Jandy LRZ Pool/Spa Heater Won't Ignite

Jun 6, 2020
11
New York
Hello, I'm looking for some help diagnosing and repairing my Jandy LRZ Pool/Spa Heater. We've enjoyed many years of trouble free use until recently. To make a long story short, the heater was running on a very hot day. The heat exchanger fins got clogged up with a sooty fine black powder. This restricted the airflow and caused a flame rollout and the unit shut down. After removing and cleaning the exchanger I tried to start the unit. It would cycle 3 times and lockout with no glow from the ignitor. I then noticed the two wires that go to the hot surface ignitor had melted together. The flame sensor wire was also damaged. I replaced both the sensor and ignitor. The unit cycles but the new ignitor does not heat up or glow either. After three attempts it locks out just as it did prior to replacing the damaged parts. I assume the ignition control box is fried but don't want to invest in one without confirming that's my issue.

After looking over the manual https://www.jandy.com/-/media/zodiac/global/downloads/h/h0299500.pdf I noticed the ignition control isn't wired like the manual shows it should be as far as the hot surface ignitor is concerned. One lead goes to the junction block as it should and the other is attached at line 2 as opposed to IGN 120.

If anyone could recommend how to test the ignition box or how to best proceed it would be most appreciated.
 
Followed the troubleshooting guide provided by ajw22 and followed the testing procedure accordingly. All VAC ranges were good and ok until I got to step 12. According to the guide the VAC should range between 105-130 at IGN120. I got a reading of 0... I decided to check the VAC at Line 2 as well seeing as how that's where one of the ignitor leads was. I got a reading there of 15... Lastly I decided to check the VAC at IGN240 and got a reading of 13. I made sure the unit was calling for heat for steps 4 through 12 but did notice that the LED indicator on the Ignition Control was not lit when calling for heat. That coupled with these readings leads me to believe the Ignition Control is the culprit. I'm going to try and find the right one and go from there. Thank You ajw22 for helping me test things out! :)
 
1941,

Looks like you've done a great job with the diagnostics. And it makes sense that the shorted IGN wires damaged the Fenwal. If you want to be absolutely certain I'd suggest one last thing. Take the connections off the Fenwal one at a time and clean then reconnect. Connection issues can cause the Fenwal to fail. And it's expensive enough that it's work the extra effort.

If you end up needing a Fenwal, I'd check parts4heating.com. They are an authorized dealer for Fenwal and had better prices than the other reputable places I tried. If for some reason you get a bad unit from them they will send the unit to Fenwal and test plus replace free if the unit tests bad. Fenwal tech support verified this for me.

I hope this helps and please to keep us informed. Finger's crossed for you!

Chris
 
I received the replacement Fenwal and it's a no go. I think it's defective. I went through the entire testing process yet again and everything was good until it came time to test the voltage at the ignitor. I got readings of 0 VAC at the ignitor with the unit calling for heat. I'm going to try and return it for a replacement and go from there. What a PITA!
 

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Hi Chris... Yes I am definitely getting 120V in. For Darns and giggles I opened up the old Fenwal and saw that the solder connection on the board at the 120V spade connector was burned up. I re soldered the connection and reinstalled the unit. Ignitor came to life and the heater fired up and ran beautifully for about 1 minute. Then I noticed water pouring onto the burners and flame sensor which shut the whole thing down. Wow what a kick in the nutz... I was extremely careful when I removed the exchanger and used a soft bristle brush with vinegar and water to clean it. I have no idea where the hole(s) might be. Kind of took the wind out of my sails for the night. :(
 
1941,

Wow! That's awful and sounding more like my fiasco every day. So good news is that it appears you did get a bad Fenwal and were able to fix it, right? Where did you get it? Did you hook it up as shown in the diagram or to line 2 as previously installed?

As to the water leak. When you removed the tube bundle did you replace the o-rings? This could be the leak or you could have thinning tubes and now have a pin hole leak. When you removed it did the ends of the tubes look thinned? This often happens from incorrect water balance. This can sometimes be fixed with new o-rings.

Chris
 
Hi Chris, I fixed my old Fenwal by resoldering the connection at 120V and connecting the ignitor there as this was the correct connection per the manual as opposed to L2. The defective new one is in the box to be returned. I bought it from supplyhouse.com. I've requested a replacement.

As to the water leak, when I removed the heat exchanger I removed the whole assembly and never removed the sides so the O-rings were never disturbed. If I recall correctly the leak got worse as the unit heated up. My guess is it opened up the pin hole(s) or crack more with thermal expansion...

I'm going to remove the heat exchanger again and see if I can spot the leak. If I do tear it down and remove the side "tanks" I'll check and see how thin the copper tubes are. If they are thinned then I'll have to replace it I guess. I wonder if I could slide slightly smaller copper pipes into the existing tubes? Anybody tried that yet? :)

Oh and thanks for sticking with me and my debocle! :)
 
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