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.
Interesting materials:
What is additional professional education? What is the foundation of the goal tree method? What are the sources of soil pollution? What is the source of motives and goals? What is the place of registration of a legal entity? What is the method of environmental law? What is the base of a right quadrangular prism? What is the basic unit of vocabulary learning? What is the main source of energy in a cell? What is vegetable oil?
Scheme and principle of operation
To understand why this happens, you need to know the principle of operation of the kettle and its electrical circuit. The model range of these household appliances is very diverse, but the operating principle and assembly diagram are almost identical for all, with rare exceptions: for example, a built-in timer.
The electric kettle works quite simply: through a strong cord with a plug at the end, the voltage from the socket is transmitted to the XP1 contacts located in a massive stand - it is on it that the device is installed while boiling water. At the bottom of its body there is a special connector that interacts with the contacts of the stand.
The SA1 thermal switch provides manual switching on and automatic switching off of the device after the water begins to boil. The thermal protection switch is always active and does not take part in the daily operation of the product - it only works when the kettle is turned on without water. Then the current goes to the tubular heating element (TEN), and a glowing light on the indicator signals that the product is in operation.
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.
Causes of malfunctions
So, why does the kettle turn off without bringing the water to a boil?
- The most common cause of such a malfunction is a defect in the bimetallic strip. The metal from which it is made undergoes repeated expansion and contraction during the operation of the device. It is not surprising that over time the plate becomes deformed and loses its properties, which is why the electric kettle turns off at the wrong moment. Of course, this only applies to those devices that have worked for more than one year. Although low-quality Chinese products can “please” the owner with such a defect literally a few months after purchase. You can repair the plate by bending it into the correct position. However, this is a temporary measure, and soon the kettle will have to be changed, because... repair (replacement of the plate) in this case is not cost-effective.
- Another common reason why an electric kettle may turn off before the water boils is scale on the bottom and walls of the product. This especially often happens in models with an open heating element - it overheats, and the device’s overheating protection is triggered. To remove formations, it is enough to boil a minimum amount of water with the addition of one packet of citric acid - this procedure can be repeated several times. To speed up the process of getting rid of plaque, you can add a couple of tablespoons of vinegar - this will speed up the cleaning.
- If it's not scale, then the thermostat may be broken. You can contact a specialist to replace it, but it’s easier to buy a new product - the cost of repair is approximately equal to the cost of a new kettle.
- The reason for turning off before the water boils may be a broken or poorly made switch - if the device turns off ahead of time, and after 15 minutes (during this time the bimetallic platinum cools down and returns to its original position) turns on on its own, then this is a signal to the user that the switch is not working correctly.
- Frequent leaks of the product, even in the form of a few drops, lead to the kettle turning off before the water boils. It is necessary to check the housing of the device - according to statistics, most often microcracks from temperature changes occur in devices whose housing is made of glass or plastic.
- Loose fastening of the heating element to the product body is a common cause of premature shutdown of the device. If you are using a product with an open type heating element, then this will be easy to check without even disassembling the kettle. If the heating element is a closed type, then you need to contact the service center for the help of a specialist - it is better not to go inside the product yourself.
- During long-term use, the rubber gasket, which serves as an insulator between the body and the compartment on the bottom where the heating element is located, may wear out, but this fact cannot be verified without completely dismantling the device. This information will be useful to home craftsmen who independently decided to find the reasons for the failure of the device.
At what degrees does it boil?
Regardless of the type of appliance used, under normal conditions water boils at the following temperatures (in the most common units of measurement):
| Celsius, 0С | Fahrenheit, 0F | Kelvina, K |
| 100 | 212 | 373,15 |
However, it should be taken into account that in different devices, despite the same boiling point, the time to achieve the process is still different.
Just as the boiling point decreases with decreasing pressure, so with increasing pressure it increases . This principle has found practical application in kitchen appliances - pressure cookers.
The boiling point in them reaches a record for everyday conditions - 120-130C. This allows you to speed up the cooking process (as opposed to mountainous areas - when it boils, but does not cook).
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.
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.
Protection system
Heating elements on an electric kettle are installed during the assembly process at the manufacturer's factory and depend on its volume: the power of the heating element varies between 0.5-2.5 kW. When heated, they emit a large amount of heat, so in order to avoid a fire, the designers have provided effective protection against overheating.
Round bimetallic plates are used as temperature sensors, with a special selection made in the center. They should fit tightly to the bottom of the kettle; for better heat transfer, their surface is lubricated with a paste with excellent heat-conducting properties.
When carrying out any complex repairs, it is not recommended to remove this grease.
Temperature sensor
The plate is assembled from two metals with different coefficients of thermal expansion, firmly glued together. When heated strongly, it bends due to different expansion of the metals.
To turn off the device, the bimetallic plate is connected to the contacts by means of a ceramic rod in the following way: one end of it rests against the disk, and the other supports the plate of the contact group. The mechanism of action is very simple: the plate bends, the rod moves and the contacts are disconnected.
Ceramic rod and bimetallic plate
This type of protection has only one negative nuance: after cooling, the membrane returns to its original state, and the contacts can close - the heating element will begin heating. To prevent the electric kettle from turning on on its own, two such disks are installed: one works in the overheating protection system, the second is connected directly to the switch and completely disconnects the device from the mains voltage.
