Modern refrigerators Hotpoint Ariston with technology No Frost have become the standard for most kitchens, eliminating the need for regular manual defrosting. This technology is based on a complex but well-established algorithm for alternating cooling and automatic defrosting cycles, which is controlled by an electronic module. Understanding exactly how air circulation and moisture removal occurs helps not only to operate the equipment correctly, but also to timely diagnose malfunctions, such as ice freezing in the freezer or insufficient cooling of food.
The main difference between the models Ariston from old drip-type systems is that the main heat exchanger is hidden from the user’s eyes and is located behind the rear panel. Air is forced through this evaporator with a powerful fan, after which it is distributed to all shelves through a system of special channels. That is why in such refrigerators you will never see ice on food, and the temperature is distributed evenly throughout the entire volume of the chambers, which is critical for maintaining freshness.
Consideration of the internal structure will allow you to better understand the technical characteristics of your model and understand which sounds are normal operation of the compressor, and which signals a failure in the system. The key element of the entire system is the defrost sensor, which determines the moment the evaporator begins to defrost, preventing it from becoming completely covered with ice. Next, we will analyze in detail each stage of the unit's operation.
The basic principle of refrigerant circulation and air flow
The foundation of the operation of any refrigeration equipment, including Hotpoint Ariston, is built on the physical process of boiling and condensation of the refrigerant (freon) in a closed circuit. The compressor compresses the freon gas, turning it into a high-temperature liquid, which then flows into the condenser (usually a grille on the back wall or foam pipes on the sides of the housing). Here the gas gives off heat to the environment and turns into a liquid state, after which it passes through a filter-drier and a capillary tube, where it expands sharply and boils in the evaporator, absorbing heat from the chambers.
In systems No Frost cold air from the hidden evaporator does not just fall down, but is actively pumped by the fan. Fan located directly behind the rear wall of the freezer compartment and turns on synchronously with the compressor (or according to a thermostat signal). It creates pressure that forces the air to pass through the fins of the evaporator, where it is cooled and deprived of moisture, which settles in the form of frost on the cold tubes.
After cooling, the air flow is distributed through the air duct system. Part of the cold air remains in the freezer, and the other part flows through special dampers into the refrigerator compartment. This design allows you to maintain the set temperature in both compartments using just one compressor and one main cooling circuit, which makes the design energy efficient and compact.
The design of the hidden evaporator and defrost system
The heart of the system No Frost is evaporator, which in models Hotpoint Ariston is usually made in the form of a coil with aluminum fins. Since moist air from the chambers is constantly driven through it, frost inevitably forms on its surface. If this ice were not removed, it would quickly clog the air ducts and the refrigerator would stop freezing. To solve this problem, an automatic defrosting cycle has been introduced.
The defrosting process is initiated by the electronic control unit at certain intervals or according to sensor readings. At this moment, the compressor and fan are turned off, and the Defrost heating element (tubular electric heater) located under the evaporator coil turns on. Thermal energy melts the accumulated ice, turning it into water.
⚠️ Attention: Frequently opening the refrigerator doors leads to a large amount of moist air getting inside. This forces the No Frost system to work harder, which can lead to more frequent defrost cycles and increased energy consumption.
The resulting water flows through a special groove into the drainage system. In the lower part of the housing, usually above the compressor, there is an evaporation tank (bath). Water drips into this container and evaporates naturally due to the heat generated by the operating compressor. Thus, the system is completely autonomous and does not require human intervention to remove moisture.
What will happen if the defrost sensor burns out?
If the defrost sensor fails and shows incorrect data (for example, that the temperature is too low), the heating element may not turn on in time. This will lead to the evaporator becoming coated, the fan will begin to make noise, touching the ice, and will stop moving air. As a result, the food in the refrigerator compartment will begin to deteriorate, although the freezer can continue to freeze locally.
Temperature control: the role of dampers and thermostats
Unlike simple refrigerators, where the temperature is controlled only by the frequency at which the compressor is turned on, in Hotpoint Ariston No Frost more fine-tuning is used. air damper (Damper) is responsible for the distribution of cold between the freezer and refrigerator compartments. This is a mechanical or electrical valve that opens and closes, allowing cold air from the freezer to enter the upper compartment.
Temperature control is carried out using electronic sensors (thermistors), which constantly transmit data to the control module. Depending on the model, a refrigerator can have from two to four sensors installed: one in the freezer, one in the refrigerator, one on the evaporator and sometimes an additional one in the freshness zone. Based on these readings, the controller decides to turn on the compressor, fan or heating element.
