The situation when the refrigerator Posis works without interruption is familiar to many owners of this equipment. It seems like the unit is just doing its job diligently, but in fact this is the first signal of a serious failure in the cooling system. If the compressor hums for days on end, and the temperature inside the chamber does not drop to the set values, it means that the thermal balance is disturbed.
This symptom cannot be ignored, since constant operation the engine leads to rapid overheating of the windings and melting of the insulation. At best, you risk replacing an expensive motor, at worst, a wiring fire. It is necessary to immediately figure out why the refrigerator compartment stopped reaching the target temperature and turned off.
In this article we will analyze in detail the mechanical and electrical causes of failure, characteristic specifically for the Russian brand Pozis. You will learn how to carry out initial diagnostics yourself and in what cases calling a specialist becomes inevitable.
Features of operation of Pozis refrigerators and signs of malfunction
Refrigerators Posis, produced at the Zelenodolsk plant, are traditionally distinguished by their reliable design and maintainability. However, even time-tested models are subject to wear and tear. The normal compressor operating cycle involves periodic switching on and off, depending on the settings of the thermostat and the load of the chambers. When the unit does not turn off, this means that the temperature sensor “does not see” the cold or the system cannot accumulate it.
You can visually determine the problem by several signs. First, pay attention to the back wall: if the radiator grille is hot, but the inside is warm, then coolant is circulating, but not cooling. Secondly, listen to the sound of the motor: a strained hum or clicking sound indicates an overload.
⚠️ Attention: If you smell burning or see sparking in the area of the start relay, immediately disconnect the device from the power supply. Further operation in this condition is prohibited.
Modern models with the system No Frost may behave differently than classic “drip” systems. In them, continuous operation of the compressor is often associated with a failure of the defrost system, which we will discuss in the following sections. It is important to distinguish between the “fast freezing” mode, which is activated by a button, and the emergency operating mode.
Mechanical damage and refrigerant leak
The most common reason why Pozis refrigerator does not turn off is a freon leak. The refrigerant circulates in a closed circuit, and if the seal is broken, the pressure drops. The compressor tries to compensate for the lack of gas, working for wear, but cannot create the necessary cold.
A leak can occur anywhere in the circuit: in the evaporator, foamed into the wall, or in accessible copper tubes. Often the cause is metal corrosion or mechanical damage when defrosting with a sharp object. In models Pozis with a foamed evaporator, this is especially critical, as it requires complex repairs.
It is difficult to diagnose a leak on your own, but you can pay attention to indirect signs:
- 📉 The temperature inside the chambers is higher than the set temperature, food begins to deteriorate.
- 🔊 The compressor works continuously, but to the touch it may not be hot, but warm or even cold.
- 💧 Oily spots may appear in the area of the compressor or on the floor (oil comes out along with the gas).
- ❄️ In the freezer, a “fur coat” freezes in only one corner or freezing is completely absent.
If suspicion falls on a leak, refilling yourself with freon without finding and eliminating the leak will not give a long-term effect. The gas will go away again in a few days or weeks.
Why can’t you ignore running “idle”?
Operating a compressor without a sufficient amount of refrigerant leads to overheating. The oil, which should circulate along with freon for lubrication, stagnates. This causes the piston group to jam and the motor to fail in a matter of hours.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” of the refrigerator, which gives the command to turn the engine on and off. If this unit fails, the contacts may “stick” in the closed state. As a result, the compressor receives current constantly and does not stop, even if there is already “Antarctica” inside. Pozis refrigerator This unit has failed, the contacts may “stick” in the closed state. As a result, the compressor receives current constantly and does not stop, even if it is already “Antarctica” inside.
In models with electronic control, the role of a thermostat is performed by air sensors. Their readings may be distorted due to oxidation of contacts, broken wiring, or software failure of the controller. Often the problem lies not in the sensor itself, but in the place of its attachment: if it does not fit tightly to the wall of the evaporator, it reads the temperature of the air, not the cooling element.
For mechanical thermostats, the following check algorithm is typical:
- Remove the adjustment knob and get to the thermostat housing.
- Disconnect the contacts and close them directly (observing safety precautions).
- If the refrigerator turns on, the circuit is intact, the problem is in the regulator itself.
However, if when the contacts are closed, the engine does not start, then the problem is deeper - in the starting relay or the motor itself. Replacing a thermostat is a procedure accessible to a home craftsman, but requires care when installing the capillary tube.
Problems with the defrost system in No Frost models
If your Posis is equipped with a system No Frostthen continuous operation of the compressor often associated with freezing of the evaporator. Normally, once every 8-12 hours the heating element turns on and thaws the ice. If this process is disrupted, the ice blocks air circulation, and the temperature sensor does not detect cooling.
