There are many reasons that cause RV refrigerators not to work properly.  Cooling units fail, Heating elements fail, boards fail...Sometimes it's because the customer just has too much inside the refrigerator and it can't get enough air circulating around the food to cool. The baffle in the flue tube can become burned and disformed and cause the heat going through the flue not to circulate properly.  I have even had one customer that placed a plastic bag over the roof vent which would not allow the heat to escape from the back of the refrigerator (no heat escaping, no cooling, refrigerator stops working!)  Sometimes it's because of an installation issue.  Then there are those cases like the photo above, Mud Daubers.....They love to build nests where there is propane.  I don't know why, but they prefer to find their way into water heaters, furnaces and yes, even your refrigerator.  In this instance, the customer had a failed power board that would not allow the refrigerator to operate correctly on either LPG or electric.  But as you can see, the mud daubers had completely blocked off the burner area with mud.  So, check for these pesky little critters regularly, it may save you hundreds of dollars in repairs.

During the summer months it's a good idea to put a screen over your furnace vents to keep those mud daubers out of your heat exchanger, burner and blower wheels.  In this furnace the orifice was completely plugged with dirt.