Specifically, in my freezer. This happened as the weather got cold last year too, but not in the 6 previous winters we’ve lived here, and as everyone asking for tech support says, we didn’t change anything. The freezer is already set at the highest temperature (and I’ve tried lowering the temperature with no effect).
The refrigerator came with the apartment, so there’s a limit to what we can do in terms of repairing or replacing, though I do wonder what would happen if we replaced the refrigerator-freezer with a better, or at least newer, one at our expense but without consulting the landlord. Though that’s not about to happen in any case.
A bad seal is my guess too. Even the best of them seem to need replacing every 5-10 years, and it’s possible to damage them without realizing it.
I have a full-size freezer and I could actually tell which part of the seal was going bad by looking at where the frost was heaviest.
Your landlord should be willing to replace it (that was the policy at the two buildings I managed for a time), but they’re not terribly expensive or challenging to do yourself. Since abad seal is wasting energy, it’ll probably pay for itself.
If I’m not mistaken – Don’t frost-free freezers have a de-humidifier mechanism to suck all the moisture out of the air to prevent frost? If so, maybe that’s quit working.
In addition to too much moisture going in, there may be a problem with the defrosted water going out. There’s a tube leading out of a small tray under the coils in the freezer compartment. If this gets blocked (with crud or ice) then the meltwater can’t get out and it evaporates/sublimes and reforms ice all over the place.
The simplest way to unclog it if it’s ice jammed is to do a manual defrost. Really let the freezer get warmed up. If that doesn’t work, then you need to take off a cover or two in the back of the freezer compartment and clean by hand. Fun stuff, of course.
As to the seals, they may not be working right if the doors are out of alignment. It may be possible to adjust them.
There’s web sites which can run you thru basic DIYer steps for things like this.