Sudden cessation of cooling or, on the contrary, excessive freezing of food often indicates a failure of the temperature control system. In refrigerators Nord a thermostat is responsible for this process, which opens or closes the electrical circuit depending on the temperature of the evaporator. If you notice that the compressor works without stopping or does not turn on at all, and the light inside is on, most likely the problem lies in this unit.
Replacing the thermostat yourself is a real task for a home craftsman who has basic skills in working with tools. However, before starting work, you must make sure that the cause of the malfunction has been correctly established, since similar symptoms may appear if there is a freon leak or a malfunction of the start relay. Diagnostics must be carried out carefully so as not to replace serviceable parts.
In this article we will analyze the algorithm of actions necessary for safe dismantling the old sensor and installing a new one. You will learn how to choose the right analogue if the original part is no longer in production, and what nuances connections exist for different models of refrigeration equipment.
Signs of a malfunctioning thermostat
Understanding what exactly thermostat requires replacement, comes with an analysis of the behavior of the refrigerator. The main indicator is the operating mode of the compressor: if it hums continuously, without turning off for rest, or is silent for days until the food begins to deteriorate, this is the first alarm signal. In normal operation, the unit should turn on and off cyclically, maintaining the set temperature.
Another obvious sign is the formation of a “snow coat” or ice crust on the back wall of the refrigerator compartment, even if the food is not frozen to the point of stone. This indicates that the sensor is stuck in the on position or is not reading the evaporator temperature correctly. It is also worth paying attention to the adjustment knob: if it scrolls endlessly or, conversely, is jammed and does not move, the mechanical part of the device is destroyed.
Sometimes a breakdown of the thermostat is disguised as other problems. For example, if the capillary tube of the sensor breaks, the refrigerant escapes and the system stops responding to changes in heat. In such cases, a simple replacement may not help; a deeper diagnostics system will be required.
Preparing tools and choosing an analogue
To successfully carry out repair work, you do not need complex professional tools, a standard home craftsman’s kit is enough. The main thing is to ensure safety and access to the internal components of the refrigerator. Before starting any manipulations, be sure to disconnect the appliance from the power supply by removing the plug from the socket.
You will need the following tools:
- 🔧 Screwdrivers (Phillips and flat) for removing panels and terminals.
- 🔪 Knife or side cutters for carefully removing insulation or trimming excess capillary length.
- 🧤 Gloves to protect hands from sharp metal edges.
- 🧼 Dry rags for cleaning contacts from moisture and dust.
Selecting a new part is a critical stage. Thermostats are marked with an alphanumeric code (for example, TAM 133, K 59, T-130). The numbers and letters indicate the on/off temperature range and the length of the capillary tube. If you have not found the original, you can use a universal analogue, but it parameters must match the original as much as possible.
Is it possible to install a thermostat with a longer tube?
Yes, you can. The excess length of the capillary tube is carefully rolled into a spiral and placed inside the refrigerator body, making sure that it does not touch the moving parts of the compressor and hot components. The main thing is not to damage the thin tube.
Removing the old thermostat
The process of removing a faulty sensor in refrigerators Nord usually does not require complete disassembly of the case. The thermostat is most often accessed through the top of the refrigerator compartment or through a plastic casing that hides the light bulb and temperature control. First you need to remove the regulator handle by pulling it towards you.
Next, you should unscrew the screws securing the plastic panel. Be careful with plastic latches; they can become brittle with time and cold temperatures. After removing the panel, you will see the thermostat itself, mounted in the hole, and the capillary tube coming from it, which goes deep into the chamber to the evaporator.
The next step is to disconnect the electrical wires. Before doing this, it is strongly recommended to photograph the connection diagram or sketch it, so as not to mix up the contacts during assembly. Usually the terminals are simply removed from the thermostat spots. Then the capillary tube is carefully pulled out from the mounting socket. If it is stuck or clamped, act without sudden jerks so as not to damage the evaporator.
