Jandy LRZe IGN Low voltage to gas valve *solved*

[johnb6050]

I have an older model Jandy LRZE pool heater and it is giving the IGN fail error. I have dealt with this before and typically resolved it through replacing various parts. This time is a little different and I couldn’t find anything in forums with these specific symptoms.

When the heater goes through the IGN sequence, everything works like it’s supposed to up to the moment the Fenwal is trying to power the gas valve. When the gas valve is powered it immediately end the IGN attempt.

I pulled the connector off of the “Valve” terminal on the ignition controller, and I am only getting 12v when the ignition controller send power to that terminal. If I connect the wire from the ignition controller to the valve I get 6-7v at the end of that wire.

I purchased a new Fenwal ign controller. Replaced the wiring from the Fenwal to the gas valve. When the Fenwal tries to power the gas valve it immediately drops out. I still am getting 12v at the Fenwal terminal and 6-7v at the gas valve.

Is this an issue with the ground?

 

[ajw22]

Welcome to TFP.

Are you working off the manual?

Have you traced 24V within the heater?

 

[johnb6050]

Yes sir. I am getting 24v at the transformer, to the control board, to the Fenwal ign control, via wire shown as “2” in your illustration.

It seems to be 24v throughout, except for the Valve terminal on the ign control. When there is a call for gas it shows 12v at the terminal. When I hook the wire to the control board only, I get 12v at the control panel but 6v at the gas valve.

It is somewhat baffling because I replaced the ign control and wiring. I can’t find any resistance in the wiring. I even get 24v from the control board to the ign control on the “W” wire when there is a call for heat.

The weird changes in voltage have me thinking it could be a ground issue.

 

[johnb6050]

Ok. I think I may have narrowed it down further. I am only getting 22v from the “W” yellow wire from the control board. The control board is brand new and it was doing it on the old one, so I suspect it is the connector where the “W” wire goes in.

I bypassed and went straight from the transformer to the W terminal on the IGN control with the full 28v and it fired right up and ran fine.

So my next step is to figure out what is wring with the connector.

 

[ajw22]

Check for corrosion on the connector pins.

Try a contact enhancer like Stabilant 22A ...

Amazon.com

 

[johnb6050]

I took the pin out of the connector and the voltage straight off the PIB was 13.6v. So now I am wondering if I just happened to get a faulty PIB.

Re-pinned the “w” wire in the connector and still getting 13v. When the IGN controller tries to activate the gas valve it drops to 7v. So now I am also wondering about the power into the PIB. It shows 28.8, same as the transformer, but when it calls for heat and send power to the IGN, it drops to 28.4. The transformer also drops to 28.4. I may see if I can find another 24vac power supply to test if it is somehow the transformer.

 

[johnb6050]

Solved.

Turns out I am an idiot. The high limit sensors evidently in-line for the voltage. They were returning 13v. Bypassed the high limit and it works fine. Turns out you do need to follow step by step the guide for diagnosing.

Kind of interesting that the high limit was sending enough voltage back to avoid tripping a fault, but the lower voltage was then passed on to the “W” wire calling for heat.

Just need to order a new high limit sensor. Thank you for your help!