Most calls about a freezer start the same way: the light comes on, the motor seems to run, and yet the ice cream has gone soft. That combination is actually useful information. A freezer with power and a running compressor has narrowed the list of suspects, and a few careful observations can usually tell you which half of the list you're dealing with.
This walkthrough is for three kinds of units: the freezer section of a regular refrigerator, a frost-free upright, and a chest freezer in a basement or garage. The logic is similar for all three, but the likely culprits differ.
First, measure instead of guessing
What the control panel shows is the temperature you asked for, not the one you have. Tuck a dial or digital appliance thermometer between two frozen packages (or into a cup of water left to freeze), close the door, and check it after six to eight hours. FoodSafety.gov's target for a freezer is 0°F or below.
What you see tells you where to go next:
- •A few degrees high: often a setting, a door that isn't closing fully, or a packed-solid cabinet blocking air.
- •Somewhere in the 20s: typical of frost blocking the airflow or a fan that has quit.
- •Near or above freezing, and climbing: the sealed system or the compressor's starting parts are more likely, and it's time to move food.
Is the problem the room?
Freezers reject heat into the room around them. When that room is hot, they have to work harder, and when it's very cold, some designs stop running the way they should.
Around here, the summer version is the common one. A freezer in an attached garage or an unfinished utility room sits through long stretches of heat and heavy, humid air every July and August. The condenser has less of a temperature difference to work with, the compressor runs longer, and every door opening lets in moist air that turns into frost. Some units simply can't keep up.
Look up the ambient temperature range for your exact model. It's in the installation section of the manual, and the model number sits on a sticker somewhere in the cabinet: the inner side wall, under a shelf, or near the base on a chest model. If your garage regularly goes outside that range, the most effective fix may be relocation rather than any part.
Read the frost
Frost is the most useful clue a freezer gives you, and it points in different directions depending on the type.
Chest freezers and manual-defrost uprights
These have no defrost system. Frost builds on the walls over time and is supposed to be scraped or melted off by the owner. A thick layer insulates the food from the cold surfaces, so a freezer that "used to work" can lose ground gradually. If the walls carry more than about a quarter inch, defrost it: empty it into coolers, unplug it, prop the lid, and let it melt with towels down. Don't chip at it with anything sharp. A puncture in the wall can reach the refrigerant tubing, and that ends the freezer.
Frost-free uprights and refrigerator freezers
These are supposed to stay nearly clear. They run a heater on the evaporator coil every so often to melt frost, then drain the water to a pan underneath. Unplug the unit and take off the rear cover in the freezer compartment. If you find the coil buried in a solid block of white ice, the defrost system has failed. The usual suspects are the heater, the defrost thermostat or bimetal, or the control that schedules defrost.
A coil covered in a thin, even frost is normal. Ice concentrated at the bottom of the coil, or water frozen in the drain trough, points instead toward a clogged defrost drain.
Frost on the food, not the walls
Snowy packages and frost around the door opening usually mean warm, damp air is getting in. That brings us to the door.
The door and the gasket
Close the door on a dollar bill in several spots around the frame and tug it out. You should feel drag every time. Places where it slides out freely are places where air is leaking.
Common reasons:
- •The gasket has a fold or kink from a bag that got caught in it.
- •The unit is tilted forward, so the door doesn't swing closed on its own.
- •An overfilled door shelf or ice bin holds the door slightly open.
- •The gasket has hardened and cracked with age.
A kinked gasket often recovers if you warm it with a hair dryer on low and press it back into shape. A cracked one needs replacing, and gaskets are ordered by the model number.
Airflow inside the cabinet
Frost-free freezers move cold air with an evaporator fan, usually behind the rear panel. With the door open, press the door switch and listen. Most fans run when the switch is held in. If the compressor is running and you hear no fan and feel no air from the vents, the fan motor or its wiring is suspect.
Also check that the vents aren't blocked. A freezer stuffed to the ceiling, with bags pressed against the back wall, can starve its own air supply.
The condenser and the fan underneath
Most upright refrigerators and many freezers have a condenser coil near the floor, cooled by a small fan. Pet hair and dust collect on it, which makes the whole system run hot. Unplug the unit, pull the kick plate, and vacuum what you can reach with a brush attachment. If the unit is running and that fan isn't spinning, it needs attention.
On many chest freezers the condenser tubing is hidden inside the cabinet skin, which is why the sides feel warm to the touch. That's normal. Give them a few inches of open space and don't box them in with storage.
Signs that point to a bigger problem
- •The compressor starts, hums briefly, then shuts off, and repeats that cycle every few minutes.
- •The unit is completely silent even though the light works.
- •The back of the unit is cold but the cabinet is warm.
- •A section of the evaporator frosts and the rest stays bare.
- •You hear hissing, or find an oily spot under the machinery compartment.
These can mean a start relay or overload, a control board, a restriction, or a refrigerant leak. None of them are owner repairs. Sealed-system work involves recovering refrigerant under EPA rules and brazing the tubing, and whether it's worth doing depends heavily on the age and type of freezer.
Saving the food in the meantime
If the thermometer shows the freezer is losing ground, don't wait. Move what you can into a working freezer or into coolers with ice. Food that still has ice crystals, or reads 40°F or below, can be refrozen according to FoodSafety.gov. Perishables that have sat above 40°F for over two hours belong in the trash. Our power outage guide goes into more detail on judging food.
When to call us
If you've defrosted, cleaned the coils, checked the gasket and the freezer still won't reach 0°F, book a visit through our freezer repair page. On the visit we'll take real temperature readings, test the defrost circuit, fans and starting parts, and walk you through the fault and the price. You decide before anything is replaced. If the freezer is older and the problem is in the sealed system, we'll tell you plainly if replacement makes more sense; our repair-or-replace guide walks through that decision.
For a combination refrigerator where both sections are warm, start with our article on a refrigerator that isn't cooling instead.
Common questions
Why is my freezer cold but not freezing?
Usually because air isn't circulating well. A frosted evaporator coil or a dead fan lets the cabinet sit in the 20s, cold to the touch but not cold enough to keep food hard.
Can a garage freezer stay out there all summer?
Only if the garage stays within the model's rated ambient range. Check the manual. If it's rated for a narrower range, it will run constantly in hot weather and may fall behind.
How often should a chest freezer be defrosted?
Once the frost layer reaches roughly a quarter inch. For many households that works out to once or twice a year. Humid months tend to build frost faster, especially if the lid is opened often.