Modern refrigerator is a complex unit in which the cooling and defrosting processes are strictly regulated electronics. Many users mistakenly believe that everything in this device should be cold, and the presence of a heating element causes them to be confused. However, without a heat source, the system No Frost and drip defrosting simply would not be able to function, turning into a solid ball of ice.
A heating element, or tubular electric heater, is a metal tube, inside of which a nichrome spiral is insulated with a dielectric. Its main task is to heat the air in certain areas of the unit at a strictly designated time. Engineers We introduced this element to solve the problem of ice buildup on the evaporator, which is hidden behind plastic panels.
If you notice that a snow coat has formed on the back wall of the freezer, or water has stopped flowing into the drainage hole, most likely the problem lies in the defrost system. Understanding how this unit works will help you avoid an expensive call to a technician or, conversely, diagnose a serious compressor breakdown in time.
⚠️ Attention: Any work on diagnosing and replacing the heating element should be carried out only after the device is completely disconnected from the power supply. A voltage of 220 volts is dangerous to life, and residual moisture inside the case can become a conductor of current.
Principle of operation and purpose of the heater
The main function heating element is the periodic melting of ice, which inevitably forms on a cold evaporator during the operation of the compressor. In refrigerators with manual defrosting, this process occurs naturally when you turn off the appliance. In automatic defrosting systems, the heating element is turned on by a signal from a timer or an electronic control module.
The operation cycle is as follows: the compressor cools the freon, moisture from the air condenses on the evaporator and freezes. At certain intervals (usually every 8–12 hours), the compressor stops and turns on Defrost heating element. It heats the radiator fins, turning ice into water, which flows into the pan and evaporates naturally.
It is important to understand that heating does not occur constantly, but pulsed. If the heating element worked continuously, the temperature in the chambers would rise to critical values, and the products would spoil. Thermoregulator or a defrost sensor strictly monitors the temperature of the heater and turns it off as soon as all the ice has melted.
Types of heating elements in modern refrigerators
The design of heating elements can vary significantly depending on the brand and model of your refrigeration equipment. Manufacturers use different configurations to maximize heat distribution and minimize energy consumption. Knowing the type of heating element you have is necessary when searching for a replacement part.
The most common option is a tubular heating element, which is mounted directly under the evaporator or goes around its perimeter. There are also glass heaters that are more resistant to corrosion, but are less common. Some models Samsung or LG use special drain heaters that prevent it from freezing.
Is it possible to use a universal heating element?
Theoretically, you can choose a heater of similar power and dimensions, but the factory mountings and shape the tubes may not match. It is better to look for an original spare part or a high-quality analogue that exactly matches the model of your refrigerator.
The heating element of the “crying” evaporator in drip systems deserves special attention. It is located at the bottom of the rear wall of the refrigerator compartment and prevents the condensate drain channel from freezing. In the freezer compartments of the system No Frost a more powerful circuit is used, often consisting of several sections connected in series.
Symptoms of a malfunction of the defrost system
Determine what Heating element of the refrigerator out of order, this can be determined by a number of characteristic signs that appear long before the unit stops completely. Ignoring these symptoms can lead to compressor overload and costly replacement. Carefully monitor the operation of your device.
The most obvious sign is the formation of a “coat” or block of ice in the freezer, especially if it is a model with a No Frost system, where there should be no ice at all. There may also be an increase in temperature in the main chamber, since the evaporator, covered with ice, ceases to effectively cool the air.
- ❄️ On the back wall of the freezer you can see a thick layer of snow or ice that does not melt after defrosting.
- 💧 Water flows out from under the refrigerator or accumulates on the floor inside chamber.
- 🔊 The compressor works almost non-stop, trying to compensate for the lack of cold.
- 🌡️ Food in the refrigerator compartment begins to deteriorate faster than usual, despite the motor running.
⚠️ Attention: If you see ice in only one corner of the freezer, this may not indicate only for a breakdown of the heating element, but also for a malfunction of the defrost sensor or timer. Diagnostics requires checking the entire chain.
