A freezer should hold 0°F. Once it drifts much above that, ice cream softens, ice cubes stick together and meat starts to thaw at the edges. The reason a freezer stops freezing usually falls into one of three buckets: the air around it is too hot, frost has blocked the cold air, or something in the airflow or cooling system has failed.
This guide covers upright freezers, chest freezers and the freezer section of a refrigerator. The checks are similar; where they differ, it's noted.
First, protect the food
Put an appliance thermometer in the freezer, between packages, and leave it for a few hours. That gives you a real number to work from.
While you sort out the problem:
- •Keep the door or lid closed. Every opening lets warm, humid air in.
- •If you have a cooler and ice, move the most valuable items into it.
- •A full freezer holds its temperature longer than a half-empty one. According to USDA guidance, a full freezer keeps food safe for about 48 hours without power, a half-full one for about 24, provided the door stays shut.
- •Food that still has ice crystals, or that has stayed at 40°F or below, can be refrozen safely, though quality may suffer.
If the freezer has been warm for a long time and you aren't sure how long, throw out meat, fish and anything that has fully thawed. When in doubt, don't risk it.
Bucket one: the freezer is too hot where it sits
Every freezer has an ambient temperature range in its owner's manual: the range of room temperatures it was designed to run in. Above that range it may run nonstop and still not get cold enough.
In this area, the usual culprit is the garage. Many homes keep a second freezer in an attached garage, and in summer that space can get far hotter than the house. A standard freezer that worked fine all winter can lose ground in June. Some models are sold as garage-ready and are designed for a wider range; most are not.
Signs that heat is the problem:
- •The freezer struggles only in the hottest months, or only in the afternoon.
- •The cabinet sides feel hot to the touch. Many freezers use the outer walls to shed heat, so they're warm normally, but very hot is a warning sign in a hot space.
- •The compressor runs almost constantly.
What helps:
- •Give the freezer the clearance the manual specifies at the back and sides. A freezer pushed tight into a corner can't release heat.
- •Keep it out of direct sun from a window or open garage door.
- •Clean the condenser coils (more on that below).
- •If the garage is simply too hot for the model, moving the freezer inside, or replacing it with one rated for the space, is the real fix.
The garage laundry article covers other ways the garage affects appliances.
Bucket two: frost is in the way
Chest freezers and manual-defrost uprights
These freezers don't defrost themselves. Frost builds on the walls each time the lid opens, and in a humid climate it builds faster. Thick frost insulates the cold walls from the food, and once it reaches the lid seal it can stop the lid from closing tight, which lets in more moisture and makes things worse.
If you have more than about a quarter inch of frost, defrost the freezer: unplug it, move the food to coolers, leave the lid open and let the frost melt. Use towels and a pan to catch water. Don't chip at the ice with a knife or screwdriver; it's easy to puncture a refrigerant line hidden in the wall.
Frost-free freezers
A frost-free freezer has an evaporator coil hidden behind a panel and a timed or adaptive defrost system that melts frost off it. If the defrost heater, its thermostat or the control fails, frost builds on the coil until air can't pass through.
Signs:
- •A layer of frost or snow on the back panel inside the freezer.
- •Cooling that slowly fades over days or weeks.
- •A freezer that works again for a while after being unplugged for a day, then fades again.
That last pattern is the giveaway. Unplugging melts the frost, which restores airflow briefly. It's a useful test, but it isn't a fix. The defrost system needs to be checked.
Bucket three: airflow and cooling parts
Door seals
A torn, flattened or dirty gasket lets humid air in. That adds frost and warms the cabinet. Close the door on a strip of paper at several points around the seal; if it slides out with no resistance, that spot isn't sealing. Clean the gasket with warm soapy water first, as sticky residue can hold it open.
Overloading
Packages pressed against the vents block circulation, especially in a refrigerator's freezer section, where the fan pushes air through a few small openings. Leave space around the vents.
Evaporator fan
In a frost-free freezer, the evaporator fan moves cold air across the coil and into the cabinet. When it stops, the freezer warms even though the compressor runs. Open the door and listen: on many models the fan pauses when the door opens, so press the door switch and listen for it. A grinding, squealing or silent fan is a problem.
Condenser coils and fan
The condenser releases the heat the freezer removes. On uprights and refrigerators it's usually underneath, behind the toe grille, or on the back. Dust and pet hair blanket it and reduce cooling. Unplug the unit and vacuum the coils with a brush attachment. If the unit has a condenser fan near the compressor, make sure it spins freely.
Sealed-system and control faults
If the freezer is clean, sealed, not overloaded and in a reasonable room, and it still won't get cold, the issue may be the compressor, its start components, a refrigerant leak or the control. Those need a technician with the right tools. Never cut or open refrigerant tubing yourself.
Common questions
My freezer is cold but the fridge above it is warm. Is that the same problem?
It's related. In most refrigerators the fresh-food section is cooled by air sent from the freezer. A blocked air duct, a stalled fan or frost on the evaporator often warms the fridge first. Our refrigerator not cooling guide covers that pattern.
How do I know my freezer is at the right temperature?
Use a thermometer, not the control dial. The dial setting isn't a temperature reading. Aim for 0°F.
Is it worth fixing an older chest freezer?
Chest freezers are simple machines. A failed thermostat or a bad start relay is often worth replacing; a failed compressor on an old unit usually isn't. We'll tell you when the repair doesn't make sense.
Getting help
If you've worked through these steps and the freezer still won't hold temperature, call or book online. Have the model number ready and mention where the freezer sits. More detail is on our freezer repair page.