A modest, even frost layer is normal. A thick buildup that keeps returning after you scrape it off is telling you something specific is wrong.
Door Seal First
Warm, humid air getting past a compressed or torn door seal is the single most common cause — the moisture in that air is exactly what forms into frost once it hits the cold interior.
How Often Is the Door Actually Opening?
Frequent door openings, or a door left slightly ajar, introduce the same problem mechanically rather than through a failed part — worth ruling out before assuming a problem.
A Sensor Problem Can Look the Same
An evaporator thermistor reading incorrectly can keep the system cooling harder or longer than it should, building excess frost as a side effect — on Classic Built-In units this can show as 10/R/01.
Getting It Fixed
Don’t just keep scraping frost off — book a diagnostic through our refrigerator repair page so the actual cause gets fixed.