Why Is Your Fridge Not Cooling? Step-by-Step Diagnostics
updated 11 July 2026
Quick answer
Most often a fridge stops cooling because the thermostat got knocked to a low setting, the airflow inside is blocked, or the condenser coils at the back are covered in dust. Before you call a repair service, check the dial setting, pull food away from the back wall, and vacuum the grille at the back. If the compressor runs nonstop and it's still warm inside, the problem may be the refrigerant, and that calls for a technician.
Step by step
- 1
Check the thermostat and operating mode
Start with the dial or control panel. Someone may have knocked it while loading groceries or set it to the lowest power. Turn the thermostat to a mid setting or higher (usually 3-4 out of 5) and make sure holiday or eco mode isn't switched on. Give the fridge a few hours and measure the temperature with a thermometer - the fridge compartment should sit at 4-5°C (39-41°F).
- 2
Unload the fridge and unblock the airflow
An overstuffed fridge doesn't cool evenly because food covers the air vents on the back wall. Pull items away from the back and the grilles, and remove whatever blocks the flow. Cold air has to circulate freely, otherwise the top stays warm while the bottom overfreezes.
- 3
Test the door seal with a sheet of paper
Put a sheet of paper between the door and the cabinet and close the fridge. If the paper slides out with no resistance, the gasket isn't sealing and warm air is getting inside. Test several spots around the door. Wash a dirty gasket with warm water and a splash of vinegar, and replace a hardened or cracked one with a new gasket for your model.
- 4
Vacuum the condenser coils at the back
The black grille or coil at the back of the fridge releases heat. When it's coated with dust and pet hair, the appliance can't keep up with cooling, and the compressor runs hot and long. Unplug the fridge and vacuum the condenser with a brush attachment. Do this twice a year, especially if you have pets.
- 5
Defrost an iced-up evaporator in a no-frost fridge
In no-frost fridges, an evaporator with a fan hides behind the back wall. When it ices over due to a faulty sensor or frequent door opening, the fan can't push cold air into the compartment. The symptom is a freezer full of frost and a warm fridge. Switch the appliance off, empty it, and leave it open for 24-48 hours until the ice is completely gone, then switch it back on.
- 6
Move the fridge away from the wall and heat sources
A fridge squeezed into a tight cabinet or standing right next to an oven, a radiator, or in direct sun has no way to shed heat. Leave a few centimeters (an inch or two) of clearance at the back and sides. In summer, when the kitchen is hot, the compressor works harder and that's normal, but excess heat around the fridge genuinely hurts cooling.
- 7
Decide when it's a job for a repair service
If the compressor won't start at all, clicks and goes quiet, or runs nonstop while the inside stays warm, there's little more you can do yourself. That usually points to a failing compressor, sensor, or fan, or a refrigerant leak. You can spot a refrigerant leak by a compressor that runs constantly while cooling barely or not at all. That's when you call a technician.
The freezer freezes but the fridge doesn't cool
This is one of the most common scenarios and usually doesn't mean a dead compressor. In most fridges the cold is produced in the freezer and reaches the fridge compartment through an air duct controlled by a flap called a damper. When that duct gets blocked with ice or the fan fails, the cold stays at the bottom while the top warms up.
First defrost the whole appliance for 24-48 hours, because often the duct was simply iced over. Also listen for the fan when you open the freezer door - silence may mean the little motor has seized or frozen in place. If the damper won't open even after defrosting, replacing it is a job for a repair service.
How much fridge repairs cost
Prices depend on the model and city, so treat these as rough figures. A call-out with diagnostics usually runs 100-200 zł (Polish złoty), replacing a door gasket 150-350 zł, and replacing a fan or sensor 200-450 zł including the part. Topping up refrigerant along with fixing the leak often costs 300-600 zł.
The priciest job is compressor replacement - it can cost anywhere from 500 to over 1000 zł. With an older fridge, do the math on whether the repair makes sense or whether it's better to put that money toward a new, energy-efficient appliance. Before you pay for service, though, run through all the free checks in this guide, because the culprit is often plain dust or a knocked dial.
Frequently asked questions
›Why is the fridge not cooling while the freezer works fine?
Usually the air duct is blocked with ice, or the fan that pushes cold air up from the freezer has failed. Defrost the whole appliance for 24-48 hours and check whether the fan runs. If the problem returns after defrosting, the fan or damper needs replacing.
›Why is my fridge humming?
Humming is most often the normal sound of the compressor or fan, especially after the door has been opened on a hot day. A louder rattle can come from the cabinet touching a wall or furniture, or from vibrations of a poorly leveled fridge. If the noise is loud, metallic, and new, move the fridge away from the wall and level it, and if that doesn't help, check the fan.
›How long does a fridge take to cool down after defrosting?
Give it at least a few hours after switching on; cooling fully down to 4-5°C (39-41°F) usually takes 12-24 hours. Don't load all your food back in right away, because it will strain the freshly restarted compressor. Measure the temperature with a thermometer before deciding something is wrong.
›Can hot weather stop a fridge from cooling?
Yes, in a hot kitchen the compressor runs longer and harder, and if the condenser at the back is dusty, the appliance may not keep up. Move the fridge away from heat sources, leave clearance at the back, and vacuum the grille. During a heatwave, turning the cooling setting up one notch helps too.
›How do I know the compressor has died?
The compressor won't start at all, or just clicks and goes quiet every few minutes, and the fridge stays warm despite correct settings. It may also be hot to the touch and noticeably louder than usual. That's a job for a repair service, because you can't replace a compressor yourself.