A little frost is normal, but a sheet of ice on the back wall or a freezer that frosts over after every defrost has a real fault. It is almost always the defrost system, the seal, or the drain.
Notes by Brand
| Brand | What It Usually Means |
|---|---|
| Sub-Zero | Frost on the rear evaporator panel usually means the defrost heater or bimetal has failed and stopped clearing the coil. |
| Viking | Ice building at the base often traces to a defrost drain that has frozen and blocked. |
| Liebherr | Frost with a warming cabinet points to a defrost sensor or heater fault triggering an alarm. |
| True Residential | A torn freezer door gasket lets humid air in and frosts the compartment repeatedly. |
| Monogram | A stuck damper or a failed defrost timer leaves frost that returns after each cycle. |
What to Check First
- Check the freezer door gasket for tears or gaps that let humid air in.
- Look for ice in the defrost drain at the base of the compartment.
- Note whether frost returns quickly after you clear it, which points to defrost.
- Avoid chipping ice off the coil, which can puncture the evaporator.
Do not chip the ice. Never use a knife or pick on a frosted evaporator; a punctured coil turns a small defrost repair into a sealed-system job.
Book a Diagnostic Visit
We confirm the fault, then quote the repair in writing. Diagnostic and travel fees, if applicable, are confirmed before the appointment and before repair approval.