Sudden silence in the kitchen when the usual hum of a working unit disappears, or, conversely, the complete inability to start the device after defrosting is always an alarming signal. Refrigerator motor, or compressor, is the heart of the entire refrigeration system, and stopping it almost always means the risk of food spoilage. Owners are often faced with a situation where the light inside the chamber is on, but the motor is silent, or only clicks are heard, after which the device goes silent again.
Before you panic and call a technician, it is necessary to conduct an initial diagnosis to understand the scale of the problem. Sometimes the reason lies in a banal power surge or tripped protection, and in other cases it is a serious breakdown compressor or a refrigerant leak. Understanding the principles of operation and typical symptoms allows you to save time and money, at least approximately estimating the cost of future repairs.
In this article we will analyze in detail the main reasons why the motor stops working, consider methods of self-checking and point out those situations when professional intervention is strictly necessary. Important to know: if the compressor has become hot temperature and does not start, repeated attempts to turn it on can permanently damage it.
Primary diagnostics: checking the power supply and thermostat
The most common reason why a refrigerator stops freezing is trivial - lack of electric current in the outlet or a broken power cord. Even if the light on the panel is on, this does not always mean that there is sufficient voltage being supplied to the motor. It is necessary to check the integrity of the cable, especially at the base of the plug, where kinks most often occur. You should also make sure that the plug fits tightly into the socket and try connecting another device to the network, for example, a hair dryer or lamp.
The second important element is thermostat (thermostat). It is he who gives the command to the engine to turn on when the temperature in the chamber rises above the set one. If the control knob is set to minimum (maximum cold) or, conversely, is turned to the “0” position (off), the motor will not start. In older models, mechanical thermostats can simply fail, breaking the compressor power circuit even when the chamber is warm.
- 🔌 Check for voltage in the outlet using an indicator screwdriver or by connecting another electrical appliance.
- ❄️ Make sure the handle The thermostat is not in the extreme left or right position, try turning it a few notches.
- 💡 Check whether the light inside the chamber is on when the door is open - this is a basic indicator of the current supply.
If everything is in order with the socket and the regulator knob, but the motor is silent, the problem may lie deeper. In models with electronic control (No Frost), temperature sensors often fail and send an incorrect signal to the control module. In this case, the “brains” of the refrigerator may “think” that it’s already cold enough inside and not start the cooling cycle.
Faults in the starting relay and protective device
One of the most common technical reasons why the engine does not start is failure starting relay. This small element is responsible for supplying a starting pulse to the motor windings. If the relay is stuck or burnt out, you may hear a distinctive clicking sound, followed by a buzzing sound that lasts a few seconds, followed by another clicking sound and silence. This triggers thermal protection.
A protective device (thermal relay) is installed to prevent overheating of the windings. If the engine tries to start, but cannot turn over due to problems with the starting mechanism, the current increases sharply, heats up the bimetallic protection plate, and it opens the circuit. After cooling (usually 15-30 minutes), the refrigerator tries to start again and the cycle repeats. This phenomenon is called "cyclic startup".
⚠️ Attention: If you hear a motor hum for 5-10 seconds, followed by a shutdown click, immediately unplug the refrigerator. Continuing such startup attempts can lead to an interturn short circuit and combustion of the compressor.
Diagnostics of the relay often requires opening it or replacing it with a known good one. Visually, traces of soot or melted plastic may be visible on a burnt relay. It is also worth checking the contacts: oxidation or burning of the terminals prevents the normal flow of current. In some cases, simply cleaning the contacts with fine sandpaper helps, but more often the unit needs to be replaced.
How to check the starting relay with a multimeter?
To check the relay, you need to ring its contacts. Under normal conditions, the resistance should be close to zero. If the meter shows infinity or very high resistance, the circuit is open and the relay must be replaced. Also check the relay coil - its resistance should correspond to the passport data (usually 30-60 Ohms).
Problems with the compressor: from jamming to combustion
The most unpleasant scenario is a malfunction of itself compressor. The motor may be electrically correct, but mechanically seized. The piston group inside the sealed casing may have worn out, or the liners may have rotated. In this case, the motor hums, but cannot start the pistons, which triggers the protection described above.
The other extreme is an interturn short circuit of the windings. If the engine burns out, it stops responding to the supply of voltage at all or knocks out the circuit breaker (plugs) in the apartment when you try to turn it on. You can check the integrity of the windings with a multimeter by measuring the resistance between the contacts on the compressor body (starting, operating windings and common contact). Resistance must be within certain limits (usually from 10 to 30 Ohms), and not high or zero.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Silence, no reaction | No current, thermostat burnt out, winding break | Check the socket, ring the circuit |
| Humming for 5-10 seconds, then clicking | Faulty start relay, jammed compressor | Replace the relay, check the compressor |
| Knocks out plugs in the apartment | Short circuit in the wiring or motor | Turn off urgently, call a technician |
| The motor is hot, but does not work | Thermal protection has tripped, freon leak | Allow to cool, look for leaks |
If diagnostics show that the compressor is mechanically faulty or burnt out, independent repairs at home are impossible. The unit needs to be replaced, which involves evacuation of the system, charging with refrigerant and sealing the pipes. This is work for a certified specialist with the appropriate equipment.
The influence of refrigerant leakage on engine operation
Many do not know that the lack of freon (refrigerant) in system directly affects engine performance. Modern refrigerator models are equipped with sensors that monitor pressure or temperature. If it occurs refrigerant leak due to a microcrack in the circuit or corrosion, the pressure in the system drops. The compressor, trying to pump up pressure, runs idle, overheats and is switched off by the protection.
In older models without sophisticated electronics, the motor can work almost constantly, trying to reach the set temperature, but not cooling the chamber. This leads to rapid wear and eventual combustion of the engine due to overload. Signs of a leak are often swelling of the back wall inside the refrigerator or the appearance of oily spots under the unit.
- 📉 The engine runs non-stop, but the temperature in the chambers does not drop below +10°C.
- 🔥 The compressor is very hot to the touch, sometimes it is painful to touch it.
- 💧 The appearance of puddles or oily traces under the refrigerator or on the floor next to it.
You cannot add freon “just like that.” First you need to find the leak, solder it and only then refill the system. If you simply add gas, it will leave again after a while, and the compressor will continue to operate in emergency mode.
⚠️ Warning: Refrigerants used in modern refrigerators can be flammable or toxic in high concentrations. Independent soldering of the circuit without pumping out the remaining gas is prohibited and dangerous to life.
Problems with the No Frost system and ventilation
In refrigerators with the system No Frost the engine may not start due to problems with defrosting. If the defrost heating element, defrost sensor or timer (control module) is faulty, the evaporator becomes overgrown with ice. The ice coat blocks the operation of the fan that blows on the evaporator. In some models, an overheating sensor for the fan or the evaporator itself blocks the start of the compressor to prevent an accident.
It is also worth paying attention to the fan (if your model has one, it is usually located at the bottom rear). If the fan is clogged with dust or jammed, heat transfer is disrupted. The compressor overheats because the freon does not cool in the condenser, and the thermal protection turns off the motor. Regular cleaning of the rear grille from dust and animal hair is a mandatory preventative procedure.
Checking the No Frost system requires partial disassembly of the refrigerator. It is necessary to remove the back panel in the freezer and visually assess the amount of ice. If there is a “sdrift” there and the sensors are intact, it is possible