How to check the thermostat on an Indesit refrigerator yourself: step-by-step guide with photos

The thermostat (or thermostat) is the “brain” of the refrigerator Indesit, which controls the temperature in the chambers and controls the operation of the compressor. If it fails, the equipment begins to work incorrectly: it freezes the food, does not turn off, or, conversely, stops cooling. In 80% of cases, a thermostat malfunction can be diagnosed independently, without the help of a technician.

In this article you will find 5 proven ways to check the thermostat from visual inspection to testing with a multimeter. We will look at how to determine a breakdown based on indirect signs, what tools are needed for diagnosis, and what to do if the thermostat is really broken. All methods are suitable for popular models Indesit — B16FNX, C138G, T18, DF4180 and others with mechanical control.

Before you start checking, make sure that the problem is not related to other components: door seal, fan (in models with No Frost) or leakage Freon. If the refrigerator does not turn on at all, first check the socket, power cord and fuse.

1. Signs of a thermostat malfunction: when a check is needed

The thermostat in refrigerators Indesit does not break down immediately - usually its “death” is preceded by characteristic symptoms. Here top 7 signsthat should alert you:

• 🔄 The compressor is running. without stopping - the motor hums constantly, without turning off for “rest” (normally, the cycle is 20-30 minutes of operation and 10-15 minutes of pause).
• ❄️ Formation of a “snow coat” on the back wall of the refrigerator compartment (in models without No Frost) or excessive icing of the freezer.
• 🌡️ The temperature does not correspond to the set one —products freeze at minimum settings or, conversely, spoil at maximum.
• 🔌 The refrigerator does not turn on after defrosting or turning off the electricity (with a working outlet and power cord).
• 🔊 Clicks without starting the compressor — characteristic sounds of the relay operation are heard, but the motor does not starts.
• 💡 The light inside is on, but there is no cooling - this indicates an open circuit of the thermostat.
• 🔄 Spontaneous shutdown refrigerator, followed by turning on after 5-10 minutes.

If you observe at least 2-3 of these symptoms, the probability of the thermostat breaking down is 90%. However, a final diagnosis can only be made after testing. For example, constant operation of the compressor may be associated with both a freon leak and a malfunction of the start relay.

⚠️ Attention: In refrigerators Indesit with electronic control (for example, series EWT or BIAA 13) it is not the mechanical thermostat that is responsible for the temperature, but the temperature sensor control board. Diagnostics of such models requires other methods!

2. Where is the thermostat located in the Indesit refrigerator

In most models Indesit the thermostat is located inside the refrigerator compartment, next to the light bulb. To get to it, you need to:

1. Disconnect the refrigerator from the mains (remove the plug from the socket).
2. Remove all products from the top shelf (if the thermostat is located on top).
3. Remove the plastic cover or protective casing - it is secured with latches or screws (a Phillips head is required screwdriver).

Externally, the thermostat looks like a small box with temperature control knob (in mechanical models) or without it (in electronic ones). 2-4 wires are connected to it and capillary tube a thin copper tube that goes to the evaporator. Do not confuse it with freon lines!

In some models (for example, Indesit BI 16 or C 132 G), the thermostat can be hidden behind the rear panel of the refrigerator compartment. In this case, you will have to unscrew the screws and remove the internal lining.

What does the Indesit thermostat look like?

Usually it is a plastic or metal case measuring 5x5 cm with markings (for example, K59-L1550, Danfoss 077B6 or Ranco K59). The body has contacts for connecting wires and a hole for a capillary tube. In mechanical models, a temperature switch knob is attached to the thermostat.

3. Preparation for testing: tools and safety measures

To diagnose the thermostat you will need:

• 🔧 Phillips and flathead screwdrivers (for dismantling the panel).
• 📊 Multimeter (tester) - to check the resistance and continuity of the circuit.
• 🧊 A plate of cold water or ice (for testing the thermostat reaction).
• 📝 Marker or tape - to mark the wires when disconnecting.
• 🔌 Extension cord with grounding (if the outlet is far from the workplace).

Safety rules:

• 🚫 Do not test the thermostat under voltage - this may lead to electric shock!
• 🧤 Wear rubber gloves if the device is wet.
• 🔌 Unplug the refrigerator before any manipulations.
• 🔧 Do not pull on the capillary tube - it is easily damaged.

If you do not have a multimeter, you can check the thermostat the “old-fashioned” way - by closing the contacts (more on this below). However, this method does not provide a 100% guarantee of diagnosis.

⚠️ Attention: In refrigerators Indesit with a system No Frost the thermostat is often integrated with a defrost timer. If you are not confident in your skills, it is better to contact a specialist - an incorrect connection can damage the control board.

4. Method 1: Checking the thermostat with a multimeter (accurate method)

This is the most reliable diagnostic method that allows you to identify open circuit, short circuit or incorrect resistance. Follow the instructions:

1. Remove the thermostat (as described above) and disconnect all wires from it. Memorize or photograph the circuit connections!
2. Find pins 3 and 4 (usually they are signed or marked with arrows). These are the terminals that close/open when the temperature changes.
3. Set the multimeter to the dialing mode (or measure resistance at 200 Ohms).
4. Touch the probes to contacts 3 and 4:
   • 🔴 If at room temperature the circuit closed (resistance ~0 Ohm) - the thermostat is working.
   • 🟢 If the circuit open (resistance is infinite) - the thermostat is faulty.

Immerse the capillary tube in ice for 2-3 minutes and repeat the measurement:

• 🔴 If the circuit opened —the thermostat is working correctly.
• 🟢 If the circuit remained closed —the thermostat must be replaced.

