Thermopot does not pump water: reasons, do-it-yourself repair, how to check, video

Disassembling the thermopot

First you need to remove the top cover so that it does not interfere in the future. Turn the device over and use a flat screwdriver to pry up the support ring, which is secured with latches. You need to apply some force to rotate this element.
Next you will see a couple of screws (there may be 3-4 of them) that need to be removed using a shaped screwdriver.
Now again take a flat tool and remove the bottom of the thermopot, which is also secured with latches, so it requires force.

Now all the electronic stuffing is in front of you. Inspect all contact blocks and terminals, make sure that everything is connected (disconnection can occur, for example, if the device is dropped).

Perform disassembly only if you have basic knowledge of electrical engineering!

Thermal switches

They are usually located on the walls of the tank and on the bottom of the device. In the second case, the part is fastened with two screws and a pair of wires extend from it, put on the contact terminals. To improve heat transfer, the contact point between the thermal switch and the housing is treated with a special white paste. Disconnect the terminals and pull out the switch. In a quiet position it should be turned on - this needs to be checked with a tester (resistance will be 0 Ohm). Screw a couple of suitable wires to it and lower it into boiling water. If the resistance has increased to infinity, it means that the sensor is operational, because it has turned off. Otherwise, it must be replaced with a similar one. Below are several varieties of these parts.

An electrical specialist will help you select the right thermal switch.

Side thermal fuses

They are fixed on the walls of the tank (approximately in the middle). But there are models where these elements, which look like small cylinders, are installed on the bottom. They operate at a temperature of +105-110 °C. Their purpose is to turn off the device if you forgot to pour water into it, but have already inserted the plug into the socket. If these elements operate at temperatures below +100 °C, then the thermopot will heat up, but not boil the water, as is the case in your case. To check this, place the part in heating water: if the thermal fuse trips before the liquid boils, it needs to be replaced.

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Do-it-yourself thermopot repair

Thermopot device

A thermopot is essentially an electric kettle combined with a thermos. Unlike an electric kettle, an additional heating element was added to the design of the thermopot, used to heat water, and a controller controls its operation and maintains the temperature within 75º - 95º C. In many thermopots, in addition, a pump is installed to supply water. The water heating tank is covered with a casing that protects against burns and serves as the outer shell of the thermos, reducing electricity consumption to maintain the temperature. If the enclosure is made of metal, it is grounded (see electrical diagram) to protect against electric shock. All main components of the thermopot are located at the base of the body.

Electrical circuit of thermopot

The electrical circuit diagram of thermopots of various models and manufacturers does not differ significantly from the one shown below:

Diagram of a thermopot with one temperature sensor (Fig. 1)

Schematic diagram of a thermopot with two temperature sensors (Fig. 2) (Electrical diagram of a thermopot Elenberg-TH630)

Parts and components used in the thermopot:

The water pump is an electric motor with an impeller in a sealed housing that, when turned on, supplies water to the thermopot spout. Power supply 12V DC. It is attached with a bracket with screws to the body through a silicone gasket, which protects the motor from overheating. The impeller itself rotates due to a magnet, a very interesting design, a magnet on the motor shaft rotates the impeller with a similar magnet.

Temperature sensor (thermal switch, thermal relay) -
normally closed , when the required temperature is reached (95º - 125ºC) it opens the contacts. Designed for switching 10A 250V. It is attached to the surface of the tank with screws; for better thermal contact, thermal paste, type KPT-7, is used. You can check it with a multimeter by turning it on for continuity and heating the temperature sensor to a temperature above 125ºС; when the threshold value is exceeded, the contacts open.

The pump does not pump water

A common problem is that the potter stops supplying hot water. Pouring it with a ladle is an unpleasant prospect. And without water supply, the device turns into a regular electric kettle with improved thermal insulation. Repair of the thermopot in this case depends on the type of breakdown. If the pump does not turn on, there are two options - power problems or a burnt out motor. If it hums, but the water does not flow or flows with little pressure, the pump may be clogged or the impeller is faulty.

