Connecting the thermostat to the refrigerator: instructions with photos and diagrams

The thermostat is the “brain” of the refrigerator, responsible for maintaining the set temperature. When it fails, the compressor either works without stopping or does not turn on at all, which leads to food spoilage or equipment breakdown. Replacing a thermostat is one of the most common repair operations that you can do yourself, saving on calling a technician.

In this article we will look at how to properly connect the thermostat to refrigerators of different brands (Samsung, LG, Atlant, Biryusa etc.), what tools you will need, and what to pay attention to when working with electricity. You will learn how to test the thermostat for functionality, where the temperature sensor is located in your model, and how to avoid common mistakes when connecting. If you have never dealt with repairing household appliances, don’t worry: we will give step-by-step instructions with photos and diagrams that will make the process clear even for beginners.

Important: before starting work be sure to unplug the refrigerator and defrost it. This is not only a safety issue, but also a necessity for accurate diagnosis. If the compressor was turned on immediately before the repair, let it cool for 10–15 minutes - this way you will avoid false readings when checking the thermostat.

1. Signs of a malfunctioning thermostat: when replacement is needed

Before you take up a soldering iron or screwdriver, make sure that the problem is in the thermostat. Here are the key symptoms of its breakdown:

• 🔴 The compressor does not turn on — the refrigerator does not cool, the light inside is on, but the motor is silent. This may indicate an open circuit in the thermostat.
• ❄️ Continuous operation of the compressor —the engine hums without stopping, the freezer is covered with a thick layer of ice. Most likely, the thermostat is “stuck” in the “on” position.
• 🌡️ Temperature mismatch —the refrigerator compartment is too warm or, conversely, freezes the food, the adjustment knob is turned to the correct position.
• 🔌 Clicks without starting — characteristic sounds of relay operation are heard, but the compressor does not start. There may be a problem with the thermostat contacts.

If you observe at least one of these signs, there is a high probability that the thermostat requires replacement. However, before purchasing a new sensor be sure to check it with a tester - sometimes the problem lies in broken wiring or oxidation of contacts.

⚠️ Attention: On electronically controlled refrigerators (for example, Samsung No Frost or LG Inverter), the thermostat may be part of the board management. In this case, replacing only the sensor is impossible - repair or replacement of the entire module is required.

2. Tools and materials for connecting the thermostat

For work you will need:

If you are not sure about the thermostat model, take a photo of the old sensor and show the photo to the seller at the spare parts store. Most thermostats are marked, for example:

• K59-L1411 — for refrigerators Atlant and Biryusa,
• WDF19 —for models Indesit i Ariston,
• 25T65-4 — for Samsung with the system No Frost.

Where to buy a thermostat? Optimal options:

• 🛒 Specialized stores of spare parts for household equipment (for example, "Rembyttekhnika").
• 🌍 Online platforms: AliExpress (longer wait), Yandex Market or Ozon (faster, but more expensive).
• 🔧 Brand service centers - sometimes sell original parts with a guarantee.

3. Where is the thermostat located in the refrigerator: search by model

The location of the thermostat depends on the design of the refrigerator. Here are typical places:

• 🔘 Inside the refrigerator compartment —the most common option. The thermostat is hidden under a plastic cover or temperature control knob (for example, in Atlant MHM-170 or Biryusa 10).
• 🔌 Outside, on the back wall —typical for older models (ZIL, Minsk) or some Indesit. Look for a box with wires next to the compressor.
• ⚙️ In the control unit — in refrigerators with an electronic display (for example, Samsung RL-34 or LG GA-B409), the thermostat can be built into the board.
• 🧊 In the freezer compartment —rarely, but found in two-compressor models (Liebert, some Bosch).

To find the thermostat:

1. Unplug the refrigerator.
2. Remove the shelves and drawers, if they interfere with access to the panel with the temperature knob.
3. Carefully pry up the plastic cover with a screwdriver - the thermostat is usually hidden under it.
4. If the sensor is not inside, inspect the back wall (after moving the refrigerator aside).

Important! In refrigerators with a system No Frost The thermostat is often combined with a defrost timer. In this case, replacement requires more skills - you may need to solder the contacts on the board.

What does the thermostat look like?

Usually it is a small box (3-5 cm) with plastic or a metal body, from which a thin capillary tube (temperature sensor) extends. On the body there are terminals for connecting wires and model markings. In older models, the thermostat may be round with an adjustment knob.

