How to remove the starting relay from the compressor of an Indesit refrigerator

Has your refrigerator Indesit stopped cooling, and the compressor only hums or clicks, but does not start? In 80% of cases, the problem lies in a failed start relay. This small device is responsible for starting the engine by sending a short-term impulse to the starting winding. If you notice that the motor is trying to start, makes a loud click and immediately goes silent, most likely it’s time to replace this particular part.

Before starting repairs, you must completely disconnect the electrical appliance from the network. Working with electrical components requires following basic safety rules. Even if you think you are simply removing the cover, the risk of electric shock while the unit is plugged in remains high. After unplugging, move the refrigerator away from the wall to provide free access to the back of the case.

To work, you will need a minimum set of tools: flat-head and Phillips screwdrivers, pliers and, preferably, a multimeter to check the serviceability of the old part. Replacing a relay is one of the most accessible procedures for a home DIYer and does not require special technical skills or sophisticated equipment. The main thing is to act carefully so as not to damage the fragile tubes of the cooling system.

Design and principle of operation of the starting relay

The starting relay in refrigerators Indesit is a compact plastic case, inside of which the switching mechanism is hidden. Depending on the model of the unit, an electromagnetic or posistor device can be used here. Electromagnetic relays operate by current passing through a coil, which draws in the core and closes the contacts of the starting winding. The more modern posistor models use the property of a ceramic element (posistor) to sharply increase resistance when heated, opening the circuit.

When the compressor starts, a high inrush current flows through the windings. It is this that allows the engine rotor to overcome inertia and begin to rotate. As soon as the motor picks up speed, the current drops, and the relay should turn off the starting winding, leaving the working winding. If this mechanism sticks or burns out, the engine cannot reach operating mode, which leads to its overheating and activation of the protective thermal relay.

It is important to understand that starting relay and the thermal relay are often structurally combined into one unit or mounted side by side. Thermal protection is responsible for shutting down the motor in case of overcurrent or temperature. When diagnosing, they often change the entire assembly, since the service life of these elements is approximately the same, and the failure of one often entails a quick breakdown of the second.

What is the difference between the RT and RZ relays?

The RT (starting) relay is responsible for starting the engine, closing the circuit starting winding. The relay RZ (thermal) opens the circuit when overloaded. In modern Indesit models, they are often combined into a single housing, which simplifies replacement, but requires the selection of an exact compatible model by catalog number.

Fault diagnosis before disassembly

Before removing a part, you should make sure that the problem is in it, and not in the compressor itself. Primary diagnosis is carried out visually and auditorily. If, when you turn on the refrigerator, you hear a characteristic click, followed by the hum of the motor, lasting 1-2 seconds, and then again a click and silence - this is a classic sign of a faulty starter. The compressor tries to start, but cannot without the help of the relay.

There is a simple but effective test method, which is often called the “shaking method”. If a knock is heard inside the plastic relay case when shaken, as if from broken glass or a broken piece, it means that the ceramic posistor is destroyed. In this case, replacement is inevitable; such a part cannot be restored.

However, external signs are not always accurate. Sometimes the relay looks intact, but the contacts inside are burnt and do not conduct current. For an accurate check it is necessary multimeter. After switching the device to dialing mode, check the resistance between the contacts. If the circuit does not ring or the resistance is infinitely high, the part is faulty. It is also worth inspecting the contacts for oxidation or carbon deposits, which may interfere with normal current flow.

Preparation for dismantling and safety measures

Safety is the number one priority in any repair of household appliances. The refrigerator should not just be turned off with a button, but completely disconnected from the electrical network. Remove the plug from the socket. This will eliminate the risk of accidental electric shock, especially if you have to touch metal parts of the case or wiring during operation.

Move the unit away from the wall at a sufficient distance so that you can move freely around it. You will need access to the lower rear where the compressor is located. If the floor is slippery, place a piece of cardboard or a rag under the legs of the refrigerator to avoid scratching the coating when moving.

Allow the compressor to cool down if it was running before. The temperature of metal parts may be high, which can cause burns. In addition, heated plastic elements become more fragile and may crack if handled carelessly. Prepare the workplace: cover the floor with newspapers or rags, since technical oil may drip from the compressor when removing the relay.

Step-by-step instructions: how to remove the relay

The process of removing the start relay in refrigerators Indesit is standardized, but requires care. On the back of the compressor you will see a black casing covering the electrical part. In some models it may be metal or plastic, secured with latches or screws. Carefully remove this protective casing by bending the latches or unscrewing the fasteners.

Under the casing you will see a compressor shank with three contacts, on which the starting relay is attached. It is usually fixed on these contacts and is additionally held due to a tight fit. An electrical wire connects to the side of the relay. The first step is to disconnect this wire. Often it is secured to a terminal block or simply inserted into a connector. Do not pull on the wire itself; hold the connector with pliers or your fingers.

