Modern refrigerators Ariston with the No Frost system often face the problem of a “fur coat” growing on the evaporator, which leads to the device’s failure to freeze food. Most often, the cause is a failure heating element, which is responsible for the periodic thawing of the radiator. If you notice that the chamber has become warmer and an ice lump has formed on the back wall, you need to diagnose the heating element
Before starting work, it is important to understand that Defrost heating element is an active circuit element that operates under voltage. The malfunction can be caused either by natural wear of the nichrome spiral or by a short circuit. In this article, we will look at how to safely remove a part, test it with a multimeter and determine whether replacement is needed.
To carry out high-quality diagnostics, you will need a basic set of tools and an understanding of the principles of operation of electrical circuits. You should not ignore the symptoms, since a running compressor with an evaporator clogged with ice will quickly fail from overload. Correct and timely checking the heating element will help extend the life of the entire refrigeration unit.
Symptoms of defrost heater malfunction
A heater breakdown can be determined not only by the appearance of the evaporator, but also by indirect signs of refrigerator operation. The No Frost system in models Ariston is designed so that the ice freezes cyclically and then melts. If the melting cycle is disrupted, this is immediately reflected in the temperature inside the chambers.
Owners often confuse the breakdown of the heating element with a freon leak or a compressor malfunction, although the symptoms may be similar. The main difference is that when the heater burns out, the compressor works almost without interruption, trying to compensate for the loss of cold. The ice plug blocks air circulation, and the cold simply does not enter the main volume of the chamber.
⚠️ Attention: If you hear a cracking sound or see sparking inside the freezer when the refrigerator is running, immediately unplug the appliance. This may indicate a breakdown of the insulation of the heating element on the housing, which is life-threatening.
There are a number of characteristic signs that indicate problems with the defrost circuit:
- ❄️ A large lump of ice or a snow coat has formed on the back wall of the freezer.
- 🌡️ The temperature in the refrigerator compartment has increased, food begins to deteriorate faster than usual.
- 🔊 The compressor hums continuously, without going into rest mode, since the temperature sensor does not detect cooling.
- 💧 Water has appeared at the bottom of the refrigerator or under the vegetable drawers, which does not have time to evaporate.
The presence of even one of these symptoms requires immediate intervention. Ignoring the problem will result in ice completely blocking the air supply channels, and the refrigerator will stop cooling completely. In some models Ariston the emergency temperature indicator may light up.
Preparation for diagnostics and safety precautions
Before proceeding with disassembly and inspection heating elementit is necessary to ensure complete safety of the work. A refrigerator is a complex electrical device, and working with its internal components requires compliance with strict rules. Any manipulations are carried out only with the appliance completely disconnected from the power supply.
To access the heating element, you will need to remove the back panel of the freezer. In most models Ariston it is secured with plastic latches and several screws. Be careful, as plastic after prolonged use at low temperatures becomes brittle and can easily crack if handled carelessly.
☑️ Preparing to check the heating element
You will need the following tools for diagnostics:
- 🔧 Set of screwdrivers (phillips and flat) for removing panels.
- 🔌 Multimeter (tester) for measuring circuit resistance.
- 🧤 Gloves to protect hands from sharp edges and dirt.
- 📸 Smartphone for photographing the wiring diagram before disconnecting.
The critically important step is complete defrosting. Even if there appears to be little ice, moisture can remain in hidden cavities and cause a short circuit when voltage is applied during tests. Leave the refrigerator turned off with the doors open for at least 12 hours, preferably for a day.
Access to the heating element and visual inspection
After defrosting and removing all shelves and drawers in the freezer, access to the back wall opens. In refrigerators Ariston with the No Frost system, the evaporator and heating element are located exactly there. Carefully unscrew the mounting screws and remove the plastic panel, freeing access to the insides.
The defrost heating element is usually a curved metal tube or quartz element located at the bottom of the evaporator or passing through its fins. In some models it is hidden under a layer of thermal insulation or a protective casing. Carefully inspect the element for visible damage.
A visual inspection can immediately answer the question about the condition of the part. Look for the following signs:
- 💥 Blisters or tears in the shell of the heating tube.
- 🔥 Traces of insulation melting or blackening at the fastening points.
- ⚡ Oxidation or burnt contacts at the places where the wires are connected.
- 💧 The presence of rust or corrosion that could damage the seal.
Location features in different models
In some modifications of Ariston Hotpoint, the heating element can be built directly into the aluminum profile of the evaporator. In such cases, replacement requires complete disassembly of the heat exchanger or the use of a universal heater of suitable power and geometry.
If there are no visual defects, this does not guarantee serviceability. The nichrome spiral inside the tube could burn out without external manifestations. Therefore, an obligatory step is an instrumental check using a multimeter. Do not rely only on the appearance of the part.
Checking resistance with a multimeter
The most reliable way to find out whether Defrost heating elementis working is to measure its electrical resistance. To do this, switch the multimeter to resistance measurement mode (Ohm, indicated by the symbol Ω). Select the measurement limit in the range of up to 2 kOhm (2000 Ohm), since a working heating element usually has a resistance within hundreds of Ohms.