Three main elements are involved in the defrost chain: a heating element, a defrost sensor and a timer (or electronic module). Failure of any of them leads to a “snow plenum” inside the housing. Air stops flowing into the chambers, the refrigerator hums, trying to cool the volume, but to no avail.
Main symptoms of defrosting malfunction:
- 🧊 A thick layer of ice is visible on the back wall of the freezer (disassembly required).
- 💨 There is no cold air coming out of the vents.
- 🔌 The compressor is hot and runs non-stop.
Diagnostics often require complete defrosting of the unit within 24 hours. If after this the refrigerator started working in normal mode, but after a couple of days the problem returned, it means that one of the elements of the defrosting system is faulty and requires replacement.
☑️ Diagnostics of the No Frost system
Wear of the seal rubber and leakage
It would seem like a simple rubber band on the door, but it is precisely this that ensures the tightness of the chamber. If seal it does not fit tightly, warm air from the room constantly enters the chamber. The temperature sensor detects the heating and commands the compressor to work harder.
Over time, rubber Pozis loses elasticity, cracks or deforms. Also, the cause of a loose fit may be a misalignment of the door due to loose hinges or too much loading of the shelves on the door. You can check the tightness with a simple test with a sheet of paper: hold the sheet with a door and try to pull it out. If it is pulled out without resistance, the seal requires replacement or adjustment.
What to do if the rubber is intact, but the cold passes:
| Problem | Symptom | Solution |
|---|---|---|
| Contamination | The rubber is sticky, there are gaps | Wash with soapy water |
| Deformation | Waves, dents on the rubber | Warm with a hairdryer and straighten |
| Door distortion | Uneven gap around the perimeter | Hinge adjustment |
| Wear | Cracks, lack of magnetic property | Replacing the seal |
Sometimes it is enough to simply align the door by tightening the screws on the hinges to eliminate air leaks. In the cold season, the rubber can “stiffen”, and it needs time to restore its shape after opening the door.
Malfunctions of the starting relay and compressor
The most expensive and difficult option is wear of the compressoritself. If the motor has exhausted its service life, its performance drops. It may hum, creating the appearance of work, but not develop enough pressure to circulate freon. In this mode, the refrigerator does not turn off, trying to reach the set temperature.
Often the culprit is the start relay. This device starts the engine. If the relay contacts are burnt or the mechanism is jammed, the compressor may either not start or operate in emergency mode, constantly turning on and off (or not turning off at all if the contacts are stuck).
⚠️ Attention: Checking the compressor requires special tools (pressure gauges, testers). If you do not have experience working with live electrical equipment, entrust this work to a professional.
Signs of a dying compressor:
- 🔨 Knocking or clanging noise when starting.
- 🔥 Excessive heating of the motor housing (impossible to touch hand).
- ⚡ Frequent clicks of the relay (attempt to start).
In some cases, replacing the starting relay with a similar one helps. If the problem is in the mechanical part of the engine (scuffing in the cylinder, broken valves), the entire unit will need to be replaced. For refrigerators Posis this is often economically feasible, since new motors are more reliable than restored ones.
External factors and operating conditions
The reason is not always a breakdown. Sometimes Pozis refrigerator does not turn off due to improper operating conditions. For example, if the device is installed close to the wall, the ventilation of the condenser is disrupted. The motor overheats and works less efficiently, which causes the cooling cycle to be delayed.
The room temperature also affects. If the refrigerator is in the kitchen, where in the summer it is +30°C, or near the radiator, it has to work in increased mode. In such conditions, continuous operation may be an attempt by the system to cope with external thermal load.
Another factor is the load of the chambers. If you put a large amount of room temperature food in a warm refrigerator, it will take a long time to cool this volume. It is normal if after a few hours it turns off.
The influence of the thermostat position
Do not set the thermostat knob to maximum (usually number 5 or 6) unless necessary. This forces the compressor to work almost non-stop, which shortens its service life.
Frequently asked questions (FAQ)
Is it possible to leave the Pozis refrigerator on, if it does not turn off, overnight?
It is strictly not recommended. Long-term operation without stopping will lead to overheating of the wiring and melting of parts. This is a fire hazard. It is better to temporarily turn off the device, defrost it and call a technician.
How long should the Pozis refrigerator compressor normally work?
In normal mode, the operating coefficient is about 30-40%. That is, out of one hour the compressor works for 20-25 minutes and rests for 35-40 minutes. If it works for 40 minutes or more without a break, this is a cause for alarm.
Why does the refrigerator not turn off after defrosting?
If you have just defrosted the unit and turned it on, it can work for a long time (up to 2-3 hours), cooling the empty volume. If it does not turn off for more than 5-6 hours, perhaps the evaporator was damaged during defrosting or the seal was broken.
Where can I find the electrical circuit for the Pozis refrigerator?
The circuits are usually located on the back wall of the device or in the operating instructions. They can also be found on the manufacturer’s official website according to the model indicated on the nameplate.