The top freezer in my Kenmore refrigerator has quit freezing. It quit suddenly. I'm not sure if the condensor is running but the blower at the back of the freezer unit is running constantly but the temp is only 38 degrees. I have turned up the cold knob from 3.5 to 4 and turned the usage knob to indicate more freezer usage but the blower just keeps running but the temp is staying the same. I bought the unit about 25 years ago (new) so it might just be tired. There is no ice build up anywhere. Any suggestions?

The evaporator fan in the back of the freezer blows over the cooling coils. Those coils are typically hidden from view behind a panel.

The problem you describe would lead me to suspect that the coils are iced over. That is why there is some cold, but not enough. The fan is blowing over a block of ice. An overfilled freezer is another possibility.

Iced over coils may be the result of a malfunctioning defrost system, a plugged drain tube, a poor seal on the door seals to the cabinet resulting in a lot of moist air entering the freezer (or fridge) or the refrigerant level is under pressure (needs more refrigerant added).

Most refrigerators never need refrigerant added, but after 25 years, it could be that yours does. However, it can only be done by a pro, and it probably isn't worth investing that kind of money in such an old fridge.

I recommend you start by unplugging the fridge and inspecting the coils inside the freezer. If they aren't iced over, then the door seals may be still be the problem by letting in warm air.

There are many possibilities. You should also take a look at our refrigerator diagnostic page.

Let us know what you find.

Shortly after I posted, the freezer started getting colder and when I last checked, it was minus 22. There was a lot of food in it, which I had removed when I saw things thawing out. Apparently removing the food permitted better circulation and permitted the coils to thaw out. It seems to have healed itself. Thanks for the advice

That is great news. You gotta love those easy fixes.