FURNACE NOT LISTED ON THERMOSTAT

My TT air conditioner died before I ever took the trailer out for the first time. Dometic had a bad run and I got lucky. When the dealer replaced it under warranty, I brought it home and did my usual OCD double checking. I saw that the furnace was no longer listed in the thermostat. I took it back to the dealer and the service guy spent 2 hours trying to figure it out. Then he called the service manager over. As soon as he explained what was happening, the service manager told him the dip switches inside the roof unit were set wrong. Took 5 minutes more to fix, and most of that was getting the ladder.