Quick answer: Check whether the freezer door closes fully, whether food or a shelf is pushing against it, and whether the gasket is dirty, folded, or damaged. Wipe the seal gently and follow your model’s manual for defrosting. Do not chip frost with a knife or force the gasket back into shape.
Start at the seal, not the frost
Frost is visible, but it may not be the original problem. Close the door on a thin sheet of paper and pull gently. A little resistance around several points suggests the gasket is making contact; a loose section, a gap, or a paper sheet that slides out easily deserves a closer look. This is only a simple check, not a test of the appliance’s full cooling performance.
Inspect the folds for crumbs, sticky residue, or a corner that has rolled inward. Look inside the freezer as well. A drawer, package, or shelf that sits too high can hold the door open by a few millimeters.
Clean and dry the gasket carefully
Unplug the appliance only when your owner’s manual says it is appropriate for the task and it is safe to do so. Use warm water and a soft cloth to wipe the gasket folds. For a narrow groove, a soft brush can loosen residue without cutting the rubber. Dry the gasket and the frame before closing the door.
Do not use a sharp tool to remove frost near the seal, and do not pour hot water into the freezer unless the manual specifically directs that method. Sharp tools can puncture a liner or gasket. If a full defrost is needed, use the manufacturer’s instructions and protect the floor from meltwater.
When the gasket is not the whole story
If the door closes normally but frost returns quickly, food is thawing, the motor runs unusually often, or the appliance shows an error, stop troubleshooting by cleaning alone. The issue may involve airflow, a defrost system, a hinge, or another component that needs service. Keep the door closed as much as practical while deciding what to do with temperature-sensitive food.
For a related seal-cleaning task, see how to clean a refrigerator door gasket gently. You can also review the refrigerator coil guide, but always follow the appliance manual for access and service limits.