2017 182G - Funace Not Working

Looking for help on my furnace issue so I can avoid taking it back to dealer for warranty repair -- I don't want my Pod gone for too long and I don't trust the dealer to fix the issue.  I've owned RVs in the past, so pretty sure I have an actual issue vs user error.

I have a 182G with a Suburban Furnace, T-stat is the standard white Dometic that is square in shape and about 3" x 3".  The issue is that the once the furnace gets the Pod up to temp and the t-stat shuts it down, the furnace will not come back on (blower or heater) once the temp drops below the t-stat setting.

Here is my test this am:  34 degrees outside.  Turned on furnace using T-stat and set desired temp to 58 degrees.  Furnace fired right up, and ran for awhile until the temp reached 58 degrees, and shut off (so far so good).  Opened door, window, and turned on roof vent in the camper to drop the temp, and furnace never kicked back on, despite my stand-alone thermometer reading 45 degrees.  Any ideas?  Some thoughts I have:

1). How can I determine if the issue is with T-stat or furnace?

2). Made an appointment with the dealer, and based on my desription to the service tech he thought it was either a sail switch or limit switch gone bad.  After reading, I don't think it's a sail switch, as the blower won't come on either.  Will a faulty limit switch prevent the blower from kicking on too?

Thanks, 

Seth