Dometic Dual Thermostat

[sharpei3]

Have 2016 Sierra 5th wheel
When turn on furnace a.c. runs and can not
Set 2 different temps??

[Wiscampsin]

AC probably isn't running, just the fan. Try setting fan to AUTO.

[sharpei3]

So is the fan suppose to run? I have it on auto
Why can't I set 2 different temp

[5picker]

Originally Posted by sharpei3

So is the fan suppose to run? I have it on auto
Why can't I set 2 different temp

Your thermostat is not like a house stat that allows an A/C temp to be set and a heater temp to be set. You have to set the temp for which ever mode you want to use.

The reason the A/C fan blows when you select heat is because you have the fan mode set to 'on.'
Set the fan mode to 'auto' and the A/C fan won't come on with the furnace.

Many people like that feature though as it distributes the warm air more evenly. (warm air rises)