Diagnostics and checking the heating element with a multimeter
Before going to the store for a new part, you need to make sure that the problem is in the heater, and not in the wiring or control module. To do this, you will need a simple multimeter and access to the insides of the unit. The verification procedure is quite simple if you follow safety precautions.
First you need to completely defrost the refrigerator within 24 hours. The back panel of the freezer is then removed, revealing access to the evaporator. Visually inspect the heating element: there should be no swelling, tube ruptures or signs of obvious corrosion. However, a visual inspection does not give a 100% guarantee, so a device is needed.
☑️ Algorithm for checking the heating element
Switch the multimeter to the resistance measurement mode (usually the range is 200 Ohms). Attach the probes to the contacts of the heating element. A working element should show a resistance ranging from 200 to 600 Ohms, depending on the power. If the device shows one (open) or zero (short circuit), the part requires replacement.
It is also important to check the heating element for breakdown on the body. One probe is applied to the contact, and the second to the metal tube of the heater. In good condition, the multimeter should not react (show infinity). The presence of any resistance indicates a violation of the insulation, which is dangerous due to electric shock.
Table: Comparison of characteristics of heating elements of different brands
When choosing a spare part, it is important to take into account not only the dimensions, but also the electrical parameters. Below is a table with approximate characteristics of heaters for popular brands.
| Brand | Average power (W) | Size | Mounting features |
|---|---|---|---|
| Indesit / Ariston | 320 - 400 | Arc-shaped | Inserted into the grooves of the evaporator |
| Samsung | 250 - 350 | Straight / U-shaped | Fixation with clips |
| LG | 300 - 450 | Complex shape | Often assembled with a sensor |
| Bosch / Siemens | 280 - 360 | Direct | Fixed with screws |
Please note that the power of the heating element directly affects the defrosting speed. Installing an element with a smaller number of watts will lead to incomplete melting of the ice, and with a larger number it can overload the wiring or melt the plastic elements of the case.
Step-by-step instructions for replacing the heating element
Replacing a heating element is a procedure accessible to a home craftsman with basic skills. The main thing is to act consistently and not use excessive force, as the plastic in old refrigerators becomes brittle. Before starting work, make sure that you have a new heating element and the necessary tools.
Remove all shelves and drawers from the freezer. Remove the rear plastic panel by unscrewing the mounting screws. If the panel is frozen, do not tear it off by force - use a hair dryer to gently warm the perimeter. Find the old heating element, usually it is attached to brackets or in the grooves of the evaporator.
Disconnect the wires from the old heater (after photographing the connection diagram). Install a new element, repeating the path of the old one. Connect the wires, observing polarity (if it is important for a specific sensor in the circuit) and the reliability of the contacts. Reassemble the panel in reverse order.
After assembly, do not rush to load the products. Turn on the empty refrigerator and let it run for 2-3 hours. Check if the water goes into the drain and if there is a burning smell. If everything is in order, you can load the chambers with products.
Why does the heating element burn out in the refrigerator?
The main reason is corrosion of the metal tube under the influence of moisture and aggressive environment. Over time, the shell becomes thinner, the nichrome spiral burns out or a breakdown occurs on the body. Also, the cause may be a power surge in the network or a malfunction of the thermostat, which does not turn off the heating in time.
Is it possible to temporarily do without a heating element?
You can only operate a refrigerator with a faulty heating element in manual defrost mode. You will have to regularly (every 1-2 weeks) completely turn off the unit and wait for the ice to melt naturally. Constant work with a frozen evaporator will lead to compressor failure.
How to extend the service life of the heating element?
To increase the life of the heater, it is recommended not to allow the doors to be opened for a long time, which reduces the flow of moist air. It is also important to ensure that the door seals are in good condition. Regular, at least preventative defrosting once a year (even for No Frost) will help clean the system of salt deposits.