☑️ Dismantling steps
Installing a new thermostat and connection diagram
Installation of a new element is carried out in the reverse order, but requires attention to detail. The capillary tube of the new thermostat must be inserted into the same hole from which the old one was removed. The immersion depth must correspond to the original, otherwise the sensor will read the temperature of the air, not the evaporator, which will lead to incorrect operation.
When connecting the wires, be guided by the photograph taken earlier or the markings on the case. The following designations are most often used:
- 🔌 Contact 3 —phase input from the network (or from a protection relay).
- 🔌 Contact 4 —output to the compressor.
- 🔌 Contact 6 —output to the lighting lamp (lights up when the compressor is turned off).
Some models Nord with the No Frost or drip defrosting function may have additional contacts for the fan or defrost heating element. If you are replacing a regular thermostat with a more complex one, or vice versa, make sure that the functionality is the same. After connecting the terminals, check the reliability of the contact by lightly tugging the wires.
| Contact marking | Purpose | Wire color (typical) | Note |
|---|---|---|---|
| 3 | Power (Input) | Red / Brown | Common for all circuits |
| 4 | Compressor (Output) | Black / Green | Closes when cooling |
| 6 | Light lamp | Orange / White | Opens when the motor is running |
| Grounding | Case | Yellow-green | Connects to a metal plate |
Setup and initial startup
After installing the thermostat and assembling the plastic panels, you can proceed to testing. Plug in the refrigerator. In the first minutes of operation, you should hear a characteristic click - this is the relay activated, starting the compressor. If the motor hums, it means the chain is assembled correctly.
Now you need to adjust the position of the regulator knob. Usually it has a scale from 1 to 5 or from “Min” to “Max”. Set the knob to the middle position (for example, “3”). Let the refrigerator run for a few hours until it reaches the temperature and turns off on its own. If it turns off - thermostat it is working and selected correctly.
If the compressor runs too long or stops too quickly, it may need adjustment. Some thermostat housings have an adjustment screw hidden under a seal or plug. Turning this screw changes the response temperature. However, without a special thermometer and experience, it is better not to change the factory settings, but to rely on the standard knob.
Common mistakes when replacement
Even experienced craftsmen sometimes make mistakes that can negate all efforts. One of the most common is damage to the capillary tube during installation. Thin copper easily pinches or breaks if handled roughly. As a result, the gas evaporates and the new thermostat stops responding to temperature.
Another mistake is ignoring the condition of the wire insulation. If the wires are old and cracked, they must be replaced or insulated with heat shrink. In conditions of high humidity inside the refrigerator, the bare contact will quickly oxidize or cause a short circuit.
They also often forget to check the tightness of the thermostat tube to the evaporator. If the instructions for your model Nord indicate the use of a special pressure plate or glue, this cannot be neglected. An air gap between the sensor and the cooling surface will lead to large operating errors.
⚠️ Attention: The capillary tube of the thermostat is filled with freon under pressure. It is strictly forbidden to bite, bend at an acute angle or pierce the tube. This will not only damage the part, but can also be dangerous.
⚠️ Attention: All work on replacing electrical components should only be carried out with the refrigerator completely disconnected from the network. Failure to follow electrical safety rules may result in electric shock.
FAQ: Frequently asked questions
Where is the thermostat in the Nord refrigerator?
In most models Nord The thermostat is located inside the refrigerator compartment, in the upper right or left corner. It is hidden under a plastic panel where the light bulb is also located. In some older models, the control knob may be on the external control panel, but the sensor itself is still inside.
Is it possible to temporarily short-circuit the thermostat?
Yes, this is possible for diagnostics or as a temporary measure. You need to connect the wires coming from the network and to the compressor (usually pins 3 and 4), bypassing the regulator itself. However, in this case, the refrigerator will work continuously until you unplug it from the outlet manually, which threatens food freezing and icing.
Why does the new thermostat click, but the refrigerator does not turn on?
If there is a click, it means the contacts open and close, but the compressor does not start. Possible reasons: the compressor starting relay is faulty, the motor-compressor itself has burned out, or the contact in the circuit has been broken (the terminal is poorly placed). Also, the problem may be in the fuse link, if it is provided for in the design.
How to check the thermostat with a multimeter?
Necessary