Failure of the defrost system is one of the most common reasons why cold air stops circulating in the refrigerator compartment, and a “fur coat” builds up in the freezer. The central element of this system is often Tubular Electric Heater, which is responsible for melting the ice on the evaporator. If this unit fails, ice blocks the ventilation ducts and the refrigerator stops freezing, although the compressor can work continuously.
Diagnostics of the heating element does not require deep knowledge in electronics, but requires compliance with safety precautions and the presence of a basic measuring instrument. In this article we will look at how to use a multimeter, what indicators are considered normal and when a part must be replaced. Understanding the principle of operation will help you save time on calling a technician or avoid buying unnecessary spare parts. check the heating element of the refrigerator with a multimeter, what indicators are considered normal and when the part must be replaced. Understanding the operating principle will help you save time when calling a technician or avoid buying unnecessary spare parts.
Before you start disassembling the unit, it is important to make sure that the problem lies in the heater, and not in the defrost timer or temperature sensor. Often, users mistakenly use heating elements, ignoring other components of the circuit. Visual inspection and the initial check of symptoms is the first step to an accurate diagnosis. If you notice that the back wall of the freezer is covered with a thick layer of ice, and the fan is humming, but does not move air, the probability of a heater malfunction is high.
⚠️ Attention: Any work to check the electrical components of the refrigerator is carried out exclusively with the power disconnected from the mains! Unplug the plug from the socket before removing the back panel.
Signs of a malfunction of the defrost heating element
Understanding the symptoms allows you to localize the problem even before disassembling the case. When heating element burns out, the defrost cycle does not physically start, even if the control electronics give a signal. Ice continues to accumulate with each compressor operation cycle, gradually turning into a monolithic piece.
One of the indirect signs is the operation of the compressor. The unit can hum almost continuously, trying to reach the set temperature, but due to the evaporator clogged with ice, the cold does not enter the chambers. In models with the system No Frost this leads to rapid defrosting of food in the main chamber when the freezer compartment is running.
Sometimes the heating element may be electrically functional, but have mechanical damage. Corrosion or leakage of the tube leads to a short circuit to the housing. This causes the plugs to be knocked out or the RCD to trip when the defrost mode is turned on. It is also worth paying attention to the condition of the evaporator itself: if the ice lies unevenly, with “bald spots” in the places where the heater is installed, this is a sure sign of its partial inoperability.
Necessary tools for diagnostics
For a high-quality check, you will need a minimum set of tools that most home craftsmen can find. The main device is multimeter (tester), capable of measuring resistance (Ohms) and checking the integrity of the circuit (continuity). Without it, the diagnosis will only be tentative.
In addition to the measuring device, you will need screwdrivers (phillips and flat) to dismantle the panels. Some refrigerator models LG, Samsung or Indesit may require special attachments, for example, Torx. It would also be useful to have a flashlight for inspecting hard-to-reach places behind the back wall of the freezer.
- 🔧 Multimeter with the function of measuring resistance up to 2 kOhm.
- 🪛 Set of screwdrivers (PH1, PH2, flat).
- 🔦 Flashlight or headlamp light.
- 🧤 Dielectric gloves (recommended).
It is important that the multimeter probes are in good working order and that the battery in the device is not discharged, otherwise the resistance readings may be distorted. Before starting work, wipe the probe contacts with a dry cloth to eliminate errors.
Access to the heating element: disassembling the freezer compartment
To get to the heating element, you need to remove the back panel in the freezer compartment. The process may vary depending on the design of the refrigerator. In most models, you will need to completely defrost the unit for 10-12 hours so that the ice does not interfere with dismantling and does not damage the plastic latches. No Frost You will need to completely defrost the unit within 10-12 hours so that the ice does not interfere with dismantling and does not damage the plastic latches.
First, all shelves and drawers are removed. Then the visible screws holding the plastic casing are removed. Often the fasteners are hidden under decorative plugs or located behind air dampers. Proceed carefully, plastic becomes brittle in the cold and breaks easily.
Secrets of removing panels
If the panel cannot be removed, do not use force. Check to see if you forgot to remove the screws at the bottom or behind the trim strip. Sometimes it is necessary to remove the air duct going into the fridge compartment.
After removing the panel, access to the evaporator - a copper or aluminum coil - will open. The heating element is usually located at the bottom of the evaporator or surrounds it around the perimeter. Visually assess the condition of the part: there should be no swelling, cracks or traces of burning.
⚠️ Attention: Do not pick out the ice with a knife or sharp objects! Damage to the evaporator tubes will lead to freon leakage and expensive repairs that cannot be performed independently.
