The situation when the refrigerator regularly freezes food in the lower compartment, but suddenly becomes warm in the main chamber, often takes you by surprise. This is a common malfunction that can indicate a number of problems: from a simple drain blockage to a serious failure compressor or refrigerant leak. There is no need to panic, as in many cases the cause can be eliminated yourself or the damage can be minimized before the technician arrives.
Understanding the operating principle of your unit will help you quickly diagnose the problem. In No Frost and drip-type systems, the circulation of cold air occurs differently, and their breakdowns also differ. If the freezer continues to work, then the compressor is most likely alive, and the problem lies in the distribution of cold or thermoregulation.
In this article we will examine in detail the main reasons why the refrigerator does not maintain the temperature in the upper compartment. We will look at typical symptoms, diagnostic methods and possible solutions so that you can make an informed decision on further actions.
Violation of tightness and problems with the seal
One of the most common and easily fixable causes of loss of cold is a violation of the door seal. If sealing rubber is worn out, dirty or deformed, warm air from the room constantly enters the chamber. The compressor tries to compensate for the heat loss, working for wear, but there is enough cold in the freezer, but there is no more in the upper compartment.
Check the condition of the rubber around the entire perimeter. There should be no cracks, tears or sticky residue that would interfere with a tight fit. Sometimes it is enough to simply wash the seal with warm water and soap to restore its elasticity and adhesion.
⚠️ Attention: If the rubber has lost its shape, try heating it with a hairdryer at low temperature or pouring boiling water over it, and then close the door tightly. If this does not help, the part will need to be replaced.
Also pay attention to the door hinges. Over time, they can weaken and the door warps, creating a gap on one side. In this case, the cold air “leaves” without having time to cool the food in the refrigerator compartment.
- 🔍 Visually inspect the seal for microcracks and tears.
- 🧼 Wipe the elastic band with a soft cloth, removing fat and crumbs.
- 🚪 Check the tightness of the fit by closing the door on a sheet of paper: it should pull out with force.
- 🔧 If necessary, tighten or replace the door hinges.
Malfunctions of the defrost system in No Frost refrigerators
If you have a refrigerator with a system No Frost, then the most likely reason for the lack of cold in the upper chamber is a malfunction in the defrost system. In such models, cold is generated in the freezer and forced by a fan into the refrigeration compartment through special channels.
When a defrost sensor or timer fails, a “coat” of ice begins to grow on the evaporator. This ice blocks the air channels, and cold air simply cannot enter the upper chamber. At the same time, it can be very cold in the freezer, since the evaporator is located there. Defrost heating element, defrost sensor or timer, a “coat” of ice begins to grow on the evaporator. This ice blocks the air channels, and cold air simply cannot enter the upper chamber. At the same time, it can be very cold in the freezer, since the evaporator is located there.
You can diagnose this problem by listening to the operation of the unit. If the fan is humming, but no air flows, or you hear the blade grinding on the ice, this is a sure sign of freezing. In some models, frost or ice may appear on the back wall of the refrigerator compartment.
How to defrost a refrigerator correctly?
To completely defrost, unplug the appliance, open the doors and leave for at least 24 hours. Do not use a hairdryer or hot water to speed up the process to avoid damaging the plastic and evaporator tubes. Make sure that the water flows into the pan and not onto the floor.
The solution to the problem is to completely defrost the refrigerator. If, after 24 hours of turning off and turning on again, the cold appeared, but after a week or two it disappeared again, it means that one of the elements of the defrost system (heating element, sensor, timer) requires replacement.
Problems with the temperature control damper
In many modern models, especially with one compressor, the flow of cold air from the freezer to the refrigerator compartment is regulated special damper (damper). This mechanical or electronic device opens and closes the channel at the command of the thermostat.
If the damper is stuck in the closed position or the motor that controls it is burned out, cold air stops flowing into the upper compartment. In this case, the freezer operates normally, often even supercooling the food while the temperature in the refrigerator compartment rises.
You can check the operation of the damper by reaching the air duct (usually it is located on the back wall of the refrigerator compartment or at the top). If, while the compressor is running, the damper does not respond to changes in temperature settings, it will need to be replaced.
