Connecting the K59 thermostat to the refrigerator: diagram, instructions and typical errors

Thermoregulator K59 is one of the most common thermostats for domestically produced household refrigerators. It is installed in models Atlant, Biryusa, Stinol and others. But even experienced craftsmen sometimes make mistakes when connecting, which leads to unstable operation of the equipment or breakdown of the compressor. This article will help you figure out how to properly replace or install a thermostat K59, avoiding typical problems.

Many refrigerator owners are faced with the need to replace the thermostat due to its failure - the unit stops turning off, freezes too much or, conversely, does not cool. The cause may be either mechanical wear or power surges. Connecting the K59 thermostat requires care and understanding of the operating principle of the system. If you have never dealt with electrical circuits, it is better to entrust the work to a specialist - a mistake can cost more than calling a specialist.

In this article we will look in detail at:

• 🔍 How it works thermostat K59 and where it is located in the refrigerator
• 🔧 Step-by-step instructions for connecting with photo diagrams
• ⚡ Typical errorswhich lead to compressor breakdown
• 📊 How to check performance after installation
• ❄️ Temperature setting for optimal operation

Design and principle of operation of the K59 thermostat

Thermoregulator K59 is an electromechanical device that supports the set temperature in the refrigerator compartment. It consists of:

• 🔘 Bellows tube with refrigerant (freon) that responds to temperature changes
• 🔌 Contact groupsclosing/opening the compressor power supply circuit
• 🎚️ Adjusting screw to adjust the response range
• 🔗 Housings with terminals for connecting wires

When the temperature in the chamber rises, the pressure in the bellows tube increases, and the contacts close - the compressor turns on. When cooled to the set value, the contacts open and the motor turns off. The K59 thermostat has no electronic components - it works solely due to the physical properties of the gas in the tube, which makes it reliable, but sensitive to mechanical damage.

The terminals are usually marked on the thermostat body:

• 3 — general contact (220V power supply)
• 4 — compressor output
• 6 — contact for the lighting lamp (if any)

In some modifications (for example, K59-Lthere may be an additional terminal for a signal lamp or fan. Before connecting, be sure to check the diagram of your refrigerator model —the location of the terminals is sometimes different.

Where is the K59 thermostat located in the refrigerator

In most models, the thermostat is located inside the refrigerator compartment, next to the lighting lamp. The exact location depends on the brand:

• 🔹 Atlant, Biryusa: under the top cover, on the right or left (behind the plastic panel)
• 🔹 Stinol, Indesit: can be hidden behind the back wall or in the upper corner of the camera
• 🔹 Old Soviet refrigerators (ZIL, Minsk): often mounted on the side wall of the lamp

To get to the thermostat:

1. Unplug the refrigerator.
2. Remove the plastic cover or cover (usually it is held on by latches or screws).
3. Disconnect lamp protective casing (if it interferes).
4. You will see a small box with a tube and wires - this is the thermostat.

The bellows tube of the thermostat is attached to the evaporator (the back wall of the chamber) using a metal clamp or clip. Do not tear off the tube by force - it is fragile and damage will require replacement of the entire thermostat.

What to do if the thermostat tube is torn off?

If the bellows tube is damaged, the K59 thermostat cannot be restored - it will have to be replaced completely. Attempts to solder or seal the tube will lead to refrigerant leakage and incorrect operation.

Step-by-step instructions for connecting the K59 thermostat

Before starting work, prepare the tools:

• ⚡ Screwdriver (Phillips and flat)
• 🔧 Pliers or wire cutters for crimping terminals
• 📸 Multimeter (for checking contacts)
• 🔌 Electrical tape or heat shrink tube

Order connection:

1. Disconnect the refrigerator from the network and defrost it (if you need to replace the thermostat).
2. Remove the protective panel and disconnect the wires from the old thermostat. Take a photo of the connection diagramso as not to confuse the wires!
3. Carefully remove the bellows tube from the mount on the evaporator.
4. Install a new thermostat K59 in place of the old one, securing it with screws or latches.
5. Connect the wires to the terminals according to the diagram (see table below).
6. Fix the bellows tube on the evaporator (it should fit tightly to the metal for accurate temperature measurement).
7. Assemble the panel back and turn on refrigerator.

Wire connection diagram for thermostat K59:

Wire colors may vary depending on the refrigerator model. Always refer to the factory markings or diagram, and not on the color of the insulation.

Typical connection errors and how to avoid them

Even a small mistake when installing a thermostat can lead to serious damage. Here are the most common problems:

• ❌ The wires on the terminals are mixed up 3 and 4 → the compressor runs continuously or does not turn on.
• ❌ Poor contact at the terminals → the thermostat is buggy, the refrigerator turns off spontaneously.
• ❌ The bellows tube is not attached to the evaporator → the thermostat operates with a delay or incorrectly.
• ❌ Using a thermostat with a different range temperature (for example, K57 instead K59) → incorrect cooling mode.

⚠️ Attention: If after connecting the compressor does not turn off for more than 2 hours, turn off the refrigerator immediately! This is a sign that the thermostat contacts are stuck closed. Long-term operation without stopping will lead to overheating and failure of the motor.