4. Thermostat connection diagrams: step-by-step instructions

Before disconnecting the wires take a photo of their location or draw a diagram. This will help to avoid errors when connecting back. Typical diagrams for different models:

Diagram 1. Classic refrigerator (Atlant, Biryusa, Stinol)

In such models, the thermostat is connected in series with the compressor. Procedure steps:

Turn off the power and defrost the refrigerator|

Remove the plastic panel with the temperature knob|

Disconnect the capillary tube from the evaporator (carefully, do not bend it!)|

Take a photo or mark the wires before disconnecting|

Connect the wires to the new thermostat in the same sequence|

Install the sensor in place and secure the panel|

Check the operation of the refrigerator (the compressor should turn on/off)-->

Scheme 2. Refrigerators with electronic control (Samsung, LG)

Here the thermostat can be part of the board or connected via a connector. Algorithm:

1. Remove the top cover of the refrigerator (usually secured with 2-4 screws).
2. Find the control unit - it can be hidden under a foam cover.
3. Disconnect the thermostat connector (on the board it is usually labeled as THERMISTOR or TEMP SENSOR).
4. Connect the new sensor, observing the polarity (if there are “+” and “–”)).
5. Check the resistance of the sensor with a multimeter (for most models at room temperature it should be within 4–7 kOhm).

Diagram 3. Two-chamber refrigerators (Indesit, Ariston)

In such models there may be two thermostats - separately for the refrigeration and freezer compartments. Replacement is carried out in the same way, but:

• 🔹 Check which sensor is faulty (usually the refrigerator thermostat fails).
• 🔹 In the freezer, the sensor can be built into the evaporator - you will need to defrost and dismantle the back panel.

Critical error: never connect the thermostat directly to a 220V network without a compressor! This will lead to a short circuit and can burn the wiring.

5. Checking the thermostat with a multimeter: how to check for a malfunction

Before changing the thermostat, make sure that it is really broken. To do this:

1. Remove the thermostat without disconnecting it. capillary tube.
2. Switch the multimeter to continuity mode (or measure resistance at 200 Ohm).
3. Connect the probes to terminals 3 and 4 (usually they signed; if not, see the diagram for your model).
4. Turn the thermostat knob from the minimum to the maximum position:
   • 🔊 If you can hear sound signal (or the resistance changes from 0 to ∞) - the thermostat is working.
   • 🚫 If the readings do not change, the sensor is faulty.

For more accurate diagnostics:

• 🧊 Place the capillary tube in a glass with ice water for 2-3 minutes. A working thermostat should open the circuit (show infinite resistance).
• 🔥 Then heat the tube with your hands or warm water - the circuit should closed (resistance 0 Ohm).

If the thermostat does not respond to temperature changes, it needs to be replaced. In rare cases, the problem lies in oxidation of the contacts —they can be cleaned with sandpaper or alcohol.

⚠️ Attention: In refrigerators with an inverter compressor (LG, some Samsung), the thermostat may not ring in the standard way. In this case, check the resistance of the sensor (usually 4–10 kOhm at +20°C).

6. Typical mistakes when connecting a thermostat and how to avoid them

Even experienced craftsmen sometimes make mistakes that lead to repeated errors. breakdown. Here's what you shouldn't do:

• ❌ Mix the wires - if you connect the phase and zero incorrectly, the compressor may burn out. Always check the diagram or photograph!
• ❌ Bend the capillary tube - this will break its tightness, and the thermostat will show the wrong temperature.
• ❌ Use a thermostat from another model —even if it looks similar, the temperature range may not match.
• ❌ Forget about grounding —in metal refrigerators (ZIL, Minsk) this can lead to electric shock.
• ❌ Live soldering —always unplug the refrigerator from the mains before work!

A common problem after replacement is the compressor does not turn on. Reasons:

• 🔌 Incorrect wire connection (check the diagram).
• 🔋 The starting capacitor is discharged (need call).
• 🧊 The thermostat is not in contact with the evaporator (check the fastening of the capillary tube).

If after replacement the refrigerator works but does not turn off, the new thermostat may be set to too low a temperature. In mechanical models, this is adjusted by the screw on the sensor housing (see the instructions for the specific one). model).

7. Replacing the thermostat in refrigerators of popular brands

The design of thermostats may vary depending on the manufacturer. Let's consider. nuances for the most common brands:

Atlant and Biryusa

• 🔧 Thermostat is usually model K59 or TAM-133, located under the temperature knob.
• 🔌 The wires are connected through terminals - they can be easily disconnected with a screwdriver.
• ⚠️ Carefully monitor the capillary tube: it is attached to the evaporator with a plastic clamp.

