The design of the electric kettle is very simple: during active boiling of water, steam collects in the upper part of the body, which, if there is a large accumulation, is discharged into a special channel where the limit switch is located. When the temperature is high, it triggers and disconnects the device from the network. When the water boils, steam collects in the free space between the water level and the lid of the product, then the water vapor flows through a special channel to a bimetallic plate made of two different metals, which bends when heated and opens the contacts - the thermal switch turns off.
Why is there a tube inside the kettle?
The kettle has protection against overheating (starting without water). The tube inside the kettle (see photo) is a system for automatically turning off the kettle when water boils, which also performs the “No steam” function. … This allows for very precise pouring and dosing of water.
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Principle of operation
Despite the fact that there are many manufacturers of electric kettles, each of them has a completely similar electrical circuit. Differences can only be in small elements. For example, they are now improving electrical devices by installing a control system containing different timers.
But even all the innovative light bulbs and backlights do not make the internal structure more complex; it still remains extremely simple, so that even a beginner can understand the operation of the device.
All modern devices have two parts:
- stable stand with cord;
- product body containing a container and heating element.
The structure of an electric kettle
Electricity is supplied through a wire to the contacts of the device, which are located inside the stand. This is done to prevent a person from accidentally touching a current-carrying wire. Some contacts are located right on the bottom of the electric kettle stand.
When the kettle is on the stand, the terminals close during operation, as a result of which the electricity travels further through the wires to the thermal switch, which does its work in two modes:
- mechanical shutdown by pressing a button located on the body;
- Automatic shutdown after water boils.
Immediately after turning on the device, electricity penetrates the heating element. And the person sees that the light is on, which indicates that the kettle is working.
After the kettle reaches a boil, steam penetrates the bimetallic plate in the thermal switch, usually located near the lid where the two different metals come into contact with each other. When heated, one of the plates bends, which is why automatic shutdown occurs.
Operating principle of an electric kettle
Disassembling the electric kettle
To understand why the device turns off prematurely, it is necessary to partially or completely disassemble it, which will allow you to quickly find the faulty unit and repair it or completely replace it. The dismantling algorithm will be considered using the example of a kettle from a brand manufacturer - Bosch. At the bottom of its case there are four screws that need to be removed. To do this, select a screwdriver that matches the screw heads. A cross is usually suitable.
But recently, the manufacturer has begun to use protection against attempts at self-repair. For example, he can hide the bolts under plastic plugs, which can be easily pulled out by prying them with something sharp. Or use one screw (or all) with a non-standard head. Then you will need a two-pronged fork type screwdriver, which can be replaced with tweezers. You can also do it yourself by sawing a groove in the flat blade of a regular screwdriver with a needle file.
Advice! If the self-tapping screw does not want to unscrew, then the easiest and fastest way to deal with this problem is to heat it up a little by applying the switched-on soldering iron to the head. The plastic will soften slightly and the screw will come out easily.
The last level of protection is the clever latches on the case and the lid itself. There is an opinion that sometimes removing the cover is more difficult than making the repair itself. In this case, two thin screwdrivers will help. The first one is pushed under the lid to create a gap. And the second one in this gap is to find the place of the latch and carefully release it.
Important! After disassembling the electric kettle, be sure to check all wire connections for integrity. Loose contact can cause many problems, including early shutdowns.
Why don't electric kettles turn off after boiling water?
During operation of the electric kettle, malfunctions occur. We will tell you why the electric kettle does not turn off automatically after boiling and how to fix such a breakdown.
How to turn off an electric kettle: principle of operation
After switching on, electricity is supplied to tubular heating elements (heating elements), which are located on a stand or built into the bottom of the household appliance. The operation of the heating elements causes the water to heat up and boil.
Steam is generated and accumulates under the lid . Having reached a certain concentration, it moves into a channel that leads to the switch. In front of it is a bimetallic plate. When heated, it acts on the switch, the button snaps off, and the device is disconnected from the network.
Having understood the principle of operation, it is easier to understand why an electric kettle does not turn off after the water boils.
Why does the electric kettle not turn off when it boils?
There are several reasons for an electric kettle to malfunction.:
- The kettle lid is not closed or not closed tightly . In this case, the steam formed as a result of boiling does not move through the channel that leads to the switch, but exits through the cracks to the outside. As a result, the shutdown mechanism does not work.
- The kettle has a missing or uneven filter . As a result, the lid does not fit tightly to the edges, and steam escapes through the cracks. Automatic shutdown of equipment does not work.
- The kettle is dirty . In order for it to work without failures, it is periodically descaled.
- The steam outlet channel leading to the switch is clogged. This problem occurs with older models of household appliances. The new models feature an improved design that takes this aspect into account.
