Why does frost build up inside a freezer at all?
Every time warm, humid air enters a freezer — through the door or a leak — the moisture in that air freezes onto the coldest surfaces inside, usually the back wall or evaporator coil area. A small amount is normal; heavy, fast-accumulating frost means more air is getting in than the defrost cycle can keep up with.
Is it the door seal?
Check first — it's the most common cause and the easiest to verify. Run the dollar-bill test around the full perimeter of the door: close it on a bill at several points and see if it slides out easily anywhere. A gap anywhere lets humid air stream in continuously, especially given Dallas's own humid summer air whenever the kitchen or garage door opens nearby.
Could it just be how often the door's opened?
Yes, especially with kids or a busy household — every opening introduces a fresh batch of humid air that has to be pulled back down to freezing. This isn't a malfunction, but heavy frost from frequent openings is still worth managing by organizing contents for quicker access and minimizing how long the door stays open.
What if the seal is fine and openings are normal?
That points to the automatic defrost system itself — a failed defrost heater, timer, or thermostat means the unit never runs its scheduled defrost cycle, and frost just keeps accumulating unchecked. This is a $130–$230 repair depending on which component has failed.
Call (469) 886-1122 if the door seal checks out and frost keeps building — we'll test the defrost system directly.