Thermal relay Indesit refrigerator: how to check it yourself without errors

Thermal relay is a small but critical element in refrigerators Indesitthat protects the compressor from overheating and overloads. When it fails, the equipment either refuses to turn on or works intermittently, which leads to food spoilage and increased energy consumption. The problem is that the symptoms of a relay malfunction are often confused with breakdowns of the thermostat, control board or the compressor itself. —and this leads to unnecessary expenses for repairs.

In this article we will look at how to accurately diagnose a thermal relay in refrigerators Indesit (including popular models C 132 G, TN 116, B 18 and series No Frost), without resorting to the help of a technician. You will learn what tools you will need, how to correctly “ring” the contacts with a multimeter, and why checking by eye or by replacing parts at random is the worst solution. We will also reveal typical mistakes that beginners make when diagnosing and provide a checklist for safe work with electrical components.

⚠️ Important: If your refrigerator Indesit is still under warranty, independent disassembly will lead to it cancellation. In this case, contact the service center Indesit Hotpoint Ariston (contacts are indicated in the warranty card).

Signs of a thermal relay malfunction: when is it time to check

Thermal relay (aka start-protection relay) in refrigerators Indesit usually does not break suddenly, but signals problems in advance. Here are the key symptoms that should alert you:

• 🔴 Refrigerator does not turn on at all —the light inside is on, but the compressor is silent. This may mean that the relay is “stuck” in the open state.
• ⚡ Compressor buzzes, but does not start —a characteristic low-frequency sound is heard, but the motor does not start working. Often this indicates a break in the relay winding.
• ❄️ Refrigerator turns on for 5-10 seconds and turns off —the cycle repeats endlessly. This is how a relay with burnt contacts or a faulty bimetallic plate behaves.
• 🔥 The relay body hot to the touch (more than 60°C) is a sign that it is operating in constant overload mode.
• ⚠️ An error appears on the display (if any) F05, F08 or E01 —in models Indesit with electronic control this is often associated with the relay circuit.

Please note: if the refrigerator Indesit it does not freeze, but the light inside is on, the problem may lie not in the relay, but in the thermostat or freon leak. In this case, it is better to start diagnostics by checking the temperature in the chambers and inspecting the evaporator for the presence of frost.

💡 Tip: Before disassembling the refrigerator, make sure that the problem is not in the surge protector or socket. Connect another device (for example, a table lamp) to the same outlet - if it works, then the problem is in the refrigerator.

Where is the thermal relay in the Indesit refrigerator

In most models Indesit (for example, C 132 G, B 16, TN 116) the thermal relay is attached directly to the compressor housing and is closed with a plastic or metal cover. To get to it:

1. Unplug the refrigerator and move it away from the wall (you will need access to the back panel).
2. Remove the bottom decorative cover (it is usually held on by latches or screws).
3. On the compressor (black metal tank with tubes) you will see a small box the size of a pack of cigarettes - this is the start-up relay. It is connected to the compressor with three wires (usually red, black and white).

In models with a system No Frost (for example, Indesit DF 4180) the relay can be hidden under a panel at the bottom of the refrigerator or behind the back wall. Here you will also have to remove the fan protective casing.

⚠️ Attention: Do not confuse the thermal relay with thermostat (it is located inside the chamber, next to the light bulb) or starting capacitor (cylindrical part next to the compressor). These elements are checked differently!

Tools for testing: what you will need

To diagnose a thermal relay in refrigerator Indesit you don’t need professional instruments - a basic set is enough:

If you do not have a multimeter, you can use indicator lamp (220V light bulb with wires), but this method is less safe and does not provide accurate resistance data. It is also useful marker or tape tapeto mark the wires when disconnecting.

Step-by-step instructions: how to check a thermal relay with a multimeter

Now let's move on to the diagnostics itself. The main task is to check the integrity of the circuit and the functionality of the bimetallic plate of the relay. Follow this algorithm:

Step 1: Disconnecting and dismantling the relay

1. Unplug the refrigerator and wait until the compressor cools down (15-20 minutes).

2. Carefully remove the relay from the compressor by disconnecting the terminals. Remember or mark their location!

3. On some models Indesit the relay is secured with latches - do not break them, but carefully press them out with a screwdriver.

Step 2: External inspection

Inspect the relay for:

• 🔥 Burnt or melted contacts (especially on the “legs” of the relay).
• 💨 Carbon deposits or black spots inside the case (a sign of a short circuit).
• 🔧 Cracks on the plastic case (may indicate mechanical damage).

Step 3: Check multimeter

Switch the multimeter to mode call (or measuring resistance at 200 Ohms) and take the following measurements:

1. Ring normally closed contacts (usually this terminals 3 and 4 on the relay diagram). At room temperature they should be closed (resistance ~0 Ohm).
2. Check coil integrity (terminals 1 and 2). The resistance should be within 15–40 Ohm (the exact values depend on the relay model).
3. Heat the relay (for example, hairdryer or immersing in hot water for 1-2 minutes) and check the contacts again 3 and 4. When heated, they should open (resistance → ∞).

If the contacts do not open when heating or do not close when cooling - a relay faulty.

Step 4: Test under load (optional)

For 100% confidence, you can check the relay under load:

1. Connect the relay back to the compressor, but do not reinstall it.

2. Plug in the refrigerator for 10-15 seconds. If the compressor starts and operates stably, the relay is working properly. If not, replacement is required.

⚠️ Attention: Do not keep the relay energized for more than 20 seconds without installing it on the compressor - this can lead to overheating!

