Formation of an ice coat in in the freezer compartment of a No Frost system refrigerator is the first alarm indicating a malfunction in the defrosting cycle. When the evaporator becomes covered with ice, the cold stops circulating through the chambers, and the equipment stops freezing food, although the compressor may continue to hum. In 80% of cases, the cause of such a malfunction is Defrost heating elementwhich has stopped heating and evaporating condensation from the radiator.
Before calling a technician or buying new equipment, it makes sense to carry out independent diagnostics. Heating element is a part that is quite realistic check at home if you have a basic set of tools on hand. In this article, we will analyze the verification process in detail so that you can accurately determine whether the heating element is to blame for the breakdown of your unit.
Modern refrigerators, be it Indesit, Samsung, LG or Bosch, work on similar principles, but access to components may differ. Defrost is critical a process without which the No Frost system turns into an ordinary crying refrigerator, only with forced air circulation, which is quickly blocked by ice. Understanding how this unit works will help you avoid unnecessary costs.
Signs of defrost heater failure
Symptoms of failure heating element often do not appear immediately, but increase gradually. At first, you may notice that your refrigerator is louder or its cycles become more frequent. However, the most obvious sign is the ice. If you see that the back wall of the freezer is covered with a dense layer of ice or snow, and the food has begun to thaw, this is a direct cause for concern.
The second important marker is the operation of the compressor. When the evaporator is clogged with ice, the fan (if it is not blocked) drives warm air, and the temperature sensors require the motor-compressor to work non-stop. Refrigerator tries to compensate for the lack of cold by constant operation, which leads to overheating and increased energy consumption. If your electricity bill has increased sharply, check the defrosting system.
- 🧊 A thick layer of ice or “coat” has formed on the back wall of the freezer.
- 🔊 The compressor works almost without interruption, the hum has become more intense.
- 🌡️ The temperature in the refrigerator compartment is higher than normal, food spoils faster than usual.
- 💧 Puddles of water periodically appear under the refrigerator or inside the chamber (during manual defrosting).
Sometimes the problem can be not only in the heating element itself, but also in defrost sensor or timer. However, statistics from service centers show that burnout of the heater coil most often occurs due to natural wear and tear or power surges in the network. Ignoring these symptoms can lead to more serious failures, such as compressor failure due to overheating.
⚠️ Attention: If you find ice in only one corner or on one side of the evaporator, this may indicate an air distribution problem or a faulty fan, not just Heating element.
It is also important to consider the age of your refrigerator. In older models Atlant or Stinol the resource of the heating elements could have already been exhausted simply due to time. In new models with inverter compressors diagnosis is a little more complicated, since the electronics can block the start of defrosting in case of errors of other sensors.
Necessary tools for diagnostics
To carry out high-quality diagnostics, you will need a minimum set of tools that most home craftsmen can find. The main requirement is safety and accuracy of measurements. Without a special device, such as multimeter, it is impossible to check the integrity of the heater circuit, since it is impossible to visually determine a break in the tungsten filament inside the sealed tube.
In addition to the measuring device, you will need tools to disassemble the case. The design of refrigerators from different brands may differ: in some places you need Phillips screwdrivers, in others you need hexagons. For example, in refrigerators Liebherr screws with hidden heads are often used, which are difficult to reach without removing the panels.
- 🔌 A multimeter (tester) is required for measuring resistance and checking for breakdown.
- 🔧 A set of screwdrivers (phillips and flat) - for dismantling panels and fastenings.
- ✂️ Pliers or pliers - for removing clamps and terminals.
- 🧤 Gloves and hair dryer - for carefully defrosting the ice before removing the heating element.
Pay special attention to the choice of a multimeter. Any model with Ω (Ohm) and dialing mode is suitable for household needs. Make sure the batteries in the device are charged, otherwise the readings may be incorrect. Cheap Chinese testers may give an error, so when receiving borderline values, it is better to double-check the result.
⚠️ Attention: Before starting any work on disassembling the refrigerator, be sure to disconnect it from the power supply! Working with live electrical appliances is deadly.
Also prepare a container for water and rags. When disassembling the evaporator, residual water from melted ice may leak out of the system. If you plan to remove the heating element completely, a hairdryer will help you quickly free the fastenings from the ice crust without damaging the plastic elements of the refrigerator compartment.
The procedure for accessing the heating element in different models
Access to the defrost heater is almost always in the freezer. However, the path to it may be different. Most No Frost refrigerators (Samsung, LG, Indesit) require you to remove the back panel inside the freezer. In some models, such as older Bosch or Siemens, access may be through the top of the freezer compartment or even through the bottom drawer.
The disassembly process usually begins with removing all shelves, drawers and containers. Then the guides are dismantled. Be careful with plastic latches - in the cold the plastic becomes brittle and breaks easily. If the panel cannot be removed, do not use force; you may have missed a hidden screw under the decorative plug.
In models with a bottom freezer, access to evaporator is often complicated by the presence of a ventilation system. You may need to remove not only the back wall, but also the air ducts. In refrigerators Electrolux i Zanussi The heating element can be built into the lower part of the evaporator and covered with an additional casing.
If you are faced with a model where access is difficult, it is recommended to find the exact disassembly diagram (exploded view) for your specific modification. There are no universal solutions here: in some cases the heating element is inserted into grooves, in others it is secured with clips or screws. The main thing is to get to the place where the heater is attached and its electrical contacts.
Often access is blocked by ice. If after removing the panel you see that the evaporator is covered with ice, let it thaw naturally or use a hair dryer on the lowest setting. It is strictly forbidden to mechanically chip ice with a knife or screwdriver - you can damage the freon tubes, and then repairs will become economically unfeasible.
