Finding the installation location of temperature sensors in the refrigeration room equipment Hotpoint Ariston often becomes the first step in self-diagnosis of faults. If your unit stops freezing, begins to “cry” or, conversely, turns food into ice blocks, the reason may lie in incorrect sensor readings. Understanding where these elements are physically located will help you save time when calling a technician or correctly formulate the problem when calling for service.
The design of modern models, especially systems No Frostimplies the presence of several independent sensors that monitor different zones. In older single-chamber models with mechanical control, everything is simpler - there is usually one thermostat. However, in complex two-chamber systems, electronics read data from the evaporator, from the air flow and even from the freshness zone. Accurate knowledge of the location of these components is critical for conducting a continuity test with a multimeter or visual inspection for contact oxidation.
In this article we will analyze in detail the architecture of the cooling system of brands Hotpoint i Ariston. You will learn how to get to hidden elements, what tools are needed to dismantle plastic panels, and what to look for when checking the functionality of the sensors. Remember that interfering with internal components requires care, since plastic elements become brittle at low temperatures.
The principle of operation of the temperature control system
Before you begin disassembling, you need to understand how exactly the electronics Hotpoint Ariston controls the climate inside the chambers. The basis of the system is control module, which receives signals from thermistors. These sensors change their electrical resistance depending on the ambient temperature. The module analyzes these changes and makes a decision: turn on the compressor, start defrosting or activate the fan.
Unlike old mechanical thermostats, which simply opened the circuit when a certain point was reached, electronic sensors operate in continuous mode. They transmit an analog signal, allowing the processor to precisely regulate the operation of the unit. If one of the sensors fails and transmits incorrect data (for example, it shows -50°C when it is +5°C), the refrigerator may work without stopping or not turn on at all.
⚠️ Attention: When diagnosing, always disconnect the refrigerator from the power supply. Working with the electronic module under voltage may result in a short circuit or electric shock.
The control system in models with No Frost is especially complex, as it must balance between cooling and preventing ice fouling. A defrost sensor, for example, monitors the temperature of the evaporator and gives a command to turn on the heating element when the ice reaches a critical mass. An error in its operation will lead to either insufficient defrosting or overheating of the system.
Sensors in the No Frost freezer
In the freezer compartments of the system No Frost there are usually two main temperature sensors installed. The first is responsible for monitoring the general temperature in the chamber, and the second (defrost sensor) directly monitors the condition of the evaporator. You can find them only by reaching the back wall or a hidden box behind the panel.
The air sensor is often located at the top of the chamber or built into the plastic fan casing. It measures the temperature of the circulating flow. If it is faulty, the refrigerator may hum constantly or pause for too long. The defrost sensor, as a rule, is attached directly to the evaporator fins or inserted into a special hole in the aluminum tube.
- 🌡️ Evaporator sensor: Attached to the aluminum radiator tube, often in the lower or middle part.
- 💨 Air flow sensor: Located in the cold air outlet area, sometimes combined with control unit.
- ❄️ Protection thermostat: An additional element that prevents overheating in the event of a malfunction of the main system.
For access to these elements in most models Hotpoint Ariston you will need to remove the back plastic panel inside the freezer. It is secured with latches and sometimes with screws hidden under decorative plugs. Be careful: after prolonged use, the plastic may become brittle, so heating it with a hairdryer before removing it is not recommended; it is better to act slowly at room temperature.
☑️ Access to freezer sensors
Location of sensors in the refrigerator compartment
In the main In the camera, the situation may differ depending on the type of cooling system. If you Full No Frost, then the sensors here work similarly to freezers, but control the freshness zone. In models with Direct Cool (drip system), the sensor is often built into the wall or hidden behind a decorative trim.
Often users are looking for a mechanical thermostat with a rotating handle. In modern electronic models Ariston i Hotpoint it is not present - everything is regulated through the control panel, and measurements are made by electronic thermistors. They can be located in the air supply duct (if there is a fan) or directly at the rear wall.
Particular attention should be paid to the “zero freshness” zone or “optimization zone”, if provided by the model. There may be a separate sensor there to accurately maintain the temperature around 0°C. Its malfunction will lead to spoilage of meat or fish ahead of schedule.
⚠️ Attention: The design of the internal lining of the refrigerator compartment often does not allow easy access to the sensors without partially disassembling the housing. Make sure that the problem is in the sensor before disassembling the chamber.
In some models, the temperature sensor of the refrigerator compartment is integrated into the control unit, which is placed outside, on the top of the door or at the top end of the case. In this case, to replace it, you do not need to go inside the camera; just remove the top cover. However, the sensitive element itself can be carried inside through the wires.