For models with a thermostat Danfoss or Ranco the normal resistance between contacts 3 and 4 at room temperature should be within 0–50 Ohm. If the readings are outside these limits, the part is faulty.

Take a photo of the thermostat marking|Disconnect all wires, mark them with a marker|Order a similar thermostat (for example, on AliExpress or at a service center)|When installing a new thermostat, do not confuse the capillary tube with freon -->

5. Method 2: Testing without instruments (closing contacts)

If you do not have a multimeter, you can test the thermostat “short” by closing the contacts bypassing the regulator. This method is only suitable for mechanical models Indesit!

1. Unplug the refrigerator.
2. Remove the thermostat cover and disconnect the wires from it.
3. Find the contacts going to the compressor (usually these are brown and red/orange wires).
4. Connect them together insulated wire or with a paper clip.
5. Plug in the refrigerator.

Test results:

• ✅ If compressor started and is working —the thermostat is faulty (needs replacement).
• ❌ If the compressor does not start —the problem is in the start relay, compressor or control board.

⚠️ Important: Do not leave the contacts closed for more than 5-10 minutes - this can lead to overheating of the compressor!

6. Method 3: Cold water test (for mechanical thermostats)

This method allows you to check whether the thermostat responds to changes in temperature. You will need a plate of ice water.

1. Remove the thermostat without disconnecting the capillary tube.
2. Immerse only the capillary tube in ice water (not the whole thermostat!).
3. Wait 3-5 minutes and listen:
   • 🔊 If you hear click - the thermostat is working (reacts to cold).
   • 🔇 If there is no click - the thermostat does not work.

This method is less accurate than checking with a multimeter, but it helps to identify jammed mechanism inside the thermostat. If there is a click, but the refrigerator still does not work, the problem may be a jammed mechanism contacts or wires.

7. Method 4: Visual inspection of the thermostat and wiring

Sometimes a malfunction of the thermostat is visible to the naked eye. Inspect the part for:

• 🔥 Burnt or melted contacts —this indicates a short circuit.
• 💧 Traces of corrosion or oxidation on metal parts.
• 🧊 Damage to the capillary tube (kinks, cracks, gas leak).
• 🔌 Loose or oxidized wires —they can cause false alarms.

Also check integrity of wire insulationgoing to the thermostat. If it is damaged, this can lead to short circuits and unstable operation of the refrigerator.

Symptom	Probable cause	Solution
Burnt contacts	Short circuit or power surge	Replacing the thermostat, checking the power filter
Corrosion on the tube	Gas leak from the capillary	Replacement thermostat (cannot be repaired)
Oxidized wires	High humidity in the chamber	Cleaning contacts with alcohol, sealing connections
Cracks in the housing	Mechanical damage	Replacement with a new thermostat

⚠️ Attention: If the capillary tube of the thermostat Indesit is damaged, it cannot be repaired - only a complete replacement of the part! Attempts to solder or seal the tube will lead to incorrect operation of the sensor.

8. Method 5: Checking the thermostat in Indesit refrigerators with No Frost

In models with a system No Frost (for example, Indesit DF 5200 or ITF 118) the thermostat is often combined with defrost timer and a defrost sensor. Here the diagnostics are more complicated:

1. Disconnect the refrigerator from the mains.
2. Remove the back panel of the freezer (you will need to unscrew the screws).
3. Find temperature sensor —it looks like a small plastic cylinder with wires.
4. Disconnect the sensor connector and check its resistance with a multimeter:
   • 🔴 At room temperature: ~5–7 kOhm.
   • 🟢 When cooling (in the refrigerator): ~20–30 kOhm.

If the resistance does not change or is equal 0/infinity, the sensor is faulty. In this case, it is also worth checking control board —it may not send signals to the thermostat.

For models Indesit with an electronic display (for example, EWT 28752) self-diagnosis is difficult - it requires a special tester for the board or computer diagnostics.

FAQ: Frequently asked questions about Indesit thermostats

Is it possible to repair the thermostat or just replace it?

Thermostats Indesit cannot be repaired - they can only be replaced. Exception: oxidized contacts (they can be cleaned with alcohol). The average cost of a new thermostat is 800–2500 rubles, depending on the model.

Which thermostat is suitable for my Indesit refrigerator?

The number of the original thermostat is indicated on its body (for example, K59-L1550 or Danfoss 077B6344). An analogue with the same characteristics is suitable for replacement. Popular replacements:

• Ranco K59 → K59-L1550, K59-L1943;
• Danfoss 077B6 → 077B6344, 077B6550.

What happens if you leave a faulty thermostat?

The consequences depend on the type of failure:

• If the thermostat stuck in the “on” position the compressor will burn out from overheating.
• If the thermostat does not turn on the compressor —the food will spoil and ice will form on the back wall.
• If the thermostat gives false signals —the refrigerator will turn on and then turn off, which will shorten the life of the motor.

Is it possible to replace the thermostat yourself?

Yes, if you have basic skills with a screwdriver and a multimeter. The main thing is do not mix up the wires when connecting, do not damage the capillary tube. In models with No Frost it is better to entrust the replacement to a specialist.

How much does it cost to replace a thermostat in the service?

Cost of work in service centers:

• Replacement thermostat in a mechanical refrigerator: 1500–2500 rubles.
• Replacement of the temperature sensor in No Frost: 2000–3500 rubles.
• Diagnostics + replacement: 2500–4000 rubles.

The price depends on the model and region.