The user can adjust the temperature using the control panel located on the outside of the door or inside the chamber. When you change settings, you are not changing the compressor power, but the target values at which the electronics will interrupt or resume cooling cycles. This allows you to maintain the temperature with high precision, which is especially important for the zone Zero Degree or similar compartments in top models.
Typical malfunctions of the No Frost system and their symptoms
Despite its reliability, the system No Frost is subject to wear. The most common problem is the failure of elements of the defrost system. If the heating element, thermal fuse or defrost sensor stops working, the evaporator becomes covered with ice. Visually this may not be noticeable, but the symptom will be the hum of the fan (it touches the ice) and the lack of cold in the refrigerator compartment when the freezer is running.
The second common problem is a clogged drainage channel. If the melt water does not have time to go into the evaporation bath, it begins to overflow over the edge of the groove and flow into the refrigerator or onto the floor under the device. This often happens due to food particles or mold getting into the exhaust tube.
The blower fan may also malfunction. If its wing is unbalanced or the motor is burned out, air circulation stops. In this case, the food in the freezer may begin to thaw, and condensation or ice will appear on the back wall of the refrigerator compartment, since warm air will not be blown onto the evaporator.
☑️ Symptoms of a defrost system breakdown
Comparison of characteristics: No Frost versus Drip system
To better understand the advantages and features of the technology installed in your Hotpoint Ariston, it is useful to compare it with the classic drip system. In drip refrigerators, moisture settles on the back wall, freezes and periodically thaws by gravity, while in No Frost the moisture is constantly frozen.
| Parameter | No Frost system | Drip system |
|---|---|---|
| Education ice | Absent (automatic defrost) | Periodic formation of ice on the wall |
| Temperature distribution | Uniform throughout the entire volume | Possible temperature changes |
| Humidity in the chamber | Lower (products can dry out) | Higher (products remain juicy longer) |
| Noise level | Higher (works fan) | Lower (compressor only) |
| Energy consumption | A little higher due to the heating element | A little lower |
It is important to note that low humidity in refrigerators No Frost requires proper storage of food. Opened foods, especially vegetables and fruits, quickly lose moisture and become airy. Therefore, the use of containers with lids or cling film in such models is not just a recommendation, but a necessity to preserve the quality of food.
Operating rules to extend service life
For the stable operation of your Hotpoint Ariston it is important to follow certain loading rules. Do not place hot food inside the chamber - this creates a sharp jump in humidity and temperature, causing the system to wear out. It is also not recommended to fill the refrigerator with food more than 70-80% in order to leave space for free circulation of air flow.
Regular hygiene also plays a role. Although the system is called "frost-free", the drainage hole requires periodic inspection. Once every six months, it is recommended to carefully clean it with a special soft brush or warm water to prevent the formation of plugs from mucus and dirt.
⚠️ Attention: When defrosting the refrigerator (for example, for general cleaning), it is strictly forbidden to use sharp objects to chip ice or direct a stream of hot water directly at the plastic case. A sharp temperature change can cause cracks in the plastic and damage to the foamed circuit.
Compliance with the temperature regime in the room where the refrigerator is located is also critical. If the room is too hot or too cold (below +10°C), the compressor may not work correctly or not turn on at all, since this is outside the climatic class of the device.
Frequently asked questions (FAQ)
Why does the Hotpoint Ariston refrigerator make a loud cracking or buzzing sound?
Most often this sound is produced by the blower fan, which touches the ice frozen on the evaporator with its blades. This is a sure sign of a malfunction of the defrost system (the heating element, sensor or timer has burned out). Diagnostics and replacement of defective elements are required.
How often do you need to defrost a No Frost refrigerator?
Technically, the No Frost system does not require defrosting to remove ice. However, manufacturers recommend turning off the device and washing it 1-2 times a year to maintain hygiene, eliminate odors and clean the drainage channels from contaminants.
Why does water or ice appear in the refrigerator compartment on the back wall?
In No Frost models, this may indicate that the air duct damper is closed or clogged, and cold air is not flowing, or vice versa - too much moisture is supplied. Also, the reason may be a loose door or damage to the seal.
Is it possible to install an Ariston refrigerator close to the wall?
No, for normal operation of the condenser and the ventilation system of the compressor compartment, it is necessary to leave a gap of at least 5-10 cm from the back and side walls to the furniture. Violation of this rule will lead to overheating and increased energy consumption.