Sudden silence of the refrigerator or, conversely, its characteristic hum followed by a click and stop are classic signs of a faulty start relay. It is this small but critical element that is responsible for starting the compressor engine, without which circulation of the refrigerant and, as a result, cooling of the products is impossible. If you notice that the motor is trying to start, makes a dull sound, but stops a second later, most likely the problem lies in this particular unit, and replacing it is often the only way out.
The process of restoring the unit's functionality does not require deep knowledge in electronics, but it will require you to be attentive, careful and follow basic safety rules when working with electrical appliances. Replacement start relay is one of the most common repair operations faced by owners of household appliances, and with the right approach it takes no more than 20-30 minutes. It is important to understand that ignoring the problem can lead to more serious consequences, including overheating and failure of the compressor itself, the cost of replacing which is disproportionately higher.
Before taking active steps, you need to make sure that the diagnosis is correct and prepare the workplace. Don't panic if you are not a professional craftsman, since the design of most modern refrigerators, be it Indesit, Atlant or Beko, implies the ability to independently service the main components. The main thing is to strictly follow the algorithm of actions and not to make excessive physical efforts where delicacy is required.
Fault diagnosis and signs of breakdown
The first step in any repair is the accurate identification of the problem, since the symptoms of a non-working relay are often confused with a breakdown of the compressor or thermostat itself. The main sign that starting device has failed is the cyclic turning on and off of the motor: you hear a click, the motor hums for a few seconds, then a second click is heard, and there is silence. This cycle can be repeated endlessly until you disconnect the device from the power supply, which is a protective reaction of the thermal relay built into the system.
Visual inspection often helps confirm guesses without the use of complex measuring equipment. If you remove the casing and remove the relay, you will notice traces of soot, melted plastic on its body, or even smell an unpleasant burning smell, which clearly indicates overload and breakdown. In some cases, if you shake the relay next to your ear, you can hear a knocking sound from the internal parts, which indicates mechanical destruction of the contacts or core inside the housing.
⚠️ Attention: If after replacing the relay the situation has not changed and the compressor still hums, but does not start, the piston mechanism of the motor itself may be jammed, and then more complex repairs or replacement will be required unit.
For more accurate diagnostics, professionals use a multimeter to check the resistance of the windings and the integrity of the contacts. However, even without the device, preliminary conclusions can be drawn: if the relay is cold and does not make sounds when trying to start, there may be a problem in the electrical circuit, and if it gets very hot and smells, that is where the problem lies. It is also important to check the condition of the contacts on the compressor itself, since oxidation can prevent the normal flow of current.
Preparation of tools and selection of a new relay
The success of the operation directly depends on proper preparation and the availability of the necessary tools at hand. You don't need a complex professional kit; a basic DIY kit is enough, including a flathead and Phillips screwdriver, pliers and, preferably, a multimeter for testing. It is also a good idea to have a rag on hand to clean the contacts and perhaps WD-40 or a similar product if the terminals are heavily oxidized and require cleaning.
Choosing the correct replacement is critical, as start relays come in different types and variations depending on the power and type of compressor. There are positor relays that operate by changing the resistance of the heating element, and induction (electromagnetic), the principle of operation of which is based on the magnetic field of the coil. By mixing up the types or selecting a device with the wrong operating current, you risk not starting the motor or burning out a new part in the first seconds.
In order not to make a mistake with the choice, it is best to remove the old relay and select an analogue according to the markings indicated on its body. Pay attention to parameters such as the number of contacts (two or three), the orientation of the compressor rod (vertical or horizontal) and the permissible current range. If the original part cannot be found, you can use universal analogues, but in this case you must strictly follow the connection diagram, which is often printed on the packaging or accessories of the new part.
Is it possible to use a relay from another refrigerator model?
Yes, you can if the electrical parameters and type of fastening match. The key is the matching of the cutoff current and the number of contacts. However, it is better to look for an original or a proven analogue, since universal solutions sometimes require modification of the case or contacts.
When buying a new part, pay attention to the quality of the plastic and assembly: cheap Chinese analogues may not have markings or have play in the contact group, which is unacceptable. Reliable contactor should sit tightly on the compressor terminals and not dangle due to vibration. It is also worth checking the condition of the thermal protection if it is built into the relay housing, since its malfunction can also block the start.
Removing the old starting relay
The process of removing a faulty part begins with ensuring complete safety, so the first step is to disconnect the refrigerator from the electrical network. Unplug the power cord and move the unit away from the wall to allow easy access to the rear where the compressor is located. Let the equipment stand for 10-15 minutes so that the residual voltage in the circuits dissipates and the compressor cools down, as it can be very hot.
Next, you should carefully remove the protective casing, which is usually secured with latches or bolts. In some models, for example, in old refrigerators Zil or Minsk, the casing may be secured with a clamp that needs to be loosened. After removing the cover, you will see a black cylindrical or box-shaped compressor, to the bottom or side of which the required relay is attached.
☑️ Stages of dismantling the relay
The dismantling process itself requires care, since the plastic housings of old relays often become fragile with time and temperature. First you need to remove the retaining bracket or frame that holds the relay to the compressor terminals. Then carefully disconnect the wires that go to the relay, having previously noted or photographed their location, since a mixed-up contact can lead to a short circuit.
⚠️ Attention: Never pull on the wires to disconnect them, hold only the plastic ones terminal tips, otherwise you may break the wire inside the insulation, which will create problems during assembly.
