The situation when you open the refrigerator door and it’s warm inside always takes you by surprise. Food begins to deteriorate, an unpleasant odor appears, and panic sets in. The refrigerator does not freeze - this is a signal that there is a failure in the refrigerant circulation or temperature control system. In some cases, the problem is solved by simple defrosting, in others, the intervention of a technician is required.
Before calling a specialist, it is worth conducting an initial diagnosis. Often, users do not notice obvious things: incorrect installation, clogged drainage, or incorrect settings. Understanding the principles of operation of the compressor and thermostat will help you quickly determine the source of the malfunction.
In this article we will take a closer look at the mechanical and electrical reasons for the lack of cold. You will learn how to distinguish a compressor breakdown from a freon leak and when self-repair can be dangerous for equipment.
Operating rules and user errors
Often the reason that The refrigerator does not freezelies not in a breakdown, but in a violation of operating rules. For example, if the unit was just delivered and immediately turned on, the oil in the compressor might not drain into the crankcase. This leads to dry operation and rapid wear of parts.
Another common mistake is loading hot foods. The thermostat may not be able to keep up with the sudden temperature rise, and the compressor will work hard trying to cool the chamber. It is also worth checking the tightness of the door.
⚠️ Attention: If you notice that the rubber seal on the door has torn or come off, the cold will evaporate. The compressor will run continuously, but will not reach the desired temperature.
Check whether the refrigerator is overloaded. If food is placed close to the back wall or blocks the ventilation openings (in No Frost systems), air circulation is disrupted. As a result, there may be ice in one corner and heat in the other.
Problems with the thermostat and temperature sensors
One of the key parts responsible for turning the motor on and off is thermostat (thermostat). If it is faulty, the compressor may simply not receive a signal that the temperature in the chamber has increased. As a result, the unit remains turned off, and the products melt.
In modern models with electronic control, instead of a mechanical thermostat, temperature sensors (thermistors) are used. They transmit data to the control module. If the sensor “lies” or the circuit breaks, the control board can block the start of the compressor or, conversely, keep it on constantly.
Diagnostics of the thermostat often requires checking multimeter. However, there is an indirect sign: if during defrosting the refrigerator starts to work, and after the temperature has risen it is silent again, most likely the problem is in the temperature control chain.
Faults of the compressor and start relay
The heart of the refrigerator is compressor. If it hums but does not get cold, or is completely silent, the problem may be in the start relay. This device is responsible for starting the engine. If it breaks down, the compressor may try to start, click and turn off after a few seconds.
The situation when the motor hums but does not start often indicates an interturn short circuit of the windings or jamming of the piston group. In this case, a characteristic hum is heard, and then a click of the protection. Long-term operation in this mode is unacceptable.
Symptoms of a burnt-out compressor
Black coating on the tubes, a burning smell, no vibration of the case when plugged in, cold condenser (grid at the back).
Replacing a compressor is a complex process that requires evacuation of the system and refilling freon. It is impossible to carry out this procedure on your own without special equipment.
Refrigerant (freon) leakage and system blockage
If the refrigerator is working, the compressor is humming, but there is no cold at all or it is weak, there is a high probability refrigerant leaks. Freon circulates in a closed circuit, and if a microcrack appears in the tube of the condenser or condenser, the gas evaporates.
Signs of a leak:
- 🧊 The condenser (grid at the back) remains cold or warm only in entrance.
- 🔊 The compressor works almost without interruption.
- ❄️ A “fur coat” appears in the freezer only at the entrance of the tubes, and the rest of the space is warm.
Another mechanical problem is clogged capillary tube. An ice plug may form in the system or debris (wear products) may enter, blocking the freon flow. In this case, the pressure in the system drops and cooling stops.
⚠️ Attention: Searching for leaks and refilling with freon are jobs that require a license and equipment. Independent attempts to “add gas” can permanently disable the equipment.
