The "5" is the coldest setting on both AC and propane.
The Dometic 4223 is a continuous run fridge without any thermostatic control. The AC knob regulates how much AC power gets to the heater the same way a dimmer regulates incandescent lights. Similarly, the propane knob is a valve that controls how much gas goes to the burner.
I strongly suggest you get a wireless outdoor thermometer ($10 at Walmart) to monitor temps inside the fridge. Put the send unit inside the fridge. Our receiver will work inside our minivan while towing. We replace the batteries in both receiver and transmitter once a year (remove the batteries when we return from a camping trip).
Depending on how well Forest River complied with the Dometic installation instructions, your fridge may or may not keep cool in 85+ degree outside temps, even at max settings. There is a thread I wrote on the A-frame forum
http://www.forestriverforums.com/for...ge-104964.html about my experiences with making the 4223 cool consistently and well on my A-frame.
When I was done with the Reflectix, insulation, and installing the fan, I would turn on my 4223 fridge the night before on AC "5". By morning the temp would be in the high 20s. While towing (had to use DC), I turned the fridge and/or fan on and off to keep temps between 29 and 40. Upon arrival, set propane or AC to 3 to start and adjusted further as needed, based on fridge temp.
hope this helps
Fred W
2019 Flagstaff T21TBHW A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time
Linear Mode