The relay itself is removed by moving downwards and slightly backwards. It fits snugly on the compressor contacts, so a little force may be required. Rock the part from side to side while pulling it away from the motor. Be careful not to damage the copper cooling system pipes that go to the compressor. They are thin and easily deformed, which can lead to freon leakage.

If the relay cannot be removed by hand, you can carefully pry it with a flat screwdriver at the junction with the compressor housing, but this must be done be extremely careful not to crumble the old plastic. In older models Indesit the plastic may be dry and brittle.

Compatibility table and relay types

When replacing, it is important to choose the right analogue. Indesit refrigerators use various types of starting devices. Below is a table to help you navigate the markings and types.

Pay attention to the power of your compressor, it is indicated on the nameplate (metal sticker) on the motor housing. For compressors up to 1/4 HP. Usually some types of relays are used, for more powerful ones - others. Using a relay that is not suitable for the cut-off current will either cause the motor to not start or the starting winding to burn out.

Is it possible to install a relay from another brand?

Often relays from Atlant or Stinol refrigerators are suitable for Indesit if the mounting dimensions and current characteristics match. However, it is better to look for original spare parts or high-quality universal analogues with adjustable cut-off current.

Installing a new part and checking operation

Installing a new starting relay is done in the reverse order of removal. Insert the part onto the compressor contacts until it stops. You should feel a distinctive click or tight fit. Make sure the relay sits straight and is not askew. If it is installed crookedly, the contacts may not close, or the part will quickly fail.

Connect the electrical wire to the corresponding connector on the relay. Check that the connection is secure: the wire should not dangle or spark. Reinstall the compressor guard, securing it with latches or screws. Make sure that no wires get under the fasteners or are pinched.

After assembly, turn on the refrigerator. In the first seconds, listen carefully: the engine should start confidently without prolonged hums and clicks. The compressor should run smoothly. After 10-15 minutes of operation, check the temperature of the condenser (grid at the back) - it should begin to heat up evenly, which indicates the circulation of the refrigerant.

⚠️ Attention: If after replacing the relay the compressor continues to hum and does not start, turn it off immediately device This may indicate an interturn short circuit in the windings of the motor itself or jamming of the piston group. Further attempts to start may permanently damage the compressor.

Frequent errors during replacement and their consequences

One ​​of the common mistakes is ignoring the condition of the wiring. When replacing a relay, people often forget to check the wire going to it. If the insulation has melted or the contacts have oxidized, the new relay will also quickly fail. Always clean the contacts and, if necessary, replace damaged sections of the wiring.

Another mistake is installing a relay “at random” without checking compatibility. Visually they may be similar, but have different cutoff currents. For example, installing a relay with a lower current on a powerful compressor will cause it to open the circuit too early, preventing the motor from developing the required speed. Conversely, a relay with a high current may not turn off the starting winding in time, which will cause it to overheat.

Also, novice craftsmen often forget about the orientation of the relay. The device body usually has arrows or inscriptions UP (top) and TOP. Posistor relays are sensitive to position in space. If installed upside down, gravity will interfere with the correct opening of contacts or the operation of internal mechanisms, which will lead to incorrect operation of the refrigerator.

Can an old relay be repaired rather than replaced it?

Theoretically, the electromagnetic relay can be disassembled and the contacts can be cleaned of carbon deposits. However, this is a temporary measure. The spring loses its elasticity, and the contact coating wears off. PTC relays cannot be repaired, since the destruction of the crystal is irreversible. Experts recommend installing a new part immediately to avoid repeated repairs in a month.

Why does a new relay burn out after a short time?

If a new relay fails quickly, it is not the reason. Most likely, the problem is in the compressor itself: it is “difficult” to start due to worn-out mechanical parts or oil problems. Also, the cause may be unstable voltage in the network. In such cases, it is recommended to install a voltage stabilizer or check the compressor for an interturn short circuit.

Where can I find the markings of a suitable relay for Indesit?

The markings are located on the plastic body of the removed relay itself. Look for codes like 180234, RT-12, R600a or PTC. Also, the spare part number can be found in the technical documentation of the refrigerator or on the manufacturer’s website by entering the model of your unit (for example, Indesit DF 418).

Is it dangerous to change the relay yourself if the refrigerator is under warranty?

Yes, this is dangerous in terms of loss of warranty. Opening the compressor protective casing and interfering with the electrical circuit is often regarded by service centers as a violation of the terms of warranty service. If the warranty period is still valid, it is better to call an official technician.

⚠️ Attention: Technical characteristics of compressors and relays in Indesit refrigerators may vary slightly depending on the year of manufacture and the specific modification of the model. Always check the parameters (power, type of refrigerant, cut-off current) with the data on the nameplate of your device before purchasing spare parts.