The situation when the upper chamber of the refrigerator suddenly stops cooling food is one of the most common and alarming for the owner of household appliances. You open the door, and instead of pleasant cold there is room temperature, and the food begins to quickly deteriorate. This can happen either with an old model or with a relatively new unit purchased just a couple of years ago. In most cases, the problem lies in a violation of the circulation of the refrigerant or a malfunction in the temperature control system.
There is no need to panic at such a moment, but you should not hesitate to diagnose. Double-chamber refrigerators are designed so that the cold is generated in one compartment (most often in freezer) and is distributed throughout the entire volume. If this balance is disrupted, the top section is the first to suffer. Understanding the basic principles of operation will help you quickly determine whether the breakdown is fatal or whether it can be fixed yourself without calling a technician. Below we will analyze in detail the main scenarios for the development of events.
The first thing to do is to assess the scale of the disaster. Check to see if the compressor is working at all, if there are any unusual sounds, and how much ice is frozen in the freezer. Often the answer to the question of why the top does not freeze lies in basic things that are easy to overlook in a hurry. Let's look at the main technical reasons and ways to solve them.
Malfunctions of the thermostat and temperature sensors
One of the first reasons why upper chamber stops receiving cold is the failure of the thermostat. This small device is responsible for turning the compressor on and off depending on the temperature inside the chambers. If its contacts are stuck or the sensor has lost sensitivity, the compressor may simply not start when necessary, or, conversely, work without stopping, causing icing of the evaporator and blocking the airflow.
In modern models with the system No Frost electronic sensors play the role of a mechanical thermostat. Their readings are read by the control module, which makes the decision to start cooling. If the sensor in the upper chamber “lies” and shows that it is -5°C there, although in fact it is +15°C, the cooling system will not turn on. Replacing such an element often requires disassembling the internal panel.
⚠️ Attention: Before replacing the thermostat or sensors, be sure to disconnect the refrigerator from the power supply for at least 15-20 minutes. This will allow you to reset errors in the electronic module and avoid short circuits when manipulating the wiring.
Thermostat diagnostics are often carried out by the method of exclusion. If you don’t hear a click when you turn the regulator knob (in mechanical models) and the compressor is silent, this is probably where the problem lies. In electronic systems, you will need a multimeter to check the resistance of the sensor at different temperatures.
Problems with the compressor and start relay
The heart of any refrigerator is compressor. It is he who pumps the refrigerant through the pipe system. If the upper chamber does not freeze, but the lower (freezer) compartment can barely cope or is also warm, the compressor may not be working at full capacity or does not start at all. Often the culprit is the starting relay - the part that gives the initial impulse to the engine.
Signs of a compressor malfunction can be different. It may hum, click and try to start, but immediately stall. In other cases, it runs constantly without turning off, but does not create enough pressure to circulate freon. This condition is called "compressor does not hold pressure." In such a situation, upper chamber remains warm, since the refrigerant does not reach its evaporator.
If you hear a loud click, followed by a hum, and then silence, and this repeats cyclically, most likely the thermal protection of the compressor has tripped due to a faulty start relay. Replacing this part is one of the most common and inexpensive procedures in refrigerator repair.
It is important to note that if the compressor has overheated (become hot to the touch), it must be allowed to cool before attempting to start again. Constant attempts to turn on an overheated motor can lead to an interturn short circuit of the windings, which will require replacement of the entire unit.
Freon leakage and blockage of the capillary system
The most unpleasant technical reason for the lack of cold in the upper compartment is refrigerant leak (freon). In a system where gas circulates under pressure, any violation of the tightness - be it a microcrack in the evaporator tube or metal corrosion - leads to a gradual or sudden release of gas to the outside. Without a sufficient amount of freon, the refrigeration capacity drops, and first of all, the zone farthest from the compressor stops freezing - usually the upper chamber.
The second option for a similar problem is clogged capillary tube. An ice or oil jam could have formed in the system, or moisture got in, which froze and blocked the freon flow. In this case, the compressor may work properly, creating pressure, but circulation is not possible. Symptoms are often similar to a leak: the freezer may work poorly, and the top may not work at all.
Diagnosing a leak or blockage at home is difficult. Often on the back wall inside the refrigerator you can notice swelling or, conversely, dents on the evaporator tubes. Also, a sign of a leak may be a black coating on the filter-drier or tube near the compressor.
Is it possible to fill a refrigerator with freon yourself?
Independent refilling is possible only if you have professional equipment (vacuum pump, pressure gauge station, scales) and soldering skills. It is impossible to simply “add gas” without evacuation of the system - remaining air and moisture will lead to rapid failure of the compressor.
Failure of the No Frost and defrosting system
In refrigerators with the system No Frost cold is supplied to the upper chamber by a fan through special channels. If these channels become clogged with ice, airflow stops and the upper compartment stops freezing, although the freezer may be in perfect order. The reason for the formation of an “ice plug” most often lies in a malfunction of the defrosting system.
