The situation when there is a refrigerator the freezer does not work, and the main department continues to cool food, often takes you by surprise. You open the door, expecting to see frost and frozen processed foods, but instead you feel only room warmth. This is a sure sign that the refrigerant circulation cycle is broken or the control system has failed. In most cases, the unit continues to hum, the light inside is on, but the cold simply does not enter the lower compartment.
The first thing to do is not to panic and carry out an initial diagnosis. Often the problem lies not in the breakdown of expensive components, but in a banal violation of operating rules or resetting settings. No Frost systems and classic drip models may behave differently, but the principles of troubleshooting are similar. If you notice that food has begun to defrost, immediately assess the scale of the problem.
In this article we will look in detail why The refrigerator has stopped freezing in the lower compartment. We will cover mechanical failures, electrical failures and software glitches. Understanding the operating principle of your model will help save time and money, since in many cases repairs are possible on your own without calling a technician.
Primary diagnostics and simple causes
Before disassembling the back wall or looking for a multimeter, it is worth eliminating basic errors. Sometimes reason for the lack of cold it is banal and lies in inattention. Check that the freezer door is securely sealed. If the seal (elastic band) is worn out, dirty or deformed, warm air constantly enters the chamber. The compressor, even working properly, does not have time to compensate for this heat influx.
⚠️ Attention: If the sealing gum has cracks or has lost elasticity, replacing it is the only solution. Temporary measures like lubricating with oil give only a short-term effect.
The second important point is the temperature regime. Someone in the household could accidentally touch the control panel and switch the refrigerator to “Vacation” mode or simply reduce the freezing power to a minimum. In modern models with electronic control failure in the control board this can lead to the fact that the cooling command simply does not reach the actuators.
It is also worth checking for “air locks”. If the freezer is filled to capacity with food, cold air cannot circulate. In systems No Frost this is critical, since the fan must move air freely through the channels. Overfilling the chamber blocks the flow, and the temperature inside rises, although the sensors may show normal.
Problems with the defrost system (No Frost)
If you have a refrigerator with a No Frost system, and it has stopped freezing, in 80% of cases the automatic defrosting system is to blame. The principle of its operation is simple: the heating element is periodically turned on, which melts the ice on the evaporator, water flows into the pan, and the fan disperses the cold. If one of the elements of this chain breaks, the evaporator becomes overgrown with a “fur coat”, which blocks the flow of cold into the chamber.
Most often it fails Defrost heating element. This is a heating element that burns out over time, like a light bulb. Also, defrost sensors (defrosters) often break down, which stop sending a signal to turn on the heating, or the defrost timer, which “sticks” in cooling mode. As a result, ice freezes on the evaporator in a thick layer, blocking the air supply channels.
⚠️ Attention: An attempt to defrost the refrigerator with a hairdryer or knife while the compressor is plugged in can lead to damage to plastic parts or puncture of the freon pipe.
The problem can be diagnosed by indirect signs. If you hear that the compressor is running longer than usual, but there is no cold, or if you do not feel any air flow from the fan when you open the door, the problem is freezing. Sometimes the ice plug is visible visually if you remove the back panel inside the chamber.
To eliminate the malfunction, the unit must be completely defrosted for at least 24 hours. This will allow the ice to melt naturally. If after turning on the refrigerator worked normally, but a week later the situation repeated itself, it means that one of the elements of the defrost system (heating element, sensor, timer) requires replacement.
Faults of the compressor and start relay
The compressor is the “heart” of the refrigerator. If it does not work or does not work correctly, refrigerant circulation it is impossible. However, if the main compartment of the refrigerator is freezing but the freezer is not, this often indicates a loss of compressor performance. It may hum, but not create enough pressure to pump freon through the entire circuit, especially through the long freezer coil.
A common cause of startup failure is start-protection relay. This is a small part that fits onto the compressor contacts. Inside it there is a coil and a bimetallic plate. Over time, the contacts burn out or the mechanism sticks. If the relay is faulty, the compressor either does not start at all, or it hums for a few seconds and clicks, after which it turns off.
In more complex cases, the problem lies in the mechanical wear of the compressor itself. The valves inside the motor may lose their seal. In this case, the compressor operates silently or with increased noise, but there is no pressure in the system. It is difficult to check this without a pressure gauge station, but you can touch the capacitor (the grille at the back): if it is warm only at the outlet of the compressor, and then cold, there is no circulation.
Symptoms of an interturn short circuit in the compressor winding
If the compressor gets very hot (more than 90 degrees) in 10-15 minutes of operation and is turned off by the thermal relay, this may indicate a short circuit in the winding turns. In this case, repairs are not economically feasible; replacement of the unit is required.