Step-by-step instructions: how to check the heating element with a multimeter
The most reliable way to check is by measuring electrical resistance. To do this, put the multimeter in resistance measurement mode (indicated by Ω), selecting the limit of 2 kOhm (2000 Ohm). If the device has a “dialer” mode (beeper), it can also be used to quickly check for a break.
Disconnect the wires from the contacts of the heating element. Usually they are fixed with terminals or simply pressed tightly onto the terminals. If the contacts are oxidized, carefully clean them. Place the multimeter probes on the two heater terminals. Polarity in this case does not matter.
☑️ Algorithm for checking with a multimeter
Interpretation of the device readings:
- 📉 Resistance 200–800 Ohm: The heating element is serviceable and in working condition.
- ♾️ Unit on the screen (infinity): Internal break in the spiral, the heating element is burnt out and requires replacement.
- 📉 Resistance is close to zero: Short circuit inside the element (rare).
In addition to the main resistance, it is important to check that there is no breakdown to the housing. Press one probe to the metal body of the heating element (or to the terminal, if the body is not accessible), and the second to any of the contacts. The device should show infinity. If there is at least some resistance value, the element “breaks through” to ground, it is dangerous to use it.
Resistance standards and table of values
Resistance values may vary depending on the power of the heating element and its design. Standard tubular heaters for residential refrigerators typically range from 150 to 400 watts. Knowing the power, you can approximately calculate the expected resistance using the formula, but it is easier to rely on reference data.
Below is a table of typical values for various powers. Remember that the permissible error is about 10%.
| Heating element power (W) | Expected resistance (Ohm) | Typical application |
|---|---|---|
| 150 - 200 | 250 - 350 | Small freezers, drip system |
| 250 - 300 | 160 - 220 | Standard No Frost (Indesit, Ariston) |
| 350 - 400 | 120 - 160 | Large two-chamber refrigerators |
| 450 - 500+ | 80 - 110 | Chest freezers, industrial cabinets |
If your measurements differ radically from the tables (for example, the device shows 50 Ohms for a low-power heating element or 5 kOhms for a powerful one), this is a reason to doubt the serviceability of the part. It is also worth considering that a cold heating element always has less resistance than a heated heating element, but the difference in room conditions is insignificant for initial diagnosis.
It is important to check not only the heating element itself, but also the integrity of the supply wires. Often, a break occurs not in the tube itself, but at the junction of the wire with the heater output due to corrosion or overheating. Ring each section of the circuit separately.
Replacing the heating element and checking adjacent elements
If the diagnostics showed a break or breakdown, the heater must be replaced. Burnt heating elements cannot be repaired. When purchasing a new part, pay attention to the geometric dimensions (length, bends) and method of fastening, since there are no universal models. For refrigerators Beko, Atlant or Stinol the shapes of the heaters may differ significantly.
However, simply changing the heating element is half the battle. If the heater burned out, the control circuit could also fail. Be sure to check defrost sensor (thermostat) that is located on the evaporator. If it is “stuck” in the open state, the new heating element will not turn on either. Also check the fuse, which often comes in conjunction with the heating element.
Installing a new one element is performed in reverse order. Make sure that the heating element fits tightly to the evaporator along its entire length for effective heat transfer. Use heat-resistant grease on the contacts, if provided by the design, to prevent oxidation.
⚠️ Attention: Do not plug in the refrigerator until you are sure that all wires are securely fastened and do not touch the rotating parts of the fan or hot surfaces of the compressor.
Frequently asked questions questions (FAQ)
Is it possible to temporarily operate a refrigerator without a heating element?
Technically, the refrigerator will freeze, but only until the evaporator is completely covered with ice. This may take from 3 to 7 days depending on the moisture content of the food and how often the doors are opened. After this, the cold will stop entering the chamber. Long-term operation in this mode is harmful for the compressor, which will wear out.
Why did the new heating element burn out immediately after installation?
The most likely reason is a malfunction of the defrost sensor or timer. If the sensor does not open the circuit after defrosting, the heating element continues to heat “dry,” which leads to its rapid overheating and combustion. Also, the cause may be poor contact in the terminal block.
How often do you need to change the heating element in the refrigerator?
The service life of a high-quality heating element is 7-10 years or more. Frequent replacements (every 1-2 years) indicate a systemic problem in the control electronics or power surges in the network. In such cases, it is recommended to install a voltage stabilizer.
Does the brand of the refrigerator affect the difficulty of replacement?
Yes. In some models (for example, old Liebherr or Bosch), access to the heating element may require complete defrosting during the day and the dismantling of many plastic elements. In modern models, access is often simplified, but more complex composite heaters are used.