Modern refrigerators operating using technology No Frostare complex units where dozens of different components are responsible for cooling and maintaining the temperature. One of the key elements, but often invisible to the user, is the heating device, which, oddly enough, is needed here for the operation of the cold system. Many owners of equipment are faced with a situation when air stops circulating in the chamber, and an ice coat grows on the evaporator, and it is at this moment that the question arises about the role of the heater in the freezing cycle.
The abbreviation Heating element stands for Tubular Electric Heater, and its main task in the context of refrigeration equipment is to prevent evaporator freezing. Unlike older models with manual defrosting, where the ice accumulated and waited for human intervention, in automatic defrosting systems this process occurs without user intervention. Understanding the operating principle of this unit is necessary for anyone who wants to extend the life of their equipment and avoid expensive compressor repairs.
In this article we will analyze in detail the design of heating elements, their types, as well as symptoms indicating failure of this part. You will learn how to carry out initial diagnostics with a multimeter and whether it is worth taking on the replacement yourself. Refrigerators Indesit, Atlant, Bosch Other popular brands use similar principles for organizing defrosting, so the information will be useful to owners of most modern models.
The principle of operation of the defrosting system and its role heater
The main function The defrost heating element is to periodically melt the ice that inevitably forms on the evaporator fins during operation of the refrigerator. When moisture from food evaporates and condenses on cold pipes, it turns into frost. If this frost is not removed, it will turn into a monolithic block of ice, which will block the air supply to the products and cause the compressor to wear out. The heater is turned on by command thermostat or the electronic control module at certain intervals.
The operating cycle is as follows: the compressor cools the chamber, then turns off, and the defrost timer starts. At this moment, the fan stops so as not to fan the heat, and turns on heating element. The ice melts, the water flows into a special tray and evaporates. It is important to understand that the heating element operates for a very short time - usually from 15 to 30 minutes - after which the cooling mode takes effect again. Violation of this balance leads to either underheating (ice does not melt) or overheating (food spoils).
⚠️ Attention: If you notice that the back wall in the freezer is covered with a thick layer of ice, and in the refrigerator compartment, on the contrary, it is too warm, this is a sure sign that the defrosting system is not working correctly. Do not ignore the first symptoms, as an ice jam can damage the fan blades.
There are several types of heaters used in various technologies. Most often, there are tubular models that are mounted directly under the evaporator or built into its structure. Also, modern models can use heaters in the form of glass tubes or even film options that are glued to the surface. Each type has its own installation and testing features.
Main types of heating elements used in refrigerators
Engineering solutions in the field of automatic defrosting are developing, and today in refrigeration units you can find various modifications of heating elements. The choice of a specific type depends on the design of the evaporator and the model of the refrigerator. The most common option remains the classic tubular heating elementmade from a nichrome spiral sealed in a metal tube. Such elements are reliable, but are susceptible to corrosion during prolonged contact with water.
The second popular type is quartz heaters. They are a glass tube with a vacuum or inert gas inside, which quickly heats up when voltage is applied. Their advantage is instant access to operating mode and high heat transfer. However, glass is more fragile, and in case of mechanical damage (for example, when defrosting ice carelessly with a knife), such an element instantly fails.
- 🔹 Open spirals: are rarely used, mainly in older models, they are a nichrome thread on a mica substrate.
- 🔹 Built into the evaporator: The heating element is soldered directly into the aluminum radiator tubes, which makes replacing it extremely difficult and often requiring replacement of the entire assembly.
- 🔹 Capillary tube heaters: small elements that heat only the exit area of the capillary tube, preventing its clogging ice.
When searching for spare parts for repair, it is important to pay attention not only to the dimensions, but also to the power and voltage. The standard voltage is 220-230 V, and the power varies from 150 to 400 W depending on the volume of the chamber. Installing an element with less power will result in the ice simply not having time to melt within the time allotted by the timer.
Symptoms of a malfunctioning heating element
Diagnosis of a heating element failure often begins with a visual inspection of the condition of the products and the interior of the chamber. Since the heater does not operate constantly, its failure is not always immediately noticeable. The first and most striking sign of a malfunction is the formation of a “fur coat” or a block of ice on the back wall of the freezer compartment, even if the refrigerator is operating in No Frostmode. Ice blocks the air channels, and the cold stops flowing into the main chamber.
The second symptom is the constant operation of the compressor without interruptions. Trying to compensate for the lack of cold air circulation, temperature sensors command the motor to run continuously. This leads to increased energy consumption and engine overheating. In some cases, you can hear a crackling or humming sound produced by a fan whose blades touch frozen ice.
| Symptom | Probable cause | Risk level |
|---|---|---|
| Ice on the back wall | Faulty heating element or thermostat | High |
| Heat in the refrigerator compartment | Blocking of channels with ice | Medium |
| Compressor not turns off | Attempt to compensate for heat | High |
| Water on the floor under the refrigerator | Drain overflow due to ice | Low |
It is also worth paying attention to the frequency of defrosting. If you have to defrost your refrigerator more than once every 6-8 months, this is a signal that the defrosting system is not working at full capacity. Sometimes the heating element may be partially working (part of the turns have burned out), which reduces its efficiency, but does not completely disable it.
