The situation when the refrigerator stops turning off or, conversely, stops starting, often confuses the owner. In most cases, the cause of this behavior is the failure of the thermostat, which is the “brain center” of the cooling system. Especially often in household refrigerators of domestic and imported production there is a model There 133, known for its reliability, but which tends to develop a resource after 5-7 years of operation.
Before calling a technician or buying a new unit, it is worth conducting independent diagnostics to exclude simpler breakdowns. Checking the thermostat does not require deep engineering knowledge, but requires accuracy and a minimal set of tools. If you notice that the food in the main chamber begins to freeze, and the compressor hums without stopping, or it is warm in the chamber, but the motor is silent, these are direct signals to action.
In this article, we will analyze in detail the algorithm of actions that will help determine whether thermostat There 133 is to blame for your problem. We will consider visual inspection methods, “folk” testing methods and professional diagnostics using a multimeter, so that you can make an informed decision on repairs.
The principle of operation and design of the thermostat There 133
Thermoregulator There 133 is an electromechanical device that closes and opens an electrical circuit depending on the temperature in the refrigerator compartment. Inside the housing there is a bellows tube filled with sensitive freon gas. When heated, the gas expands, the pressure in the tube increases, and mechanically opens the contacts, turning off the compressor. When cooling, the reverse process occurs.
The model There 133 is usually equipped with one contact group and is intended for single-chamber refrigerators or for controlling the compressor in two-chamber models with one cooling chamber. On the case you can often find marking T-133 or 133-3, which indicates specific temperature response ranges. Understanding this mechanism is critical for correct diagnosis.
It is important to note that the capillary tube, which is the very sensitive element, can have different lengths. For There 133 the standard length is considered to be a segment of about 0.75 - 1.3 meters, but when replaced, this value may vary depending on the modification. Incorrect length or damage to the tube will result in incorrect temperature readings.
⚠️ Attention: Before starting any work on disassembling the refrigerator, be sure to disconnect the appliance from the power supply. Working with live electrical wiring is deadly and can lead to a short circuit.
External signs of a thermostat malfunction
Diagnostics should always begin by analyzing the symptoms that your refrigerator exhibits. Thermoregulator There 133 rarely fails without a trace, most often it gives signals long before the work stops completely. If you ignore the first warning signs, repairs may be more expensive due to food spoilage or compressor failure.
One of the most obvious signs is the continuous operation of the compressor. If the motor hums for hours without pausing to rest, and the temperature in the chamber drops below normal (food freezes), this indicates that the thermostat contacts are “stuck” in a closed state. The gas in the bellows could have evaporated, or the mechanism simply jammed.
The opposite situation - the compressor does not turn on at all. In this case, the refrigerator is silent, it is warm inside, but the light is on. This means that the circuit is open and does not close even when the temperature rises. It is also worth paying attention to the adjustment knob: if it turns too easily or, on the contrary, tightly, this is a sign of mechanical damage to the internal parts.
There is a list of symptoms that can with a high degree of probability suggest a breakdown of this particular unit:
- 🧊 It is too cold in the refrigerator compartment, an ice crust forms on the back wall, although the regulator is turned to minimum.
- 🔇 Complete lack of reaction from the refrigerator to turning the thermostat knob from the “off” position to the “max” position.
- 🔌 The compressor starts only after lightly tapping the regulator handle or the refrigerator body.
- 💡 The light in the chamber is on, but the motor is silent (provided the starter is working properly relay).
Preparation for diagnostics: tools and access
In order to check thermostat There 133, you will need a minimum set of tools. The main device will be a multimeter (tester), which can be purchased at any electrical goods store. Without it, accurate diagnosis is impossible, since it is impossible to determine the integrity of the circuit “by eye.”
The second necessary element is access to the thermostat itself. In most refrigerators, it is located inside the refrigerator compartment, under a plastic cover or just behind the light bulb. You will need a flathead screwdriver to carefully remove the decorative panels, and perhaps pliers to remove the terminals.
☑️ Preparing to check the thermostat
The dismantling process usually looks like this: first remove the control knob (sometimes it is simply pulled together, sometimes it has a locking screw for a slot). Then the screws holding the casing are unscrewed. Be careful with the wiring - the wires may be short, and a sudden movement will lead to their breakage at the very terminals.
Methods of testing with a multimeter
The most reliable way to determine the performance There are 133 is to ring its contacts with a multimeter in resistance measurement mode (Ohm). To do this, you need to remove the thermostat from the refrigerator by disconnecting all the wires. Be sure to remember or take a photo of the connection diagram so that you don’t mix up the contacts during assembly.
