So far it sounds like the printed circuit board relay contacts are bad, I could write you a book and that would only confuse the issue.
Lets do a heat stress test on the printed circuit card.
Use a hair drier to slowly warm the printed circuit card up to120F or a bit warmer, but not over 140F... if there is any change in the error codes or other furnace behavior... the card has a cracked micro circuit, invisible a few atoms wide is all it takes, that opens and closes as the card expands and contracts... that proves a bad printed circuit card.
No change however does not prove the card is good however... but a change proves the card is definitely bad.
If that fails to show any change
Next please attach a well focused, close up photo of the wiring diagram glued inside the service panel, the picture needs to be taken from straight on, in very good light.
You can use the paper clip- icon at the right end of the tool bar at the top of this dialog box to attach it here.,Include a picture of the thermostat wire connections to the printed circuit board in the same area.
If you have an error code showing, tell me what the code read out is on the wiring diagram or a sticker next to the diagram please.
If there is no paper clip-icon, look for the '+attach files'link at left of your send button.
I can mark it up with trouble shooting instructions.
We can go from there.