Disconnect the wires from the heater contacts. If the connectors are heavily oxidized, it is better to clean them or carefully tighten them to ensure reliable contact of the tester probes. Attach the multimeter probes to the contacts of the heating element and observe the readings on the display.
⚠️ Attention: Before measuring, make sure that the contacts of the heating element and the multimeter probes are dry. Water is a conductor and can distort the readings, creating a false impression of the health of the circuit.
Measurement results are interpreted as follows:
| Multimeter readings | Diagnosis | Actions |
|---|---|---|
| 1 (or OL, Infinity) | Open circuit (spiral burned out) | Replacing the heating element |
| 0 - 10 Ohm | Short circuit | Replacing the heating element and checking the wiring |
| 200 - 800 Ohm | Normal (depending on power) | The heating element is working, look for another reason |
| Floating values | Unstable contact inside | Replacing the heating element |
For most household refrigerators Ariston resistance in the range from 200 to 600 Ohms is considered normal. The exact value depends on the power of the specific heater, which is usually 150–400 W. The higher the power, the lower the resistance.
Checking for breakdown on the body
Even if the spiral is intact, the heating element may be faulty due to insulation failure. In this case, the current may flow to the metal body of the evaporator or the refrigerator itself, which creates a risk of electric shock and tripping of the RCD in the panel.
To check for breakdown, switch the multimeter to the dial mode (with a sound signal) or resistance measurement to the maximum limit (Megaohms). Apply one probe to the contact of the heating element, and the second to the metal tube of the heater or the evaporator body.
In good condition, the device should show infinity (one in the most significant digit) and be silent. If you hear a squeak or see any resistance values other than infinity, it means that the insulation is broken.
- 🔇 Silence and "1" on the screen - the insulation is normal, there is no breakdown.
- 🔊 Sound signal - there is a breakdown in the case, operation is prohibited.
- 📉 Digital values - current leakage, the part requires replacement.
The use of a broken heating element is unacceptable. Even if it continues to heat, the moisture inside the chamber can become a conductor, and the refrigerator will begin to “shock” when touching handles or food. This is a direct threat to safety.
Diagnostics of related elements
Often the reason for the lack of defrosting lies not only in the heateritself, but also in the controls. The defrost circuit includes a thermostat (defrost sensor) and a thermal relay (overheat protection). If they are faulty, the current simply will not reach the heating element, even if it is completely working.
The defrost thermostat should close the contacts at low temperatures (usually below -5°C or -10°C) and open when heated. Check it with a multimeter: at low temperatures (you can cool it in the freezer) it should ring, and at room temperature it should open the circuit (or vice versa, depending on the type of sensor).
Thermal relay (bimetallic protection) is located at the entrance to the heating element and opens the circuit if the temperature exceeds a critical one (usually +70...+80°C). When cold it should be closed. If the relay is “stuck” in the open state, the heating element will never turn on.
It is also worth paying attention to the defrost timer or electronic control module. In older models Ariston the mechanical timer could wear out and get stuck in cooling mode. In modern models, the board is responsible for everything, and diagnostics require special knowledge.
Replacement and final recommendations
If the check confirms the heating element is faulty, it must be replaced. Buy original spare parts or high-quality analogues that exactly match the geometric dimensions and power. Installing a more powerful heater may lead to overheating of the plastic parts, and a less powerful one may result in incomplete defrosting.
When installing a new part, make sure that it fits tightly to the evaporator or is correctly installed in the grooves. Poor thermal contact will cause heat to escape into the air rather than melting the ice. Securely secure the wires so that they do not touch the moving parts of the fan.
⚠️ Attention: Technical characteristics of refrigerators may vary depending on the year of manufacture and the specific series. Always check the parameters of the new part with the markings on the old one or consult the manufacturer’s official documentation.
After assembly, turn on the refrigerator and check the first cycle of operation. Make sure that after a certain time (usually 6-12 hours) a normal defrost occurs. If ice begins to accumulate again, the problem should be looked for in the sensors or control system.
Frequently asked questions (FAQ)
Is it possible to temporarily operate the refrigerator without a defrosting heating element?
Theoretically, it is possible if you manually defrost the refrigerator every 5-7 days. However, this is inconvenient and reduces the life of the compressor. Without regular defrosting, ice will block the air channels, and the cooling efficiency will drop to zero.
Why does the heating element burn out in Ariston refrigerators?
The main reasons: natural wear and tear of nichrome, corrosion of the housing due to constant moisture, voltage surges in the network or a malfunction of the thermostat, due to which the heater works longer than expected time.
What resistance should a working heating element have?
For most Ariston models, the range from 200 to 600 Ohms is considered normal. The exact value depends on the power (W) and voltage (220V). Calculation formula: R = U² / P.
Is it necessary to change the thermostat together with the heating element?
It is recommended to change the defrost thermostat preventively, especially if it is older than 5-7 years. The old sensor may incorrectly turn off the new heating element, which will lead to repeated breakdown or ineffective operation.