Replacing the thermostat in the refrigerator: how to change the thermostat on your own

The thermostat (or thermostat) is a key element of the refrigerator, responsible for maintaining the set temperature. When it fails, the unit stops freezing, works without stopping, or, conversely, does not turn on at all. Replacing a thermal relay is one of the most common repair operations that can be performed without calling a technicianif you act carefully and follow the instructions.

In this article we will look at how Diagnose a thermostat malfunction yourselfto select a suitable replacement, dismantle the old part and install a new one. You will learn what tools you will need, how to avoid common mistakes and what to do if after replacement the refrigerator still does not work. The material is suitable for most models Atlant, Indesit, Samsung, LG, Beko and other brands with mechanical controls.

Before starting repairs, make sure that the problem is in the thermostat, and not in the compressor, start relay or freon leak. To do this, it is enough to carry out a simple test with a multimeter - read how to do this below.

Symptoms of a thermal relay malfunction: when replacement is needed

The thermostat does not break down immediately - usually its malfunction appears gradually. Here main symptomsthat indicate the need for replacement:

• 🔴 Refrigerator does not turn on after disconnecting from the network (the light inside is on, but the motor is silent).
• ❄️ The compressor operates continuouslywithout turning off for rest, which leads to icing of the rear wall.
• 🌡️ Temperature in the chambers does not correspond set values (too high or, conversely, the food freezes).
• 🔊 The relay clicks are audible, but the engine does not start (there may be a problem with the thermostat contacts).
• 🔄 The refrigerator turns off spontaneously turns on after long periods of time.

If you observe at least one of these signs, there is a high probability that the thermostat has failed. However, before replacing, it is worth excluding other reasons:

• 🔌 Check is the door closed tightly - sometimes the seal wears out and warm air gets inside.
• 🧊 Make sure that super freezing mode is not enabled (if your model has it).
• ⚡ Check mains voltage —the problem may be power surges.

If after these checks If the problems persist, proceed to diagnosing the thermal relay. In 80% of cases, replacing it solves the problem.

How to check a thermostat with a multimeter: step-by-step diagnostics

Before changing the thermostat, you need to check for functionality. To do this, you will need a multimeter (tester) in resistance measurement mode. Here's how to do it:

1. Disconnect the refrigerator from the mains and remove all products from the chambers.
2. Remove the protective cover of the thermostat (usually it is located inside the refrigerator compartment, next to the light lamp or on the top panel).
3. Disconnect terminals with wires from the thermostat (remember or take a photo of their location!).
4. Switch the multimeter to mode Ω (200 Ohm) and connect the probes to contacts 3 and 4 (usually they are signed).

Now you need to check the resistance in two states:

• 🔹 At room temperature (the thermostat is not cooled): the resistance should be 0 Ohm (closure of contacts).
• 🔹 After cooling (put the thermostat in the freezer for 10-15 minutes): the resistance should become ∞ (open).

If in both cases the readings do not change (for example, always 0 or always ∞), the thermal relay faulty needs replacement. Also inspect the contacts for oxidation or burning this is another sign of a breakdown.

What to do if there is no multimeter?

You can check the thermostat “by ear” - when you turn the temperature control knob, a slight click should be heard inside it. If there is no click or it is barely audible, the part is faulty.

⚠️ Attention: Some modern refrigerators (for example, Samsung No Frost or LG Inverter) are equipped with electronic thermostatswhich are checked differently. If your model has a display and buttons instead of a mechanical handle, it is better to contact a specialist.

Choosing a new thermostat: how not to make a mistake with the model

You can choose a replacement thermostat by labeling the old or by refrigerator model. Here's what you need to consider:

• 📌 The brand and model of the thermostat (for example, K59-L1430, Danfoss 077B6, Ranco K59). Usually it is indicated on the body of the part.
• 🔧 Type of fastening: some thermostats are fixed with screws, others with latches.
• 🔌 Number and location of contacts (most often 4 or 6).
• 📏 Length of the capillary tube (it must match the old one, otherwise the thermostat will not work correctly).

If you are not sure of the choice, use one of the methods:

1. Search by refrigerator model in catalogs spare parts (for example, PartMaster, Spare parts for refrigerators or eBay).
2. Consultation in service center - bring an old thermostat, and they will select an analogue for you.
3. Photo of the old part —send the seller a photo with clear markings.

The cost of a thermal relay varies from 500 to 3000 rubles depending on the brand and model For budget refrigerators (Birusa, Polar) universal thermostats are suitable K59 or Danfoss, for premium ones (Liebherr, Bosch) it is better to take original spare parts.

⚠️ Attention: When purchasing a thermostat for refrigerators with a system No Frost check whether a defrost sensor is needed (defrosterIn some models, the thermostat and sensor are combined into one unit.

Tools and preparation for replacing the thermostat

To replace the thermostat you will need:

New thermostat (check compatibility)

Phillips and flathead screwdriver

Multimeter (for double checking)

Pliers or wire cutters

Insulating tape or heat-shrinkable tube

Photo or wiring diagram

Rubber gloves (optional)-->

Also prepare your workplace:

• 🧹 Disconnect refrigerator from the mains and defrost it (if there is ice).
• 📦 Remove all shelves and drawers from the refrigerator compartment for free access to the thermostat.
• 🔦 Organize good lighting - you can use a flashlight or table lamp.