Hidden location in channels
In some Hotpoint Ariston models, the sensor is hidden in a heat-insulating channel running between the walls. To get to it, you have to remove the side panels of the refrigerator body, which requires complete defrosting and care with foam.
Sensors of the defrost system and their testing
The defrost system is the most loaded unit in No Frost, and sensors play a key role here. The main defrost sensor must be triggered when the evaporator heats up to a certain temperature (usually +10...+15°C) in order to turn off the heating element. If it is “stuck”, the heating element will heat up constantly, which is dangerous.
The sensor is checked using a multimeter in resistance measurement mode (Ohm). At room temperature, a working thermistor usually shows a resistance in the range from 5 to 10 kOhm (the value depends on the specific model and type of sensor). When cooling, the resistance should increase, and when heating, it should fall.
If the multimeter shows an open circuit (one on the screen) or a short circuit (zero), the sensor is clearly faulty and requires replacement. It is also worth checking the integrity of the wires going to it, as they are often chafed or interrupted by ice.
| Sensor type | Normal resistance (at 20-25°C) | Location | Symptom malfunction |
|---|---|---|---|
| Evaporator sensor | ~6.6 kOhm | On the fins of the radiator | Increasing “fur coat”, ice in the chamber |
| Air sensor (chamber) | ~10 kOhm | In the air flow | Incorrect temperature, compressor does not turn off |
| Defrost sensor (protective) | Depends on models | Near the heating element | Overheating of the system or lack of defrosting |
It is important to understand that resistance can vary. For accurate diagnostics, it is better to find technical documentation (service manual) specifically for your model Hotpoint Ariston. There are no universal values for all refrigerators, although the ranges are often similar.
Dismantling and access to internal components
The process of gaining access to sensors in refrigerators Hotpoint i Ariston requires sequential removal of elements. First, the chamber is cleared, then the shelves, guides and decorative strips are dismantled. Only after this is access to the technical stuffing possible.
In the freezer, you need to unscrew the fastening screws of the rear panel. They can be hidden under plastic plugs that need to be carefully pryed off with a knife or screwdriver. After removing the panel, the evaporator and the wires with sensors suitable for it will open in front of you.
- 🔧 Tools: Phillips screwdriver, flat-head screwdriver (for latches), multimeter.
- 🧤 Protection: Gloves (sharp edges of the evaporator metal) and knee pads (if you work on the floor).
- 📸 Photo fixation: Take a photo of the wire connection diagram before disconnecting.
When removing plastic panels, do not use excessive force. If the panel does not fit, check to see if you forgot to unscrew a screw or remove the top cover. Plastic is very fragile in the cold, and one wrong movement can lead to breakage of the mounting lugs, which will then have to be restored with glue.
Typical faults and error codes
Modern refrigerators Hotpoint Ariston equipped with a self-diagnosis system. If the sensor fails, an error code is displayed on the display or through blinking indicators. For example, a flashing temperature indicator may indicate an open circuit in the sensor.
A common problem is oxidation of the contacts in the sensor connector due to moisture. Even if the thermistor itself is good, the oxidized terminal will produce high resistance and the module will think that the temperature is too low. In such cases, it is enough to clean the contacts with alcohol or contact-flushing liquid.
⚠️ Attention: If after replacing the sensor the error does not disappear, the problem may be in the control module or in a broken wiring inside the case (in the insulation).
It is also worth considering that the module software may have bugs. In rare cases, an electronics “glitch” simulates a sensor malfunction. Resetting settings (rebooting) sometimes helps if the sensor is physically intact. To do this, unplug the refrigerator from the outlet for 15-20 minutes.
FAQ: Frequently asked questions
Is it possible to replace the temperature sensor with a universal one?
Technically, it is possible if you use an analogue with a similar resistance (B-parameter). However, it is better to use original spare parts Hotpoint Ariston or proven analogs (for example, NTC 10 kOhm), since a mismatch in characteristics will lead to incorrect operation of the refrigerator.
Where is the main sensor located in older models without electronics?
In older models, the role of the sensor is performed by a mechanical thermostat with a bellows. Its bulb (sensitive element) is located inside the chamber (often in the lampshade or on the wall), and the body itself with contacts is outside or behind the control panel.
Why does the refrigerator run jerkily after replacing the sensor?
Perhaps the new sensor has a different resistance curve than what the module requires. Also, the reason may be poor contact in the connector or that not only the sensor, but also the defrost heating element is faulty.
How to check the sensor without a multimeter?
It is impossible to accurately check without instruments. An indirect sign - if when the sensor wires are shorted (simulating a certain temperature), the refrigerator’s reaction changes, it means that the circuit to the module is intact, but the sensor itself may be incorrect. But it’s safer to use a tester.