Checking the thermostat of an Indesit refrigerator: signs of failure and 5 diagnostic methods

Thermoregulator (thermostat) is a key component of the refrigerator Indesitresponsible for maintaining the set temperature. When this element fails, the compressor either works without stopping or does not turn on at all, which leads to food spoilage or overheating of the motor. In 80% of cases, a thermostat malfunction can be identified independently, without resorting to the services of a technician.

In this article we will analyze 5 methods for checking the thermostat from visual inspection to testing with a multimeter, and we will also tell you how to distinguish a thermostat failure from problems with the compressor or start relay. All instructions are adapted for popular models Indesit (series C 132, B 18, T 16 etc.) and do not require special skills. If your refrigerator has stopped freezing or, conversely, does not turn off, start diagnostics with the thermostat.

Signs of a malfunctioning thermostat in the Indesit refrigerator

The first signal of problems with the thermostat - unstable operation of the compressor. Normally, the motor should turn on for 10–20 minutes, then turn off for 30–40 minutes (the cycles depend on the set temperature and chamber load). If you notice one of the following deviations, the probability of a thermostat failure exceeds 70%:

• 🔴 The compressor does not turn on —the refrigerator does not freeze, the light inside is on, but the motor is silent. In this case, the socket is working, and the plug does not heat up.
• ❄️ Continuous operation of the motor —the compressor hums without stopping, the rear grill is hot, the food is frozen (a “fur coat” of ice grows on the walls).
• 🌡️ The temperature does not correspond to the settings —in the freezer +5°C instead of −18°C, or in the main compartment −3°C with +4°C set.
• 🔊 Clicks without starting the engine —the characteristic clicks of the start relay are heard, but the compressor does not start (may indicate a breakdown of the relay, but the thermostat is also not working check).

Important: similar symptoms can be caused by freon leaka clogged capillary tube or a malfunction of the electronic control unit (in models with a display). However, the thermostat is the most vulnerable and cheapest element to repair, so diagnostics begin with it.

⚠️ Attention: If the refrigerator Indesit with the system No Frost stops cooling, first check the fan and defrost heater. In these models, the thermostat rarely fails separately - more often the problem is complex.

Does not turn on at all|Works without stopping|Doesn't freeze, but there is light|Other-->

Where is the thermostat in the Indesit refrigerator

In most models Indesit the thermostat is located inside the refrigerator compartment, behind the plastic control panel. The exact location depends on the series:

• 📍 Classic models (for example, Indesit C 132, B 18) - the thermostat is hidden under the round cap of the temperature knob (usually at the top of the chamber, on the right or left).
• 📍 Modern models (series TIA, EWT) - the thermostat is integrated into the electronic unit on the top panel (removing the cover may be required).
• 📍 Double-chamber refrigerators - often install two thermostats: one for the refrigerator compartment, the second for the freezer (the second is usually located behind the back wall of the freezer compartment).

To get to the thermostat:

1. Disconnect the refrigerator from the power supply.
2. Remove the temperature control knob (pull it toward you or pry it with a screwdriver).
3. Unscrew the screws (or snap off the latches) of the plastic panel.
4. Carefully remove the thermostat - it is mounted on a bracket and connected to the capillary tube (do not bend it!).

The photo below shows a typical thermostat for Indesit (marking K59, L125, TAM125 etc.). A capillary tube (thin copper) goes to the evaporator, and the wires are connected to the compressor through a relay.

Photo of the Indesit thermostat

Most Indesit thermostats are marked with the rated current (for example, 6A or 10A) and the manufacturer (Danfoss, Ranco, Orbis). If the marking is erased, take a photo of the device before purchasing a replacement - this will help you choose an analogue.

Method 1: Checking the thermostat without instruments (visual inspection)

Before using the multimeter, inspect the thermostat for mechanical damage and obvious defects:

The capillary tube is not pinched or torn

Thermostat housing without cracks and traces of melting

Contacts are not oxidized (green coating or black dots)

The wires are not frayed and are firmly fixed in the terminals-->

Pay attention to capillary tube - it should be solid, without creases. If the tube is kinked or damaged, the thermostat will give incorrect readings. Also check if the tube is disconnected from the evaporator (in this case, the sensor does not “feel” the temperature).

If everything looks fine, proceed to testing the contacts. To do this:

1. Remove the terminals from the thermostat (draw or photograph the connection diagram!).
2. Check whether the contacts are “stuck” in the “closed” or “open” position.
3. Turn the thermostat knob from the minimum to the maximum position - a slight click should be heard (this triggers the opening mechanism).

⚠️ Attention: In models with electronic control (display, touch buttons), the thermostat may not be a mechanical, but an electronic sensor. It is checked only with a multimeter in resistance measurement mode.

Method 2: Testing with a multimeter (step-by-step instructions)

For accurate diagnostics, you will need a multimeter (or tester) with a continuity test mode. Test algorithm:

1. Preparation: Disconnect the refrigerator from the network, remove the thermostat (as described above) and disconnect all wires from it. Mark the terminals so as not to confuse them during reassembly.
2. Setting up the multimeter: Switch the device to the dialing mode (diode or sound wave icon) or resistance measurement (200 Ohm).
3. Testing the contacts:
   • Attach the probes to the terminals 3 i 4 (usually these are the compressor contacts). In the knob position at “0” (off), the circuit should be open (resistance → ∞).
   • Turn the knob to maximum cooling (for example, to “7”) - the circuit should closed (resistance → 0 Ohm, sound signal when dialing).

Checking the temperature sensor: Connect the probes to terminals 1 i 2 (thermostat power supply). The resistance should be in the range of 2–5 kOhm (the exact values ​​depend on the model).