- Breakage of the bimetallic plate , which cuts off the electricity when boiling. In case of this failure, the device is turned off manually. To restore automatic shutdown, the plate is replaced.
- Switch malfunction . In order for the device to function normally, the switch is changed.
- Contacts have oxidized . The problem is eliminated with sandpaper, which is used to clean them.
Most of the reasons why the electric kettle does not turn off when boiling can be eliminated independently . If technical knowledge is not enough, the device is taken to a repair service.
Attention! A faulty electric kettle is either repaired or replaced with a new one - the safety of users depends on this. If you turn on faulty equipment and leave it unattended, there is a risk of fire. The water in the kettle that does not turn off gradually boils away. If it evaporates while the kettle is running, it will cause a fire.
How to troubleshoot
If the electric kettle does not automatically turn off after boiling water, the first thing to do is inspect :
- Check that the lid is closed and that there are no chips or cracks through which steam is escaping.
- They look at how the filter is installed inside the equipment . It should stand level so that the lid of the kettle fits tightly to the edges.
- Check for scale on the walls and bottom . If scale has formed in the electric kettle, it should be thoroughly cleaned and washed.
- through which steam moves to the switch is clogged The channel opening is located on the handle side between the lid and the wall. It should be clean, without scale plugs. Most often, the hole gets clogged in older models, since it is very small. If the hole is clogged, it is cleaned.
If there are no visible faults, then the breakdown is more serious , and its elimination requires technical knowledge. To find it, the household appliance is disassembled.
Take it for repair or fix it yourself
Some breakdowns are difficult to fix at home on your own , so contact a qualified technician. If the plate, switch or microcircuits are broken, this indicates improper operation of the electric kettle.
After consultation with a specialist, they determine what is more profitable - repairing the old equipment or buying a new one. If repairs cost less than buying a new kettle, the device is taken to a workshop.
Advice. When purchasing, choose a high-quality electric kettle with a guarantee from a reputable manufacturer. It will last longer than cheap Chinese counterparts.
DIY repair
When repairing it yourself, an electric kettle that does not turn off after boiling water is disassembled to get to the switch, bimetallic plate and contacts . To do this, unscrew the screws on the bottom cover and remove it. Unscrew the screws on the handle.
When disassembling, remember the sequence of actions to make it easier to put everything back together.
Advice. To facilitate the subsequent assembly of the household appliance, record the disassembly process on camera.
First, inspect the switch . If it breaks, the part is replaced with a similar one. It is not recommended to repair the switch yourself - this may lead to incorrect operation of the device.
If the contacts are burnt or oxidized , they are cleaned with fine-grained sandpaper. Then wipe with thick felt to remove scratches.
If the power button fails , it is replaced with a new one.
The device is then assembled. Before turning on, check whether everything is done correctly . To do this, pour water into the electric kettle, place it on a towel and wait 30 minutes. If the fabric does not get wet during this time, it means that the device is assembled correctly and can be used.
A wet cloth under the kettle indicates that the seal may have been dislodged during repairs. Then the equipment is disassembled again and the gasket is put back in place.
How to prevent breakdowns in the future
To prevent further damage, the electric kettle is used correctly:
- close the lid tightly;
- install the filter so that it stands level and does not interfere with the lid closing;
- do not use the device during voltage fluctuations in the electrical network;
- Do not heat the water many times in a row.
The smooth operation of equipment also depends on proper care . The kettle is filled only with purified water and descaled periodically.
To ensure that the electric kettle lasts longer and without breakdowns, buy high-quality equipment from trusted brands with warranty service.
Conclusion
Using damaged equipment is unsafe for the user and his property. If the kettle no longer turns off automatically after boiling, it should be repaired immediately or replaced with a new one.
There are several reasons why an electric kettle does not turn off when boiling. Many of them resolve on their own. Complex problems are repaired by qualified specialists. If the electric kettle is under warranty, contact the seller.
Causes of malfunction
The main reason for the breakdown of an electric kettle is a large accumulation of scale on the bottom and walls of the device. This problem most often happens with devices where the heating element is completely open. If scale has already completely covered the bottom of the kettle, then you should not immediately disassemble it, this will not help. You can simply fix it by cleaning it with citric acid - this is the most reliable method.
Lime in the electric kettle
In a situation where the kettle turns off prematurely, that is, before the water boils, this may indicate a breakdown of the heat-resistant switch. In this case, you will have to take the device to a specialist or purchase a new one.
Attention! Even small leaks in an electric kettle can lead to premature shutdown of the device. In this case, the first thing you need to do is carefully check the case for cracks and chips. Most often, this problem occurs in teapots made of low-quality plastic or glass.