Refrigerant leak and capillary system blockage
The two most unpleasant technical malfunctions are freon leak and capillary tube clogged. In both cases, the permeability of the refrigerant is impaired. In the event of a leak, the gas gradually evaporates through microcracks in the sealed joints or evaporator. When clogged, the tube becomes clogged with oil oxidation products or moisture, which has turned into an ice plug.
The symptoms of these problems are similar. The compressor works almost non-stop, trying to gain temperature. The condenser (rear grill) may only be half hot or completely cold. It is warm in the freezer, and in the main compartment it may be a little cooler than in the room, but the food is not cooled.
It is impossible to determine the location of a leak or blockage at home. This requires the use of leak detectors, pressurized nitrogen, and special evacuation and charging equipment. If you hear hissing during operation or see oily spots under the refrigerator, this is a sure sign of depressurization.
⚠️ Attention: Self-filling the refrigerator with freon without evacuation of the system will lead to rapid failure of the compressor. The moisture remaining in the tubes will turn into ice and clog the system.
Failures in electronics and temperature sensors
Modern refrigerators are crammed with electronics. The control module, which receives data from temperature sensors, is responsible for the distribution of cold. If the sensor in the freezer “lies” and shows that it is already -20°C, although in fact it is +5°C, the controller simply will not turn on the compressor or fan. a control module that receives data from temperature sensors. If the sensor in the freezer “lies” and shows that it is already -20°C, although in fact it is +5°C, the controller simply will not turn on the compressor or fan.
The evaporator sensor often fails. It controls the defrosting process. If it shows incorrect data, the system may either not start defrosting at all (which leads to freezing), or heat the evaporator for too long, defrosting all the food. Oxidation of the contacts on the control board itself is also possible, especially if the refrigerator is in a room with high humidity.
Electronics diagnostics require a multimeter. It is necessary to “ring” the sensors for resistance and check the readings with a table of values for a specific model. For example, for a temperature sensor NTC Typical resistance at room temperature is about 10-50 kOhm, but it changes depending on heating.
Table of main faults
For ease of diagnosis, we have collected the main symptoms and probable causes in a single table. This will help you quickly navigate the problem.
| Symptom | Probable cause | Difficulty of repair | Required equipment |
|---|---|---|---|
| The compressor is humming and clicks, but does not start | The start relay is faulty or the compressor is jammed | Low / High | Screwdriver, multimeter |
| The refrigerator runs non-stop, there is no cold | Freon leak or capillary blockage | High (requires a technician) | Vacuum pump, pressure gauges, freon |
| It’s warm in the freezer, ice on the back wall | Malfunction of the defrost system (heating element, sensor) | Average | Multimeter, screwdriver |
| The compressor does not turn on, the indication is on | Electronics failure or faulty sensor | Medium / High | Multimeter, refrigerator circuit |
| Fan noise, weak air flow | Fan freezing or breakdown | Low | Screwdriver |
Action plan to restore operation
If you find that the freezer is not freezing, follow the algorithm. First, rule out simple causes: check the door is tightly closed, make sure that the food does not block the ventilation ducts, check the temperature settings. If this does not help, move on to more complex measures.
Try a complete defrost. Unplug the refrigerator, open all doors and leave it for at least a day. Best for two. This is guaranteed to remove ice jams in the system No Frost. After turning on, listen: the fan should start working and after 20-30 minutes the compressor should start working.
☑️ Algorithm of actions in case of breakdown
If defrosting does not help, technical diagnostics will be required. You will need a multimeter to test the circuits. Check the integrity of the defrost heating element and the resistance of the sensors. If you do not have the skills to work with electrical appliances, it is better to stop at this stage and turn to professionals, as further actions can be dangerous.
What to do if after defrosting The refrigerator started working, but after 3 days it stopped again?
This is a classic sign of a malfunction of one of the components of the defrosting system. Most likely, the heating element is burnt out, the defroster sensor is broken, or the relay is stuck. Ice accumulated again and blocked the channels. The faulty part needs to be replaced.
Is it possible to operate the refrigerator if only the freezer is not freezing?
For a short time - yes, the food in the main compartment will not spoil. However, long-term operation in this mode is harmful to the compressor, which wears out trying to reach a non-existent temperature. In addition, melting food in the freezer can create a flood.
Why does the top of the freezer freeze, but the bottom does not?
Cold air is heavier than warm air and sinks down. If it's warm below, it means the circulation is disrupted. Most often this is caused by an ice plug in the air supply channel or a malfunction of the fan, which does not drive the cold into the lower levels.
How often do you need to defrost a No Frost refrigerator?
Technically, the system No Frost does not require defrosting. However, manufacturers recommend performing preventive defrosting once a year for hygiene and checking the operation of the system. If you notice a decrease in efficiency, defrosting is the first diagnostic step.