If, when you turn the knob, the contacts 3-4 do not close/open, the thermostat is faulty. Also a sign of a breakdown is zero resistance between all terminals (short circuit) or its absence (open circuit).

Method 3: Testing the thermostat in the refrigerator without dismantling

If you do not want to remove the thermostat, you can check its performance “in place” using a short circuit contacts. This method is only suitable for mechanical thermostats!

Instructions:

1. Unplug the refrigerator.
2. Remove the plastic panel to gain access to the thermostat terminals.
3. Disconnect the wires from the terminals 3 and 4 (usually they lead to the compressor).
4. Connect these terminals together with a piece of wire or a screwdriver (close the circuit).
5. Plug in the refrigerator.

Results:

• ✅ If the compressor worked —the thermostat is faulty (needs replacement).
• ❌ If the compressor does not start —the problem is in the starting relay, compressor or electrical circuit (check the relay and motor windings).

⚠️ Attention: Do not leave the terminals closed for more than 1-2 minutes! A compressor without thermostat control will operate continuously, which can lead to its overheating.

Method 4: Checking the thermostat in the freezer

In two-chamber refrigerators Indesit (for example, Indesit BIAA 13 or DF 5200) the freezer often has a separate thermostat. Its diagnosis has nuances:

• 🔧 Access: The freezer thermostat is usually located behind the rear panel of the compartment. To get to it, you need to defrost the chamber, remove the shelves and unscrew the panel fastenings.
• 🌡️ Temperature conditions: The normal resistance of the freezer sensor at +20°C is about 4–6 kOhm. When cooling to −18°C, the resistance should drop to 1–2 kOhm.
• ⚡ Electrical diagram: In the freezer, the thermostat is often connected to a defrost heater (in systems No Frost). Before checking, turn off the heater, otherwise the readings will be incorrect.

For testing:

1. Disconnect the refrigerator, remove the back panel of the freezer.
2. Disconnect the thermostat connector (usually it is connected to electronic unit).
3. Measure the resistance between the sensor contacts at room temperature and after cooling (for example, by putting the thermostat in the freezer for 10 minutes).

If the resistance of the sensor does not change when the temperature changes, this is a 100% sign of its malfunction.

Method 5: Diagnostics of the electronic thermostat (for modern models)

Refrigerators Indesit with a display (series EWT, TIA) are equipped with electronic thermostats (thermistors). They are checked differently:

1. Localization of the sensor: An electronic thermostat looks like a small plastic cylinder with two wires. It can be built into the evaporator or mounted on the back wall of the chamber.
2. Disconnection: Disconnect the sensor from the control board and measure its resistance at different temperatures:
   • +20°C - 4–6 kOhm;
   • 0°C - 10–12 kOhm;
   • −18°C - 20–30 kOhm.

Checking power: Make sure that 5V or 12V is supplied to the control board (depending on the model). Without power, the electronic thermostat will not work.

If the resistance of the sensor does not change or is equal to 0/∞, it needs to be replaced. For accurate diagnosis, it may be necessary checking errors on the display (in models with self-diagnosis). For example, a code F04 or F05 often indicates a problem with the temperature sensor.

What to do if the thermostat is faulty: repair or replacement

Mechanical thermostats cannot be repaired —they are only replaced. The cost of a new thermostat for Indesit is from 800 to 2500 rubles (depending on the model). You can do the replacement yourself:

1. Buy a thermostat with the same markings (for example, Danfoss 077B6 or Ranco K59).
2. Disconnect the refrigerator, remove the old thermostat (as described above).
3. Connect the wires to the new thermostat in the same order (use the photo with the old circuit!).
4. Install the capillary tube in its original place (it should fit tightly to the evaporator).
5. Assemble the panel and check the operation of the refrigerator.

If you If you are not confident in your abilities, contact a specialist. The average cost of replacing a thermostat at a service center is 1500–3000 rubles (including work).

⚠️ Attention: After replacing the thermostat, do not turn on the refrigerator immediately. Wait 10–15 minutes - this time is needed to stabilize the pressure in the system.

FAQ: Frequently asked questions about Indesit thermostats

Is it possible to repair a thermostat yourself without buying a new one?

Mechanical thermostats cannot be repaired - their design is sealed and non-separable. The only thing you can do is to clean the contacts from oxidation (if this is the problem). the sensors also cannot be restored.

How to distinguish a thermostat failure from a compressor malfunction?

If the compressor does not turn on, but when the thermostat terminals are closed, the thermostat starts to work - the problem is in the thermostat. If the compressor does not respond even to a direct short circuit, check. starting relay or motor windings. 3–4 The thermostat starts to work - the problem is in the thermostat. If the compressor does not respond even to a direct short circuit, check the start relay or motor windings.

Why does the Indesit refrigerator work without stopping, but the thermostat is working?

Possible reasons: freon leak, clogged capillary tube, malfunction of the electronic unit (in models with a display) or fan failure (in systems No FrostAlso check). door seal - if it is worn out, warm air enters the chamber, and the compressor tries to compensate for the heat influx.

Which thermostats are suitable for replacement in Indesit?

For most models Indesit brand thermostats are suitable Danfoss (series 077B6, 077D6), Ranco (K59, L125), Orbis (TAM125). The main thing is the match in rated current (indicated on the body of the old thermostat) and the type of capillary tube (length and diameter).

Is it necessary to defrost the refrigerator before replacing the thermostat?

Yes, defrosting is required! This is necessary for safety (eliminates the risk of electric shock) and simplifies access to the thermostat. In addition, when replacing the sensor in the freezer, ice may interfere with the correct installation of the capillary tube.