Indesit i Ariston

• 🔧 Thermostats are used WDF19 or KIX-15.
• 🔌 In two-chamber models, the refrigerator compartment sensor is hidden behind a plastic panel on the ceiling.
• 🛠️ For dismantling you will need a Torx screwdriver T20.

Samsung i LG s No Frost

• 🔧 The thermostat is often combined with a control board (model PS-34 or analogues).
• 🔌 To replace, you need to unsolder the old sensor and solder a new one (you need a soldering iron and flux).
• ⚠️ After replacement, you may need to reset errors through the service menu (see the instructions for the model).

Stinol i Nord

• 🔧 Thermostats K57 or RTK-3, located outside on the back wall.
• 🔌 The wires are connected through connectors - they cannot be cut, only carefully disconnected.
• 🛠️ When replacing, check the protective relay circuit (can be combined with thermostat).

To accurately identify the thermostat, use the serial number of the refrigerator (located on the nameplate on the back or inside the chamber), you can use it on the Internet to find an original spare part.

⚠️ Attention: In refrigerators Liebert, Bosch and some thermostats may have non-standard connectors. If you are not confident in your soldering skills, it is better to contact the service. Electrolux thermostats may have non-standard connectors. If you are not confident in your soldering skills, it is better to contact the service.

8. What to do if after replacing the thermostat the refrigerator does not work.

Have you replaced the thermostat, but the compressor does not start? Don't panic - check the following:

1. Power: Make sure that the plug is firmly inserted into the socket and there is voltage in the network (check the refrigerator light).
2. Start relay: If you hear it when you turn it on. there is a click, but the compressor does not hum - the relay may have burned out. It is located next to the compressor in the black box.
3. Capacitor: Test it with a multimeter (should show resistance, and then gradually increase to infinity).
4. Open circuit: Check if one of the wires was disconnected when installing the thermostat.
5. Freezing the capillary tube: If the sensor was pinched or bent, it may show false data. Try to carefully straighten the tube.

If the compressor hums but does not start:

• 🔊 Perhaps motor jammed try turning it manually (turning off the power!) To do this, remove the protective casing and slowly turn the shaft. compressor.
• 🔋 Check voltage on the windings (between terminals C, S and R there should be 20–40 Ohm).

If all checks are passed, but the refrigerator does not work, the problem may be control board (for electronic models) or break of compressor winding. In this case, you can’t do without professional diagnostics.

FAQ: Frequently asked questions about connecting the thermostat

Is it possible to replace the thermostat without soldering?

Yes, in most mechanical refrigerators (Atlant, Biryusa, Stinol) the thermostat is connected via terminals or connectors. Soldering is only needed if the wires are oxidized or broken off. In electronic models (Samsung, LG), sometimes it is necessary to solder the sensor to the board.

What thermostat is suitable for a refrigerator Indesit BIAA 13?

Thermostat WDF19 or its analogs are suitable for this model: KIX-15, Danfoss 077B6. The main thing is that the temperature range matches (usually from -24°C to +10°C). Before purchasing, check the markings with the old thermostat.

What will happen if you connect the thermostat incorrectly?

The consequences depend on the error:

• If you confuse phase and zero, the compressor may burn out when turned on.
• If you connect incorrectly capillary tube - the refrigerator will work without stopping or, conversely, will not turn on.
• If you use a thermostat with a different temperature range, the food will freeze or spoil.

Always check the connection diagram!

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

The cost depends on the refrigerator model and region:

• For mechanical refrigerators (Atlant, Biryusa) — 1500–2500 rub. (with spare parts).
• For electronic (Samsung, LG) — 3000–5000 rub., since board diagnostics are required.
• In Moscow and St. Petersburg, prices for 20–30% higher than in the regions.

Independent replacement costs 500–1500 rubles. (the cost of the thermostat).

Is it possible to repair the thermostat, or only replacement?

In 90% of cases, the thermostat is not repaired - it is replaced with a new one. Exceptions:

• If the problem is oxidized contacts -they can be cleaned.
• If the wire is unsoldered —it can be soldered back.
• If clogged capillary tube —it can be blown out (but this is a temporary solution).

In other cases (open circuit, loss of tightness) replacement is required.