Lennox G50UH(X) series LED indicator

littlepilgrim

Hi, I have one of these furnaces and it stopped working yesterday. I have tried everything to reset it and they didn't work. Today I went up in the attic and checked the LED lights and they were flashing to indicate;

1.Improper main ground
2.Broken ignitor; OR: Open ignitor circuit
3.Line voltage below 75 volts

It has been working fine for quite a while...

I did let the filter get pretty dirty and a friend said it is likely one of the sensors got dirty as a result. My question is which one and where do I find it?
(I have replaced the filter and need to get it turned back on ASAP)

Thanks.

how

(1) Checking all ground wires connections from board right back to the circuit box.

(2) checking igniter....

If igniter is OK - check for bad connections on ignition circuit.


(3) Check what the L1 line voltage to neutral at the board is.