Jandi LXi 400K CHK IGN FAULT (Ignition lockout - three flashes on Fenwal)

[Exlonghorn]

Here's the sequence:
With Pump and Heater on...

1. Blower turns on
2. Pre-purge completes
3. Hot surface igniter glows (visually confirmed)
4. Gas valve clicks (but didn't measure with meter)
5. Trial for ignition
6. Burners ignite (can see them and feel the heat blowing out the top vents)
7. After about 5-7 seconds, the burners kick off and the gas valve audibly clicks closed- can smell residual gas for a bit
8. Repeats steps 2-4 3 times and then goes into lockout with the Fenwal giving 3 flashes

Here's a video - mostly have to listen for the different steps. Gas click on at 0:36. Can barely hear the burner igniting and burning at 0:40. Burner shuts off at about 0:45. Last cycle kicks on at 2:40. Burner ignites at 2:43. Kicks off at 2:47 - immediately followed by the three flashes on the Fenwal.

Troubleshooting steps:

1. Pulled and cleaned the flame sense rod with steel wool
2. Visually checked the ceramic insulator on the flame sense rod is not cracked, chipped, or broken
3. Wires and connections appear good
4. Vacuumed out the combustion box
5. Visually inspected all the boards and wires - no burns, blisters, etc.
6. I assume the hot surface ignitor is good since the burner is being lit successfully

I understand the minimum flame sense signal strength is 0.7 DC microamps. What are the test points to measure this? One will be the single wire coming from the flame sense rod. Is the other at the transformer? Frustrating as everything seems to be working properly....the burner just won't stay lit. Perhaps just replace the flame sensor? If that's all it is, then I'll take a shot at ordering a replacement.

Otherwise, looking at the general condition of the unit (over 11 years old), I'm inclined to just replace it rather than burn money on having a repair guy come out (and a lot of the parts are pretty pricey). Leaning towards a RAYPAK 400K BTU DIGITAL NATURAL GAS POOL HEATER - P-R406A-EN-C - 009219. Going with copper versus Cupronickel. Looks like this runs off a 3-wire remote and should hook into the AqualinkRS automation. Anyone have a recommendation on a source to buy it from? I'm considering poolsupplyunlimited.com as their asking price is quite reasonable (almost too reasonable?) Raypak Digital Natural Gas Pool Heater 399k BTU | Electronic Ignition | P-R406A-EN-C 009219 P-M406A-EN-C 009965
I'm just concerned about shady webfronts that act as a passthrough, and with heaters apparently being in short supply due to the recent winter storm and pandemic, I'm surprised their web chat said they have "plenty".

 

[ajw22]

Heater Flame Sensing - Further Reading

www.troublefreepool.com

@setsailsoon has worked through these problems in a Jandy heater.

If you get the Raypak heater connect it using the 2 wire firemans switch control to the Aqualink. There is no advantage to trying to make the 3 wire work.

 

[setsailsoon]

Ex,

Check your gas supply. It's amazing how often this can be the problem. I've purchased from Pool Supply Unlimited. Worked fine but no phone number to call. You have to communicate by email. I guess this is part of how they supply at lower price. You'll have no warranty for anything Jandy and very limited for the others. I was OK for limited so long as it's not something like a salt system that has a cell that can fail after a year or more. Most all other items work for years if they work a week or two.

Chris

 

[setsailsoon]

I understand the minimum flame sense signal strength is 0.7 DC micro amps. What are the test points to measure this? One will be the single wire coming from the flame sense rod. Is the other at the transformer?

There are two metal terminals on the side of the Fenwal usually beside the led light that blinks. They are very close together inside a connector space so you need micro clips on the meter probes or you can build a test connector for them. Make the connection with power off so you don't accidentally short them. You can also measure voltage that is a way to infer amperage if you don't have a meter that can measure micro amps.

Chris

 

[Exlonghorn]

Ex,

Check your gas supply. It's amazing how often this can be the problem. I've purchased from Pool Supply Unlimited. Worked fine but no phone number to call. You have to communicate by email. I guess this is part of how they supply at lower price. You'll have no warranty for anything Jandy and very limited for the others. I was OK for limited so long as it's not something like a salt system that has a cell that can fail after a year or more. Most all other items work for years if they work a week or two.

Chris

Chris,

Thanks for the pointer. The heater would fire up and run fine periodically (but hasn't successfully fired up since around December) so that's what made me think it wasn't a gas supply problem. But you're right, better to check. Have you heard of the gas valves going bad?

 

[Exlonghorn]

Ex,

Check your gas supply. It's amazing how often this can be the problem. I've purchased from Pool Supply Unlimited. Worked fine but no phone number to call. You have to communicate by email. I guess this is part of how they supply at lower price. You'll have no warranty for anything Jandy and very limited for the others. I was OK for limited so long as it's not something like a salt system that has a cell that can fail after a year or more. Most all other items work for years if they work a week or two.

Chris

So since I'm in Texas, if I do replace the heater I believe I'll need the Low NOx version. I noticed that the Raypak operates off a pilot light?? Is that an always-on pilot like an old home water heater?

