The situation when the refrigerator compressor is humming, the indicators are on, and the temperature inside the chamber is far from normal causes panic in any home cook. Products begin to deteriorate, an unpleasant odor appears, and there is an urgent need to figure out why the refrigerator works, but does not freeze. Often the reason lies not in the breakdown of complex electronics, but in banal operating errors that can be corrected in a few minutes.
However, this symptom cannot be ignored. If the unit operates in enhanced mode, trying to achieve the specified temperature parameters, this leads to overheating of the motor and rapid failure of expensive components. In this material, we will take a detailed look at the mechanics of the cooling process, typical malfunctions and ways to fix them on your own or by calling a technician.
The first thing you need to do when you hear the continuous hum of the motor is to listen to the nature of the sound and check the tightness of the door. Sometimes the problem is solved by simply adjusting the legs or defrosting, but in 80% of cases it is a violation of the tightness of the circuit or a malfunction in the refrigerant circulation system.
Problems with the seal and chamber tightness
The most common reason that refrigerator stopped freezing properly is a violation of the tightness of the internal volume. The rubber seal located around the perimeter of the door loses its elasticity over time, cracks or deforms. Through the resulting cracks, warm air from the room constantly flows into the chamber.
Sensors record the increase in temperature and signal the compressor to work without stopping. The motor is trying to “freeze out” excess heat, but due to the constant flow of warm air this is impossible. As a result, you hear the continuous operation of the equipment, and the food inside remains warm.
To check the condition of the seal, it is not necessary to call a technician. There is a simple and effective method known as the “paper test”.
- 📄 Take a regular sheet of paper or a banknote.
- 🚪 Insert the sheet between the seal and the refrigerator body, then close the door.
- 🧲 Try to pull the sheet out: if it comes out easily without resistance, This means that the seal does not fit in this place.
- 🔄 Walk around the entire perimeter of the door in this way to find all problem areas.
If the seal is simply dirty, wash it thoroughly with warm water and soap. In case of deformation, you can try to restore the shape by heating the rubber with a hairdryer or boiling water. However, if the material is cracked, only replacing the seal a new one will help.
⚠️ Attention: Do not use aggressive solvents or abrasive sponges to clean the seal. This will accelerate the destruction of the rubber and lead to a complete loss of tightness, after which the refrigerator will no longer keep cold even with a new motor.
Faults of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” of the cooling system, which gives the command to the compressor turn on or off. If this element fails, it can constantly send a “low cold” signal, causing the engine to idle. In models with electronic control, they are responsible for this temperature sensors, which are also susceptible to breakdowns.
Symptoms of a thermostat malfunction often manifest themselves in the form of a complete absence of shutdown cycles. The refrigerator hums for days, trying to achieve a non-existent ideal, while there may be ice in the freezer and heat in the refrigerator. This is a classic sign that the control system is “stuck” in active freezing mode.
In modern models LG or Samsung sensor diagnostics are often carried out through the service menu or displayed as an error code on the display.
- ❄️ The evaporator sensor may indicate incorrect data if it has shifted or become covered with ice.
- 🌡️ The air sensor in the chamber often fails due to power surges.
- 🔌 Oxidation of contacts in the thermostat circuit leads to a break in the control signal.
Replacing the thermostat in mechanical models - a procedure that can be done with your own hands if you have basic skills in working with the tool. In electronic systems, it may be necessary to reflash the board or replace the control module, which is best left to specialists.
How to check a thermostat with a multimeter?
To check a mechanical thermostat, you need to remove it, immerse the capillary tube in cold water with ice and ring the contacts with a multimeter. When the temperature drops, the contacts should close or open (depending on the type). If there is no resistance or it does not change, the part is faulty.
Freon leakage and impaired refrigerant circulation
One of the most serious reasons why The refrigerator does not freezeis a refrigerant (freon) leak. Freon is a working fluid that, circulating through a system of tubes, takes heat from the chambers and releases it into the environment. If the amount of gas in the system drops, the cooling efficiency decreases sharply, even if the compressor is working properly.
A leak can occur anywhere in the circuit: due to corrosion of tubes in the foamed part of the body, mechanical damage during transportation, or manufacturing defects in welds. It is almost impossible to detect a leak visually, since freon is a colorless and odorless gas. An indirect sign is the appearance of a yellowish coating on the tubes or swelling of the refrigerator wall.
