The manual for the thermostat is in the Atwood Air Conditioner book, buried on page 12.
I set it to ON, mode = HEAT, fan = AUTO and left the furnace button OFF. It doesn't blow real hot air like a furnace, just warm air through the AC ducts. I raised the temperature a couple degrees and it ran continuously for about 5 minutes and the temperature went up to the new setting. The temperature outside was about 50 and it had no problem keeping the RV at 72, it cycled on and off every couple minutes. Overnight, the temperature got into the lower 40's and I pressed the furnace button = ON, it works like a traditional RV furnace. The heat pump probably would have kept up but I wanted to test the furnace.
I used the remote control to see if it worked, which it did. The only use for it that I can think of would be to for the passenger to adjust the unit without unbelting when you're driving, it's probably pretty handy.
2015 FR3 30DS
Towing 2016 Chevy Sonic LT