Last week I noticed some things weren't completely frozen in our upright freezer I thought it was just new stuff or maybe the door hadn't been shut completely. After a couple days, I noticed the temperature display had increased to 17 degrees even though it's set at 0. The compressor has been running a LOT, but the freezer is in our garage in Phoenix, so I figured that was just the heat.

So yesterday I emptied out the bottom half and removed the evaporator cover. Sure enough, they were covered in ice, but a pretty even coat. I did this a couple minutes at a time to avoid letting the freezer temp increase too much. The time it took to work out the cover allowed the temp to get up in the 40's. After the temperature got back down to freezing, I tried to manually start the defrost cycle from the control board. I got the De on the display and the compressor and fan shut off as expected. But there was no heat on the heating element.

Once it was cooled back down, I tried using the blow dryer to thaw the frost. It was a very slow process and I stopped after a few minutes because the freezer temp was in the 60's. It took the rest of the evening for it to cool back down to 30ish. Before going to bed, I set the cover back in the freezer so it was over the evaporator, but not all screwed in. By this morning, the temp was down to 21.

I checked the evaporator this morning and it was still a little too much frost, but not totally thick like before. If it's just the frosted coils restricting air flow, shouldn't it still get the temperature back down lower? Or do they need to be totally clear to tell if it will cool? Or do I need to completely reinstall the cover and re-load the bottom of the freezer to judge? I've been trying to avoid having it open more than a minute at a time, but that makes it hard to do anything.

Should I keep going down the path of diagnosing defroster issues, or should I be concerned that it isn't cooling well even with the majority of frost gone?