A sudden stop of the compressor or chaotic clicking of the Indesit refrigerator often indicates a malfunction of the start relay. This small plastic block is responsible for starting the engine and turning it off after reaching operating mode. If you hear characteristic clicks, but the engine does not start, or it turns on for a couple of seconds and stalls, the problem most likely lies in this unit.
Before calling a technician or buying a new part, it is worth conducting independent diagnostics using a multimeter. This is a simple device that allows you to measure electrical resistance and determine the integrity of contacts. In this article we will look at how to correctly remove the relay, take measurements and understand whether the device can be repaired or requires replacement.
Usually the relay is located in the back of the refrigerator, attached to the compressor. To access it, you only need a screwdriver and a tester.
Signs of a faulty start relay
You can determine what start relay has failed not only by the lack of cold, but also by the specific sounds and behavior of the compressor. Users often confuse a relay failure with a malfunction of the motor itself, which leads to unnecessary expenses on the purchase of a new compressor. Understanding the symptoms will help you save time and money.
The most common symptom is the characteristic sound that the refrigerator makes. There is a loud click, followed by a pause, then another click. This works thermal protectiontrying to start the engine, but the relay does not close the starting winding circuit. As a result, the compressor hums for several seconds and goes silent.
Sometimes you may notice that the relay housing or the compressor itself gets very hot. This happens because the current in the windings increases, but the motor cannot turn over. If you touch the plastic housing of the relay and it is hot, this is a clear signal that a breakdown or sticking of the contacts has occurred inside.
⚠️ Attention: If after the click the compressor hums for more than 10-15 seconds and does not start, immediately turn off the refrigerator. Prolonged operation in this mode can lead to burnout of the motor windings.
Visual inspection can also provide important clues. If you remove the cover and see blackened plastic, burn marks or melted contacts, further diagnostics with a multimeter may be unnecessary - the part definitely requires replacement. However, for complete confidence and to exclude other causes (for example, a break in the wiring), testing with a tester is mandatory.
Preparation for diagnostics and dismantling
To carry out high-quality diagnostics, it is necessary to properly prepare the workplace and tools. You will need a Phillips screwdriver, pliers and, of course, a multimeter. Before starting work, make sure that the refrigerator has been unplugged from the outlet for several minutes so that the capacitors discharge and the hot elements cool down.
Dismantling begins by removing the rear protective panel at the bottom of the refrigerator. The relay is usually mounted on the side or top of the compressor and secured with a metal bracket or plastic clips. Carefully bend the clips and remove the assembly along with the capacitor, if it is integrated into the overall structure.
After removing the unit, you need to disconnect the wires. Before doing this, it is recommended to photograph the connection diagram so as not to confuse the contacts during assembly. Usually the relay is simply removed from the three pins of the compressor, and the wires are connected to it through the terminals.
☑️ Preparation for checking the relay
It is important to carefully handle the wires suitable for the compressor. They can be stiff due to heat, and if pulled suddenly there is a risk of damaging the insulation or tearing off the terminal. If the wires are strongly stuck to the contacts, you can carefully warm them with a hairdryer, but under no circumstances use an open flame.
Design and types of relays of Indesit refrigerators
In Indesit brand refrigerators, two types of starting devices are most often used: posistor and induction (electromagnetic). Understanding the difference between them is critical, since the method for testing them with a multimeter is significantly different. PTC models are more modern and are common in refrigerators of recent years of production.
Posistor relay works due to the property of the ceramic element (posistor) to sharply increase resistance when heated. When cold, it passes current, starting the engine, heats up and opens the starting winding circuit. Induction relays operate on the principle of an electromagnet, which opens contacts when certain currents are reached.
How to distinguish relay types visually?
A posistor relay usually has a more compact black or gray plastic case with one or two wires going to capacitor. Induction ones often look like larger blocks with a visible coil inside a transparent or translucent case, although they are rare in modern Indesit models.
Inside the case of a posistor relay there is a ceramic element itself and contacts. Over time, the posistor may crumble from overheating, turning into powder, or simply lose its properties. In induction relays, the main problem is burning of contacts or jamming of the core.
For a multimeter, it is important to know which contacts to call. There is usually a marking or diagram on the relay body indicating the input (L, N) and output to the compressor. If the markings are erased, you will have to focus on the location of the contacts relative to the compressor pins.
Checking a posistor relay with a multimeter
Checking a posistor device is the most common task for owners of Indesit refrigerators. Set the multimeter to resistance measurement mode (ohms) to the 200 or 2000 ohms limit. First, check the continuity of the circuit between the input contacts.
Attach the probes to the contacts leading from the power plug. If the device shows one or infinity, it means there is an open circuit. If zero, a short circuit is possible. The normal resistance of the posistor itself in a cold state ranges from 3 to 50 Ohms, depending on the model.