Step-by-step instructions for diagnosing a heating element with a multimeter
Before buying a new part, you need to make sure that it is faulty. To do this, you will need a simple digital multimeter. Important: before starting any disassembly and diagnostic work, the refrigerator must be completely disconnected from the power supply for at least 2 hours, and preferably for a day, so that all the ice melts and protects you from electric shock.
You can get to the heating element by by removing the back panel in the freezer compartment. In some models LG, Samsung or Beko this requires removing shelves and drawers. After dismantling the panel, you will see the evaporator and the heating element located next to it. A visually serviceable heating element should not have swelling, cracks or traces of corrosion penetrating the tube body.
☑️ Checking the heating element with a multimeter
The process of measuring resistance is as follows:
- Set the multimeter switch to resistance measurement mode (Ohm) to the limit of 2000 Ohms.
- Touch the contacts of the heating element with the probes (having previously disconnected the wires from them).
- Look at the readings of the device. A working element should show resistance in the range
200-500 Ohm(the exact value depends on the power). - If the device shows “1” or “OL” (infinity), it means there is a break in the spiral inside, and the heating element must be replaced.
⚠️ Attention: Be sure to check the heating element for breakdown on the housing. Press one probe to the contact, and the second to the metal tube of the heater. The device should not show any resistance (there should be a “break”). If there is at least some significance, using such a heating element is dangerous - this can lead to an electric shock through the body of the refrigerator.
Replacing the heating element: nuances and procedure
If the diagnostics have confirmed a malfunction, we proceed to replacement. In most cases, the heating element is attached to the evaporator body using special brackets or clips. Bend them carefully, being careful not to damage the aluminum radiator fins, which are very soft and easily deformed. Deformation of the fins will worsen heat transfer and the efficiency of the refrigerator as a whole.
When installing a new element, make sure that it fits tightly to the surface of the evaporator along its entire length. Gaps are not allowed, since heat must be transferred directly to the ice crust. If in your model the heating element is inserted into special grooves, lubricate them with a thin layer of thermal paste or simply make sure that the channels are clean before installation.
What to do if a new heating element is not on sale?
As a last resort, you can try to restore the old element if the break is visible visually and is located at the edge of the tube. However, this is a temporary measure. It is safer to find an analogue with similar parameters (power and dimensions) from another manufacturer by adjusting the fasteners.
After installation, reassemble the structure in the reverse order. Pay special attention to connecting the wires: they should fit tightly, without oxides. If the terminals are old and darkened, it is better to clean them or replace them with new ones. Before the final assembly of the panels, you can conduct a test run, but without products, in order to control the first defrost cycle.
Prevention and service life of heating elements
The average service life of a high-quality heating element is 7-10 years, however, the aggressive environment inside the freezer and temperature changes can shorten this period. The main enemy of the heater is moisture and salts contained in the water, which, when freezing and thawing, create an aggressive chemical composition that corrodes the metal shell. Regular defrosting (even for No Frost systems once every year and a half) helps remove salt deposits.
It is also important to monitor the condition of the rubber seals on the doors. If the rubber does not fit tightly, warm, moist air enters the chamber, which leads to increased ice formation. In such conditions, the heating element is forced to work with overload, which reduces its resource. Replacing the seal is a simple procedure that will greatly facilitate the operation of the defrost system.
- ❄️ Do not load hot products into the chamber - this creates excess humidity.
- ❄️ Check the operation of the fan - if it is humming or standing still, the ice will not melt evenly.
- ❄️ Do not use sharp objects to chip ice - the risk of damaging the heating element or evaporator is very high.
Frequently asked questions (FAQ)
Is it possible to operate a refrigerator if the heating element does not work?
Technically, the refrigerator will freeze, but only until the ice completely blocks the air channels. After this, the compressor will work non-stop, consuming a lot of energy and risking burning out. Long-term operation in this mode will lead to failure of more expensive components.
Why does the refrigerator still freeze over after replacing the heating element?
The reason may not be in the heater itself, but in adjacent parts: a defrost sensor (thermostat), a timer or a fuse. It is also possible that the drainage hole becomes clogged, which is why the water does not drain away, but freezes below.
How long does the heating element heat during defrosting?
Usually the heating cycle lasts from 15 to 30 minutes. The exact time depends on the operating algorithm of the control board and the amount of frozen ice. After reaching a certain temperature (usually +10..+15°C on the evaporator), the sensor turns off the heating.
What is the danger of self-aligning the heating element tubes?
The heating element tubes inside are filled with quartz sand to insulate the spiral. If, during alignment, the tightness of the tube is broken or the internal structure is damaged, a short circuit to the housing will occur, which is life-threatening.