A sudden stop in the operation of refrigeration equipment or, conversely, its continuous hum often indicates the failure of the temperature sensors. If your Position stops freezing or has turned food into an icy monolith, in most cases it is thermoregulatorthat becomes the culprit. This small unit is responsible for maintaining a given temperature regime inside the chambers, closing and opening the electrical circuit of the compressor depending on the readings.
Diagnostics of this element requires care and compliance with safety precautions, since you will be working with electric current and refrigerant. Before calling a technician or buying a new part, you need to conduct a series of simple but informative tests that will help you understand whether it is worth changing the regulator or whether the problem lies deeper. In this article, we will analyze in detail the algorithm of actions for checking the serviceability of the thermostat.
Main signs of a thermostat malfunction
Symptoms of failure thermostat often are twofold: the refrigerator either does not turn on at all, or works without stopping. In the first case, the compressor is silent, and there is room temperature inside; in the second, the unit hums around the clock, trying to cool the chamber to unattainable values. Understanding these signals is the first step to successful repair.
Pay attention to the following alarm bells that indicate the need for inspection:
- ❄️ The compressor does not start even after defrosting and long periods of inactivity.
- 🔊 The motor-compressor works without interruptions, without taking a break.
- 🌡️ There is a “snow coat” in the fridge compartment or food begins to freeze at the back wall.
- 💡 The light in the chamber is on, but there is no cold (with the compressor running, this may indicate a leak, but is often confused with thermoregulation).
It is important to note that similar symptoms can occur if the start-up relay or the compressor itself malfunctions. Therefore visual diagnostics must be accompanied by an instrumental check.
⚠️ Attention: If you notice that the regulator clicks, but the compressor does not start, this may indicate burnt contacts inside the thermostat itself or a problem with the start relay. Do not try to start the unit repeatedly - this may lead to burnout of the motor windings.
Preparation for diagnostics and safety precautions
Any work related to the electrical components of the refrigerator Pozisshould be carried out only after completely disconnecting the device from electrical networks. Unplug the plug and make sure there is no access to water or wet surfaces. Ignoring this rule may result in electric shock.
To carry out high-quality diagnostics, you will need a minimum set of tools. The main device will be multimeter (tester), which will allow you to ring the circuit for the presence of resistance. You may also need a flathead and Phillips screwdriver to remove the plastic panels.
The preparation process includes the following steps:
- 🔌 Completely disconnecting the refrigerator from the AC mains.
- ❄️ Defrosting the chambers for 10-12 hours (if there is a suspicion of icing of the evaporator).
- 🛠️ Preparing a workplace with good lighting.
- 📸 Taking photographs of the wiring diagram before disconnecting them.
☑️ Preparation for inspection thermostat
Remember that in some models Pozis access to the thermostat may be limited by decorative panels or lampshades. Act carefully so as not to damage the plastic latches.
The location of the thermostat in different Pozis models
The design of refrigerators Pozis varies depending on the year of manufacture and series. In most modern models, the thermostat is located inside the refrigerator compartment. However, its exact location depends on the type of control.
In classic models with mechanical controls, the regulator is often hidden under the lampshade or mounted in one of the side walls. You can get to it by carefully prying up the plastic casing. In models with electronic control or hidden mounting, the sensor can be located behind the rear panel inside the chamber or even in the technical compartment at the back of the unit.
Let's consider the main location options:
- 📍 Inside the chamber under lampshade: typical for RD series models, where the adjustment knob is brought out, and the unit itself is hidden behind the lamp.
- 📍 On the side wall: often found in older models, where the thermostat housing is visible immediately after opening the door.
- 📍 Behind the rear panel: in some modifications, access requires removing the plastic cover of the rear wall of the refrigerator compartment.
Features of the capillary tube
The capillary tube of the thermostat is a thin copper conductor filled with refrigerant. It is very sensitive to mechanical damage. Under no circumstances bend it or pull it with force, otherwise the seal will be broken and the device will stop responding to temperature changes.
If you cannot find the thermostat visually, refer to the operating instructions for your specific model Position, where diagrams of the components are shown.
Visual inspection and mechanical check
Before handling the multimeter, conduct a thorough visual inspection of the device. Often the cause of a malfunction can be detected with the naked eye. Pay attention to the integrity of the case, the presence of traces of melting, soot or oxidation on the contacts.
