Thermopot is a mixture of a kettle and a thermos. To maintain a certain temperature of the liquid in the device, a heating function is provided. Despite the fairly reliable design, the device fails over time, and the question arises: is it possible to repair the thermopot with your own hands?
Thermos kettle device
Consider the key elements of thermopot.
- Tank made of corrosion-resistant steel.
- Spirals (heating elements) built into the body. One element is designed to boil water, and the other maintains the required temperature. To prevent short circuits, each spiral is wrapped in special “beads” made of ceramics.
- Water supply system. It consists of a pump, motor, blowers and connecting tubes for transporting fluid. The power supply of the engine fluctuates around 8-12 V. For more advanced models, this figure is increased for 24 V.
- The electronic unit. Here is a time relay responsible for the forced activation of the heating coil. Here you can also see the elements that form the local voltage for both the engine and the relay itself.
- Control chip. This part is responsible for activating the thermopot modes: “Liquid supply” and “Re-boiling”. LEDs are also included here – event indication: green light indicates the temperature maintenance mode, and red indicates the heating process.
- Thermal switch. Sometimes this part is called a thermal interrupter, a temperature sensor, or a thermostat. The correct operation of the kettle is completely dependent on this element.
The thermal switch looks like a small barrel made of ceramic. Inside the case there are two paired metal contacts. Depending on the type of device contacts are either closed or open.
In the first case, when the critical temperature is reached, the line opens and the coils are turned off. When the water cools to a certain degree, the contacts close, starting the heating process. The cut-off and turn-on temperatures are usually fixed. In budget models, indicators are set by default, while in more expensive solutions there is the possibility of manual selection.
If the thermal switch is out of order or simply does not work, then in this case there is fuse. The temperature limit of operation of the latter is within + 125-150⁰С. The element is mounted next to the thermal switch and closed with a metal plate. Less commonly, the fuse is located at the bottom of the tank. In many respects it depends on the specific model of the kettle.
It often happens that the fuse is the cause of the thermal pot failure. It opens the circuit and prevents the switch from working correctly. Accordingly, the kettle does not turn off, as well as the indication. Therefore, if the device breaks down, first of all it is worth checking the fuse.
The next reason for the failure of the kettle is the thermal switch itself. If there is an ohmmeter at hand, then it is very simple to exclude it: it has zero resistance at a temperature of + 25-30⁰С. Otherwise, the switch must be replaced.
The principle of operation of the thermopot
After filling the tank with water and turning on the device, the heating elements begin to heat the liquid to a boil. Upon reaching 100⁰С, the relay is activated and the thermopot automatically switches to the heating mode. The latter consumes about 70-100 W, while boiling is ten times more – from 1000 to 2500 W, which depends on the specific model.
Important! The cooling of water in the device occurs at about the same speed as in a conventional thermos, thanks to a heat-resistant flask that retains heat. That is, even in the off state, the liquid will remain hot noticeably longer than in a classic electric kettle.
After the water temperature reaches the minimum values, the thermal switch is activated, activating the heating elements to maintain a certain degree. All devices of this kind are equipped with a feed system. That is, there is no need to tilt the thermopot. It is enough to place the glass on a special platform and press the corresponding key. Water will be supplied under pressure, the strength of which depends on the model chosen.
Budget thermopots have, as a rule, up to 4 modes, which are needed to indicate the minimum and maximum temperature thresholds. More expensive devices have much more adjustment options. In addition, they are equipped with some additional functionality: switching on by timer, “no steam” mode, self-cleaning, advanced protection, additional tank, etc.
The most common causes of breakdowns are the following parts of the device:
- network wire;
- control module;
- water pump;
- electric heaters;
- thermal switch.
Before you repair the thermo pot with your own hands, you should disconnect it from the mains. After that, in order to “ring out” the wire of the device with a tester, it must be disconnected. To do this, unscrew the screws on the bottom of the device and remove it. You will see the terminals to which it is attached power cord. Disconnect the cord and start “ringing” it with a tester. If the cord is in order, you can proceed to further troubleshooting.
