The first start of a new or defrosted refrigerator is always a moment of anticipation. Owners often wonder: why has the compressor been humming for several hours, but the inside is still not as cold as expected? Understanding the physiology of the unit’s operation in the first hours of operation will help to avoid panic and false calls to the technician.
The time for initial entry into mode depends on many factors: the volume of the chambers, the type of refrigerant, the temperature in the room and even the amount of food inside. Standard time a period of 2 to 8 hours is considered to set the initial temperature, but this range can vary.
You should not immediately load the cameras with products if you have just turned on the device. Let the equipment “accelerate” idle. This will allow the system to evenly distribute the refrigerant and cool the internal volume without unnecessary load on the motor.
It is important to understand that modern inverter models and older single-compressor units behave differently. If your refrigerator belongs to class No Frost, it will require more time for the initial cooling of the evaporators hidden behind plastic panels.
Initial startup: stages of entering the mode
The primary cooling process cannot be called instantaneous. Immediately after being connected to the network, the compressor begins to build up pressure, starting the circulation of freon along the circuit. In the first 30–40 minutes, you can hear the characteristic sounds of liquid flowing - gurgling or hissing.
Normal phenomenon continuous operation of the motor during the first 3–5 hours is considered. During this period, the electronics (or thermal relay) does not yet give a command to stop, since the sensors record a temperature significantly higher than the set parameters.
If after 6-8 hours of operation without load the refrigerator does not turn off, this may be a signal of a problem, but not always. Sometimes it takes longer if the room is hot or the door has been opened frequently to check the temperature.
⚠️ Attention: If the refrigerator operates for more than 12 hours without a break and it is not cold inside, immediately unplug it. Long-term operation “idle” without reaching the temperature can lead to the compressor burning out.
Factors influencing the duration of operation
Why does one refrigerator reach the desired temperature in two hours, while the other “hums” for half a day? There are a number of objective reasons slowing down this process. Ignoring these factors can lead to erroneous conclusions about equipment failure.
One of the key parameters is ambient temperature. If you install the unit in an unheated kitchen or garage, where the temperature is below +10°C or above +32°C, the operation algorithms may be confused and the cooling process may be delayed.
The volume of the refrigeration chamber also matters. The larger the liter volume, the more air needs to be cooled. Models with the system Full No Frost spend additional time cooling the evaporator itself before cold air begins to enter the chamber.
- 🌡️ Room temperature: in hot weather, heat exchange occurs more slowly.
- 📦 Availability of products: a full load takes longer than an empty one camera.
- 🚪 Tightness: frequent opening of doors reduces the compressor efforts to nothing.
Do not forget about correct installation. If the refrigerator is moved close to the wall, air circulation around the condenser (grid at the back) is disrupted. This leads to overheating and increased operating time.
Compressor work and rest standards
After the refrigerator has reached the initial temperature, it goes into normal operation. This mode is characterized by cyclicality: a period of work is replaced by a period of rest (parking).
Under ideal conditions operation coefficient is about 30–40%. This means that the compressor should run for approximately 10-15 minutes, then rest for 20-25 minutes. However, these figures are conditional and depend on the settings of the thermostat.
If you set the temperature to a minimum (for example, +2°C in the main chamber), the refrigerator will work longer and the pauses will become shorter. This is normal, since it is more difficult for equipment to maintain low values in a warm room.
| Parameter | Normal | Critical value |
|---|---|---|
| Operating time | 10–20 min | More than 40 minutes without stopping |
| Rest time | 15–30 minutes | Less than 5 minutes |
| Inside temperature | +3...+5°C | Above +7°C or below 0°C |
| Condenser temperature | Hot (40-50°C) | Barely warm or scalding |
It is worth noting that in winter, when the apartment is cool, the cycles may change. The refrigerator requires less effort to maintain cold, so it can turn on less often.
Why may the refrigerator not turn off at all?
