This unit has never been connected to water. It maintains perfect temperature. When it was moved to do some kitchen remodeling, they noticed the exterior wall, behind the ice room had rusted through and a large chunk of ice had formed. I have since cut off all that rusted sheet metal and removed the ice. It runs great. I noticed ice forming on the exposed insulation after a week of removing it. I have no idea why this is happening. Could it be a design flaw? Would adding more insulation solve the problem? Do I need to add sheet metal or something to seal out the ambient air? Any suggestions are welcomed. Has anyone seen this before? If so, what was the fix? I appreciate any thoughts or suggestions.