A freezer that won't hold 0°F has one of five problems — and the order you check them in matters. Start with the cheapest checks (door seal, coils) before assuming the compressor is failing.
Most freezer symptoms get diagnosed and fixed on the first visit. Flat $149 diagnostic — fully waived when you approve the repair.
Step-by-step
Set the freezer to 0°F. Use a freezer thermometer — built-in displays lie. Wait 24 hours. If you can't hold 0°F with a thermometer placed in the middle, you have a real problem.
Close the door on a dollar bill. Pull it out — strong resistance = good seal. Slides freely = bad seal letting warm air in. Clean with warm soapy water and reseat, or replace ($50–$100 part).
Pull the freezer out. Coils are at the back or underneath. Dust + lint = compressor runs constantly without producing cold. Vacuum with a brush attachment. Do this every 6 months — single most-skipped maintenance task.
Hold the door switch in (or press it with a finger). You should hear a steady whoosh from the back wall of the freezer. Silence = evaporator fan motor dead. This is the #1 cause of a freezer that's running but not cold ($120–$180 part, 30-minute swap).
Empty the freezer, remove the back panel (4–6 screws). A solid sheet of frost on the evaporator coil = stuck defrost system (heater, thermostat, or control board). Manually thaw with a hair dryer to confirm — if it cools normally for 1–2 days then warms back up, defrost system is the culprit.
Pull freezer out, find the black cylinder at the bottom-back. Hot to the touch and silent = bad start relay (often $40 part). Clicking every few minutes = overload tripping, compressor failing. Both warrant a tech.
Stop and call
Safety + model triggers
Compressor is hot and silent OR clicking every few minutes.
Failed start relay or compressor — keep cycling and you'll burn the windings.
Hissing, gurgling, or oily residue near the compressor.
Refrigerant leak — sealed-system work requires EPA certification by law.
Frost rebuilds on the evaporator within 24 hours of clearing it.
Stuck defrost heater drawing constant current — fire risk in the freezer cabinet.
Sub-Zero, built-in column, panel-ready, or chest/commercial freezer.
Different layouts, dual sealed systems, and proprietary boards — generalist parts don't fit.
Other reasons to call
FAQs
Almost always the evaporator fan motor in the freezer (it serves both compartments on most models). Without airflow over the evaporator coil, neither side gets cold properly. Listen for the fan with the door switch held in.
0°F (-18°C) is the standard. Anything warmer slows freezing and shortens food storage life. Anything colder wastes electricity and stresses the compressor.
A full freezer holds safe temperatures for ~48 hours unopened, ~24 hours half-full. After that, refreeze only food that still has ice crystals — anything fully thawed should be cooked or discarded.
Either the evaporator fan failed (no air movement to the food), the evaporator coil is iced over (defrost system stuck), or the condenser coils are dust-caked (compressor running but can't reject heat). Check in that order.
Door gasket: $189–$280. Evap fan motor: $220–$320. Defrost system: $250–$400. Start relay: $189–$240. Sealed system (compressor/refrigerant): $600–$1,200 — usually time to replace. Our flat $149 diagnostic is waived with repair.
Related service
Standalone uprights, chest freezers, garage-rated units, and built-in freezer columns — we fix them all. Same-day windows across Minneapolis, St. Paul, and Central MN with sealed-system techs, OEM parts on every truck, and a flat $149 diagnostic that's waived when you approve the repair.
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