The situation when you open the refrigerator door, and the heat inside or the food has begun to thaw, always causes panic. This is not just a household inconvenience, it is a risk of losing food supplies and costly repairs in the future. Before calling a technician, it is necessary to conduct an initial diagnosis to understand the scale of the problem. Often the reason lies in trivial things that can be fixed on your own in a few minutes.
However, there are also more complex technical faults that require the intervention of professionals. Compressor it may hum, but not start, or the unit operates silently, but does not produce cold. Understanding the operating principles of refrigerant and the heat removal system will help you correctly describe the problem to a specialist. In this article we will analyze in detail all possible failure scenarios.
You should not ignore the first signs of unstable operation of the equipment. If you notice that a “fur coat” has appeared on the back wall, and the food is deteriorating faster than usual, this is a signal. System tightness could have been damaged, or one of the sensors has failed. Let's look at the main reasons why your refrigerator does not cool.
Primary diagnostics and simple operating errors
Before sinning on complex electronics or gas leaks, it is worth eliminating the human factor. Very often the equipment is working properly, but does not work correctly due to incorrect installation or configuration. Check whether it fits snugly sealing rubber along the perimeter of the door. If air from the room gets into the gap, the compressor simply does not have time to cool the internal volume.
Pay attention to the location of the unit. If it stands close to the wall or in a niche without gaps, the heat exchange is impaired. Condenser (the grille at the back) should be freely blown with air. Also check the temperature settings - perhaps one of the household members accidentally switched the regulator to the “vacation” or minimum cooling mode.
⚠️ Attention: If you have recently defrosted or washed the refrigerator, do not turn it on immediately. Allow the equipment to stand turned off for several hours so that the refrigerant stabilizes, otherwise the compressor may burn out upon startup.
A common mistake is loading warm products. If you put a hot pan in the chamber, the sensors will record a sharp jump in temperature. The unit will work hard, trying to reduce the temperature, but due to the inertia of the system, the cold may be distributed unevenly. In such cases, it is better to temporarily turn off the device, let it cool and start again with empty shelves.
Also check the integrity of the power wires and the condition of the socket. Power surges could cause the controller to reset. Some models electronic control require a full reboot cycle: unplug from the network for 15 minutes and turn on again.
Faults in the defrosting system in No Frost models
If you have a modern refrigerator with system No Frost, and it stopped freezing, in 80% of cases the problem lies in the defrosting system. The operating principle of such units is the circulation of cold air, which is pumped by a fan. If the evaporator becomes overgrown with ice, air stops passing through the channels and cold does not enter the chamber.
Three main elements are responsible for the defrosting process: Defrost heating element, a defrost sensor and a timer (or electronic module). If the heating element burns out, the ice does not melt and blocks the fan. If the sensor is faulty, it does not give a command to turn on the heater. As a result, the evaporator turns into an ice monolith.
- ❄️ Symptom 1: There is slight cold in the freezer compartment, and warmth in the refrigerator compartment.
- 🔊 Symptom 2: You do not hear the characteristic noise of the fan when open door.
- 💧 Symptom 3: Water appears under the vegetable drawers or on the floor under the refrigerator.
Diagnostics often require partial disassembly of the rear panel of the freezer. A visual inspection of the evaporator will indicate the presence of an ice coat. If there is ice and the heating element is intact, the power circuit and sensors are checked. Replacing the heating element yourself is possible if you have the skills to work with a multimeter and a screwdriver.
How to check the defrosting heating element with a multimeter?
To check, you need to remove the back panel of the freezer, find the heating element (usually a curved tube under the evaporator) and ring its ends with a multimeter in resistance measurement mode. If the device shows infinity (break), the heating element is faulty and requires replacement. The resistance rate is usually from 200 to 400 Ohms.
Problems with the compressor and start relay
The heart of any refrigerator is compressor. It is he who pumps the refrigerant through the system. If the compressor is silent, it means there is no circulation of freon and, accordingly, no cold. However, it often happens that the engine hums, clicks, tries to start and immediately stalls. This is a classic sign of a faulty start relay or the compressor itself.
The start relay is a small plastic block that fits over the contacts of the compressor. Inside there is a coil or posistor, which gives the initial impulse to start the engine. Over time, the contacts burn out and the mechanism sticks. Replacing the relay is the simplest and cheapest repair procedure that you can do yourself.
If after replacing the relay the situation has not changed, and the compressor still hums for a few seconds and turns off, there may be a problem with turn-to-turn short circuit the motor windings. In this case, the motor gets very hot. You cannot operate such a unit - it is a fire hazard. The compressor needs to be replaced, which is a complex and expensive procedure.
| Symptom | Probable cause | Difficulty of repair | Cost |
|---|---|---|---|
| Silent, does not respond | Open circuit, burned out module | Average | Average |
| Buzzes and clicks | Start relay, compressor wedge | Low / High | Low / High |
| Works constantly | Freon leakage, wear | High | High |
| Vibrates strongly | Shock absorbers are destroyed | Low | Low |
It is important to note that inverter compressors, which are found in models LG, Samsung, Bosch of recent years, are diagnosed differently. They do not make loud clicks, but change speed smoothly. If such a compressor fails, it is often necessary to replace not only the motor, but also the control board.