⚠️ Attention: The design of refrigerators is constantly changing. The manufacturer may change the location of components in a new batch of equipment. Always check the technical documentation for your specific model.
Method of checking the heating element with a multimeter
This is the most important diagnostic stage. After you have reached the heating element and freed it from the ice, you need to disconnect the wires from it. They are usually secured with terminals or connectors. Carefully remove them, being careful not to pull the wires themselves, so as not to break them at the base.
Switch the multimeter to resistance measurement mode (Ω). Select the range 2 kOhm (2000 Ohm). Touch the probes to the contacts of the heating element. A working heater should show a certain resistance. If a unit or an infinity symbol is displayed on the screen (∞ or OL), it means that the circuit is broken and the heating element has burned out.
Normal resistance for heating elements of No Frost refrigerators usually varies in the range from 200 to 400 Ohms. The exact value depends on the power of the element and the network voltage. If the device shows a value close to zero, this may indicate a short circuit inside the spiral, which is also a malfunction.
In addition to checking for a break, it is necessary to exclude a breakdown to the housing. This is a situation where current “leaks” to the metal part of the refrigerator, which can be dangerous for the user. To do this, press one probe of the multimeter to the contact of the heating element, and the second to the metal tube or heater body. The device should show infinity. If there is at least some resistance, the heating element is faulty and requires replacement.
☑️ Checklist for checking the heating element
If your multimeter has a mode “continuity” (with a sound signal), use it to quickly check for a break. However, this mode will not show the exact resistance and will not help identify changes in the characteristics of the spiral when it is intact, but does not work correctly. Therefore, the mode Ω is a priority.
Table of normal resistance values
To make it easier for you to navigate the device readings, we have compiled a table with approximate values for various types of heating elements. Remember that a deviation within 10-15 Ohms can be considered acceptable, but a strong discrepancy indicates a problem.
| Heating element type / Power | Normal resistance (Ohm) | Failure sign |
|---|---|---|
| Standard tubular (400-500 W) | 200 - 250 Ohm | Infinity (break) or 0 (short circuit) |
| Powerful heater (600-800 W) | 120 - 160 Ohm | Resistance is significantly higher than normal |
| Glass heating element (modern models) | 300 - 350 Ohm | Any deviation from the passport data |
| Heating element with thermostat (assembled) | Depends on temperature | Check when heating is required |
Please note that the resistance may “float” slightly depending on the temperature of the heating element itself. A cold element may show slightly less resistance than a hot element. However, the order of the numbers must be preserved. If you see values in thousands of Ohms, this is definitely a break.
In some complex systems, for example, in refrigerators Sharp or Hitachi, the heating element may consist of several sections. In this case, you need to check each section separately if the design allows you to disconnect the contacts inside the assembly. Often only one part of the spiral burns out, which leads to inadequate operation of the entire defrost system.
Why do heating elements burn out?
Defrosting heating elements most often fail due to dry operation (if the sensor is stuck and does not turn off the heating), corrosion of the housing (especially in high humidity conditions) or surges network voltage. Also, frequent defrosting cycles reduce the life of the spiral.
Replacement and final recommendations
If the check shows that Defrost heating element it is faulty, it must be replaced. Repair by soldering or twisting in this case is impossible and dangerous, since the heater operates in an aggressive environment (water, temperature changes). Buy an original spare part or a high-quality analogue that matches the power and geometric dimensions.
When installing a new element, make sure that it fits tightly in the grooves of the evaporator. Poor contact with the surface of the radiator will result in heat escaping into the air rather than melting ice, and the new heating element will quickly burn out. Also check the condition of the wire insulation - they should not touch the heating tube.
After assembly, do not rush to load the products. Turn on the empty refrigerator and monitor its operation for one full cycle (about 2-3 hours). Make sure that the freezer gets cold, and then normal defrosting occurs (you will hear a characteristic hissing or crackling sound).
- 🛠️ Use only original fasteners or their complete analogues when assembling.
- 🧊 Make sure the drainage hole is free of debris and ice before turning on.
- 🔌 Check the reliability of the connection of the terminals - they should not get hot during operation.
Timely replacement of the heating element will extend the life of your refrigerator and save food. Do not forget that ignoring the problem with defrosting for a long time can lead to the fan becoming jammed with ice, which will require replacing two units instead of one..
Frequently asked questions (FAQ)
Is it possible to temporarily operate a refrigerator with a faulty heating element?
Technically, the refrigerator will work, but the cooling efficiency will drop sharply. You will have to defrost it manually regularly (every 3-5 days), completely unplugging it for 10-12 hours. Long-term operation in this mode is harmful to the compressor.
Why did the new heating element burn out a week after replacement?
Most likely, the problem is not in the heating element itself, but in the control circuit. Check defrost sensor (thermostat) and timer. If the sensor is “stuck” in a closed state, it does not give a command to turn off the heating, and the heating element operates continuously, overheating and burning out.
Which heating element is better: aluminum or glass?
Glass heating elements (quartz) are considered more modern and durable, as they are less susceptible to corrosion. However, aluminum tubular heaters are cheaper and easier to install. It is better to install the type that is provided for by the design of your refrigerator.
Is it necessary to change the defrost sensor along with the heating element?
Preventive replacement of the sensor is not necessary if it is working properly. However, if your refrigerator is more than 7-10 years old, it makes sense to replace the sensor, since they have approximately the same resource, and its failure can lead to the burning of a new heating element.