A refrigerator that held temperature in April can start losing ground in August. The kitchen is warmer, the doors open more often, and any weakness in the cooling system shows up. Many "not cooling" problems turn out to be airflow, dirt or defrost faults rather than the expensive kind, and a few simple checks will usually tell you which you're dealing with.
First, measure the temperature
Before you change anything, find out how warm it really is. Put an appliance thermometer in a glass of water on the middle shelf of the fresh-food section and leave it for several hours, ideally overnight. Do the same in the freezer, between packages.
- •Fresh food: 40 °F or below. Around 37 °F is a common target.
- •Freezer: 0 °F.
A reading of 42 °F on a shelf that gets opened constantly during a party isn't a fault. A reading of 50 °F the next morning is.
While you wait, make sure the controls haven't been bumped to a warmer setting, and that nothing (a tall container, an overfilled bin) is blocking the air vents inside either compartment.
Read the pattern
Where the warmth shows up tells you a lot.
| What you notice | What it usually means |
|---|---|
| Freezer cold, fresh food warm | Air isn't reaching the fresh-food section: evaporator fan, damper or frosted-over coil |
| Both sections warm, compressor running | Condenser can't shed heat, or a sealed-system problem |
| Both sections warm, compressor silent | Start relay, compressor, control board or power supply |
| Frost on the freezer back wall | Defrost system has stopped working |
| Warm plus a clicking every few minutes | Compressor trying to start and failing |
Checks you can do safely
Clean the condenser coil
Unplug the refrigerator first. On most freestanding models, the condenser is under the unit behind the front grille or on the back. It sheds the heat the refrigerator pulls out of the food. When it's coated in dust and pet hair, the compressor runs longer and the inside warms up, and that effect is worse in a hot room. If the refrigerator lives in the garage, the heat itself may be the limit, which our garage refrigerator guide explains.
Remove the grille, and use a long, narrow coil brush and a vacuum to clean the coil and the area around the fan. Built-in refrigerators usually have the coil at the top behind a grille. Check the manual before removing anything on those.
Check clearance and the condenser fan
Refrigerators need room to exhaust warm air. If yours has been squeezed into a tight opening during a kitchen update, it may be recirculating its own heat. Check the installation clearances in the manual.
With the unit running, you should feel warm air coming from the bottom front or back. On models with a condenser fan, a compressor that runs with no airflow means the fan may have failed.
Check the door seals
Close the door on a sheet of paper and pull it out at several points around the gasket. You should feel resistance. A loose seal lets humid air in, and that moisture turns to frost on the evaporator coil. Clean the gasket with warm soapy water. Food residue can stop a gasket seating properly. A gasket that's torn or flattened needs replacing.
Also check the refrigerator is level from side to side, with the front slightly higher than the back so the doors swing closed on their own.
Listen for the evaporator fan
Open the freezer and listen. On most frost-free refrigerators, you should hear a fan running inside the freezer when the compressor is on. Many models stop the fan when the door opens, so press the door switch in with a finger. No fan noise, with a cold freezer and a warm fresh-food section, is a common failure.
What frost tells you
Take everything off the back wall of the freezer, or remove the panel if your manual shows how, and look for frost.
- •An even, thick coat of frost or solid ice on the back panel usually means the defrost system has stopped running. The coil has iced over and air can't pass through it. That's typically a defrost heater, a defrost thermostat or sensor, or the control.
- •Patchy frost on only part of the coil can point to a refrigerant problem.
A manual defrost buys time. Unplug the refrigerator, move the food to coolers, prop the doors open and let the ice melt completely, with towels down. That can take most of a day. If cooling comes back and then fades again over a week or two, the defrost system needs repair. Don't use a heat gun or sharp tool on the ice.
When it's the sealed system
The sealed system is the compressor, the coils and the refrigerant between them. Faults here include leaks, restrictions and compressor failure. They're less common than airflow and defrost problems, but they're the ones that decide whether a refrigerator is worth repairing.
Signs that point in that direction include both sections warming with the compressor running and a clean coil, patchy frost, and a compressor that's hot and runs without stopping. Diagnosis needs gauges and refrigerant handling equipment, so this isn't a do-it-yourself job.
On an older, basic refrigerator, a sealed-system repair can cost a large share of a new unit's price, so weigh the age of the fridge before committing. Our repair or replace guide walks through that decision.
Protect the food while you troubleshoot
A closed refrigerator keeps food cold for about four hours after it stops cooling, according to USDA guidance. Keep the doors shut, move the most perishable items to a cooler with ice, and throw out anything that has sat above 40 °F for more than two hours.
When to call
Call for service if the refrigerator is still warm after cleaning the coil, clearing the vents and confirming the doors seal, or right away if you hear clicking with no compressor start, smell burning, or see frost building up again after a defrost. Our refrigerator repair page explains what a diagnosis covers, and brand pages such as Samsung refrigerator repair cover model-specific faults. If you're also finding water on the floor, see our guide to a refrigerator leaking water.
Frequently asked questions
Does my refrigerator need a refrigerant recharge?
Refrigerators are sealed systems and don't use up refrigerant. If the charge is low, there's a leak, and adding refrigerant without finding and fixing it doesn't solve anything.
How often should I clean the condenser coil?
Once or twice a year is typical. More often if you have pets, or if the refrigerator is in a garage.
Should I turn the thermostat to its coldest setting?
Only briefly, if at all. When the cause is a dirty coil, a stopped fan or an iced-over evaporator, a colder setting just makes the compressor run longer without fixing anything, and it can freeze food in the fresh-food section once the fault clears. Set it back to its normal position.