Pay special attention to the capillary tube. It should not have creases, cracks or swelling. If the tube is disconnected from the evaporator or the sensor dangles in the air without touching the cooled surfaces, correct operation is impossible. The sensor must be tightly fixed in a special socket or pressed against the evaporator.
| External sign | Probable cause | Action |
|---|---|---|
| Frosting of contacts | Overload or bad contact | Replacing the thermostat |
| Crack in the tube | Mechanical damage, freon leakage | Replacing the thermostat |
| Oxidation of terminals | Moisture ingress | Cleaning contacts or replacing |
| Sensor displacement | Incorrect installation | Installation in a standard place |
Also try to gently twist temperature control knob from the far left to the far right. You should hear clear clicks. If the handle scrolls silently or, conversely, is jammed, this is a sure sign of internal failure of the mechanism.
⚠️ Attention: During a visual inspection, do not use sharp objects to pick the contacts. This may lead to a short circuit the next time you turn it on or damage to the wire insulation.
Diagnostics with a multimeter: step-by-step instructions
The most accurate result is obtained by checking thermostat using a multimeter in resistance measurement mode (Ohm). This method allows you to determine whether the circuit closes when the temperature of the sensor changes.
First, you need to remove the terminals from the thermostat contacts. Take a photo of their location in advance so that you don’t mix up the wires during assembly. Usually there are two or three. If there are three contacts, then the third, as a rule, is responsible for the indicator lamp or the No Frost system, and you can ignore it for now, checking the main power contacts.
Checking algorithm:
- Set the multimeter in continuity mode or resistance measurement mode (200 Ohms).
- Touch the two main contacts of the thermostat with the probes.
- At room temperature, the circuit should be closed (numbers close to 0 will appear on the screen, or a squeak will be heard).
- Place the sensitive part of the thermostat (capillary tube with a cylinder) in a container with ice water for 2-3 minutes.
- Repeat the test: with strong cooling, the circuit should open (resistance tends to infinity).
If at room temperature the multimeter shows “one” (break), and after cooling in water the readings do not change, it means that the internal contacts are burnt or stuck. This thermostat must be replaced.
Compatibility table and markings of thermostats
When purchasing a new part, it is important to know that thermostats for refrigerators Position may have different markings, but similar technical characteristics. Most often, sensors manufactured by TAM, K-59, K-50 or their analogues are used.
Not all regulators are interchangeable. Differences may be in the length of the capillary tube, the temperature range of operation and the method of attachment. Installing an unsuitable part will lead to incorrect operation of the compressor.
The following is a table of common markings:
| Marking | Refrigerator type | Tube length | Features |
|---|---|---|---|
| TAM-133 | Single-chamber | 0.73 m | Standard for old models |
| K-59 L1102 | Double-chamber | 2.5 meters data-i="159">Rarely, for specific series | For systems with a weeping evaporator |
| K-50 L1102 | Single chamber | 2.5 m | Analog TAM-133 |
| 17M01 | With electronics | Var | Rarely, for specific series |
Always check the markings of the old part with the new one. The length of the capillary tube should be equal to or slightly longer than the original - the excess can be carefully twisted, but it is impossible to extend a short tube.
Replacing the thermostat with your own hands
If the diagnostics confirmed a malfunction, the only solution is replacement. The process does not require skills, but does require accuracy. First, dismantle the old sensor by disconnecting all the wires and releasing the capillary tube fastening.
Install the new one thermostat in the reverse order. It is important to correctly insert the capillary tube into its standard place on the evaporator and secure it with standard clamps. Poor contact of the tube with the surface of the evaporator will cause the sensor to “lie” about the temperature in the chamber.
After assembling all the panels and connecting the wires, you can turn on the refrigerator to the network. Pay attention to the first cycle of operation: the compressor should start, operate for the specified time and turn off when the thermostat clicks.
⚠️ Attention: After replacing the thermostat, the refrigerator may operate in test mode longer than usual. Do not completely load the chambers with products in the first 2-3 hours of operation, allow the unit to gain idle temperature.
If the compressor does not turn off for more than an hour and the temperature inside drops below normal, it may be necessary to (adjust) the screw on the body of the new thermostat, if it is provided for in the design.
Frequently asked questions (FAQ)
Is it possible to operate a refrigerator with a faulty thermostat?
It is highly not recommended. If the thermostat is “stuck” in the “on” position, the compressor will run without rest, which will lead to overheating and eventual combustion. If in the “off” position, the food will spoil.
Why does the new thermostat click, but the compressor does not start?
This may indicate a malfunction of the compressor start relay or the motor itself. Also check that the wires are connected correctly to the terminals of the new sensor. Perhaps the circuit does not close completely due to poor contact.
How often do you need to change the thermostat in the Pozis refrigerator?
Service life thermostat usually 5-7 years or more. However, frequent power surges or mechanical damage during defrosting can shorten this period. Planned replacement is not required, only after a breakdown.
Does the length of the capillary tube affect the operation?
Yes, it does. If the tube is too short, the sensor will not reach the temperature control zone. If it is too long, it will have to be laid in rings, which is acceptable, but requires care not to pinch the copper.