In some older models without the No Frost system and automatic defrosting, the compressor can work almost constantly if the thermostat is set to maximum and the room is hot. This is due to the design of the thermostat.
Differences between cooling systems
The time it takes to reach the mode and the nature of the operation directly depend on the type of defrosting system installed in your model. Today, two types dominate the market: the static system (drip) and No Frost.
In refrigerators with drip system cooling occurs through the back wall. Moisture condenses on it, freezes and periodically thaws. Such models, as a rule, reach the initial temperature faster when empty, since the evaporator is open directly into the chamber.
The system No Frost (or Full No Frost) is more complex. The evaporator is hidden, and the cold air is forced by a fan. The initial start-up may take longer, since the hidden heat exchanger must first cool down, and only then the fan will begin to drive cold through the chamber.
- ❄️ Static: it works quieter, the food dries less, but requires manual defrosting every six months.
- 🌬️ No Frost: does not require defrosting, faster restores the temperature after opening the door.
- ⚙️ Combined: No Frost in the freezer, drip system in the refrigerator compartment.
System owners No Frost should be prepared for the fact that the fan may work intermittently for the first couple of hours after switching on, creating a characteristic noise air.
Signs of malfunction during long-term operation
Although long-term operation in the first hours is the norm, there are symptoms indicating a breakdown. If the refrigerator hums for days, but does not cool, or a “coat” of ice forms inside while the motor is running, these are alarming signs.
One of the common reasons for endless operation is freon leak. The compressor is trying to build up pressure, humming continuously, but there is no cold. In such cases, the rear grille (condenser) often remains cold or barely warm.
Another problem is a loose fit of the door seal. If the gum becomes dry or dirty, warm air constantly enters the chamber. The temperature sensor detects the increase and prevents the compressor from going to rest.
⚠️ Attention: Be careful when touching the metal parts inside the operating refrigerator (if any) or the condenser grille at the back. They may be hot (up to 50-60°C), which is normal for a working unit.
It is also worth checking the thermostat. If its rod is stuck or the sensor is out of order, it can constantly send a “low cold” signal, causing the motor to work for wear.
☑️ Diagnosis of long operation
Recommendations for proper operation
To extend the life of the refrigerator and ensure its efficient operation, it is important to follow simple operating rules. They will help to avoid situations when equipment is working at its limit.
Do not load it into a refrigerator that has just been turned on. warm food. This will create a colossal heat load, force the compressor to work for hours without rest and can lead to overheating. Allow the food to cool to room temperature.
Defrost regularly (if the model is not No Frost). A layer of ice on the evaporator more than 5 mm thick acts as a heat insulator, interfering with cooling. As a result, the refrigerator will work longer, consuming more electricity.
Keep the condenser clean. Dust and pet hair that settle on the back or bottom of the black grille impair heat transfer. Cleaning with a vacuum cleaner once every six months is an excellent habit.
Why does the refrigerator turn on immediately after turning off?
Short cycles (works for 2 minutes, costs 2 minutes) are called "clocking". This is harmful to the compressor. Reasons: weak contact in the thermostat, freon leak or too high room temperature.
Is it normal that the side walls of the refrigerator are hot?
Yes, this is normal. In many modern models, the condenser (heat exchanger) is built into the side walls of the case. During active operation, they can heat up to 40-50 degrees.
Is it possible to turn on the refrigerator immediately after transportation?
If the refrigerator was transported lying down, you need to let it stand upright for at least 4-8 hours (preferably a day) so that the oil flows into the compressor. If you were transporting it while standing, 2-3 hours is enough.
How to check whether the refrigerator holds the temperature?
Put a regular thermometer in a glass of water inside. Leave for several hours. The water temperature should stabilize within +3...+5°C for the refrigerator compartment.
Does the amount of food affect the operating time?
A full refrigerator works more stable. Products accumulate cold and help maintain temperature when the door is opened. An empty refrigerator heats up faster and turns on more often.