Jandy LRZE Ignition Issue

[BAS Guy]

I am a building automation guy with a fairly decent HVAC background, but this one on my own pool has me stymied. Up to this point, I have replaced the ignition controller and the gas valve. I see several attempts to ignite and then it just locks out.

I see the hot surface igniter heat up, I hear the ignition controller attempt to energize the gas valve. I see my meter fluctuate for half a second, but never really registers 24VAC to the valve. When I disconnect the common/ground directly on the gas valve, I have 24VAC through the coil of the gas valve for about 5 seconds. I'm guessing the flame failure is working as it should in this case and cycles the ignition, since the valve is essentially not wired.

I have a 100VA 24VAC transformer that I wired directly to the gas valve and confirmed that it opens. I tried using this same transformer to power the entire low voltage side of the boiler (disconnected factory transformer), but did not help.

I tried jumping the common/ground of the valve straight to ground also. Just makes no sense to me. Guessing I need to check that the heat call is constant to ignition controller. Not really sure how the gas valve input on the universal control power interface works.

Any ideas?

 

[ajw22]

Welcome to TFP.

Let’s see if @swamprat69 is around.

 

[swamprat69]

I think that this may be the manual for your heater https://images.inyopools.com/cloud/documents/jandy-legacy-owners-manual-electronic-ignition.pdf. If so then this would be your fenwal ignition control Parts4heating.com: Zodiac R0491300 Ignition Control, Model All, LRZE. There is no input from the universal controller to the gas valve. The universal controller only starts the ignition sequence by closing one leg of the 24V to the "W" terminal on the Fenwal giving you 24V between the "W" terminal and the "GND" terminal on the Fenwal. All other components of the ignition sequence are handled by the Fenwal : pre-purge time (15sec), ignitor heat-up time (40sec) and ignition ( trial for ignition time {7sec} during which the gas valve is powered and the flame is proven through the flame sensor). Are the burners lighting off at all? Do you have the correct gas pressure to the burners? When was the last time that the heater was cleaned and checked?Has the flame sensor ever been cleaned?

 

[swamprat69]

In what order did you replace the ignition control and the gas valve?

 

[BAS Guy]

I think that this may be the manual for your heater https://images.inyopools.com/cloud/documents/jandy-legacy-owners-manual-electronic-ignition.pdf. If so then this would be your fenwal ignition control Parts4heating.com: Zodiac R0491300 Ignition Control, Model All, LRZE. There is no input from the universal controller to the gas valve. The universal controller only starts the ignition sequence by closing one leg of the 24V to the "W" terminal on the Fenwal giving you 24V between the "W" terminal and the "GND" terminal on the Fenwal. All other components of the ignition sequence are handled by the Fenwal : pre-purge time (15sec), ignitor heat-up time (40sec) and ignition ( trial for ignition time {7sec} during which the gas valve is powered and the flame is proven through the flame sensor). Are the burners lighting off at all? Do you have the correct gas pressure to the burners? When was the last time that the heater was cleaned and checked?Has the flame sensor ever been cleaned?

Thanks for replying. To clarify, there is a parallel connection from the ignition controller to both the gas valve and the universal controller. I am assuming it is some sort of feedback signal, but not sure what the universal board does with it. The burners do not light off at all because the gas valve coil never energizes. I put a manometer on both gas valve ports and reading 8"w.c. on the inlet and never see pressure on the outlet. I pulled and cleaned the burners before I even attempted to start the unit up. I pulled the flame sensor and cleaned off some minor corrosion with some fine grit paper.

My problem is narrowed down to the 24V signal to the gas valve. I have it for the ignition trial, but when connected to the gas valve, it drops out immediately. Initial thought was overloaded circuit (bad transformer), but problem didn't go away with a verified good 100VA transformer. And I know the gas valve coil is good when connected straight to the 100VA transformer.

Thinking about breaking out a 24V test lamp (if I can find mine...lol) or a different 24V relay coil and seeing what happens.

 

[BAS Guy]

In what order did you replace the ignition control and the gas valve?

Changed the ignition control first. I will admit I was thrown off by not getting 24V when the gas valve was connected, so it may not have needed replacement. I didn't do a deeper dive until it still wouldn't work with the new ignition controller.

 

[swamprat69]

During the ignition sequence the gas valve is powered from the "VAL terminal on the fenwal. Remove the gas valve wire from the gas valve to the "VAL" terminal on the fenwal. Check the voltage from the "VAL" terminal to the "GND" terminal on the fenwal during the ignition sequence. You should see 24V for ~ 7 secs. That 24V comes from a relay in the fenwal. If you see 24V with the gas valve wire disconnected for ~ 7 sec during the ignition sequence, leave the gas valve disconnected and jumper system 24V "hot" ("24VAC" terminanl on the fenwal) to the gas valve terminal that the disconnected wire is attached to with your manometer connected to the gas valve outlet/manifold test port. Does the gas valve open and show gas pressure at the test port? Possibilities??? A stuck gas valve solenoid or solenoid coil shorted to ground may have damaged the relay contacts in the fenwal. Replacing the fenwal without replacing the gas valve may have damaged the gas valve relay contacts in the replacement fenwal. New gas valve would not work with damaged gas valve relay contacts in replacement fenwal. Test as noted and report findings. I think, but am not sure that the parallel gas valve connection to the universal controller only reports to the controller that the gas valve has been powered????

 

[BAS Guy]

During the ignition sequence the gas valve is powered from the "VAL terminal on the fenwal. Remove the gas valve wire from the gas valve to the "VAL" terminal on the fenwal. Check the voltage from the "VAL" terminal to the "GND" terminal on the fenwal during the ignition sequence. You should see 24V for ~ 7 secs. That 24V comes from a relay in the fenwal. If you see 24V with the gas valve wire disconnected for ~ 7 sec during the ignition sequence, leave the gas valve disconnected and jumper system 24V "hot" ("24VAC" terminanl on the fenwal) to the gas valve terminal that the disconnected wire is attached to with your manometer connected to the gas valve outlet/manifold test port. Does the gas valve open and show gas pressure at the test port? Possibilities??? A stuck gas valve solenoid or solenoid coil shorted to ground may have damaged the relay contacts in the fenwal. Replacing the fenwal without replacing the gas valve may have damaged the gas valve relay contacts in the replacement fenwal. New gas valve would not work with damaged gas valve relay contacts in replacement fenwal. Test as noted and report findings. I think, but am not sure that the parallel gas valve connection to the universal controller only reports to the controller that the gas valve has been powered????

So I connected my 24V test lamp between VAL and transformer neutral and it lit up for the full 7 seconds. I connected a 24V RIBU1C relay to it and it lit up and energized the relay coil for 1 second, then dropped out. It just doesn't like having a load on it.

I jumped the gas valve to 24V hot as you suggested and it definitely opened and fired off.

Edited to add: Mocked up the new ignition controller with the old gas valve and my 100VA transformer. No 120V or FS. Powered up the controller and sent 24V directly to W. I can hear the attempt for surface heat and then after the delay the valve did actually energize for 7 seconds. Wondering if the issue is with the feedback to the universal controller and it cycles the W signal. I will test this out next. Just realized that I am not getting the lockout flash code on the ignition controller, but see it on the human interface.

Second edit to add: Put my 24V test lamp parallel to the W call. Stayed constant with the gas valve disconnected. With the gas valve wired, I definitely saw a brief blimp in the W signal when VAL energized, which essentially resets the ignition controller cycle at that point. Really leaning towards the universal board now.