Replaced 2 thermostats on Rudd propane furnace.after the furnace warms up to set temp

Are you asking how to set up your thermostat(S) for auto heat? Why two thermostats? Need a lot more details of your situation guy. Typically though you just turn the auto function OFF on the thermostat. For more details I would need the thermostat manufacturer and model number so I can consult an online manual.

Can you please clarify? Can't quite understand what you are asking.