If the thermostat is located behind the control panel (as in models Samsung RL-34 or LG GA-B409, you may need to remove the top cover of the refrigerator. To do this:

1. Unscrew the screws at the back (usually 2-4 pieces).
2. Carefully slide the cover forward and remove it.
3. Detach the plastic panel with the adjustment knob temperature.

Step-by-step instructions: how to remove the old and install a new thermostat

Now we move on to the repair itself. Follow the steps:

1. Take a photo or sketch diagram of connecting wires to the thermostat. This will help not to confuse them during reassembly.
2. Disconnect all wires from the thermal relay terminals. If the contacts are oxidized, clean them with fine sandpaper.
3. Unscrew the mounting screws (usually 1-2 pieces) and remove the old thermal relay.
4. Carefully remove the capillary tube from the fasteners. Do not bend it too much!

Now install the new thermostat:

1. Place capillary tube the new thermostat into the same fastenings as the old one.
2. Fix the thermal relay in place screws (do not overtighten!).
3. Connect wires according to the diagram. If the terminals are not labeled, be guided by the colors (usually black - ground, brown - phase, yellow-green - ground).
4. Make sure that all contacts are tightly fixed - a weak connection can lead to sparking.

After installation, check the operation of the refrigerator:

• 🔌 Plug it into the network and set average temperature (for example, +4°C).
• 🕒 Wait 15-20 minutes - the compressor should start and turn off after a while.
• 🌡️ Check whether the cold is building up in the chambers.

1) Correct connection of the wires.

2) Voltage in the socket (must be 220V).

3) Serviceability of the compressor (listen to see if it hums when starting).-->

Typical errors when replacing a thermostat and how to avoid them

Even experienced craftsmen sometimes make mistakes that lead to repeated breakdowns. Here the most common of them:

• 🔌 Incorrect connection of wires - if you confuse phase and zero, the thermostat may burn out. Always check the diagram!
• 🔧 Tightening the mounting screws - this leads to deformation of the thermostat housing.
• 🧊 Damage to the capillary tube - if it is bent or squeezed, the thermostat will show an incorrect temperature.
• 🔩 Use of an incompatible thermostat —even if it is similar in appearance, the internal parameters may not be suitable.
• 🔌 Forget to check the starting relay —sometimes the problem is not in the thermostat, but in it.

To avoid these mistakes:

• 📸 Take photos of each stage of disassembly - this will help you remember how it was connected before.
• 🔍 Check the contacts with a multimeter after connecting - make sure there is no short short circuits.
• 🛠️ Use a torque screwdriver (or do not use excessive force) when tightening the screws.

⚠️ Attention: If after replacing the thermostat the refrigerator works without stoppingmay be faulty compressor or is freon leak. In this case, professional diagnostics will be required.

What to do if replacing the thermostat does not helped?

In rare cases, replacing the thermostat does not solve the problem. This may mean that:

• 🔋 Faulty compressor start relay — it is responsible for starting the motor. Check it with a multimeter (the resistance between the contacts should be 20–40 Ohm).
• ⚡ Problems with power supply -voltage surges or faulty socket. Try connecting the refrigerator through a stabilizer.
• ❄️ Freon leak - if the compressor works, but does not freeze, the evaporator tube may be damaged.
• 🔧 Faulty motor-compressor - if it hums, but does not start, or heats up more than usual.

To diagnose these problems, you will need special tools (for example, pressure gauge for checking freon pressure or tester for starting relayIf you are not confident in your abilities, it is better to call a specialist.

How to check the starting relay?

Turn off the refrigerator, remove the starting relay from the compressor (it is secured with latches or screws), test the contacts with a multimeter:

- Between S (start) And M (motor) — resistance 10–30 Ohm.

- Between S i L (line) — ∞ (open).

If the readings are different, the relay is faulty.

If the refrigerator turns on, but does not freezetry:

1. Check temperature setting - the thermostat may be set to minimum.
2. Inspect No Frost fan (if any) - it could become clogged with ice or burnt out.
3. Test defrost heater - in No Frost systems it often fails.

FAQ: Frequently asked questions about replacing the thermostat

Is it possible to replace the thermostat without defrosting the refrigerator?

Technically yes, but not recommended. Ice on the evaporator can prevent the removal of the capillary tube, and there is also a risk of damage to parts Better. defrost the refrigerator 12–24 hours before repair.

How long does it take to replace a thermostat?

On average 30–90 minutes, depending on the model of the refrigerator and the location of the thermostat In refrigerators with top mounting. (for example, Atlant) this is done faster than in models with internal placement (for example, Samsung).

Can I use a thermostat from another refrigerator model?

Only if it is completely matches by:

• Type and length of capillary tube;
• Number and location of contacts;
• Temperature range (indicated on the body).

Universal thermostats (for example Danfoss 077B6) are suitable for many budget models, but for premium refrigerators it is better to take the original.

What happens if you connect the wires to the thermostat incorrectly?

The consequences depend on the error:

• If mix up phase and zero —the thermostat may burn out when turned on.
• If you connect incorrectly contacts compressor —the motor will not start or will run continuously.
• If you forget to connect grounding there may be an electric shock when touching the case.

Always check the connection diagram!

Do you need to call a technician after replacing it yourself? thermostat?

Only if:

• Refrigerator does not turn on after replacement;
• Compressor buzzes, but does not starts;
• The temperature in the chambers does not correspond set;
• Appears extraneous sounds (clicks, crackling).

In all these cases, the problem may be more complex than it seemed (for example, the compressor or electronics is faulty).