The thermopot does not pump water. It's not necessarily the pump. There can be many reasons

Eating problems

Oddly enough, the potter pump may not work due to a burnt-out heating coil. Look at the diagram. The pump is powered through this part of the heater. That is, if the potter does not pump water, the first thing we do is check to see if the temperature maintenance heater has burnt out.

Electrical circuit of a thermopot: one of the device options

If there are problems with the heating element, after replacing it the pump will start working. If replacing the heater is not an option, you can “build in” a separate power supply for the pump. You can find a charger with suitable parameters (most likely a constant voltage of 12 V is required), disassemble the case, and place the bridge and fuse somewhere in the case. You will have to resolder both the input and the voltage supply to the pump.

If the pump works but does not pump water

If the pump motor hums but no water flows, it may simply be clogged. In this case, it is necessary to disassemble the entire water supply path and rinse it from scale. It should help. Step by step steps:

First of all, we take photos of all the parts from all sides so that we can assemble them later.
Remove the hoses by loosening the clamps.
Disconnect the pump, wash the hoses and remove the scale.
The thermopot pump may not pump due to scale
We measure the windings (with a multimeter in continuity or resistance measurement mode). There should be no short circuit or open circuit (very small or infinitely large resistance). If there is one or the other, it is useless to clean the pump - you need to buy a new one.
If the motor is intact, perhaps the reason that the electric potter does not pump water is due to scale or debris that has gotten inside the pump and is preventing the impeller from spinning. In the pump, we remove the impeller (it is held on by magnets, just pull it), clean the blades and magnet from plaque, debris, etc.
We assemble it in reverse order, turn it on and check the operation.

Cleaning or replacing a thermopot pump is not as expensive as replacing a heating element. So this type of repair work is quite justified.

Basic thermopot malfunctions and solutions

The thermopot does not turn on

When the thermopot is turned on, the boiling mode does not turn on, the water pump works. The boiling heating element has failed, call and replace if it fails. Relay K1 is faulty (Fig. 1, Fig. 2). The power supply circuit of the boiling heating element may be broken.
When the thermopot is turned on, the boiling mode does not turn on, the water pump does not work. Check temperature sensors (F1 Fig. 1, FU1 or SF2 Fig. 2). The power cord or plug may be damaged. There may be a break in the wiring in the power supply circuit.

The thermopot does not turn off

The thermopot boils water constantly - the temperature sensor is faulty (SF1 Fig. 2). Relay K1 is faulty (Fig. 1, Fig. 2).

The thermopot often switches to boiling mode

The heating element for heating the water has failed, call and replace if it fails. There may be a break in the power supply circuit of the heating element.

Thermopot does not boil water

Thermopot takes a long time to boil

The boiling heating element has failed, call and replace if it fails. Relay K1 is faulty (Fig. 1, Fig. 2). The power supply circuit of the boiling heating element may be broken.

Thermopot pump does not work

Water level sensor in thermopot

This is a fairy tale that “wonderful repairmen” tell to housewives in order to create fog and ask for more money. I have not yet seen a single thermopot in which the water level is monitored. In a thermopot, if there is little water and it boils away, the temperature of the tank increases sharply, and the critical temperature sensor turns off the heating elements.

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Schematic diagram

If the thermopot does not work, you need to familiarize yourself with the circuit diagram.

The circuit of this device is not too complicated - even a non-professional electrician can “read” it.

It can be used to investigate the causes of failure of devices from such popular manufacturers as:

Polaris;
Vitek;
Elenberg;
Scarlett et al.

Schematic diagram

Explanation of the main symbols used in the diagram

Explanation:

S1 and S2 are temperature switches from the KSD 302 series, the first is located in the middle of the stainless steel tank and is connected in series to transmit a supply voltage of 220 Volts, the second is located in the bottom of the thermopot - current flows through it to the main heating element;
F1 – thermal fuse;
TN2 is an additional water heating coil, which should be checked to answer the question why the thermopot does not maintain the temperature;
relay S1.1 connected in parallel with the reboiling spiral;
TN1 – spiral of the main heating element;
VT1, VT2 – transistors on which there is a relay for controlling the on and off time, which open under the influence of a charged capacitor C3;
C3 is an electrolytic capacitor, charged by pulses from VD6 when the S4 button is briefly pressed;
K1 – relay winding through which electric current flows and switches S1.1;
C1, C2, VDS1 – voltage rectifiers that supply power to the time relay circuit.

