The situation when the refrigerator continues to hum, the light inside is on, and the food on the shelves begins to spoil is familiar to many. Externally, the equipment appears to be in good working order, the motor is working, but temperature conditions it is damaged. The ice in the freezer melts, and the refrigerator compartment becomes warm. This does not always mean a breakdown that requires calling a technician, but the problem cannot be ignored.
Often the reason lies in the little things: incorrect settings, clogged ventilation holes or rare defrosting. However, in some cases, this is due to a serious faulty compressor or leak of refrigerant. Understanding the principles of operation of the unit will help you quickly diagnose the problem and, possibly, save on expensive repairs.
In this article we will analyze the main reasons why the equipment has stopped freezing, and we will tell you what you can do yourself. We will consider both simple operating errors and complex technical malfunctions that require specialist intervention. The main thing is to act consistently and not panic.
Malfunctions of the thermostat and temperature sensor
One of the most common reasons for the lack of cold is failure thermostat. This element is responsible for sending a signal to the compressor to turn on and off. If the sensor is “stuck” in the “off” position or simply transmits incorrect data about the temperature inside the chambers, the motor will idle or not turn on at all, even if outwardly it seems that the equipment is functioning.
In modern models with the system No Frost electronic temperature sensors are responsible for temperature control. Their breakdown often leads to the compressor working non-stop, trying to achieve non-existent cold, or, conversely, being silent when it needs to freeze. Diagnostics of the electronic unit requires special knowledge, but you can check the mechanical regulator yourself.
To check the mechanical thermostat, it is often enough to turn the adjustment knob. If you hear a characteristic clicking sound, but the compressor does not start, the problem may be in the regulator itself or the start relay. In some cases, “resuscitation” helps: remove the handle, gently knock on the regulator body, or temporarily close the contacts to check the operation of the motor.
⚠️ Attention: Before any manipulations with the electrical components of the refrigerator, be sure to disconnect it from the network. Working with current without proper qualifications is life-threatening.
If the situation has not changed after replacing the thermostat, it is worth checking other components. Often the problem lies deeper, in the coolant circulation system or in the operation of the engine itself. Do not rush to throw away the old regulator - sometimes it can be restored, but it is easier and more reliable to install a new one.
Problems with the compressor and start relay
The heart of any refrigerator is compressor. If it works, but does not create the necessary pressure for the circulation of freon, there will be no cold. You can often observe a picture when the engine hums, tries to start, clicks and turns off. This is a classic sign of a faulty starting relay or a jammed piston group.
The starting relay is a small mechanism that supplies a starting impulse to the motor windings. Over time, the contacts in it burn or oxidize, and it ceases to perform its function. Replacing a relay is an inexpensive procedure and can often be done by yourself if you have basic skills in working with the tool.
A more serious problem is a “humming” compressor that cannot start due to inter-turn short circuit of the windings or mechanical jamming. In this case, the unit gets very hot, consumes a lot of electricity, but does not pump freon. If the compressor is hot to the touch, but no cold is generated, further operation of the equipment can lead to complete failure of the engine.
Diagnostics of the compressor requires measuring the resistance of the windings with a tester. Normal readings vary by model, but are typically between 20 and 60 ohms. If the device shows zero or infinity, the engine is faulty. It is also worth checking the condenser if your model has one, since its swelling often interferes with normal startup.
Freon leakage and capillary tube blockage
Refrigerant (freon) is the working fluid that transfers heat from the chambers to the outside. If a microcrack has formed in the system, the gas gradually evaporates. As a result, pressure in the system falls, and freon stops boiling in the evaporator, without cooling the air. Outwardly, this is manifested by the fact that the refrigerator is working, but the temperature inside is rising.
Another common technical problem is clogged capillary tube. Ice plugs or clogging with oil breakdown and oxidation products may form in the circulation system. This prevents the normal flow of freon. In such conditions, the compressor works with overload, trying to push through the plug, which often leads to its overheating.
It is difficult to diagnose a leak or blockage at home. This is usually indicated by the following signs:
- ❄️ The condenser grille at the back remains cold or only partially heats up.
- 🔊 The compressor runs longer than usual or does not turn off at all.
- 💧 The appearance of oily spots near the compressor or pipes.
- 🌡️ Absence of the characteristic noise of boiling freon inside the chambers.
To eliminate these malfunctions, you need to call a technician. The specialist will find the leak using a leak detector, seal it, evacuate the system and charge a new volume of refrigerant. It is impossible and dangerous to carry out this work on your own without equipment.
Why can’t you ignore a freon leak?
If you continue to operate a refrigerator with a leak, moisture and air will enter the system through a leaky place. This will lead to the formation of acid inside the circuit, combustion of the compressor and the need to replace expensive components, and not just refill with gas.
