Found out yesterday that the furnace...
had a clogged nozzle!
YAHOOO! So they replaced that and cleaned it and we're good to go. That's a $80-100 charge instead of $3-4k (worst case scenario charge). I had calls from my Mom, MIL, realtor all day yesterday asking what was going on. I was happy when I could finally deliver the good news. Whew!
Thanks for the positive working furnace vibes! I think they helped!