Sudden failure of the refrigerator is always stressful, because it is under threat food supplies and the family budget appear. Before calling a technician or running to the store for new equipment, it is worth conducting an initial diagnosis. Do-it-yourself refrigerator repair it begins not with replacing parts, but with a competent check of the condition of key elements of the system. Often the problem lies in small things that can be fixed in 15 minutes without special tools.
Modern units, be it Indesit, Atlant or Liebherr, are designed on a similar principle, although the electronics may differ. To understand how to check a refrigerator for serious breakdowns, it is necessary to consistently exclude external factors and simple malfunctions. In 70% of cases, a “breakdown” turns out to be a consequence of improper operation or a power surge, and not a failure of the compressor.
This guide will help you systematize the process of finding a defect. We will look at how to ring the motor, check the thermostat and assess the condition of the start relay. Remember that safety comes first, so all electrical manipulations are carried out only with the device disconnected from the network.
⚠️ Attention: Before starting any diagnostics, be sure to disconnect the refrigerator from the power supply. Working with live current is deadly.
Primary visual diagnostics and power check
The first step is always to exclude trivial causes of lack of cold. If the refrigerator does not turn on, the indicators do not light up, and it is dark inside, the problem may be a lack of voltage at the outlet. Do not rush to disassemble the unit, check the presence of current in neighboring devices. It is also worth inspecting the power cord for kinks, melts or traces of rodents, which is especially important for equipment standing on the floor.
Pay attention to the lighting inside the camera. If the light is on, it means that electricity is flowing, and the problem lies deeper - in the control or cooling system. If there is no light, but the socket is working, the door switch may have failed or the internal wiring has broken. In some models Bosch i Siemens there are factory defects in the contacts at the point where the cable enters the housing.
Check the tightness of the door. If the seal (rubber band) is worn out or dirty, cold air will escape, causing the compressor to work without interruption. This is not a breakdown in the literal sense, but requires immediate attention. Wipe the seal with soapy water and check if there are any cracks or creases on it.
It is also important to evaluate the temperature in the room. If the refrigerator is located near the radiator or in direct sunlight, the cooling system may not be able to cope with the heat influx. Condenser (black grille at the back) should be freely washed by air. Collected grease and dust on the heat exchanger reduces the cooling efficiency by 20-30%.
Diagnostics of the thermostat and temperature sensors
One of the most common reasons why the refrigerator stops cooling or, conversely, turns food into ice, is a malfunction of the thermostat. In older models this is a mechanical device with a capillary tube, in new ones it is electronic sensors NTC. If the compressor is silent, although the chamber is warm, or works non-stop, “freezing” everything around, the suspect first falls on this unit.
To check the mechanical thermostat, it must be removed. It is usually located under a plastic cover inside the refrigerator compartment or behind the control panel. Carefully remove the terminals and connect them together directly (close the circuit). If the compressor starts after being plugged in, it means the thermostat is faulty and requires replacement. This is a simple operation, accessible even to a beginner.
Electronic sensors are checked with a multimeter in resistance measurement mode. As the temperature changes, the resistance should change. If the device shows an open or short circuit, the sensor is faulty. In two-chamber models Samsung or LG there may be several sensors: in the refrigerator compartment, in the freezer and a defrost sensor.
How to find a defrost sensor?
The defrost sensor is usually attached to the evaporator (radiator) inside the freezer cameras, often hidden by a plastic panel. It controls the temperature of the heater during defrosting.
When replacing a thermostat, it is important to choose an analogue with identical characteristics. The switch-on and switch-off temperatures may differ for different models. Installing the wrong part will lead to incorrect operation: either the food will spoil or the ice coat will freeze.
Checking the start relay and compressor
If, after checking the thermostat and power supply, the compressor does not start, but only hums or clicks quietly, the problem may be in the start relay. This is a small device placed on the motor contacts. It provides a starting impulse and turns off the starting winding. Often the coil inside the relay burns out or the contacts stick, which is easily diagnosed by visual inspection and “tapping” (if the internals ringing is heard, the part is disassembled).
The compressor is the heart of the refrigerator. You can check its windings using a multimeter. There are usually three terminals on the contact group: common, starting and working. The resistance between them must be within certain limits (usually from 10 to 30 Ohms for the working winding and slightly higher for the starting winding). If the device shows infinity (open) or zero (short), the motor has burned out.
It is also important to check whether the motor is piercing the housing. Press one probe of the multimeter to any contact, and the other to the copper tube or unpainted part of the case. The device should show infinity. If there is any resistance, operating such a refrigerator is dangerous to life.
| Symptom | Possible cause | Action |
|---|---|---|
| The compressor hums, but does not start | The motor is jammed or the relay is faulty | Replace the relay, if that fails, change the compressor |
| The refrigerator does not turn on at all | No power, the thermostat has burned out | Check the socket, close the thermostat contacts |
| The motor runs without stopping | Freon leakage, wear of the seal | Check the tightness, call a technician for refueling |
| A click is heard, then silence | Thermal relay activated protection | Let it cool, check the current consumption |
⚠️ Attention: If you find that the compressor windings are “ringing” to the housing, further diagnostics with your own hands is prohibited. Professional repair or replacement of the unit is required.
