I recently learned that RV Absorbtion Refrigerators without a "cold weather" option must not be operated when outside temperature is below freezing (32 F).
Solution in the outside of the refrigerator can freeze, preventing the refrigerator from cooling and worse, causing the refrigerator boiler to overheat and cause corrosion and overpressure conditions that worst case can cause catastrophic failure and a fire to be initiated behind the refrigerator.
Before I learned all of this I started up my Norcold in December and was using my RV. Had taken steps to make sure water and holding tanks were kept above freezing. Did NOT know about the refrigerator not working when it is below freezing outside.
I don't know how far below freezing the refrigerator stops working, but at some point mine did. It was well below zero F when I noticed the refrigerator had stopped working !
I have the ARP Control Refrigerator Protection Device on my Norcold. IT SAVED ME ! When my refrigerator solution froze, causing the boiler to begin to overheat , it detected the boiler beginning to overheat and shut down the heat source before it overheated to the level that causes damage, keeping my refrigerator from being destroyed !
LOVE MY ARP REFRIGERATOR CONTROL ! ! ! Check it out on ARPRV.COM
FYI, the "cold weather" option consists of putting plumbing style heat tape around the parts of the tubing behind the refrigerator where the solution can freeze in the lower back part of the refrigerator