After disconnecting the wires, the relay is usually simply removed from the compressor rod with a slight rocking movement. If it is sticky or stuck, do not use force; it is better to carefully pry it off with a flat-head screwdriver in several places. Inspect the compressor terminals: if there is scale or dirt on them, they must be cleaned with fine sandpaper before installing a new part.
Connection diagram and installation of a new device
Installation of a new starting relay is carried out in the reverse order of dismantling, but with mandatory verification of compliance with the markings and orientation. Carefully study the diagram printed on the body of the new relay or in the instructions for it, and compare it with the arrangement of contacts on the compressor. Typically, the terminals are marked with the letters S (Start - starting winding), R (Run - working winding) and C (Common - common), and they cannot be confused.
The installation process begins with putting the relay on the compressor rod: it should snap into place with a characteristic click and sit tightly, without distortions. After this, the wires are connected to the appropriate terminals, it is important that the connection is tight and reliable. If the terminals are loose, they can be carefully tightened with pliers, but without fanaticism, so as not to damage the plastic.
In some cases, especially when installing universal relays, it may be necessary to resolder the wires or use adapters. If you are not confident in your soldering skills, it is better to contact a specialist, as poor contact will lead to heating and possible fire. Properly installed trigger mechanism should not dangle, and the wires should not touch hot parts of the compressor or sharp edges of the case.
| Terminal marking | Purpose | Wire color (often) | Check with a multimeter |
|---|---|---|---|
C (Common) |
General conclusion | White / Red | Rings with both others |
S (Start) |
Starter winding | Black / Blue | Resistance is higher than that of the working winding |
R (Run) |
Working winding | Green / Yellow | Resistance is lower than that of starting |
| Grounding | Case protection | Yellow-green | Must ring on the case |
Checking functionality after replacement
After installing the new part and assembling all the protective covers, the crucial moment of the first start comes. Plug in the refrigerator and listen carefully: in the first seconds you should hear a confident sound of the engine starting without buzzing or clicking. If the compressor started working smoothly and after some time cold appeared in the chamber, it means that Replacing the relay it was successful and the system is functioning normally.
Pay attention to the temperature of the body of the new relay during operation: in the first minutes it may warm up slightly, which is normal, but it should not be hot. If you feel intense heat or smell of burning plastic, immediately unplug the device, as this indicates incorrect installation or mismatch of parameters. It is also worth checking whether the relay is vibrating too much, which can lead to its destruction over time.
It is recommended to periodically check its condition during the first few hours of operation of the refrigerator, making sure that the on and off cycles occur correctly. If the unit reaches the desired temperature and turns off, and then turns on automatically when the temperature inside the chambers rises, the repair can be considered complete. Otherwise, if the motor runs without stopping, perhaps the problem was not only in the relay, but also in the thermostat or freon leak.
Typical errors and precautions
One of the most common mistakes is an attempt to install a relay that is not intended for a given compressor model, according to the principle “if only it fits.” This can lead to the contacts sticking or, conversely, not closing, which will cause overheating of the windings and failure of the expensive motor. Always check the technical specifications, especially the rated current and the type of refrigerant for which the compressor is designed.
Another common mistake is neglecting to clean contacts and oxidized surfaces. Installing a new relay on dirty compressor terminals creates a high contact resistance, which leads to sparking and rapid combustion of the new part. Before installation, be sure to clean the contacts with alcohol or a special cleaner to ensure perfect electrical contact.
⚠️ Attention: Technical characteristics of compressors and relays may vary depending on the year of manufacture and manufacturer. Always check the markings on the nameplate of your device with the data of the new part before installation.
Do not forget about safety: working with electrical appliances under voltage is prohibited, therefore all manipulations to connect wires should be carried out only with the cord disconnected. If you use tools with metal handles, be careful not to short the contacts to the compressor housing, as this may cause a short circuit in the network.
What to do if the new relay burns out immediately?
This may mean that the problem is not in the relay, but in the compressor itself (turn-to-turn short circuit) or in the wiring. In this case, in-depth diagnostics of the motor with measurement of winding resistance is necessary.
Frequently asked questions (FAQ)
Is it possible to temporarily start a refrigerator without a starting relay?
Theoretically, you can start an asynchronous motor manually by closing the contacts, but this is extremely dangerous and not recommended. Without a relay, the compressor will not be able to operate normally in cyclic mode, which will lead to its rapid overheating and burnout of the windings. This is an emergency measure that can finally finish off the equipment.
Why does the new relay click, but the refrigerator does not turn on?
This may indicate several problems: incorrect installation of the relay, malfunction of the new relay itself (defect), lack of voltage in the network, or, worst of all, jamming of the compressor. It is also worth checking the thermal protection relay, which may be broken.
Is the relay for refrigerators with No Frost different from conventional ones?
Fundamentally, the operation scheme of the starting relay is the same for all types of refrigerators, since it depends on the type of compressor, and not on the defrosting system. However, the dimensions, shape of the case and the location of the contacts may differ, so it is important to select the part by catalog number.
How long does a starting relay last on average?
The service life of the relay depends on the quality of manufacture, the stability of the voltage in the network and the frequency of switching on the refrigerator. On average, a high-quality relay lasts 5-7 years, but power surges or frequent power outages can reduce this period to 2-3 years.
Is it necessary to change the thermal relay along with the starting one?
If the thermal relay is built into the starting body and has signs of overheating or does not ring through the tester, replace it required. If it is working properly, you don’t need to change it “just in case,” but given their close location and the same operating conditions, they often change the entire unit.