Typical errors when checking a thermal relay

Even experienced technicians sometimes make mistakes when diagnosing relays. Here's what you can't do:

• ❌ Check the relay without disconnecting the refrigerator from the network it's life-threatening! Capacitors in the circuit can retain charge.
• ❌ Ignore external damage — if traces of melting are visible on the relay, it needs to be changed, even if the multimeter shows “normal.”
• ❌ Confuse the terminals when testing — for example, measure the resistance between 1 and 3 instead of 1 and 2. This will give false results.
• ❌ Heat the relay with an open flame (with a lighter, match) - this can damage the plastic case. Use a hairdryer or hot water.
• ❌ Install a relay from a different model —even if it looks similar. Operation parameters may differ!

Another common mistake is do not check the compressor after replacing the relay. If the motor is jammed or there is an interturn short circuit, the new relay will burn out again in a few days.

What to do if the relay is working properly, but the refrigerator does not work?

In this case, the problem may be:

- Starting capacitor (checked with a multimeter for capacity).

- Thermoregulator (rings in the "maximum" position).

- Control board (diagnosis by a specialist is required).

- Compressor (winding resistance is checked).

How to replace the thermal relay in an Indesit refrigerator

If the diagnostics showed that the relay is faulty, it needs to be replaced. For models Indesit relays of the following types are suitable:

• 🔧 DANFOSS 103N0020 — for most single-chamber refrigerators.
• 🔧 EMBRACO RSI 2,5 —for models with a compressor Embraco (for example, Indesit B 18).
• 🔧 START CAPACITOR K50-12 —for refrigerators with a system No Frost.

Replacement process:

1. Buy exactly the same relay (preferably the original or an analogue with the same parameters).
2. Disconnect the old wires from the faulty relay (it is better to mark them with a marker).
3. Install the new relay on the compressor by connecting the terminals in the same order.
4. Secure the relay to the compressor housing (usually it is fixed with a latch or screw).
5. Turn on the refrigerator and check the operation for 30 minutes.

⚠️ Attention: After replacing the relay, the refrigerator may work intermittently for the first 1-2 hours - this is normal, as the system stabilizes the pressure freon. If after a day the problem remains, look for a deeper cause (for example, in the compressor).

Indesit models with typical relay problems

Some models Indesit are more susceptible to thermal relay failures due to structural features. Here are the most “problematic” series:

If your model is not on the list, this does not mean that the relay cannot fail. Any refrigerator Indesit over 7 years automatically falls into the risk group - over time, the bimetallic plate of the relay “gets tired” and begins to operate incorrectly.

Prevention: how to extend life thermal relay

To make the relay last longer, follow these recommendations:

• ⚡ Use voltage stabilizer - surges in the network reduce the service life of the relay by 2-3 times.
• 🧹 Regularly (once every 6 months) clean the condenser (grid on the back wall) from dust - this improves heat dissipation.
• 🔌 Do not connect the refrigerator through extension cords - they can heat up and create additional load.
• 🌡️ Do not place the refrigerator next to batteries, stove or windows —overheating accelerates wear of the relay.
• 🔄 Defrost the refrigerator at least once a year (even if it has No Frost) - this reduces the load on the compressor.

If your refrigerator Indesit is already “aged” (more than 8-10 years), it makes sense to keep a spare relay ready. Its cost is from 500 to 1500 rubles, and replacement at a service center will cost 2-3 times more.

📊 Have you ever repaired a refrigerator yourself?

Yes, successfully

Yes, but nothing. it worked

No, I always call a specialist

No, but I want to learn

Frequently asked questions about the Indesit thermal relay

Is it possible to repair the thermal relay or just replace it?

Theoretically, the relay can be disassembled and the contacts can be cleaned (for example, from carbon deposits), but in practice this gives a temporary effect. The bimetallic plate and spring lose their elasticity over time, therefore repair is impractical. it is easier and more reliable to replace the entire relay.

How to distinguish a relay malfunction from a compressor breakdown?

If the relay is working properly, but the refrigerator does not work, check the compressor:

1. Disconnect the relay and apply voltage directly to the compressor (to terminals C i S).
2. If the compressor does not start or hums but does not rotate, the problem is there (interturn short circuit or jamming).
3. If the compressor is working, the relay or thermostat is to blame.

⚠️ Attention: This is a dangerous method. Work only with! with the refrigerator turned off and use dielectric gloves.

How much does it cost to replace a thermal relay in a service?

The cost of replacing the relay in service centers Indesit in 2026:

• Independent replacement (part price only) — 500–1500 rub.
• Replacement with on-site technician — 2500–4000 rub. (including diagnostics).
• Urgent repair (within 24 hours) - 4000–6000 rubles.

Prices may vary depending on the region and model of the refrigerator.

Can I use a relay from another refrigerator?

Only if it completely matches:

• Type (for example, RSI 2,5 or DANFOSS 103N0020).
• Rated current (indicated on the relay body).
• Connection diagram (location terminals).

Relays from refrigerators Atlant or Samsung are not suitable for Indesit - even if they look the same in appearance!

What to do if after replacing the relay the refrigerator works, but not freezing?

Probable causes:

• 🔹 Incorrect connection of the terminals —check the circuit.
• 🔹 Freon leak —refueling is required.
• 🔹 Thermostat malfunction —call it.
• 🔹 Compressor jammed —you need a technician's diagnosis.

If you are not sure, it is better to call a specialist - independent repairs can aggravate the problem.