Fix a chest freezer that will not cool

Steps

Goal: Confirm the symptom, rule out power and seal, then isolate the cooling fault.

• Check the chest freezer temperature with a thermometer or by feeling items. If the freezer is warm or items are thawing, the cooling has failed.
• Good: The chest freezer is warm or not cooling—proceed to Check power, seal, and overload.
• Bad: The chest freezer is cold—no action needed.

Check power, seal, and overload

Goal: Rule out power loss, lid seal leaks, and overload before opening the unit.

• Confirm the chest freezer is plugged in and the circuit breaker has not tripped. Reset the breaker if tripped.
• Inspect the lid seal for gaps or tears. Close the lid on a dollar bill—it should pull out with resistance. Replace a worn seal if it slips out easily.
• Check that the freezer is not overloaded; packed food blocks airflow. Leave space between items.
• Good: Power is on, seal is tight, and there is adequate airflow space. Proceed to Condenser coils.
• Bad: Breaker trips again immediately—call a technician. Seal worn—replace it. Overloaded—remove excess food.

Condenser coils

Goal: Clean condenser coils to restore cooling.

• Unplug the chest freezer. Pull it out and locate the condenser coils—usually at the back or behind a bottom grille.
• Vacuum dust and debris from the coils. When the coils are clean, cooling often improves.
• Good: Coils are clean. Proceed to Evaporator fan and defrost.
• Bad: Coils were very dirty—retest after cleaning; if the chest freezer still does not cool, continue to the next section.

Evaporator fan and defrost

Goal: Confirm the evaporator fan runs and clear frost if the defrost system has failed.

• Open the lid and listen when the compressor runs. You should hear the evaporator fan. If the fan is silent, it may be blocked by frost or failed. Unplug, clear frost if present, and check that the fan spins freely.
• Look at the evaporator area inside the chest freezer. Heavy frost or ice on the evaporator blocks airflow. If you see thick frost, unplug the freezer and leave the lid open for 24 hours to thaw. Place towels to catch water.
• When thawed, plug back in and test. If frost returns within a few days, the defrost heater or defrost thermostat has failed—call a pro.
• Good: Fan runs and no heavy frost. Proceed to Thermostat and compressor.
• Bad: Frost returns quickly—defrost system failure; call a technician.

Thermostat and compressor

Goal: Test the thermostat and compressor relay; replace if faulty.

• Listen at the back of the chest freezer. The compressor should hum when running. If the compressor does not start, the compressor relay or capacitor may have failed.
• Unplug the chest freezer. Locate the relay and capacitor (usually near the compressor). Test and replace with exact-match parts if faulty.
• If the compressor still does not run after replacement, the sealed system may have failed—call a pro. Do not attempt refrigerant or sealed-system repair yourself.
• Good: Compressor runs and the chest freezer cools.
• Bad: Compressor will not run after replacing relay and capacitor—call a technician.

When to get help

Call an appliance technician if:

• Frost returns quickly after thawing (defrost system failure).
• The compressor does not run after replacing the relay and capacitor.
• You suspect a refrigerant leak (hissing, oil stains).
• You are not comfortable working with electrical parts.

Do not attempt to repair refrigerant lines or the sealed system yourself.

Verification

• The chest freezer holds 0°F (-18°C) or below.
• Items freeze solid within a few hours.
• No heavy frost buildup on the evaporator.
• The evaporator fan runs when the compressor runs.
• No unusual noises or error codes.