Frost builds when humid air enters the freezer and moisture freezes on cold surfaces. A poor door seal, frequent openings, warm food, or an automatic-defrost problem can all cause excessive buildup.
Look at where the frost forms
Frost concentrated near the door or one edge usually points to air leakage. A heavy layer across the interior rear panel can point more toward an automatic-defrost problem.
Check the gasket and door closure
Clean crumbs and residue from the gasket and make sure no drawer or package prevents closure. A distorted gasket may not contact evenly; do not replace it before confirming the door is aligned.
Reduce moisture entering with food and openings
Cool food safely before freezing it in covered containers and avoid holding the door open while deciding what to remove. Uncovered containers also release moisture into the compartment.
Recurring frost after defrosting needs diagnosis
If you remove ice according to the manual and it returns quickly with a good door seal, the defrost heater, sensor, fan, or control may be failing. Do not chip ice with sharp tools that could puncture the evaporator.