Can someone tell me how to actually adjust this thermostat? Am I missing something? The "off" lever does not move either. Am I missing something? This is the thermostat on my new to me Fleetwood Cheyenne. There is a slider on the bottom that I assume controls some type of fan speed? But I don't see how to actually change the thermostat. The small lever on the top right says "off" but I can't move it at all. Any advice would be great! Thanks!