The key point is to check the ability of the posistor to change resistance. When cold it should be low. If you heat the element (for example, with a hairdryer) for 10-15 seconds, the resistance should increase sharply to several kiloohms. If the resistance does not change, the posistor is faulty.
Also check the contacts going to the compressor starting winding. In a quiet state, the circuit should be closed (resistance close to zero). If the multimeter shows a break, it means that the contacts inside are burnt or oxidized, and the current does not pass to the motor.
Diagnostics of an induction (electromagnetic) relay
If an induction relay is installed in your refrigerator, the testing method changes. Here the main role is played by the electromagnetic coil and the movable core. Using a multimeter, we check the integrity of the coil winding and the condition of the contact group.
Find the coil contacts (usually they are connected in series with the working winding of the compressor). The coil resistance should be small, usually in the range of 10-30 ohms. If the device shows a break, it means that the wire inside the coil has burned out, and the relay will not be able to create a magnetic field to open the contacts.
Pay special attention to the moving contacts. In the initial position (when the relay is on the table) they should be closed, ensuring the engine starts. Check the resistance between the start winding output and the common contact. It should be minimal.
| Check parameter | Normal value | Failure sign |
|---|---|---|
| Thesistor resistance (cold) | 3 - 50 Ohm | Infinity or 0 Ohm |
| Coil resistance (inductive) | 10 - 30 Ohm | Open (one on the screen) |
| Starting circuit contacts | 0 - 1 Ohm | High resistance or break |
| Case insulation | Infinity | Any resistance value |
It is also important to check whether there is a breakdown in the housing. Set the multimeter to continuity mode or resistance measurement mode to the maximum limit. Place one probe on the metal contact, the other on the relay body. The device should not beep or show resistance.
Analysis of readings and fault table
The data obtained must be interpreted correctly. Often, users see numbers on the multimeter screen, but do not understand what they mean in the context of the operation of the refrigerator. Below is a table that will help systematize the measurement results.
If the multimeter shows “1” at the limit of 2000 Ohms, this means infinite resistance, that is, an open circuit. If it shows “0.0” where there should be resistance (for example, on a posistor), this is a short circuit. Both conditions require replacement of the part.
Sometimes the readings may “float”. This is typical for oxidized contacts. In this case, the relay can work intermittently (periodically), sometimes starting the refrigerator, sometimes not. It is better to replace such a device, since oxidation will progress.
Pay attention to the condition of the wires leading to the relay. If the insulation is cracked or melted, even a working relay will not work correctly due to poor contact. In such cases, not only the relay is changed, but also the wiring section is restored.
Features of replacement and selection of an analogue
If diagnostics confirm a malfunction, the relay must be replaced. The main difficulty is choosing the right analogue, since there are no universal solutions. The relay is selected strictly according to the power and type of compressor installed in your Indesit refrigerator.
There is always a marking on the body of the old part. Look for codes like R600, R134a (indicates the type of refrigerant, which indirectly affects the type of compressor) or specific numbers like 17310001000. These numbers must be entered into the search when ordering a new spare part.
⚠️ Attention: Installing a relay with inappropriate characteristics (for example, from a more powerful refrigerator) will lead to the fact that it will not open the starting winding in time. This will cause the compressor to overheat and burn out.
When installing a new device, make sure that it sits tightly on the pins of the compressor. If the connectors are loose, use pliers to gently tighten the terminals, but be careful not to break the ceramic PTC resistor inside. Also check whether the relay is oriented correctly - on many models there is an arrow UP or TOPthat should face up.
After replacement, reassemble the structure in the reverse order, connect the wires according to the photo taken earlier and start the refrigerator. Listen to the operation of the unit for the first 10-15 minutes. There should be no clicks, the compressor should run smoothly and start on the first try.
Is it possible to repair a relay if a posistor is crumbled?
Theoretically, you can try to find a posistor with a similar resistance and replace it, but in practice this is impractical. The cost of a new relay is low, and finding a suitable ceramic element is difficult. It’s easier to buy a ready-made assembly.
Why does a new relay burn out after a few days?
This may indicate a malfunction of the compressor itself (turn-to-turn short circuit) or problems with the voltage in the network. Also, the reason may be improper installation or the use of a relay that does not correspond to the engine power.
Do relay contacts need to be lubricated with graphite?
No, modern contacts do not require lubrication. The use of graphite or oil can lead to the accumulation of dust and accelerated burning of the contacts, as well as a change in the electrical properties of the unit.
How to understand that the problem is not in the relay, but in the compressor?
If after replacing a working relay the situation does not change (clicks and is silent), and at the same time the resistance of the windings of the compressor itself (checked directly on the pins without a relay) in normal, the engine piston may have jammed. In this case, the compressor needs to be replaced.