If you find that the device button not working or all keys, then the cause of the problem may be a failed control unit. It is not recommended to repair it yourself, since it is necessary to have certain knowledge in radio electronics. It would be better if the service center will repair the thermos kettle.
If, after turning on the device, it does not boil water, while all heating modes, as well as automation, work, then these symptoms indicate that the heater may have burned out, or the thermostat has failed.. To find out, you need disassembly of the unit.
- Pour out the water from the container and turn the device over. At the bottom you will see screws that need to be removed.
- Using a flat object (you can use a screwdriver), remove the plastic ring from the retainers. Under it you will see a fastener that needs to be unscrewed.
- After removing the screws, remove the pallet. To continue disassembly, it is recommended to mark all the wires of the same color with a marker and photograph the location of all other conductors. This should be done so that later during assembly there are no difficulties.
- Disconnect the clamps holding the hoses connected to the pump. They can simply be cut with scissors or wire cutters.
- Disconnect the hoses from the nozzles of the electric pump.
- Remove the top cover of the thermo pot without much effort, turn it upside down and lower the tank so that it rests on the table.
- Unscrew the circuit board and set it aside.
- Under the gasket you can find 2 more screws.
- After unscrewing all the screws on the metal tray, it can be removed along with the bottom.
- Next, unscrew the 8 screws holding the cover.
- Now use a screwdriver to pry off the protective cover and remove it. You will see the heating element.
- After removing the heating element, it must be checked for an open using a tester. If the changes showed that there is damage to the heater, then it will have to be replaced with a new one, since water does not boil due to this breakdown.
In different models of units, the type of heating elements may differ. Their location may also differ. But the algorithm for disassembling the device, in most cases, is similar. To learn more about how to change heaters, you can watch the video.
If the thermopot, when trying to pour hot liquid into a cup, does not pump water, then most likely the pump does not work due to its failure. To get to the pump, you will need to disassemble the device in the manner described above. After removing all parts of the bottom, you will see the pump.
Next, do the following.
- To make it easier to remove the pump, disconnect one of the tubes connected to the pump. If the pipes are clogged with scale, it is recommended to remove them and clean them.
- Separate the pump from the housing and take care not to lose the silicone gasket.
- After that, unscrew the fasteners connecting the motor with the impeller to the pump housing.
- After disconnecting the pump housing and the motor, you will notice scale accumulationwhich interferes with the rotation of the impeller.
- Also, if you remove the impeller (it is she who is responsible for the water supply), you can find clogged magnetto be cleaned of dirt.
If, after removing all contaminants, the pump does not turn on and there is no water supply, then a new pump will need to be purchased, since these signs indicate a burnout of the motor winding.
Sometimes a situation arises when the thermal pot does not turn off and constantly boils water. Or vice versa: you poured water, the device heats it up, but turns off when the liquid is not yet boiling. Why is this happening? This fault can occur when the thermal switches are faulty. They can be found on the bottom and walls of the tank. For better contact with the surface, a special thermal paste is used.
The thermal switch, located at the bottom of the tank, is attached to it with two screws. Sometimes a manufacturer, especially a Chinese one, applies little thermal pastebecause of which the thermal relay starts to work incorrectly: the device may not turn off for a long time when boiling water.
To check the thermal relay for operability, it is necessary to disconnect it from the tank body and remove the wires from the terminals. In the normal state (without heating), the relay is in the “on” position. If you check it with a tester, the device will show a resistance of 0 ohm.
Next, you should connect 2 wires to the switch and lower it into water brought to a boil. Now measure the resistance again. If the device shows infinity, this means that the switch has turned off and it is functioning normally. If the sensor is not working, then you should purchase a new one and replace it. Regarding the replacement of the thermal switch, you can watch the following video.
Above, some breakdowns of the thermos kettle were considered, which can be completely eliminated without the involvement of a specialist. In other cases, the unit should be taken to a specialized service center for repair. But before handing over the device for repair, ask how much it will cost you. Most often, from a financial point of view, the repair is not justified, since its cost will be within the price of a new thermopot.