The situation when refrigerator buzzes without interruption is familiar to many owners of household appliances. Instead of the usual cycle of work and rest, the unit tries to maintain the temperature in the chambers around the clock, which leads to increased energy consumption and accelerated wear of components.
Often users notice a problem only when a “coat” of ice forms on the walls of the chambers, and food begins to deteriorate or, conversely, freeze. Understanding the reasons why compressor does not receive a stop signal is the first step to troubleshooting and preserving the contents of the freezer.
In this article we will analyze in detail the technical aspects of the operation of the cooling system, consider typical breakdowns and explain how to independently carry out initial diagnostics before calling master.
You should not ignore the continuous operation of the motor, as this may indicate critical violations in the tightness of the circuit or the electrical control circuit.
How the on and off cycle works
The normal operating mode of a modern refrigerator involves cyclicity. The compressor builds up pressure, the refrigerant circulates through the system, cooling the chambers, after which the motor turns off to rest. The duration of the cycle depends on many factors, including the temperature in the room and the load on the shelves.
The control process is thermostat or an electronic module. It is these components that read the sensor readings and decide whether the electrical circuit is broken or closed. If the refrigerator stops turning off, it means that the signal to stop is simply not received.
It is important to understand the difference between normal operation in extreme conditions and breakdown. In the summer, when the apartment is hot, the appliances can work longer, but pauses should still be present.
⚠️ Attention: If your refrigerator works without stopping for more than 24 hours, this is guaranteed to indicate a malfunction. Long-term operation without interruption can lead to overheating of the motor windings and thermal breakdown.
Modern models with the system No Frost have more complex algorithms, including periods of operation of the evaporation fan and defrost heaters. A failure in any of these elements can throw off the logic of the controller.
External factors: when the equipment is working properly
Before disassembling the unit or calling a technician, it is necessary to exclude external causes. Often the problem lies not in the breakdown of parts, but in incorrect operating conditions or the actions of the user himself.
The first thing you need to pay attention to is the ambient temperature. If the refrigerator is installed near the radiator, in direct sunlight or in a niche with poor ventilation, heat exchange is disrupted. The motor is forced to wear out to compensate for the constant flow of heat.
It is also worth checking the tightness of the fit doors. If the rubber seal is worn out, dirty, or the door is warped, warm air constantly enters the chamber. The temperature sensor detects the heating and commands the compressor not to stop.
The loading of the chambers also plays a role. If you place a large amount of warm food in the freezer or completely fill an empty refrigerator at room temperature, the unit will work in enhanced mode until the set parameters are reached.
Faults of the thermostat and sensors
One of the most common reasons for continuous operation is failure thermostat. In mechanical models, this device is a capillary tube filled with gas that responds to changes in temperature. If the tube has lost its tightness or is deformed, the contacts inside the thermostat stick in the “on” position.
In models with electronic control, sensors (thermistors) are responsible for control. If they malfunction, the main module receives incorrect data about the temperature in the chambers. For example, a sensor may “report” that the freezer is +10°C, although in fact it is -18°C.
- 🔧 Sticking contacts in a mechanical thermostat prevents the circuit from opening.
- ❄️ Displacement of the capillary tube of the sensor leads to incorrect readings.
- ⚡ Oxidation of contacts in the temperature sensor control circuit.
Diagnostics of a thermostat often requires dismantling it and checking it with a multimeter in different temperature conditions. In electronic systems, it is necessary to check the resistance of thermistors.
Symptoms of a malfunctioning thermostat
The refrigerator does not turn off even with minimal settings, or, conversely, does not turn on at all. In some cases, the unit may operate jerkily.
Refrigerant leak and problems with the compressor
If the refrigerator hums, but does not cool (or cools very little) and does not turn off, there is a high probability freon leaks. The pressure in the system has dropped, there is not enough refrigerant to create the required cold, so the sensors constantly require the compressor to work.
It is difficult to find the leak location on your own, since the gas is odorless and colorless. Often microcracks form in soldering areas or in the evaporator hidden under a plastic panel. An attempt to simply “refuel” the refrigerator without finding and eliminating the leak will only give a temporary effect.
Another serious problem is a decrease in the performance of itself compressor. Wear of the valves or piston group leads to the fact that the motor cannot gain the required pressure. It works constantly, trying to compensate for its weakness, but the temperature in the chambers does not drop to the required level.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Refrigerator hums, no cold | Freon leak | Looking for leaks, soldering, refilling |
| Motor is hot, buzzes loudly | Compressor wear | Replacement compressor |
| Works intermittently or constantly | Thermostat malfunction | Replacing the thermostat |
| A click is heard, no start | Start relay | Replacing the relay |
It is important to note that operating equipment with a leak or a faulty compressor can lead to complete burnout of the engine.
Problems with tightness and thermal insulation
Failure of the tightness of the circuit is not only about freon, but also about heat. If a “coat” of ice has formed in the chamber, this may block the temperature sensor or simply interfere with normal air circulation.
Particular attention should be paid to the system No Frost. If the water drainage channels are clogged or the defrost heater is out of order, the evaporator becomes covered with ice. The fan stops moving air, the sensor does not sense the cold, and the compressor runs without stopping.
⚠️ Attention: Do not try to break off the ice with a knife or sharp objects! This can lead to breakdown of the evaporator and immediate leakage of freon, which will require expensive repairs.
It is also worth checking the integrity of the heat-insulating layer of the housing. If the refrigerator is old, the insulation could move away from the walls or become saturated with moisture, which sharply reduced its efficiency.
☑️ Diagnostics of the No Frost system
Electronic control module
In modern models, the “brain” is electronic control board. If the triac that controls the compressor burns out, or a software failure occurs, the equipment may behave inappropriately.
Often the problem is solved by rebooting the module (disconnecting from the network for 15-20 minutes). However, if the failure is caused by physical damage to the elements on the board (swollen capacitors, burnt tracks), professional repair or replacement of the unit will be required.
Power surges in the network are the main enemy of electronics. If the refrigerator starts to malfunction after a thunderstorm or welders working in the house, the reason is almost certainly in the control module.
Specifics of operation in winter
If the refrigerator is installed on an unheated loggia or garage, problems may arise in winter. Mineral oils in the compressor thicken, which makes it difficult to start and operate the mechanism.
In addition, at low temperatures, the operation of the thermostat is disrupted, which may incorrectly read the indicators. In such conditions, equipment can operate in emergency mode.
Manufacturers usually indicate the climate class of equipment. Operation outside the recommended temperature range voids the warranty and shortens the service life.
FAQ: Frequently asked questions
How long should a refrigerator normally operate?
Under normal conditions, the refrigerator operates approximately 30-40% of the total time (about 8-10 hours a day). However, in summer or if the door is opened frequently, this time may increase. The main thing is the presence of pauses.
Is it possible to use the refrigerator if it does not turn off?
For a short time, it is possible, but this is a risk. Constant operation leads to overheating of the compressor. If you notice a problem, try to open the door less and call a technician for diagnostics.
Why does the new refrigerator work without interruption?
When turned on for the first time, the new unit takes time (up to 24 hours) to cool the entire volume of the chambers and stabilize the temperature. If after a day of operation it does not turn off, this is a reason to contact the service.
Does the amount of food affect the operating time?
Yes, a full refrigerator keeps the cold longer, but it also takes longer to cool initially. An empty refrigerator gains temperature faster when the door is opened, causing the motor to turn on more often.
What to do if the refrigerator hums, but does not freeze?
Most likely, there is a refrigerant leak or a clogged capillary line. It is impossible to fix this problem on your own; you need to call a specialist with equipment for vacuuming and refilling.