Help with replacement of Fenwel Ignition control in Laars LD

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W

wpartelo

0
Aug 2, 2017
11
palmer, ma
I have an older Laars Lite LD heater. After troubleshooting heater, I determined the ignition control was faulty. I ordered up a new module and found out that the replacement module requires wiring modification for my heater. It is made for the digital control panel and mine is the analog one. The part number is R0317500. The biggest difference I see is that on the old unit, the IGN and FS are separate outputs. On the new model, there is one terminal labeled IGN/FS. I found a wiring diagram for the new panel and wired it up accordingly. I have the IGN/FS going to the flame sensor and I have Red from the transformer and IGN/120 going to the Ignitor. With this setup, the ignitor does not get hot. I should be getting 120vAC between the transformer red and the IGN/120 but I get 0vAC. Can someone help me figure out what is going wrong? Testing all the other safety switches, it seems good. I get 24vAC at all of them. I am running out of ideas.

thanks
Bill
 
Bill,
Connection to the IGN should be as printed on the FENWAL. Either IGN/120 OR IGN/240 depending on your voltage to the heater, AND IGN (first picture) or IGN/FS (second picture). Your post suggests that you are trying to heat the IGN with one high voltage LINE and one low voltage leg.

Your current result is correct, it wont work!

If your heater has a separate wire for the FS (flame sensor), you may have the wrong FENWAL, or need to check the printed instructions closely. Can't remember if they needed you to combine the line and FS somehow. I did this conversion once long ago (and hated it), and have forgotten exactly how it goes. Can you picture and post the instruction sheet you got with it?

I, or someone here can probably get you through this.
 
thanks, I will try when I get home tonight. My heater does have a separate wire for the flame sensor and unfortunately the instructions that came with it just tell me to modify the wiring, but does not show you how. I can post a pick later. The instructions say is it the new replacement model for my controller though. I called Zodiak and they would not help.
 
so I wired it up similar to the original. I have the black line from the transformer to L1, Red line from transformer to L2 and the Ignitor to IGN/120 and IGN/FS. I have the Flame sensor disconnected. With this configuration, I still do not get the ignitor to heat up.

- - - Updated - - -

here are the only instructions I receivedIMG.jpg
 
I checked the wire that plugs into th and I get 24v. I do not get 24v on the th terminal. The interesting thing is that it is not 100% wired like original. One thing I noticed is that the line going into th is from F2 on the new controller and the Y/Bk lead is going to the IND and F1 lead. Wondering if I should bypass the F1 and F2 plugs.
 

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wpartelo said:
I have the IGN/FS going to the flame sensor and I have Red from the transformer and IGN/120 going to the Ignitor. With this setup, the ignitor does not get hot. I should be getting 120vAC between the transformer red and the IGN/120 but I get 0vAC.

thanks
Bill
Click to expand...

With the comment you made above, I am going to guess the red wire from the transformer is the secondary side. according to the schematic, you need to hook the 120 volt input to the unit directly to the L1 terminal. The IGN 120 goes to one leg of the igniter and the other leg of the igniter goes to the 120 neutral.

Dan

Edit
Is the feed to this unit 120 volts or 240 volts?
 
hi Dan,
yes this is the way I had originally hooked it up. the black wire from the transformer is the line voltage. that was going to L1 and the Red from the transformer is the neutral side which was connected to the Ignitor.

It is wired for 120v
 
wpartelo said:
hi Dan,
yes this is the way I had originally hooked it up. the black wire from the transformer is the line voltage. that was going to L1 and the Red from the transformer is the neutral side which was connected to the Ignitor.

It is wired for 120v
Click to expand...

Do you mean the back wire to the transformer? Your power supply to the unit, if 120, should be a black(hot) and white(neutral) wire. If there are a red and black wire you will need to check the voltage between them
 
danpik said:
Do you mean the back wire to the transformer? Your power supply to the unit, if 120, should be a black(hot) and white(neutral) wire. If there are a red and black wire you will need to check the voltage between them
Click to expand...

Wiring diagram in the manual i posted the link to show red and black from terminal block feeding transformer and module.
If he checks voltage at the places in my last post we'll have more to work with.
 
Should be firing then
Turn power on, call for heat then check for power at ignitor terminals after your purge times run out. Can't read that good on phone but it looks like you have 2 15 second purge times.
If you get power there after purge you probably have a bad ignitor.
 
when I check for power between ign/120 and ign/fs I get 0v throughout the cycle. For some reason I get 13v if I check between ign/240 and ign/fs/ if I hook the ignitor to the 240 side, it does heat up but still not enough to light the flame.
 

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