Another common cause of kettle malfunction is unreliable fastening of the heating element inside the electric kettle. If the kettle has open access to the heating element, then you can check this using a special device, but if the kettle has a heating element hidden inside, you will have to disassemble the device.
Thermal fuse malfunction is a special protection that is necessary in the event that the kettle for some reason cannot turn off even after the thermostat has been activated. In almost all cases, opening is observed at 100 degrees Celsius. But in a situation where the thermal fuse is broken, the kettle can automatically turn off at a lower temperature, thereby turning off the electric kettle before the water boils.
Main reasons for premature shutdowns
The main reason for this problem is the long service life of the boiling unit. Over many months of operation, a layer of scale and soot forms on the heater, which reduces heat transfer . Because of this, the heating element overheats, and, as a result, the protection mechanism is triggered. Even if there are only a few seconds left before the water boils, the thermostat turns off the device earlier, since it interprets this situation as a fire hazard.
Most often this happens with open-type heating elements. In such cases, you can carry out the repair yourself. And if in models with disk heaters it is enough to boil the flask with a solution of citric acid or vinegar several times, then the spiral must be removed and cleaned with a knife. You need to remove the plaque carefully, but at the same time being careful not to damage the coating of the element. Then the part should be wiped until shiny with a dry cloth. After this procedure, the heater becomes like new, the problems stop and the kettle continues to serve for a long time.
Due to age, the thermostat may not work correctly. After many years of regular expansion and contraction, the bimetallic strip becomes deformed and begins to turn off at the wrong time. Taking advantage of the fact that the protection is duplicated and both thermostats are identical, some masters swap them. Often this solves the problem.
Important! It is strongly not recommended to replace a faulty thermostat with a backup one yourself, as this may lead to a fire.
It's better to try to bend the plate into place. The measure, although temporary, is more reliable. Don't forget about low-quality Chinese stampings. The service life of such products is short, and, as a rule, they cannot be repaired.
overheat protection
In backup protection, plates with different expansion coefficients act as temperature sensors. Having a special sample inside, the plates are glued together and fit tightly to the bottom of the kettle. They are helped in this by a paste with increased heat-conducting properties, which is applied to the surface. Under no circumstances should it be removed from the thermal protection switch.
Temperature sensor
Using a ceramic rod, the plate is connected to the contacts. When heated, one of the plates bends, the rod moves and opens the circuit. But then a gradual cooling occurs, and the rod closes the connection again. This action will continue in a circle until the heating element burns out or the kettle is removed from the stand. To prevent automatic switching on, backup protection is installed, which cuts off the voltage supply to the device.
Process Features
The main function of a kettle is to boil water for tea, coffee or some other needs. Regardless of the device used (electrical device made of stainless steel or glass, enameled model for a gas or electric stove), water begins to boil when it reaches a value of 100 ºC.
The Kelvin value is 373.15 K, and the Fahrenheit value is 212 °F.
But this is true only at normal external pressure (760 mmHg) and the absence of impurities in the liquid. A change (decrease) in pressure affects the boiling point, and water in a populated area located significantly above sea level will boil at 80-90 ºC.
On the contrary, under conditions of high pressure, the contents will begin to boil at a temperature that will be higher than standard. The exact values depend on specific situations.
The time indicator is also different, and it was already noted above which kettles will boil faster. In addition to design features, the speed factor is influenced by:
- tank volume;
- impurities in water (dissolved salts);
- scale (if the walls or spiral are “overgrown” with limescale, you will have to wait longer for boiling water);
- initial temperature.
When preparing for tea drinking, these points must be taken into account.
The kettle does not turn off when boiling
Modern electric kettles have firmly entered our everyday life, and the old ones have gone with a whistle into the past. Every morning a person starts by making tea or coffee. This tradition has entered our lives as an integral part. Coming to work in winter, everyone can warm themselves with warm tea. Even sitting and chatting with friends over a cup of hot drink is much more pleasant and comfortable for anyone.
What a disappointment a person feels when he turns on his favorite kettle early in the morning and, as always, goes to the bathroom, only to return to find a most unpleasant picture. The whole kitchen is in a white fog with steamy air, and the culprit of this incident is a favorite kettle that has never failed. You immediately ask yourself why he didn’t pass out, what happened to him.
Why the kettle did not turn off when boiling: the main reasons
Every owner of such household appliances wants to understand and figure out why the electric kettle does not turn off. You don’t want to immediately drag it into repair; it often happens that there is essentially nothing to repair.
- The funny thing is that the malfunction can be due to human inattention; this is a bad closure of the lid. The accumulated steam will come out one way or another. This effect leads to a banal failure of the shutdown system.