Another common mistake is using heat shrink tube instead of electrical tape to insulate the terminals. There is high humidity in the refrigerator compartment, and if the tube is not sealed, the contacts may oxidize. It is better to use PVC electrical tape or special caps for the terminals.

If after replacing the thermostat the refrigerator is unstable (for example, it freezes too much or does not cools), check:

• 🔹 Correct connection of the wires (especially phase and zero).
• 🔹 The tight fit of the bellows tube to the evaporator.
• 🔹 Setting the adjusting screw (see the next section).

Configuring the K59 thermostat after connection

After installing the thermostat, it must be calibrated for correct operation. There is an adjusting screw on the body K59 here (usually under a plastic plug). By rotating it, you can change the response range:

• 🔩 Clockwise - increases the shutdown temperature (the compressor will work longer).
• 🔩 Counterclockwise - reduces the shutdown temperature (the compressor will turn on more often).

Optimal settings for the refrigeration chamber:

• 🥶 Compressor switch-on temperature: +4…+5°C
• ❄️ Switch-off temperature: +1…+2°C

For settings:

1. Place the thermometer in the refrigerator compartment.
2. Turn the screw in small steps (¼ turn), waiting for the compressor to operate.
3. Check the temperature 2-3 hours after each change.
4. Make sure that the motor turns off when +2°C and turns on when +5°C.

⚠️ Attention: Do not tighten the adjusting screw all the way! This may damage the thermostat mechanism. The maximum rotation is 1.5–2 full turns from the original position.

If your refrigerator has a winter mode (switch on the body), after setting the thermostat, check its operation in both positions. In winter mode, the compressor should turn on less often, since the ambient temperature is lower.

Checking the functionality of the K59 thermostat

After connecting and setting, you need to make sure that the thermostat is working correctly. To do this:

1. Checking with a multimeter:
   • Put the device into dialing mode.
   • Connect the probes to the terminals 3 and 4.
   • When you rotate the adjusting screw, a sound should be heard sound signal (closing/opening).

Test in real conditions:

• Turn on the refrigerator and wait until the compressor starts working.
• After 10-15 minutes, manually turn the adjusting screw counterclockwise - the motor should turn off.
• If the compressor does not respond, the thermostat is faulty or connected incorrectly.

If the thermostat passes the test with a multimeter, but the refrigerator is unstable, the reason may be:

• 🔹 Compressor malfunctions (does not create the required pressure).
• 🔹 Freon leak (evaporator is not cooled).
• 🔹 Contamination of the capillary tube (congestion in the system).

⚠️ Attention: If the contacts are tested with a multimeter 3 i 4 do not close in any position of the screw, the thermostat K59 is faulty and must be replaced. There is no point in trying to repair it - the mechanism is not dismountable.

For accurate diagnostics, you can temporarily connect a known working thermostat (for example, removed from another refrigerator). If the unit works normally with it, the problem is in K59.

Frequently asked questions about the K59 thermostat

❓ Is it possible to replace K59 with K57 or another thermostat?

Theoretically it is possible, but not recommended. Thermostats of the series K59 i K57 have different temperature ranges:

• K59: -24…+12°C (for refrigeration chambers)
• K57: -32…+15°C (for freezers)

If you put K57 in the refrigerator compartment, the compressor will turn on too rarely and the food will not cool to the desired temperature. As a last resort, you can use K59-P (with increased accuracy), but it is better to find the original model.

❓ Why does the new K59 thermostat not turn off the compressor?

There are several reasons:

1. Incorrect connection of wires (mixed up 3 and 4).
2. Stuck adjusting screw (try to carefully turn it in both directions).
3. Malfunction of the compressor or start relay (the thermostat is not to blame).
4. The bellows tube is not attached to the evaporator (the thermostat does not “feel” the temperature).

First check the connection diagram and position of the tube. If everything is correct, but the problem remains, the thermostat is defective (rarely, but it happens).

❓ How to check the thermostat K59 without a multimeter?

You can use the "refrigerator method":

1. Disconnect the refrigerator from the network.
2. Remove the thermostat and place it in a container with cold water (+2…+4°C).
3. Connect to the terminals 3 and 4 wires with a light bulb (220V).
4. If the light comes on, the thermostat is working. If not, replacement is required.

Be careful! Working with 220V voltage is dangerous.

❓ How much does the K59 thermostat cost and where to buy it?

The price of a new one K59 varies from 500 to 1200 rubles depending on the region and the seller:

• In stores of spare parts for household appliances (Elektrosila, Rembyttekhnika).
• On marketplaces (Yandex Market, Ozon, Wildberries).
• At service centers for refrigerator repairs.

When purchasing, check whether the thermostat is suitable for your refrigerator model (sometimes modification is required K59-L or K59-P).

❓ Is it possible to repair the K59 thermostat with your own hands?

Thermostat K59 - a non-separable device with a sealed bellows system. Any attempts to disassemble it will lead to gas leakage and loss of performance. The only option is to replace it with a new one.

Exception: if the problem is in oxidized contacts, they can be cleaned with fine sandpaper and treated with alcohol. In 90% of cases, the malfunction lies in a mechanical part that cannot be repaired.