It is worth noting that in some models the damper may become overgrown with ice due to high humidity, which also leads to its blocking. In this case, as in the case of the No Frost system, long-term defrosting will help.
Freon leakage: signs and consequences
Refrigerant (freon) leakage is a more serious malfunction that requires the intervention of a specialist with equipment for charging and soldering. Freon circulates through the system, and if it becomes scarce, it is in the refrigeration chamber that first stops getting enough cold, since it reaches it last.
If there is a leak, the compressor works almost non-stop, trying to gain temperature, but cannot do so. The condenser (grid at the back or on the sides) may be barely warm or cold, which is an alarming signal.
There may be no external signs of leakage at all, since the gas is colorless and odorless. However, if the damage is mechanical (for example, the evaporator is broken due to inaccurate defrosting), you may hear a characteristic hissing.
| Symptom | Probable cause | Action |
|---|---|---|
| The compressor is humming, but not turns off | Freon leak or blockage | Call a technician for diagnostics |
| The refrigerator is silent (does not turn on) | The compressor or relay has burned out | Check the voltage and starting relay |
| It’s warm in the refrigerator compartment, normal in the freezer | Problems with circulation or leakage | Check the damper and evaporator |
| Frost only at the entrance to the chamber | Partial leak or clogged filter | Requires professional repair |
Attempts to independently find and seal the leak without evacuating the system and replacing the filter-drier are doomed to failure. At best, you will lose time, at worst, you will finish off the compressor.
Malfunction of the thermostat or electronic module
The thermostat (thermostat) in mechanical models or the electronic control module in modern ones is responsible for maintaining the set temperature. If the temperature sensor in the refrigerator compartment is “lying” or is out of order, the “brain” of the refrigerator may assume that there is already cold there and not give a command to cool.
In mechanical models, the thermostat is usually a box with an adjustment knob. If it is faulty, the contacts may not close, and the compressor simply will not start, or will work with long breaks, insufficient for cooling.
In models with electronic control (where the temperature is set in degrees on the display), the problem may be in the sensor itself (thermistor). Its resistance changes with temperature, and if the values are outside the normal range, the controller blocks the operation of the system.
Diagnostics of the electronic module is more complicated and requires a multimeter to test the circuits. If the control board is burned out, it may incorrectly distribute power between the compressor, fan and heating elements.
Clogged capillary tube and other rare causes
Sometimes the circulation of freon is disrupted not by a leak, but by a blockage in a narrow capillary tube. An ice plug may form in the system (if there is moisture in the system) or blockage with oil oxidation products. In this case, the compressor works, the pressure builds up, but the freon does not circulate.
Signs of a blockage are similar to a leak: a cold return pipe (suction), a hot condenser only at the beginning, no cold in the chambers. Only a specialist can distinguish between a blockage and a leak based on the pressure in the circuit.
It is also worth mentioning the failure of the compressor itself. It may hum, but not pump (decompression). In this case, the motor is running, but there is no pressure in the system, and there is no cold anywhere, although the freezer can still maintain the temperature for some time due to inertia.
☑️ Diagnostics before calling a technician
Frequently asked questions (FAQ)
Is it possible to continue using the refrigerator if it does not cool the upper chamber?
Short-term - yes, if the freezer is working. However, food in the refrigerator can quickly spoil. Long-term operation in this mode is harmful for the compressor, which will work to wear out, trying to reach an unattainable temperature.
How long does it take to defrost the refrigerator to remove the ice jam?
The minimum time for complete defrosting is 24 hours. During this time, the ice in the hidden channels and on the evaporator will have time to completely melt and evaporate. Defrosting for 2-3 hours is often insufficient for the No Frost system.
Why did the refrigerator work after defrosting, but after a week it stopped again?
This indicates that defrosting eliminated the symptom (ice jam), but not the cause. Most likely, one of the elements of the defrost system is faulty: heating element, defrost sensor, timer or fuse. The defective part needs to be replaced.
Does the installation level of the refrigerator affect cooling?
Yes, it does. If the refrigerator is misaligned, oil may accumulate in one corner of the compressor and the doors may not fit tightly. Make sure that the appliance is level and the legs are adjusted.