's recommendations above first. Even though you seem to have a good flame it's hard to see through the window.
Click to expand...


Plenty of propane in the tank - 30%. All valves are open. System was working last fall when we shut down for the season.

I did check the ground wires. They don't look corroded but I re-seated everything anyway. I checked voltage at the FC+/- leads when the burner fires up. The voltage goes up to about 2v and then begins to drop down to about .3. The system then recycles 2 more times before going into error.
 
Finally I got time to pull the flame sense rod and cleaned it. But it looked kinda new and I think the prior owner mentioned having it replaced. Service call is scheduled for next Thursday in case this is a tank or regulator issue, so I have a few days to get this fixed prior.

Adding additional ground wire is my last effort. But I don't understand the point of added the additional wire at the blower flange. Why not just add it right at the mounting screw for the flame sense rod? The Fenwal tech article referenced on this site recommend that approach, unless i missunderstood..

Feedback appreciated.
 
gazerbeam said:
Finally I got time to pull the flame sense rod and cleaned it. But it looked kinda new and I think the prior owner mentioned having it replaced. Service call is scheduled for next Thursday in case this is a tank or regulator issue, so I have a few days to get this fixed prior.

Adding additional ground wire is my last effort. But I don't understand the point of added the additional wire at the blower flange. Why not just add it right at the mounting screw for the flame sense rod? The Fenwal tech article referenced on this site recommend that approach, unless i missunderstood..

Feedback appreciated.
Click to expand...
Hi, I'm having the same problem with my heater. Have you able to get your heater fixed? what was the final problem and fix? Thanks
 
gazerbeam said:
yes it started working after cleaning the sensor and adding grounding wire. Also reseated various connectors on control boards etc. That was last year. Let's hope it starts again next week when we open the pool again!
Click to expand...
Thanks, you have a picture of how you have the ground wire installed. I checked mine and found no corrosion on the the connector.
 

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