The situation when the refrigerator works without interruptionis familiar to many owners of household appliances. Instead of the usual hum followed by silence, the compressor hums continuously, trying to reach the set temperature. This is not just an irritating noise that interferes with sleep, but also a direct signal that there is a failure in the cooling system.
Continuous operation of the motor-compressor leads to a critical overheating of components and sharp increase in electricity bills. If you ignore this symptom, the resource of an expensive unit will be exhausted in a matter of weeks, not years. In some cases, the equipment may simply stop cooling, and the food will spoil.
In this article we will analyze in detail the main causes of the malfunction, from simple operating errors to complex breakdowns. You will learn how to independently carry out initial diagnostics and understand whether call a technician the problem can be solved with your own hands. It is important to act quickly before the compressor burns out completely.
⚠️ Attention: if you smell burning or see sparking in the compressor area, immediately unplug the device. Further operation is dangerous due to fire.
The influence of external factors on the operating mode
Before you panic and look for a breakdown, it is worth excluding trivial causes. Often the refrigerator does not turn off due to the fact that the operating conditions have changed. The most common situation is an increase in room temperature. If in the summer the room is hotter than +30°C, it is physically more difficult for the equipment to remove heat.
The location of the unit also affects. If it stands close to the wall or next to a hot battery, heat exchange is disrupted. The condenser (black grille at the back) does not have time to cool down, and the sensors command the compressor to continue working. Simply moving the refrigerator to a cooler place or moving it away from the wall can solve the problem.
Another factor is the dense loading of warm products. If you just returned from the store and put a pot of soup or many bags of food inside at room temperature, refrigerator it will work in enhanced mode for several hours. This is a normal situation, and after the food has cooled, the cycle returns to normal.
Malfunctions of the defrost system
In modern models with a system No Frost or Full No Frost the condition of the defrost system is critically important. If the evaporator becomes overgrown with a thick “coat” of ice, the cold stops flowing into the chamber, although the evaporator itself may be icy. The sensors see high temperature in the chamber and do not allow the compressor to stop.
Most often the timer or defrost sensor fails. In this case, the ice does not melt, but grows with each cycle. Visually this may not be noticeable, since the evaporator is hidden behind a plastic panel on the back wall of the freezer. Remove the panel and check for ice. Defrosting heating element, timer or defrost sensor. In this case, the ice does not melt, but grows with each cycle. Visually this may not be noticeable, since the evaporator is hidden behind a plastic panel on the back wall of the freezer. Remove the panel and check for ice.
If you find an ice monolith, try defrosting the refrigerator completely (for 12-24 hours with the doors open). If after switching on the problem returns after 1-2 weeks, then a defrosting system is required. You can change the heating element yourself if you have the skills to work with a multimeter and a screwdriver. replacing parts defrost systems. You can change the heating element yourself if you have the skills to work with a multimeter and a screwdriver.
How to check the defrosting heating element?
To check the heating element, you need to “ring” it with a multimeter in resistance measurement mode. If the device shows a break (one or infinity), the heating element has burned out and requires replacement. Normal resistance is usually from 200 to 600 Ohms.
Problems with sealing rubber
One of the most common reasons why the refrigerator hums incessantly is a loose door fit. Warm air enters through the cracks in the seal. The moisture from this air condenses and freezes, and the compressor tries to cool the incoming heat.
It is easy to check the seal: clamp a sheet of paper between the door and the body around the entire perimeter. If the paper pulls out too easily or falls out on its own, it means the seal is broken. The rubber could dry out, become dirty or deform over time.
In some cases, simply washing the seal with warm water and soap helps to remove grease and sticky residue. If the rubber has lost its elasticity, you can try heating it with a hairdryer or boiling water to straighten it. However, if there are cracks or tears, you will need replacement of the seal.
- 🧼 Wash the rubber thoroughly with soapy water, removing all dirt from the folds.
- 🔥 Gently warm the deformed areas with a hairdryer (do not overheat!).
- 🚪 Check the door hinges: it may be skewed and does not fit.
- 🔄 If the rubber is hard and brittle, order a new part according to the refrigerator model.
