Some frost is normal in a freezer. Heavy ice on the evaporator coil, ceiling or floor is not. It means warm, moist air is getting in or the system isn't defrosting.
The usual causes
Door not sealing
Torn gaskets, a sagging door or a failed closer let humid kitchen air in every time the door moves.
Door frame heater out
Without the heater, the door frame freezes and the gasket can't seal.
Defrost failure
A failed defrost heater, termination switch or timer lets ice build until the coil blocks airflow.
Frozen drain line
Defrost water refreezes in the drain and builds up under the evaporator. Drain line heaters prevent it.
Door propped open
Long loading sessions with the door open load the coil with frost.
Relief port problems
A stuck pressure relief port makes the door hard to open and can pull in moist air.
What to do now
- Keep the door closed and check the gasket all the way around.
- Don't chip ice off the coil. You can damage fins and refrigerant tubes.
- Watch the box temperature. If it's rising, call.
See walk-in cooler and freezer repair, or put it on a schedule with the Kitchen Care Plan.
Written by the Ace Mechanical team. We've been fixing heating, cooling, refrigeration and plumbing across Hampton Roads for more than 30 years. Questions about your own system? Call (757) 495-7782.
