Describe the pattern
Say whether ice covers one corner or a broad area and whether food touches the rear wall. Include any recent change of setting or loading.
Keep performance in the account
If food is also warming or freezing, state which items and locations. Faults involving the sealed cooling circuit are outside our service scope, so the model and symptom need screening before an appointment is offered.
A useful distinction
Some moisture on a cold interior surface can be part of ordinary operation. The useful change is persistence, thickness and an altered storage result, rather than the mere existence of a wet or frosty patch.