 

[setsailsoon]

Chris,

Thanks for the pointer. The heater would fire up and run fine periodically (but hasn't successfully fired up since around December) so that's what made me think it wasn't a gas supply problem. But you're right, better to check. Have you heard of the gas valves going bad?

Ex,

I hear you on the gas supply it's just that we've seen so many times when the owner thinks it's good only to find a valve that somebody closed or even worse corrosion on a buried line. Gas valves are extremely reliable but they do fail occasionally. @swamprat69 would be a better person to answer on this since he worked in this field so long.

Chris

 

[setsailsoon]

So since I'm in Texas, if I do replace the heater I believe I'll need the Low NOx version. I noticed that the Raypak operates off a pilot light?? Is that an always-on pilot like an old home water heater?

I don't think any have a pilot light unless you found a very old one for sale. Experts here seem to like Raypak. I personally have seed too many of them where the burner tray rusts completely out... could be the humid area I live in. If you want to try one more thing before you go buying I'd try running a ground line from the burner base to the ground on your electrical raceway. It's cheap to do and will eliminate ground corrosion affecting the flame sense circuit. If this works be sure you use a wire that has high temp insulation for the long term.

Chris

 

[Exlonghorn]

I don't think any have a pilot light unless you found a very old one for sale. Experts here seem to like Raypak. I personally have seed too many of them where the burner tray rusts completely out... could be the humid area I live in. If you want to try one more thing before you go buying I'd try running a ground line from the burner base to the ground on your electrical raceway. It's cheap to do and will eliminate ground corrosion affecting the flame sense circuit. If this works be sure you use a wire that has high temp insulation for the long term.

Chris

Thanks for the pilot info and Raypak burner tray observation. Great idea with the ground wire. Tonight I'll replace the flame sense rod, the hot surface igniter, and the fusable link. They're all cheap and easy to replace, so figure it should eliminate some variables. I'll run a new ground wire as well. If none of that works, I'll start in on the gas supply. Gas is my area of least experience, and I don't have a manometer,water column gauge, or a flow meter, so saving that for last.

 

[Exlonghorn]

I don't think any have a pilot light unless you found a very old one for sale. Experts here seem to like Raypak. I personally have seed too many of them where the burner tray rusts completely out... could be the humid area I live in. If you want to try one more thing before you go buying I'd try running a ground line from the burner base to the ground on your electrical raceway. It's cheap to do and will eliminate ground corrosion affecting the flame sense circuit. If this works be sure you use a wire that has high temp insulation for the long term.

Chris

We have a winner. Flame sense rod. Heater is back up and running.

Zodiac R0458600 Flame Sensor Rod Replacement for Zodiac Jandy LXi Low NOx Pool and Spa Heaters,Black https://www.amazon.com/dp/B004VTFWB...abc_D1J8XFV0F4CRBDGPNEV9?_encoding=UTF8&psc=1

 

[setsailsoon]

Flame sense rod rarely fails. Most often it's the connection on the wire or position in the flame. If you ever clean it, use a dollar bill nothing more course.

Glad you were able to solve this... congrats!

 

[justinfrancisjudd]

My Jandy Lxi heater was always having issues. Just bought a new house and the pool has pentair equipment, couldn't be happier to move away from their equipment as it was always something every other month, Led lights would die at 500 a pop, heater swithes failed, pump issues, swcg replaced twice, etc. One thing after the next and it was only 3 year old equipment have of it that was replaced was failing again. Just garbage if you ask me

 

[Exlonghorn]

My Jandy Lxi heater was always having issues. Just bought a new house and the pool has pentair equipment, couldn't be happier to move away from their equipment as it was always something every other month, Led lights would die at 500 a pop, heater swithes failed, pump issues, swcg replaced twice, etc. One thing after the next and it was only 3 year old equipment have of it that was replaced was failing again. Just garbage if you ask me

Wow that’s a bummer. Haven’t had any other problems with mine. 10 years old. One $54 part. Not too bad. But if more starts to go…..

 

[setsailsoon]

Jandy is not my favorite either. But I have to say my system has worked pretty well going on 8 years. Had a major lightning strike that wiped out my RS control system and fried some of the electronics in the heater. Replaced automation with Intellicenter (superb unit and superior to the other brands in my opinion). Replaced burned up boards in the heater and it's still going strong. Main reason I started switching to Pentair is the Jandy warranty policies that are not favorable to DIY repairs. Other than lightning strike and a dumb mistake I made during that repair the equipment is running fine and required no unusual repairs. I think the only thing I've done is replace the pressure gauge on the filter housing.

Chris

 

[Pool4Fool]

Flame sense rod rarely fails. Most often it's the connection on the wire or position in the flame. If you ever clean it, use a dollar bill nothing more course.

Glad you were able to solve this... congrats!

Hi, I think I have the same problem. Where is the flame sense today located? Thank you in advance

 

[setsailsoon]

Hi, I think I have the same problem. Where is the flame sense today located? Thank you in advance

On the JXI heater the igniter becomes the flame sense rod after ignition. On the LXI the flame sensing is through a separate rod that you can see in previous posts on this thread. Is that the question you are asking?