If it is one of the new Duo Therm LCD thermostats there is a senor under the plastic cover that has a limit switch of like 120 degrees. I did a walk-thru on a new Wildwood travel trailer with my neighbor in February. The mechanic told us that they could not figure out for the longest time why these new tstats will would not turn on the AC in a trailer that had been sitting out in the heat. He told us to take the cover off, put a finger over the sensor located on the bottom right if my memory serves me right, and it will read your body temperature around 100 degrees and the AC will kick on. Obviously, genius idea by Duo Therm because the mechanic said they have never been able to figure out why they did that. I will tell you though, that LCD thermostat is nice. My analog one is all over the place trying to get the temperature right in my trailer, and my neighbors is right on the money at what he sets his at. I am going to update mine to this new thermostat, and will live with taking the cover off when it is blazing hot to turn the AC on.
2006 Salem 392FKTB PT
Seasonal Camping at Pomme De Terre Lake in MO