Dometic Thermostat Error code E3

[jlaney20]

I’m getting this error code E3 on my Dometic digital thermostat. Looked it up and it is called a shorted indoor temperature sensor. Sometimes the AC and furnace are running at the same time. Don’t know where to start. Any ideas ?

[NH_Bulldog]

I would start with the furnace and AC running at the same time. That can be corrected by setting the fan control to “Auto” instead of “Low” or “High”. Then I would reset the thermostat and see if the issue is repeated.