A sudden stop in the freezer compartment is always stressful, because food supplies are at risk. If you notice that the chamber has become warmer than usual or the ice has begun to melt, you must immediately respond to the alarm. Modern refrigeration units are complex, but primary diagnostics can often be carried out independently, without calling a technician.
In this article we will look in detail at why the lower or upper chamber of your refrigerator has stopped freezing. You will learn about common breakdowns, such as thermostat malfunction or failure of the starting relay. Understanding the principles of the system No Frost and drip defrosting will help you quickly identify the source of the problem.
However, it is worth remembering that some symptoms may indicate serious internal damage that requires professional attention. For example, if compressor works, but there is no cold, this may indicate a refrigerant leak. Carefully study the signs described below in order to make the right decision on further actions.
Primary diagnosis: simple reasons for the lack of cold
Before you panic or look for a service center phone number, you should rule out trivial operating errors. It often happens that the equipment is in good working order, but its operating conditions are violated. Check whether the door is tightly closed and whether anything is preventing its seal.
Pay attention to the location of the unit. If it is too close to a wall or heaters, the cooling system may not be able to handle the load. In such cases, the capacitor overheats, and the operating efficiency drops to zero.
It is also worth checking the temperature settings. Perhaps one of the household members accidentally turned the regulator to the “minimum” position or activated the quick defrost mode. Make sure that the indicators on the control panel Indesit, Atlant or Bosch are lit correctly.
Do not ignore the condition of the rubber seal on the door. If it is worn out, dirty or deformed, warm air constantly enters the chamber. This causes the compressor to wear out, but the desired temperature cannot be achieved.
Malfunctions of the defrosting system in No Frost models
Refrigerators with the system No Frost are most susceptible to malfunctions of the evaporator. If you see that the compressor is humming, but there is no cold, and a “coat” of ice has formed on the back wall of the chamber, the problem lies in the defrost cycle. The system simply cannot reset the ice, and the air channels become clogged.
The main culprits here are three elements: the evaporator heating element, the defrost sensor and the timer (or electronic control module). If the heating element burns out, the ice does not melt. If the sensor malfunctions, it does not give a command to turn on the heating. As a result air circulation stops.
⚠️ Attention: Attempting to break off the ice with a knife or other sharp objects in the No Frost chamber is strictly prohibited. You can damage the evaporator, which will lead to an immediate release of freon and expensive repairs.
For diagnostics, it is often necessary to “drain” the refrigerator. Leave it turned off for a day with the doors open. If after turning on the freezer it started working, but a week later the problem recurred, the diagnosis is confirmed. This is a classic symptom of a system malfunction defrostation.
- 🔥 Defrost heating element —a heating element that should melt the ice on the evaporator.
- 🌡️ Defrost sensor —controls the temperature of the evaporator and turns off the heating element when the required values are reached.
- ⏱️ Timer or module —sets the intervals between freezing and defrosting cycles.
In some models, for example LG or Samsung, sensors can output error, even if they are working properly, due to oxidation of the contacts. Therefore, a visual inspection of the wiring is also required when searching for the cause.
Problems with the compressor and start relay
The heart of any refrigerator is the compressor. If it is silent, although the indicators are on, the protective relay may have tripped or the motor itself may have failed. But the opposite situation also happens: the compressor hums, clicks, but does not start.
A frequent cause of such symptoms is a malfunction start relay. This is a small part that supplies a starting impulse to the motor winding. If the relay burns out, the compressor tries to start, makes a clicking sound and stalls. Replacing this part is an inexpensive and quick procedure.
A more serious problem is an interturn short circuit in the compressor windings or its mechanical wear. In this case, the unit may be very noisy, vibrate, or simply hum without cooling. Repairing such a unit is often not economically feasible; it requires replacement of the compressor.
Pay attention to the nature of the sound. A uniform hum is normal. Metallic clanging, knocking or intermittent humming with pauses indicate that the motor is “hard” to work. This may be due to both electrical and loss of compression.
Freon leak and clogged capillary system
If the compressor runs constantly without turning off, and there is no cold in the freezer at all or it is very weak, most likely there is a refrigerant leak. Freon — This is the working fluid that transfers heat. Without it, the cooling cycle is impossible.