The best electric kettles of 2022
Kettle Kitfort KT-633 on Yandex Market
Kettle Braun WK 3110 on Yandex Market
The electric boiler was invented a long time ago and is extremely simple in its functionality. But in the modern world, program-controlled devices are already in use, which will not only boil water at a set time, but also maintain its temperature at a given level for quite a long time. Regardless of the simplicity or complexity of the design, any thing is subject to malfunctions. One of them is that the kettle turns off before the water boils. It is this problem and ways to eliminate it that will be discussed in this material.
In what time?
The boiling time of a liquid depends on several factors:
- volume;
design and material of the container;- heater type and its characteristics;
- initial temperature;
- raw or boiled water is in the kettle;
- atmospheric pressure;
- the presence of scale on the internal walls;
- presence of dissolved salts.
An ordinary 2-liter kettle on a gas burner will cope with the task in an average of 15 minutes. A standard electric model will spend approximately the same period of time on this procedure. A more advanced electric kettle with a powerful built-in heating surface will boil in 3-5 minutes.
Why does the electric kettle not turn off when it boils?
The opposite situations also happen with electric kettles, when the device does not automatically turn off when it boils. In most cases, the malfunction can be corrected by the owner of the device. The reason should be looked for in the following points.
- The steam generated during boiling in a properly working kettle is directed through a channel to the thermal switch. When the lid of the device is not closed tightly, steam escapes and does not reach its target. Therefore, the trip relay does not operate.
- The absence or uneven location of the filter affects the tightness of the lid to the body. Steam escapes through the cracks, which causes the automation to fail.
- Another reason for shutdown failure when boiling is a large accumulation of scale on the walls. Sediment particles enter the steam outlet channel and clog it.
- Failure of the bimetallic plate that turns off the electricity supply when it boils. In the event of such a breakdown, the kettle turns off only in manual mode. After replacing the faulty part, the automation will work.
- Thermal relay malfunction. For proper operation of the device, the technological unit must be replaced.
- The cause of the problem may be acidified contacts. The malfunction is eliminated by sanding with sandpaper.
To ensure that the electric kettle does not turn off before the water boils, you must carefully select the device at the time of purchase, giving preference to trusted manufacturers.
What is the vapor temperature of a boiling liquid?
The steam generated during the boiling of the kettle has the same temperature as boiling water.
Since all the energy in this process is aimed precisely at its transformation. Therefore, until all the liquid evaporates, the heating of the steam will remain at the same level . In this case, the steam can gain additional energy, and therefore increase the temperature, but only in a confined space, for example, in a pressure cooker.
When to contact a specialist
Experts do not advise starting to repair an electric kettle on your own in the following situations:
- when a person does not have the necessary knowledge and practical experience in this matter;
- when a breakdown is observed in the thermostat;
- in a situation where a crack or chip has formed in the body of the kettle;
- when it is necessary to change or repair the heating element in a model with a closed type of heater.
Repairing an electric kettle
Thus, premature shutdown of an electric kettle even before the water boils can be caused by a large amount of scale on its walls and heating element or a breakdown when the thermostat or fuse fails. Other reasons are chips and cracks on the case or poor fixation of the heating element inside the device. If scale can be cleaned at home, then in other situations it is better to contact a service center and have the electric kettle repaired.
Video about turning off the kettle
Subscribe to TechnoCouncil on social networks so you don’t miss anything:
How to disassemble the device for repair
To eliminate the cause of the malfunction of the electric kettle, it may be necessary to dismantle the device body. Manipulation allows you to repair or replace a failed technological unit.
On any model, the body parts are connected using mounting screws and latches. The work of dismantling the kettle comes down to unscrewing the screws and carefully pulling out the clever latches. Screws are usually located on the bottom of the case and at the bottom of the handle. Not all models have visible fasteners. Manufacturers practice tactics to protect devices from self-repair by using plastic covers and plugs with latches, and screws with non-standard heads. To dismantle the kettle, you will need thin flat and Phillips screwdrivers, tweezers, and a handy tool with a sharp end.
The sequence of manipulations for disassembling the device is as follows.
- Unscrew all the bolts located on the back of the kettle bottom. The number of fasteners depends on the device model. Bosch brand kettles use 4 mounting screws. If the bolts are hidden under a cover plate, you need to use a sharp object to pry it up and carefully remove the part without damaging the latch.
- On Vitek, Polaris, Scarlett and some other models, additional fixing bolts are located under the lining at the bottom of the handle. Using the same steps described above, you need to unscrew the screws.
- After removing all the fasteners, you need to carefully separate the parts of the body connected to each other: the bottom, the tank, the lid with the handle.
- The working components of the electric kettle: heating element, thermal relay, contact wires are located at the bottom of the body. The detected malfunction should be eliminated and the device reassembled in the reverse order.
Advice! When the screw is difficult to unscrew, you can slightly heat the head with a soldering iron. The plastic around the bolt will become slightly softer, which will allow you to unscrew it faster.
The best electric kettles of 2022
Kettle Kitfort KT-633 on Yandex Market
Kettle Braun WK 3110 on Yandex Market
Today, on the shelves of specialized stores selling household appliances for the home, you can find a variety of the latest models of electric kettles from different manufacturers. These devices are quite reliable and unpretentious in everyday life, but sometimes a situation may arise when an electric kettle, previously working properly, suddenly turns off, although the water has not heated up to boiling. There is no need to panic, call a technician or throw the device in a landfill, let's figure it out and find out all the reasons for the failure of the product.