Set the multimeter switch to the 200 Ohm position or continuity mode. Touch the probes to the two thermostat contacts. If the device shows “0” or makes a beep, the circuit is closed. This is normal at room temperature for most models unless the knob is in the "Off" position. Now immerse the sensitive tube in cold water with ice (temperature about 0...-5 °C). After a few minutes, the contacts should blur, and the device should indicate infinity (one in the most significant digit).
If the circuit does not ring at room temperature, try turning the regulator knob. If there is still silence after this, the thermostat is faulty, the contacts are oxidized or broken. If the circuit rings both in the heat and in the cold (after being kept in the freezer), it means that the mechanism is “stuck” and does not open the circuit.
For correct operation There 133 it is important to observe the polarity of the connection only if the thermostat is grounded, but in most household models this is not critical. The main thing is to ensure reliable contact of the probes with the terminals, cleaning them from oxides if necessary.
Table of temperature conditions and parameters
Understanding at what temperatures your thermostat should operate will help in fine-tuning. The model There are 133 has certain factory parameters, deviation from which indicates the need for replacement. Below are the average data for standard modifications.
| Parameter | Value / Description | Tolerable deviation |
|---|---|---|
| Temperature switch-on | +4...+6 °C | ± 2 °C |
| Switch-off temperature | -10...-14 °C (for freezer) / +1...+3 °C (for camera) | ± 3 °C |
| Capillary tube length | 0.75 m / 1.3 m (depending on modification) | ± 5 cm |
| Operating voltage | 220-240 V | 10% |
| Maximum current | up to 16 A | - |
Please note that the parameters may vary depending on the specific modification indicated on body. For example, There 133-1M may have slightly different response characteristics than the base model. Always check the markings.
⚠️ Attention: Technical characteristics and markings may vary slightly depending on the year of manufacture and the manufacturing plant. Always check the data on the label of a specific product before purchasing a replacement.
Replacing the thermostat: step-by-step instructions
If the diagnostics showed a malfunction, thermostat There 133 it is necessary to replace it. Repair of this unit is impossible, since the case is sealed and cannot be opened at home. The new element must have similar parameters, especially the length of the capillary tube.
Installation is carried out in the reverse order of dismantling. Carefully insert the sensing tube into the mounting hole in the chamber, being careful not to damage it or bend it at an acute angle. The bending radius must be at least 5 cm, otherwise the tube may burst and the freon will evaporate, which will make the thermostat inoperative.
What to do if the length of the tube is different?
If the new tube is longer, it can be carefully rolled into a ring and secured inside the refrigerator body (not in the chamber!). In short, installation is impossible; you need a thermostat with a suitable length.
Connect the wires to the contacts, following the diagram. They are usually color coded or numbered. After assembly, turn on the refrigerator and monitor its operation for several hours. The compressor must turn on and off at regular intervals.
The key point is the correct positioning of the tube. It should fit snugly against the wall of the evaporator or be in a special channel. If the tube hangs in the air, the thermostat will “lie” and show the air temperature in the chamber, and not the temperature of the cooling element.
Frequent errors in diagnostics and repair
One of the most common mistakes is an attempt to replace There 133 with an analogue with different temperature characteristics. For example, installing a thermostat from the freezer compartment into the refrigerator compartment will lead to food spoiling, since the cooling cycle will be too short or long.
Also, amateur craftsmen often forget to check the compressor start relay, immediately sinning on the thermostat. If the compressor hums, clicks and does not start, the problem may not be in the control circuits at all, but in the motor itself or the relay. Therefore, a comprehensive check is mandatory.
Another mistake is ignoring the condition of the wiring. Oxidized contacts or frayed wires can create resistance that simulates a thermostat malfunction. Before replacing, always visually inspect the entire electrical circuit.
☑️ Checklist after replacement
FAQ: Frequently asked questions
Is it possible to replace Tam 133 with an imported analogue, for example, Danfoss?
Yes, it is possible, but it is necessary to select an analogue according to the temperature regime and the length of the capillary tube. Imported thermostats often have more accurate calibration, but may differ in the method of fastening and the shape of the rod.
Why did the refrigerator begin to work longer after replacing the thermostat?
Perhaps the new thermostat has different shutdown parameters (lower temperature), or the sensitive tube is not installed tightly. It is also worth checking the tightness of the door and the number of loaded products.
How much does it cost to diagnose and replace a thermostat in the service?
The cost consists of the price of the spare part (about 500-1000 rubles) and the work of the technician. On average, repairs will cost 2000-3500 rubles, depending on the region and the complexity of access to the unit.
Is it possible to temporarily short-circuit the thermostat contacts?
Technically, this will start the compressor, but doing this is strictly not recommended for long-term operation. The refrigerator will freeze uncontrollably, which will lead to defrosting of food in the freezer or breakdown of the compressor due to overload.