☑️ Motor diagnostics
Defection of the No Frost system and defrost heating element
In refrigerators with the system No Frost a frequent problem is the formation of an ice block on the evaporator, which blocks air circulation. As a result, the chambers are warm, although the compressor is running. The reason lies in a violation of the defrost cycle. The main suspects: defrost heating element, defrost sensor or timer (melter).
To check the heating element, you need to get to the evaporator. To do this, remove all shelves, back wall and air ducts in the freezer. The heating element is a curved tube or glass bulb at the bottom of the radiator. Test it with a multimeter: a working element shows a resistance in the range of 200-400 Ohms. Infinity means the filament has burned out.
The defrost sensor (defroster) is also checked for resistance. Its job is to turn off the heating when the ice melts, so as not to overheat the plastic and the fan. If it “lies”, the heating element may not turn on at all or work for too long. In models Indesit i Ariston it is this small component that often fails.
Don't forget to check the drainage system. If the water drain tube is clogged with debris or ice, water will accumulate at the bottom of the chamber or drain onto the floor. You can clean it with warm water using a syringe or a soft rubber bulb.
Searching for refrigerant leaks and checking the filter drier
If the compressor runs continuously, the condenser (grid at the back) is only partially cold or warm, and there is no cold anywhere, most likely there is a freon leak. The refrigerant is the working fluid, without which heat exchange is impossible. It is difficult to find the leak on your own, but you can pay attention to the characteristic signs.
Carefully inspect the soldering areas of the tubes, especially in the lower part of the refrigerator, where moisture often accumulates. Corrosion can eat through metal. Leaks also occur in the foamed part of the housing (evaporator), which is the most difficult case to repair. This can be visually noticed by swelling of the inner wall of the chamber or the appearance of yellow oily spots.
The filter drier (copper cylinder at the compressor) is designed to remove moisture from the system. If it is clogged, the circulation of freon is disrupted. You can check this by touch: after prolonged operation, the filter should be warm, but not hot. If it is covered with frost or, conversely, an ice crust, but there is no cold, the filter is clogged.
Replacing the filter and finding leaks requires special equipment: a vacuum pump, a pressure gauge station and supplies of freon. Refilling the refrigerator doing it yourself is only possible if you have this expensive tool and the skills to work with it. An attempt to simply “add gas” without evacuation of the system will lead to rapid failure of the compressor.
⚠️ Attention: Freon can be dangerous when in contact with an open flame (it forms toxic phosgene). Do not use open fire to search for leaks.
Analysis of noise and vibration during operation
A refrigerator is not a silent technique, but the nature of the sound can say a lot about its health. The uniform hum of the compressor and the quiet noise of flowing freon are the norm. However, the appearance of grinding, knocking or whistling signals problems.
Loud knocking or vibration is often caused by improper installation. Check the adjustable feet: the refrigerator should be stable and not wobble. If it is crooked, the compressor will hit the housing or tubes when starting. Also, the source of noise may be the fan in the system No Frostif ice is frozen on its blades or hair is wound around it.
A sharp whistle or hiss may indicate a freon leak or the compressor is operating in emergency mode. If you hear gurgling immediately after turning off the engine, this is normal; freon flows in a calm state. But if the gurgling is accompanied by a lack of cold, this is a bad sign.
Why does the refrigerator shake?
A common cause of strong vibration is condenser tubes touching each other or the body. Gently push them apart with your hand (with the device turned off!) to eliminate contact.
Regular maintenance and proper installation prolong the life of the equipment. Do not ignore changes in the sound background of your unit, because timely diagnostics will help you avoid expensive major repairs.
Is it possible to replace the compressor on a refrigerator yourself?
Theoretically, yes, if you have the skills to solder copper pipes, a vacuum pump and pressure gauges. However, this is a complex process that requires precise calculation of the amount of freon. An error will lead to the breakdown of the new compressor.
Why does the refrigerator click but does not turn on?
Most often this is a sign of a malfunction of the start relay or the compressor itself (interturn short circuit). The relay tries to start the motor, the current increases, the protection is triggered and a click is heard. The relay or motor needs to be replaced.
How often do you need to defrost a No Frost refrigerator?
The No Frost system does not require regular defrosting to remove ice, as this happens automatically. However, once every 6-12 months it is recommended to turn off the appliance for washing and drying to remove bacteria and check drainage.
Is it dangerous to use an old refrigerator with a damaged wire?
It is absolutely dangerous. Damaged insulation may result in a short circuit or electric shock when touching the housing. The damaged area needs to be replaced entirely or use high-quality twisting with insulation, but it is better to replace the cable completely.