Notes:

C1 serves as a damper for excess voltage;
C2 – smoothes out electric current ripples resulting from the operation of the bridge rectifier VDS1;
Some units do not use C1, but a step-down transformer.

The device of a thermos kettle

Let's look at the key elements of a 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 ceramic “beads”.
Water supply system. Consists of a pump, motor, blowers and connecting pipes for transporting liquid. The motor power supply fluctuates around 8-12 V. For more advanced models, this figure is increased to 24 V.
The electronic unit. There is a temporary relay here, which is responsible for forcibly turning on the heating coil. Here you can see the elements that generate local voltage for both the motor 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 to indicate events: green light indicates the temperature maintenance mode, and red light indicates the heating process.
Thermal switch. This part is sometimes called a thermal breaker, temperature sensor or thermostat. The correct operation of the kettle depends entirely 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, the contacts are either closed or disconnected.

In the first case, when the critical temperature is reached, the line opens and the spirals are turned off. When the water cools to a certain degree, the contacts close, starting the heating process. The switch-off and switch-on temperatures are usually fixed. In budget models, the indicators are set by default, while in more expensive solutions there is the possibility of manual selection.

The main breakdowns associated with the heating element

Thermopots have two common types of failure:

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does not heat water, but maintains its temperature;
It warms up, but the water cools down.

This is what a heating element for a thermopot looks like

In both cases, the heating element is to blame. The fact is that in a thermopot it consists of two parts. The first turns on when you need to boil water, the second - to maintain the set temperature. Both parts are sealed in one housing, so when one of them comes out, the entire element has to be replaced.

Replacing the thermopot heating element

The heating element for a thermopot has an unusual appearance - it is a metal ring made of a strip of metal several centimeters wide with three terminals in ceramic insulators (pictured above). This type of heater is called strip heaters. They are available for different models, with different capacities. There are also different diameters. All data is indicated on the details.

Another feature: the heating element for the thermopot is double. Two different heaters of different power are sealed in one housing. In general, the power can be from 500–600 W to several kilowatts; diameter from 140–150 mm to 160–170 mm. The diameter is indicated with a difference, since it can be adjusted using a tie.

How to change the heating element in a thermopot

Operating principle 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. When 100⁰C is reached, the relay is activated and the thermopot automatically switches to heating mode. The latter requires about 70-100 W, while boiling requires ten times more - from 1000 to 2500 W, which depends on the specific model.

Important! The water in the device cools at approximately the same speed as in a regular thermos, thanks to the heat-resistant flask that retains heat. That is, even when turned off, the liquid will remain hot much longer than in a classic electric kettle.

After the water temperature reaches minimum values, the thermal switch is triggered, activating the heating elements to maintain a certain degree. All devices of this type 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 selected model.

Budget thermopots, as a rule, have 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: timer switching, “no steam” mode, self-cleaning, extended protection, an additional tank, etc.

Typical faults

The most common causes of breakdowns are the following device parts:

network wire;
control module;
water pump;
electric heaters;
thermal switch.

Network wire

Before you repair a thermopot yourself, you should disconnect it from the network. After this, in order to “ring” the device’s wire 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 where the power cord is attached. Disconnect the cord and start “ringing” it with the tester. If the cord is in order, you can proceed to further troubleshooting.

Microcircuits

If you find that a button or all keys on the device do not work, then the cause of the problem may be a faulty control unit. It is not recommended to repair it yourself, since you need to have certain knowledge in radio electronics. It would be better if a service center repairs the thermos kettle.

Electric heaters

If, after turning on the device, it does not boil water, while all heating modes are working, as well as the automation, then these symptoms indicate that the heater may have burned out, or the thermostat has failed . To find out, you will need to disassemble the unit.

