Freezer not freezing: causes and what to check

When a freezer is not freezing, start by figuring out which kind you have, because uprights, chest freezers and the freezer section of a refrigerator each fail in their own ways. Then measure the temperature with a thermometer between frozen packages; it should read 0°F. After that, work through the door seal, the vents, the location, and frost on the evaporator, in that order.

Which kind of freezer do you have?

Upright freezers

Most are frost-free, with an evaporator coil and fan hidden behind a panel at the back, much like the freezer in a refrigerator. They rely on steady airflow and on a working defrost system. Some lower-priced uprights are manual-defrost instead, with cooling tubes built into the shelves.

Chest freezers

Most are manual-defrost, with the cooling tubing wrapped around the inside walls. Many also run the condenser tubing through the outer walls, so the cabinet feels warm to the touch. That’s normal. Cold air sinks, so a chest freezer loses less of it each time you lift the lid.

The freezer section of a refrigerator

This shares a compressor, and usually a single evaporator, with the fresh-food side. If both sections are struggling, our refrigerator not cooling guide is the better starting point.

Measure before you adjust anything

1. Place an appliance thermometer between two frozen packages in the middle of the freezer.
2. Leave the door closed overnight and read it first thing in the morning.
3. Compare it with 0°F. A few degrees over is worth watching. Soft ice cream, or meat that gives under your thumb, means the freezer isn’t keeping up.

Turning the control colder rarely fixes a real fault. If you do adjust it, wait 24 hours before measuring again.

Freezer not freezing in a cold garage

Unheated garages around here often sit in the 30s and 40s °F for much of the winter. That causes trouble in two different ways.

Refrigerator-freezers. Most combination units control the compressor from a thermostat or sensor in the fresh-food section. When the garage is already close to refrigerator temperature, that sensor rarely asks for cooling, so the compressor barely runs and the freezer warms. People are surprised to find food thawing in a cold garage, but this is why.

Standalone freezers. These measure the freezer itself, so they cope better. Every model still lists a minimum room temperature in its manual, and below that the system may run poorly or not at all. Freezers sold as “garage ready” are designed for a wider range.

What helps:

1. Look up the room temperature range in your manual.
2. Ask whether the manufacturer sells a garage kit for your model. On some refrigerators, it’s a small heater near the thermostat that makes the compressor run more in cold weather.
3. If the unit isn’t rated for the garage, move it indoors for the winter, or choose a garage-ready model when it’s time to replace it.
4. Don’t wrap the cabinet in blankets or insulation, and don’t park a space heater beside it. The condenser has to shed heat.

Door seals and lids

On an upright, close the door on a sheet of paper at several points around the gasket. If it slides out with no resistance, cold air is escaping there. Overfilled door bins and a cabinet that tilts forward both keep doors from closing fully. Adjust the front legs so the door swings shut on its own from halfway open.

On a chest freezer, ice built up along the rim can hold the lid off the gasket. So can a package sticking above the basket. Weak lid hinges and torn gaskets are less common but do happen. A band of frost right around the opening is the giveaway for an air leak.

Overloading and blocked vents

Uprights and refrigerator freezers move cold air through vents, usually on the back wall. Stack bags against those vents and you’ll get warm spots, even if the rest of the freezer is fine.

Adding a large amount of unfrozen food at once causes a different problem. After a fishing trip or a big garden harvest, the freezer has to pull all that heat out, and everything already inside warms while it works. Your manual may say how much fresh food to add in a day. Use the fast-freeze setting if your model has one, spread new packages out until they freeze, and stack them afterward.

Frost blocking the evaporator

In a frost-free freezer, a coat of snow on the back panel or around the vents means the defrost system has stopped clearing the evaporator. Airflow falls off, and food near the top softens first. A manual defrost buys time, but frost that returns within a couple of weeks means a defrost part has failed.

In a manual-defrost freezer, thick frost acts as insulation and makes the compressor work harder. Defrost it when the layer gets thick. Our freezer frost buildup guide covers both situations and how to defrost without damaging the liner or tubing.

Condenser coils and fan

Uprights usually have condenser coils on the back or underneath, sometimes with a small fan. Unplug the freezer before cleaning them, then brush and vacuum away dust and lint. Chest freezers with condenser tubing in the walls have no coils to clean, but they need room around the cabinet. Some chest models have a fan-cooled condenser behind a grille near the bottom, and that grille needs vacuuming.

Compressor and start device

A click, a few seconds of humming, another click, then a pause of a few minutes before it repeats: the compressor is failing to start. The start relay or overload is a common cause and a fairly simple repair. A compressor on its way out makes the same sound, so it needs a proper diagnosis.

A compressor that runs nonstop while the freezer stays warm, with clean coils and good seals, can point to a refrigerant leak. That’s sealed-system work and needs an EPA-certified technician. Never chip at ice with anything sharp. Refrigerant tubing can sit just behind the liner, and one puncture usually ends a chest freezer’s life.

When to call a technician

• The freezer is warm in a normal indoor room, and the seals, vents and coils check out.
• You hear repeated clicking from the compressor without it starting.
• The compressor runs constantly and the freezer still won’t reach 0°F.
• Frost covers the back panel of a frost-free freezer again soon after a full defrost.
• There’s a burning smell, or the breaker trips. Unplug the freezer.

If food is already thawing, move it to another freezer or a cooler with ice before anything else. Food that still has ice crystals can go back into a working freezer.