The table below shows the main signs of a leak and their consequences for the operation of the unit:
| Symptom | What is happening in the system | Result |
|---|---|---|
| Warm condenser | The rear grill does not heat up | No heat exchange |
| Noisy operation | The compressor hums louder than usual | Trying to pump air |
| Frost on the evaporator | Ice only at the entrance of the tubes | Lack of freon for the full cycle |
| Motor shutdown | Thermal relay is triggered | Overheating due to lack of cooling |
If a leak is confirmed, simply charging with freon will not help. First you need to find the location of the damage, solder it and only then refill the system. An attempt to refill yourself without eliminating the leak will only lead to a short-term effect and repeated breakdown.
⚠️ Attention: Freon is a chemically active substance. When working with it, special equipment is required (vacuum pump, pressure gauge station). Independent manipulation of cylinders can be hazardous to health and violate environmental standards.
Clogged capillary tube and filter drier
There is a bottleneck in the refrigerant circulation system - the capillary tube. Its diameter is less than a millimeter, so it clogs (easily). The main causes of blockage are oil oxidation products, moisture trapped in the circuit, or microscopic solder particles. As a result, freon cannot circulate freely, and the pressure in the system drops.
Symptoms of a blockage are very similar to a freon leak: the refrigerator works, but does not cool. The compressor may overheat while trying to push refrigerant through the plug. Often in such cases, gurgling or periodic clicking is heard when the pressure reaches critical values.
To eliminate the blockage you need:
- 🛠️ Blowing the system with nitrogen under high pressure.
- 🔄 Replacing the filter-drier, which retains moisture and garbage.
- 💨 Vacuuming the circuit to remove air and residual moisture.
This procedure is technically complex and requires professional tools. At home, it is almost impossible to blow out a capillary without the risk of damaging other components.
Compressor malfunction: symptoms and diagnosis
The compressor is the heart of the refrigerator. If it is faulty, then normal operation of the unit is out of the question. However, there are situations when the engine hums but does not start, or starts and immediately stalls. This may indicate an interturn short circuit of the windings or jamming of the piston group.
Another option is failure of the starting relay. This is a small part that provides an impulse to start the engine. If the relay is “stuck” or burnt out, the compressor will only hum, trying to start, but the shaft will not rotate. In this case, refrigerator formally “works” (consumes current and makes a sound), but does not produce cold.
Diagnostics of the compressor includes checking the resistance of the windings with a multimeter. Normal resistance values are usually:
- 🔹 Starting winding: 30–40 Ohm.
- 🔹 Operating winding: 10–15 Ohm.
- 🔹 Between the body and windings: infinity (no continuity should).
If the resistance between the windings and the housing is zero, then an insulation breakdown has occurred. Operating such a refrigerator is dangerous - it can lead to a short circuit in the network.
⚠️ Attention: If the compressor heats up to a very high temperature (more than 90°C) and smells of scorched insulation, immediately disconnect the device from the network. Further activation may lead to a fire.
☑️ Compressor diagnostics
Operating errors and external factors
Before sounding the alarm and looking for a breakdown, it is worth eliminating trivial errors in use technology. Often users themselves create conditions under which refrigerator cannot function normally. For example, installing the unit close to the wall disrupts the ventilation of the condenser.
If the radiator grille is closed at the back, heat is not removed and operating efficiency decreases. The temperature in the room also affects the operation: if the room is hotter than +30°C, a standard refrigerator may not be able to cope with the load, even if it is working properly.
Other common mistakes:
- 🍲 Loading hot products: this sharply increases the temperature inside and causes the motor to wear out.
- 🚪 Frequent opening doors: leads to a constant influx of warm, humid air.
- 📦 Violation of the rules for placing products: if the products block the ventilation holes, the cold does not circulate.
It is also important to check whether the temperature settings are not adjusted. Perhaps one of the household members accidentally turned the regulator to the “Minimum” position or turned off the super-freezing function.
Frequently asked questions (FAQ)
Why does the refrigerator hum, but does not freeze after defrosting?
If after complete defrosting (more than 24 hours) the refrigerator did not start to freeze, perhaps there was a failure in the control system or an ice plug formed in the capillary, which did not have time to melt. The control board could also fail due to a power surge when turned on.
Can a refrigerator stop freezing due to a power surge?
Yes, power surges often damage the start relay, thermostat or electronic control module. In modern models, the temperature sensor may burn out, which is why the system stops receiving correct data about the climate inside the chambers.
What to do if it is warm in the refrigerator compartment and ice in the freezer?
This is a classic symptom of a freon leak or a clogged capillary tube. The refrigerant is not enough for a full cycle, so it only manages to cool the first section (the freezer), and does not reach the refrigerator compartment in the required volume.
How often do you need to change the seal on the door?
The service life of the seal is on average 5–7 years. However, with intensive use or the use of aggressive cleaning chemicals, it may become unusable sooner. Regularly checking the tightness will help prolong the life of the compressor.