Ice on RV Refrigerator Fins

We are new full-timers and I’ve noticed our Norcold refrigerator fins inside the unit are icing up. What causes this or is this normal? Should I ask how to prevent this? Casey D., (St. Louis, MO)

Casey, the cause for severe icing on those fins could be a couple of things. Depending on the model Norcold, it may be a mis-positioned thermistor, which is the device used to determine the cold setting on the thermostat. Or it could simply be a faulty door gasket leaking air. The first thing to do is perform, what we call, the dollar bill test. Close the lower refrigerator door(s) onto a dollar bill at various points around the entire seal, (if you have a fancy coach, use a hundred dollar bill!). With the door closed onto the bill, tug on it. You should feel a slight drag or resistance on the bill as you pull it out. If it just falls out or you feel no tug, chances are the gasket is faulty and needs replacing. Be sure to do this at multiple positions around the entire seal of each door. If that test passes with flying colors, then send me the model number and I’ll look up the exact positioning of the thermistor on those fins. Also be sure you have plenty of room for air to move about inside the cabinet section. Avoid placing wide trays that may block some of the convection movement inside the box. This too, could cause some icing on those secondary evaporator fins.