- Steam also comes out if the filter is poorly installed, it is uneven or completely absent. If it is uneven, the lid will not close tightly, it is impossible to prevent steam from escaping, and the shutdown mechanism does not work.
- One of the reasons that lead to the shutdown system not working is contamination of the device. Caring for household devices is a necessary condition for trouble-free operation. Therefore, it is necessary to clean the accumulated scale on the walls from time to time.
- For those who still have old models, the reason may be a blockage of the channel for the steam to escape. New brands, more improved for use. The developers took the problem into account and made some changes to the design of the device.
- If the switch malfunctions, there is no need to replace it.
- The reason may also be the breakdown of a special plate, which is designed to shut off the electrics when heating water. You can turn off the kettle yourself, but for safety it’s better to fix it.
- Oxidation of contacts, this does not require much intelligence; using sandpaper, the problem can be solved quickly.
Important! Not turning off household appliances largely depends on proper use and care. A breakdown can also be corrected with your own hands, only with some knowledge of the design of the device.
How to repair a kettle yourself
The first thing to do is inspect for any cracks or other damage. If the equipment on top is in good condition, look for the reason inside; perhaps the filter is installed incorrectly and this is one of the main breakdowns. Inspect for scale; if there is any, the deposit must be washed off. In older designs, check the steam vent. After a visual inspection and finding no visible faults, you must begin disassembling the household appliances.
- If the switch breaks down, it must be replaced with a new one; it cannot be repaired.
- The problem with the contacts can be solved quite easily, you just need to wipe them well with sandpaper and that’s it.
Having completed such repair work, reassemble the kettle sequentially, as you disassembled it. You can check it for correct assembly using water. We pour the liquid into the device and leave it on any fabric for about twenty minutes; if there are no traces of sputum, then the assembly of the unit was successful. Only then, connect the kettle to the power grid.
When to contact specialists
There are malfunctions that cannot be repaired at home and a call to a specialist is inevitable. If the microcircuit, switch, plate is faulty, it indicates improper use.
After consulting with a specialist, you need to determine whether it is worth repairing the device or whether it is more profitable to buy a new electric kettle. Estimating the cost of repairs and the price of a new device is not difficult. Of course, if it is more profitable to repair, then it is better not to abandon your old friend.
When you decide to buy new equipment, make the purchase as profitable as possible; high-quality branded equipment with a guarantee can last a long time and without breakdowns. But we must not forget that any household appliance requires proper handling.
The danger of a kettle that does not automatically switch off
Modern household appliances are designed by qualified specialists taking into account safety measures. Any household appliance is sold with detailed instructions for proper use; it cannot be neglected. Human safety depends on this.
If the automatic shutdown breaks down, there is a risk of fire, which has very negative consequences. Many users are accustomed to automation and can turn on the device to do their business in other rooms, but it is still unsafe.
A faulty container, when water boils unattended, is a time bomb. Gradually the water will boil away to zero point; if work stops, it will be happiness for the person. If work continues, a fire is guaranteed. Therefore, when using the device, pay attention to its complete serviceability.
Sources: https://rem.ninja/kuhnya/tehnika/chaynik-ne-otklyuchaetsya-posle-zakipaniya.html https://setafi.com/bytovaya-tehnika/chajnik/ne-otklyuchaetsya-chajnik-pri-zakipanii/ https ://electrosam.ru/glavnaja/jelektrooborudovanie/ustrojstva/termopot/
How the protection system works
The heating element and other heating elements are installed during production assembly and largely depend on the volume of the container - the maximum power of the heating element is 0.5 - 2.5 kW.
When heated, the heating element begins to release a huge amount of heat, which is why the developers came up with a rather clever fire-fighting system. Round bimetallic plates are used as temperature sensors; a special sample is created in the center of them. They should fit tightly to the base of the kettle; to increase the level of heat transfer, their surface is treated with a paste with good heat-conducting properties.
The principle of operation of the plates is quite simple - one of the plates is bent, a special rod begins to move, and the contacts are switched off. This type of fire protection has only one significant drawback - when the metal elements cool, the membrane returns to its original position, which increases the risk of contact closure.
To prevent the electric kettle from automatically turning off, two special disks are installed - one serves as an overheating protection system, and the second has a direct connection with the thermal switch and completely turns off the device from the network.
When to take it to the master
It is not recommended to undertake DIY repairs if:
- insufficient knowledge, experience and self-confidence;
- The thermostat needs to be repaired or replaced;
- you need to repair the crack in the flask body;
- We have to work with a closed-type heating element.
Advice! In such cases, contact a service workshop.
Water in a faulty kettle does not boil completely for many reasons. And only the user can decide whether to repair it himself, take it to a workshop, or buy a new one.