Three main elements are responsible for defrosting the evaporator: defrost heating element, defrost timer (or electronic module) and defrost sensor. If the heating element is burnt out, the ice does not melt and gradually builds up, blocking the air ducts. If the sensor or timer is faulty, the system “does not understand” that it is time to turn on the heating to remove ice.
To test this hypothesis, you need to defrost the refrigerator completely (at least for 24 hours, preferably two days). If, after turning on, cold appeared in both the upper and lower chambers, but after 1-2 weeks the situation repeated itself, the problem is guaranteed to be in the defrosting system.
☑️ Symptoms of a malfunction of the No Frost system
Mechanical damage and wear of seals
Do not forget about banal mechanical reasons. If sealing rubber band the door of the upper chamber is worn out, dirty or deformed, warm air from the kitchen constantly enters the chamber. The compressor tries to compensate for the heat by working without interruption, but due to the constant flow of heat, the temperature does not drop to the required values.
You can check the tightness with a simple test with a sheet of paper. Clamp the sheet with the door in different places around the perimeter. If the sheet is pulled out too easily or falls out on its own, the seal does not fit tightly. The cause may also be door distortions due to loose hinges or improper installation of the refrigerator (it must be strictly level).
Another mechanical factor is damage to the air ducts inside the refrigerator. If you packed food too tightly or bumped shelves, the plastic box that carries the cold air could crack or become dislodged. In this case, the cold air goes to the side, bypassing the food area.
⚠️ Attention: Do not try to remove frozen ice with a knife or sharp objects. You can damage the evaporator tubes, which will lead to an immediate leak of freon and expensive repairs with soldering.
Diagnostics and table of symptoms
To make it easier for you to navigate the possible causes, we have compiled a summary table. It will help you compare the behavior of your unit with the most likely malfunction. Remember that an accurate diagnosis can only be made by a specialist with diagnostic equipment.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor is silent, there is no light | Problems with an electrical network, socket or wire | Low |
| Buzzes, clicks, but does not start | Faulty starting relay or compressor | Medium |
| Works constantly, there is no cold anywhere | Freon leak or system blockage | High (needs a technician) |
| The freezer works, the top does not freeze | Problems with the fan, blockage channels, thermostat | Average |
| Cold appears after defrosting | Malfunction of the defrosting system (heating element, sensor) | Average |
Analysis of the behavior of the refrigerator is a key stage. Pay attention to the operating cycles: how long it hums, how long it rests. A normal work cycle is approximately 10-20 minutes of work and 20-40 minutes of rest (depending on the load and ambient temperature). If the refrigerator “threshes” without interruption, this is a bad sign for the compressor.
When you need to call a technician
There are situations when DIY repairs are not only impractical, but also dangerous. If diagnostics indicate freon leakage or replacing the compressor, you cannot do without special equipment and licenses. To work with refrigerants, you need skills in soldering copper pipes, evacuating the system and accurately filling with gas.
It is also worth contacting professionals if the problem lies in the electronic control module. Modern electronics are complex, and an attempt to “resolder a capacitor” without deep knowledge of circuit design can lead to permanent failure of the board. The technician will carry out diagnostics with a multimeter and a tester, pinpointing the failure point.
In addition, if your refrigerator is under warranty, any independent intervention (even a simple replacement of a light bulb, if it requires disassembling the panels) may become grounds for refusal of warranty service. In such cases, it is better to immediately call an authorized service center.
How much does the repair cost?
The cost depends on the region and model. Replacement of the thermostat - from 1500 rubles, refilling with freon - from 2500 rubles, replacement of the compressor - from 5000 rubles. and higher without taking into account the cost of parts.
Why does the upper chamber freeze, but the lower one (freezer) does not?
This is a rare but possible situation, typical for refrigerators with one compressor and the No Frost system. This usually means that the channel supplying cold to the freezer is clogged, or the damper that regulates the air flow is faulty. It is also possible that the damper gets stuck in the open position, causing all the cold to escape upward.
Is it possible to use a refrigerator if it does not freeze the upper chamber?
For a short time - it is possible if you transfer perishable foods to the freezer. However, operating equipment with a malfunction (especially if the compressor is running without interruption) leads to its overheating and eventual combustion. It is better to temporarily turn off the unit, defrost it and call a technician.
How often do you need to defrost a No Frost refrigerator?
Technically, the No Frost system does not require defrosting to remove ice. However, once every 6-12 months it is recommended to carry out preventive defrosting and washing for hygiene, removing odors and checking drainage holes. This prolongs the life of the ventilation system.
Does the temperature in the room affect the operation of the refrigerator?
Yes, significantly. If the room is too hot (above +30°C) or too cold (below +10°C, unless climate class SN is provided), the refrigerator may not operate correctly. In the cold, the oil in the compressor may freeze or the thermostat may not work, and in the heat, the compressor will wear out.