Malfunctions of the No Frost and defrost system
In refrigerators with the system No Frost a complex system of fans and heaters is responsible for heat removal and moisture removal. If one of the elements of this circuit fails, the circulation of cold air is disrupted. As a result, there may be cold in the freezer, but it does not enter the refrigerator compartment, or vice versa - everything becomes overgrown with ice and stops freezing.
Key elements that often break:
- 🌀 Fan: if it does not spin, cold air is not pumped into the chambers.
- 🔥 Defrost heating element: if it burns out, the evaporator becomes overgrown with a “fur coat” that blocks airflow.
- ⏱️ Defrost timer: does not switch operating modes, leaving the refrigerator in cooling or defrosting mode.
- 🌡️ Defrost sensor: gives incorrect commands to the control unit.
Often a sign of a malfunction of the No Frost system becomes a thick layer of ice on the back wall inside the freezer, even if it looks clean outwardly (ice may be hidden behind a plastic panel). If you hear the fan making noise or crackling, its blades may be touching ice.
The defrost heating element is checked with a multimeter for an open circuit. If the spiral is intact, check the defrost thermostat. In some LG or Samsung models, a common problem is a blown defrost fuse, which is located in the heater circuit. Replacing it takes a few minutes, but requires disassembling the back wall of the freezer.
☑️ Diagnostics of the No Frost system
Effect of improper operation on cooling
Before looking for complex breakdowns, it is worth analyzing how you use the refrigerator. Often the reason for the lack of cold is trivial and lies in violation of operating rules. For example, if you put a pot of hot soup in the chamber, the compressor may not be able to cope with a sharp jump in temperature, and the food nearby will begin to spoil.
Another common mistake is loading the shelves too tightly. Cold air should circulate freely between the products. If you filled the freezer to capacity or covered the ventilation holes with bags, the sensors will show normal temperature locally while the rest of the volume is warm.
It is also worth paying attention to the location of the refrigerator. If it is placed close to a wall or in a niche with no clearance for ventilation, the condenser (grid at the back) cannot transfer heat effectively. This leads to overheating of the system and reduced cooling efficiency.
Rubber seal on the doors is another critical element. If it is dry, dirty or the door is skewed, warm air constantly enters the chamber. The compressor wears out, but cannot compensate for heat inflows. Check the tightness of the door with a sheet of paper: if it is easily pulled out when the door is closed, the seal needs to be changed or the hinges adjusted.
⚠️ Attention: Do not place the refrigerator next to heating radiators, ovens or in direct sunlight. This creates a critical load on the cooling system, shortening the service life of the equipment.
Diagnostics and fault table
To systematize possible problems, we have compiled a table of the main symptoms and their probable causes. This will help you quickly navigate the situation and understand whether it’s worth calling a specialist or you can handle it on your own.
| Symptom | Probable cause | Difficulty of repair | Actions |
|---|---|---|---|
| Humming, but not freezing | Freon leak, blockage | High (needs a technician) | Call a specialist to find a leak |
| Clicks and turns off | Faulty starting relay | Low | Replace the relay (you can do it yourself) |
| Works without stopping | Thermostat is faulty | Average | Replace the sensor or regulator |
| Ice in the freezer, no cold | Failure of the defrost system (No Frost) | Average | Check the heating element, timer, sensors |
| Heat at the door | Damaged seal | Low | Replace the seal or level the door |
When diagnosing, it is important to take into account the age of the equipment. In older models (Atlant, Biryusa last years), mechanical thermostats often fail and evaporators leak. In modern units (LG, Samsung, Bosch), problems are often associated with electronics and the No Frost system.
If you are not confident in your abilities, it is better not to take risks. Improper disassembly can lead to damage to plastic elements or tubes, which will turn a minor repair into a major one. However, simple actions, such as defrosting or replacing the seal, are available to everyone.
Frequently asked questions (FAQ)
How long does it take the refrigerator to get cold after defrosting?
Usually it takes from 2 to 4 hours to fully reach the mode. At this time, you should not load the cameras with food. If after 6-8 hours the temperature has not stabilized, then there is a malfunction.
Is it possible to operate the refrigerator if it does not freeze?
For a short time - yes, if you are waiting for a technician. Continuous operation “idle” (especially if there is a freon leak) can burn the compressor due to lack of cooling of the windings or moisture entering the system. It is better to turn off the equipment.
Why does the refrigerator still not freeze well after replacing the freon?
Perhaps there is moisture or air left in the system, or the type of refrigerant is incorrectly selected. Also, the reason may be poor-quality evacuation of the system before refueling. A repeated call to the technician is required.
How often do you need to defrost the refrigerator?
Models with Drop System (crying wall) require defrosting 1-2 times a year. The systems No Frost do not need defrosting, but it is recommended to carry out preventive cleaning once every 6 months.