Leaks can occur in places where the tubes are soldered, due to corrosion of the evaporator (especially if you carelessly removed the ice) or mechanical damage. It is difficult to visually notice a leak, since the gas is colorless and odorless. An indirect sign may be swelling of the chamber wall or the appearance of yellow rust spots.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| The compressor runs non-stop | Freon leak | Call a technician to find the leak and refill |
| The refrigerator turns on for 1-2 minutes, then silence | Clogged capillary tube | Purge the system or replacing the filter drier |
| Dirt or oil near the tubes at the back | Mechanical damage to the circuit | Soldering the damaged area |
| The evaporator is covered with uneven ice | Lack of refrigerant | Refilling the system |
Another technical difficulty - clogged capillary tube. Oil circulates in the system, which over time can thicken or mix with breakdown products, forming a plug. Freon cannot pass through the narrow cross-section, and the pressure in the system drops.
It is impossible to diagnose these conditions without a pressure gauge station and a leak detector. It will not be possible to eliminate a leak or blockage on your own; evacuation of the system and professional charging with refrigerant certain type (R600a or R134a) are required.
Failures in the operation of electronics and thermostats
In modern models such as Beko or Haier, everything is monitored by an electronic control module. If it is “glitchy”, the refrigerator may not receive a command to turn on the compressor or fan. The error may be caused by a power surge.
In simpler models, a mechanical thermostat is responsible for the temperature. If its bellows (sensing element) has lost its tightness, the contacts will not close. As a result, the compressor simply will not start, even if the chamber is warm.
⚠️ Attention: When replacing a thermostat, it is important to use an analogue with exactly the same parameters. Installing an unsuitable model will lead to incorrect operation: either the food will be frozen, or the refrigerator will work with short cycles.
It is also worth checking the wiring. Rodents, moisture, or simply time can cause contacts to oxidize or wires to break. Inspect the wiring harnesses going from the door to the body - they often break at the bend.
How to check a thermostat with a multimeter?
To check a mechanical thermostat, remove it, immerse the sensitive tube in cold water with ice and ring the contacts. If during cooling the circuit does not close (there is no sound), the thermostat is faulty and requires replacement.
If you have a two-compressor refrigerator, then a malfunction of one of the thermostats will cause only one chamber to stop. This is an important diagnostic sign that allows you to localize the problem.
Ventilation and problems with the fan
In systems No Frost the fan is responsible for circulating cold air. If it stops spinning, the cold remains in the evaporator area (usually behind the back wall) and does not enter the chamber. As a result, the food in the freezer melts, although the unit itself is trying to freeze.
The reasons for the fan stopping can be different: frosting of the blades, failure of the fan motor or an open circuit. You can often hear the fan trying to start, making a hum, but not rotating.
- ❄️ Freezing —ice blocks rotation, complete defrosting is required.
- ⚙️ Wear bearings —the fan is noisy and sticks, needs replacement.
- 🔌 Power problem —no voltage at the motor terminals.
You can check the operation of the fan by opening the freezer door (in some models it is turned off by the door sensor, so the sensor must be pressed manually). If the blades are standing and there is a hum, there is a mechanical blockage or motor failure.
☑️ Fan diagnostics
Do not forget that in some designs the fan can stop on purpose if the door is open for too long, in order to avoid blowing cold air to the user. But when closed, it should work cyclically.
When you need to call a technician
Independent repair is possible by replacing a light bulb, thermostat, or even a start relay, if you have the skills to work with tools. However, there are situations when the intervention of a professional is strictly necessary.
First of all, this is any work related to refrigerant. Opening the circuit requires special equipment. A technician is also needed if a compressor replacement or complex repair of the electronic control board is required.
If after defrosting within 24 hours the refrigerator does not start working normally, or the problem returns after a few days, do not continue the experiments. Further operation of a faulty unit can lead to complete breakdown of the compressor, which is much more expensive.
Remember that a qualified specialist will not only replace the part, but will also conduct a full diagnostic of the system to prevent recurrence breakdowns in the near future.