Originally Posted by Al Fresco
Thanks for explaining this feature of the Dometic thermostat. Instead of a problem, I am happy to learn that it is actually a beneficial function.
Yes, that is the thermostat I have. And thank you so much for explaining how it works. I did have the fan set on the “low” setting which accounts for the fact both the furnace and air-conditioner were blowing air. (Is this function specified in the instruction manual? Or did I just miss that part of the instructions?)
As usual, knowledgeable folks on this forum have come to the rescue.
The fan settings while set in furnace mode are explained on page 9 of the manual.
One other thing I would like to point out is on page 11 of the manual.
When using the AC and the fan is set on auto, the fan will run on high when the room temperature is 5° or more above the set temperature. The fan will run on low when the room temperature is 4° or less above the set temperature.
So when first starting the AC and say the room temp is 80° and you set the thermostat to 72°, the fan will run on high until the room temp reaches 76°. At that time the fan will shut off for a couple of seconds and start back up on low. The fan will shut off when the room and set temps are equal.
When you set the fan on high or low, the fan will run continuously while the AC compressor cycles on and off.
The first few times it did this I thought something was wrong.