Dometic thermostat wrong temp

[talovestmg]

Good evening! I know similar questions have been asked before but I haven’t seen any real answers. Maybe now someone has experienced this and can help. My new 2022 Flying Cloud FB Dometic thermostat is reading 20 degrees lower than it actually is no matter if we have heat or AC on. It is set on Fahrenheit, and we have two other thermometers telling us this is so. We appear to not have the sensor by or behind the TV that others mention. Has anyone else had this issue and been able to correct it? I just picked t up two weeks ago and really don’t want it sitting in the shop for weeks or months. Thanks I’m advance!

[Rich Jenkins]

That's pretty odd. So has it always been like this? As in, when you picked it up, and did the initial checkout of the unit, was the temperature 20 degrees off?

I can't think off hand of anything that would explain why the AC/Furnace/HP would "read" 20 degrees off of nominal. Faulty thermistor maybe; a broken wire would probably result in the thermostat running open loop. Maybe check the Dometic user manual that came with the trailer for any relevant trouble shooting procedures?

Just to confirm, does this 20 degree swing apply to all modes of operation? So if you set the furnace to 50, does the coach heat up to 70? Same for the heat pump? Same for the AC?

Seems like this would be hard to fix without some parts swapping.