Empty 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 latches. Underneath you will see a fastener that needs to be unscrewed.
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After removing the screws, remove the tray. 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 there are no difficulties during assembly.
Disconnect the clamps holding the hoses connected to the pump. They can simply be cut off with scissors or wire cutters.
Disconnect the hoses from the electric pump connections.
Remove the top cover of the thermopot without much effort, turn it upside down and lower the tank so that it rests on the table.
Unscrew the PCB 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, remove the 8 screws holding the cover in place.
Now use a screwdriver to pry up the protective cover and remove it. You will see a heating element.
After removing the heating element, it must be checked for a break using a tester. If the changes show that there is damage to the heater, then it will have to be replaced with a new one, since this damage does not cause the water to boil.

What to do if the electric kettle does not turn off when boiling?

An electric kettle is a mandatory attribute of all offices and industrial sheds. This warm friend will warm you up in winter, relieve fatigue on a weekday, share homesickness at lunch, and also become a reason to take a break during a hard day at work.

However, like any device, it can fail. Having collected water and plugged in the device, while running off for a couple of minutes to call your colleagues for tea, you can return and find a Finnish sauna, the cause of which was a steaming electric kettle.

In this article we will figure out why the kettle does not turn off when it boils and how to fix it yourself.

Causes of malfunction

If the kettle does not turn off when boiling water, the causes of the malfunction may be:

its lid is not closed;
large gap between the cover and the body;
there is no filter or it is unevenly positioned;
scale formation on the walls.
the switch or the bimetallic plate that acts on it is broken.

Below we will look at instructions for repairing a kettle that does not turn off when it boils. If you are ready to disassemble the device and try to repair it yourself, read below what you need to do.

How to fix it yourself?

The electric kettle is designed in such a way that when water boils, steam collects under the lid and, having reached a certain concentration, is sent to a special section in which the switch is located. The latter, in turn, when heated, automatically releases the button, thereby disconnecting the kettle from the network. You can clearly see the design of the device in the diagram below:

The first step is to inspect the electric kettle; perhaps in a hurry and in anticipation of a break, a work colleague did not close the lid tightly, or an uneven filter prevented the lid from closing tightly

Please note that an open lid is the most common reason why the kettle does not turn off when boiling.

If everything is in order with this, then you should look inside the electrical appliance. On the side of the handle, between the lid and the wall, there is a hole for discharging steam to the switch. It must be clean, without any obstructions or scale plugs.

In old electric kettles, the hole is small and very often gets clogged, as a result of which the device does not turn off on its own when the water boils.

New models do not have this drawback, so if you want to replace the device, we recommend that you read our tips for choosing an electric kettle for your home.

If you examined everything in order and did not find the reason, most likely the electric kettle does not turn off automatically when it boils due to the switch. To get to it, you will have to disassemble the device almost completely.

To do this, you need to unscrew all the screws on the bottom cover, remove it, unscrew the screws on the handle, and remove it carefully without damaging the latches.

Try to remember the sequence of your actions so that after repair you can quickly assemble the case.

We draw your attention to the fact that the design of the switch does not provide for repair or intervention, so only replacing this unit with a similar one will allow you to repair the electric kettle with your own hands. If, at your own peril and risk, you want to repair a kettle that does not turn off for a long time when it boils, then to do this you need to get to the switch and first of all visually inspect it

If the contacts are burnt, clean them with fine sandpaper. You can learn more about the repair in the video below:

If, at your own peril and risk, you want to repair a kettle that does not turn off for a long time when it boils, then to do this you need to get to the switch and first of all visually inspect it. If the contacts are burnt, clean them with fine sandpaper. You can learn more about the repair in the video below:

Repair technology

By the way, a faulty button can even cause the electric kettle to turn off early without heating the water to a boil. In this case, you need to act according to a similar method - either change it or repair it.

Assembling the kettle occurs in the reverse order. Before connecting it to the network, fill with water and make sure there are no leaks. It is possible that the seal was moved during repairs.

Repeat disassembly and return the gasket to its place. That's all I wanted to tell you about this issue.

We hope you now know why the kettle does not turn off when it boils and how to repair it yourself.

Source https://samelectrik.ru/elektrochajnik-ne-vyklyuchaetsya-pri-kipenii.html

(Visited 1,039 times, 1 visits today) Quick kettle repair Quick kettle repair. Consultations are free. Spare parts are in stock and on order. Delivery throughout Russia. Repair of an electric kettle. Repair of a thermal switch is shown.