Failures in the No Frost system and malfunction of the timer
In refrigerators with a system No Frost the fan and defrost system are responsible for removing moisture and cold. If the evaporator is clogged with ice (due to a malfunction of the defrost heating element, defrost sensor or timer), the ice blocks the fan.
Air stops circulating between the freezer and refrigerator compartments. The freezer may be cold, but the top compartment is warm. Or the compressor will turn off due to overheating, since heat exchange is disrupted.
☑️ Diagnostics No Frost
Completely defrosting the refrigerator for 24 hours often helps. If after switching on the cold appears, but after a week it disappears again, it means that one of the elements of the defrost system (heating element, sensor, timer) is faulty and requires replacement.
Comparative table of symptoms and causes
To make it easier for you to navigate, we have collected the main symptoms in a table. Remember that only a specialist with equipment can make an accurate diagnosis.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor is silent, there is no light | No power, socket burnt out, wiring faulty | Low |
| Humming, clicking, won’t start | Start relay, compressor jammed | Medium/High |
| Works without stopping, no cold | Freon leak, capillary clogged | High |
| Ice in the freezer, heat in the refrigerator | Malfunction of the No Frost system (heating element, timer) | Average |
| There is cold, then there is no | Thermostat or sensor is faulty | Low/Medium |
When you need to call a technician
Not all breakdowns can be repaired with your own hands. If you have checked the outlet, defrosted the unit and made sure that the seal is intact, but the problem has not been solved, it’s time to call a specialist. Especially when it comes to replacing a compressor or finding a leak.
The technician will arrive with a pressure gauge manifold, a leak detector and a vacuum pump. These tools allow you to accurately determine the pressure in the system, find the location of the leak and correctly charge the refrigerator with refrigerant.
Do not try to solder the tubes or open the sealed circuit yourself. This can lead to a fire or permanent failure of an expensive unit. DIY Repair is justified only in cases of replacing a thermostat, relay or heating element, if you have skills in working with electrical equipment.
Cost of spare parts
Thermostat - from 800 rubles | Start relay - from 600 rubles | Compressor - from 4000 rubles. (without work).
Prevention and care of the refrigerator
In order refrigerator to serve for a long time and not fail at the most inopportune moment, you need to take care of it. Regular defrosting (if it is not No Frost), washing the drainage hole and checking the cleanliness of the condenser at the back will prolong the life of the compressor.
Dust on the rear grill works as a heat insulator, interfering with freon cooling. The compressor is forced to work longer to compensate for poor heat transfer. Wipe the grille with a dry cloth or vacuum it every six months.
Also keep an eye on the installation level. If the refrigerator is not level, the door may not close completely on its own. Use a building level to adjust the legs.
Why does the refrigerator hum but not freeze?
This is a classic sign of a freon leak or a clogged capillary tube. The compressor is trying to pump refrigerant, but there is either no refrigerant in the system or it is not circulating. Diagnostics by a specialist is required.
How long does it take to defrost the refrigerator?
For complete defrosting and evaporation of moisture from hard-to-reach places (especially in the No Frost evaporator) it takes from 12 to 24 hours. The minimum time is 8 hours, but it may not be enough to completely thaw the ice inside the case.
Is it possible to use a refrigerator if it does not freeze?
You cannot use it for its intended purpose - the food will spoil. Leaving a faulty unit on is also dangerous: the compressor can burn out from overheating while running idle. It is better to disconnect it from the network before the technician arrives.
What to do if there is water in the refrigerator, but there is no cold?
Water may be the result of melting ice due to lack of cold. Check if the compressor is working (vibration, sound). If it is silent, the problem is in the electrics or thermostat. If it hums, there is likely a freon leak.
How to check if the thermostat is working?
Remove the terminals from the thermostat and connect them directly (close the circuit). If after this the refrigerator turns on and starts to freeze, then the thermostat is faulty and needs to be replaced. Don’t forget to disconnect the device from the mains before doing this!