Freezer vents are frosted over not allowing the frig to be cold. I turned controls to off which are horizontal lines. Opened doors to frig and freezer. Taped the latches so lights would be off. DId not unplug. The vents in freezer after this having been done for over 3 hours are more frosted over than when it was on. Could you help me with what part I need to order to fix this? Thank you sorry model is MFF 2558VEB1

While awaiting response I turned off appliance and opened all doors. As of last night all had defrosted and so I turned back on before bed and set both frig and freezer at 4. So far all is well. Do u suggest anything? Should the humidity control be on or off? and my user book does not say how to set the humidity controls for the veg and fruit bins or the pull out drawer at bottom of frig. Would these lead to frosting problem? Thank you

Thank you - what should the freezer temp. be optimally?

Thank you - so far all is working great. Maybe wishful thinking but maybe door was not shut tight and started the cascade of events. Now that we are starting over with defrosted freezer vents maybe trouble is behind us. Thank you for your help and we will have to wait and see. This is a great website and I will definitely spread the word to my friends to be sure to check you guys out for any appliance repairs!!