Malfunctions of the thermostat
Thermostat (or electronic temperature sensor) - This is the "brain" that commands the compressor to turn on and off. If this element is faulty, it can send the wrong signal that the chamber is warm, even if it is already freezing there. As a result, the motor runs without stopping.
In mechanical models, the thermostat is a capillary tube with a bellows. Over time, the gas inside may evaporate, or the contacts may become stuck in the "on" position. In electronic models (inverter), the sensor itself or the control board often fails.
Diagnostics of a mechanical thermostat is possible at home. You need to remove it, immerse the sensitive tube in ice water and ring the contacts. If there is no click or change in resistance, the part needs to be replaced. For electronic models, it is better to use service mode or call a specialist.
Refrigerant leak and operation compressor
The most unpleasant situation is freon leak. If there is little refrigerant in the circuit, the refrigerator physically cannot reach the desired temperature. The compressor works hard 24 hours a day, trying to compensate for the lack of cooling capacity, but to no avail.
A sign of a leak is often a hot condenser (grid at the back) only partially or, conversely, cold, even though the motor is hot. There may also be swelling of the inner wall of the refrigerator compartment (in the foamed part). In such cases, it is required search for leaksevacuating and refilling the system.
It is difficult to fix a leak and refill the refrigerator yourself: you need special tools, scales and skills in soldering copper pipes. In addition, improper priming can permanently kill the compressor. If you suspect a leak, it is better not to experiment.
⚠️ Attention: The use of flammable refrigerants (R600a), which are used in most modern refrigerators, requires compliance with safety precautions. A spark during soldering can lead to an explosion.
Diagnostics of inverter and conventional compressors
The behavior of different types of motors is different. Normal compressor works in cycles: turned on at full power, turned off. If it does not turn off, this is an obvious malfunction. An inverter motor, on the contrary, can operate constantly, but at low speeds, maintaining the temperature. This is normal.
However, if the inverter refrigerator hums louder than usual and does not reduce speed, it may be faulty inverter module or the compressor itself is losing efficiency. Diagnostics of such systems requires connecting to the service connector and reading error codes.
To understand the difference and symptoms, read the table below. It will help you navigate the nature of the operation of your equipment.
| Compressor type | Normal mode | Symptom of malfunction | Nature of noise |
|---|---|---|---|
| Normal (Linear) | Working 10-20 minutes, rests 30-40 minutes | Works non-stop, freezes slightly | Uniform hum, clicks at start |
| Inverter | Works constantly, changing power | Works at maximum, without slowing down | Quiet humming, howling when accelerating |
| Linear inverter | Smooth piston movement, rare starts | Frequent attempts to start or a constant hum | Characteristic clicking sound of the piston |
☑️ Diagnostics before calling a technician
Frequently asked questions and answers (FAQ)
How long should the refrigerator operate after the first turn on?
When turned on for the first time or after a long defrost refrigerator it can gain temperature for up to 2-3 hours. At this time, you should not load it with products. If after 3-4 hours the motor does not turn off (for conventional models) or does not go into quiet mode, this is a cause for concern.
Can the refrigerator not turn off due to the heat outside?
Yes, if the refrigerator is on an unheated veranda or balcony. At temperatures below +10°C or above +35°C climate class the equipment may be disrupted. The oil in the compressor thickens in the cold or thins out in the heat, which leads to improper operation.
Is it dangerous if the compressor is very hot?
The compressor heats up to 60-90°C during operation, this is normal. But if it is impossible to touch it with your hand, or it smells like burnt insulation - dangerous. Turn off the device immediately. Overheating is often caused by contamination of the condenser at the back or a breakdown of the blower fan.
Why, after defrosting, did the refrigerator start working again without stopping?
If you defrosted the refrigerator due to ice, but did not eliminate the cause of its appearance (faulty heating element, timer, sensor), ice will start grow again. The system No Frost will stop coping, and in a few days the situation will repeat. Diagnostics of the defrost system is required.
Is it necessary to change the compressor if it works constantly?
Not always. Constant work is a symptom, not a diagnosis. Freon leakage, a clogged capillary or an electronic malfunction are often to blame. Replacement of the compressor is required only in case of mechanical jamming or interturn short circuit of the windingswhich is confirmed by the technician after inspection.