I recently obtained a copy of the operators manual for the Dometic digital thermostat that was installed in our Jayco Skylark. After reading the manual I noted that when first installed that the thermostat needs to be initialized. I wrote to Jayco and asked if this initialization also had to be done if the 12 volt power was disconnected for any length of time. They replied that anytime the thermostat loses 12 volt power it should be re-initialized and the temperature differential should be reset.
Here's how:
System Initialization
A system initialization will need to be performed by the installer after
the system is installed.
Make sure the Single Zone LCD thermostat is in the Off condition. See page 4, Quick Reference To Control Buttons.
Press the + button and, while holding it, also press and hold
the On/Off Mode button for three seconds. LCD will show
――. Press the On/Off Mode button again to turn system off.
This completes the initialization.
The furnace On/Off temperature differential should be set at this time.
To set the temperature differential the system must be Off. Press
the ― button and, while holding it, also press and hold the On/Off
Mode button for three seconds. Release the On/Off Mode button.
Then release the ― button. Press the + button to toggle between
d1 and d2, d1 for 1 degree F differential and d2 for 2 degrees
F differential.