☑️ Compressor diagnostics
Refrigerant leakage: signs and consequences
Freon is the working fluid that transfers heat from the chambers refrigerator outside. In a closed system, gas is not consumed and does not require refilling during the entire service life. If the refrigerator has stopped freezing and the compressor is running continuously, there is most likely a refrigerant leak..
A leak can occur as a result of corrosion of pipelines (especially in the foamed part of the body), mechanical damage during transportation or poor-quality factory soldering. Finding the leak location visually is almost impossible, since the gas is colorless and odorless. This requires special equipment and an ultraviolet lamp (if a marker is added to the system) or the “soapy water” method in open areas.
⚠️ Attention: Self-refilling with freon without finding and eliminating the leak is a pointless waste of money. After a week the gas will come out again and the problem will return. Repair should include finding the hole, soldering, vacuuming and refilling.
One of the indirect signs of a leak is the lack of heating of the capacitor array at the back or sides of the case. During normal operation, the sides should be warm or even hot. If the motor is humming and the metal is cold, this is a sure sign of a lack of freon in the circuit.
Sometimes the leak occurs through the evaporator, which can rust from the inside, especially if spilled aggressive liquid has been left in the chamber for a long time. In such cases, repairs may not be economically feasible, and it is easier to purchase new equipment.
Malfunctions of the thermostat and temperature sensors
Responsible for maintaining the set temperature is thermostat (in mechanical models) or electronic sensor (in models with a display). If this element fails, it can “lie” to the control module, reporting that it is already cold in the chamber, although in fact it is warm there. In this case, the compressor simply will not turn on.
In mechanical refrigerators, the thermostat is a device with a capillary tube that is inserted into the chamber. As the temperature changes, the gas inside the tube expands or contracts, opening or closing the contacts. You can check it by closing the contacts directly (temporarily!). If the refrigerator starts working, the problem is in the thermostat.
Modern units use several sensors: in the refrigerator compartment, in the freezer, on the evaporator. Diagnostics requires Read the error code from the display or by blinking indicators, since each sensor is responsible for its own area. Replacing the sensor usually does not require calling a technician and is done by replacing a part with similar parameters.
- 🌡️ Thermostat: Mechanical switch, adjusted with a knob inside the chamber.
- 💻 Sensor: Electronic component, transmits data to the board control.
- 🔧 Module: The “brain” of the refrigerator, processes signals and commands the compressor.
If the control module is faulty, it may not supply voltage to the compressor or fan. Repairing the board is possible, but often requires a qualified electronics technician. In some cases, it is easier to replace the entire module by finding an analogue for your model.
Clogged capillary pipeline and filter drier
Another technical reason for the lack of cold is a clog in the freon circulation system. Most often it gets clogged capillary tube or filter drier. This occurs due to moisture entering the system (if evacuation was performed poorly) or oil oxidation products.
The symptoms are similar to a leak: the compressor is working, the condenser is only partially hot (to the point of blockage), but there is no cold. A characteristic sign is gurgling sounds in the pipeline, which may appear and disappear. The pressure at the outlet of the compressor increases, and at the inlet it drops.
Removing a blockage is a complex procedure. The technician needs to:
- Cut off the old filter drier.
- Purge the system with nitrogen under high pressure.
- Install a new filter.
- Vacuum again and charge the system with freon.
Sometimes the blockage can be temporary (ice jam), and after a long defrosting (up to 24 hours) the refrigerator starts working. But if the problem is the oil or a dirty filter, defrosting will not help. Intervention in the circuit is required.
Frequently asked questions (FAQ)
Is it possible to operate a refrigerator if it does not freeze well?
Long-term operation in this mode is extremely undesirable. The compressor works at the limit of its capabilities, trying to gain temperature, which leads to overheating and rapid wear. In addition, bacteria actively multiply in a warm environment, which is dangerous to health.
Why does the refrigerator not turn on or freeze after defrosting?
You may have turned it on too early. After defrosting, you need to wait at least 2-4 hours for the refrigerant to settle. The wiring could also burn out if water got on the electrical contacts during washing. Check that all connectors are dry.
How long does it take for the refrigerator to get cold after turning it on?
Usually, it takes from 2 to 6 hours for the initial cooling of empty chambers. If after 10-12 hours of compressor operation the temperature has not dropped below +10°C, then there is a malfunction.
Can the refrigerator not freeze due to a power surge?
Yes, a power surge could damage the start relay, burn the compressor winding or damage the electronic control module. In such cases, diagnostics of the electrical circuit is necessary.