Do-it-yourself repair of the thermex boiler

An electric boiler is an effective solution to the problem of hot water supply for a private house. Such equipment, however, like any other, breaks down periodically.

If serious breakdowns have to be eliminated in a service center, then any more or less experienced craftsman can perform a small repair of the water heater with his own hands.

To minimize problems with the device, you should study its design and principles of operation. Usually, in private households, not flow-through, but storage models are used, which make it possible to use electricity more efficiently. Such a device consists of a heat exchanger tank, inside which a heating element is installed - a heating element, connected to the power supply.

An important part of the device is the thermostat. This element allows you to maintain a constant water temperature inside the storage tank. The water is piped to the heat exchanger. If its temperature is too low (and this is usually the case), then the thermostat gives a signal and turns on the heating element.

The water is heated until it reaches the required temperature. After that, the thermostat works again and turns off the heating element. Hot water is taken from the tank and replaced with cold water, the heating process is repeated over and over. This is a general diagram of the device and operation of a conventional storage water heater.

Flow models are arranged somewhat differently. They do not heat a static volume of water, but a stream. They use more powerful heating elements that start working when the water is turned on and stop when it is turned off. To study in more detail the operation and structure of a particular model, you need to carefully familiarize yourself with the accompanying technical documentation.

The heater tank is a sturdy stainless steel container, one or two millimeters thick. No matter how resistant this material is to corrosion, nevertheless, these processes periodically arise and develop, which leads to the flow of water from the device. One of the most common causes of such breakdowns is electrical corrosion.

To prevent it, you need to regularly, i.e. Replace the internally mounted magnesium anode annually. This element is specifically designed to prevent electrical corrosion. Over time, it wears out, and the owners of storage tanks lose sight of replacing this important part.

As a result, the tank, which has served well for some time, suddenly starts to leak. The incorrect state of the magnesium anode can also affect the state of the heating element. The outside of the storage tank is usually enclosed in a metal or plastic housing, and it also has a heat-insulating shell that prevents heat loss.

Damage to the outer shell and insulation is rare, usually due to careless handling of the device. Cracks and chips on the body of the water heater may not interfere with its operation, but this will lead to a deterioration in the properties of the heat insulator, and will negatively affect the functioning of the device as a whole.

Cold water inlet and outlet pipes - for hot water usually do not cause any problems if the installation of the heater is done correctly. Usually, a water heater is equipped with two thermostats, one of which is designed to control the water temperature, and the second monitors the state of the first device.

Sometimes a third thermostat is also used, which determines the good condition of the heating element. In any case, the broken thermostat will have to be completely replaced.There are capillary, rod and electronic types of thermostats. Their design is different, but the principle of their work is the same.

The insulating gasket not only serves to seal the connection between the elements of the water heater, it is also necessary as an electrical insulator. It is recommended to replace this element regularly at every maintenance of the water heater.

The thermostat shows exactly what temperature the water inside the device is heated to. If this element breaks down, the water heater will still perform its functions, although data on the degree of heating will not be received.

Breakdown of heating elements is a typical problem for both flowing and storage water heaters. This element works under high stress and therefore wears out quickly. If the power supply is connected, but the water in the tank does not heat up, most likely the problem has arisen with the heating element.

First, you should check if electricity is supplied to the heating element and the thermostat. In the places where the cable is connected, the presence of voltage is checked with a tester. If there is no voltage, you may need to replace the cable itself or check for a power outage throughout the house.

If there is electricity and the cable is working properly, then problems have arisen with the heating element, which will have to be replaced, or with the thermostat. To figure out what exactly broke, you need to remove the thermostat and check it with a tester. Testing the health of the heating element is carried out as follows. First, the measuring scale of the device is set to the interval of 220-250 V. Then the resistance is measured at the terminals connecting the heating element to the mains.

If there is voltage, disconnect the heating element from the network and check the potential at the terminals of the heating element. Lack of response from the tester will indicate that the device is defective. If there is a reaction, you need to continue the diagnosis. First, disconnect the water heater from the power supply. Then the heating element is disconnected from the thermostat so that the contacts of the heating element remain not isolated.

Tester contacts are applied to them and the reaction is monitored. If it is, the heating element is working, if not, it needs to be replaced. In this case, it does not matter what kind of numbers the tester produces, only the presence or absence of a reaction is important. These troubleshooting methods are suitable for both storage electric water heaters and flow-through models.

To check the serviceability of the thermostat removed from the water heater, you need to set the adjustment knob to maximum and measure at the inlet and outlet of the device. If the needle of the tester remains calm, i.e. its position does not change, which means that the thermostat is faulty and needs to be replaced.

If the arrow deviates, then you need to continue testing. Now you should set the minimum position on the thermostat and attach the test leads of the tester to the contacts. It will not be easy to continue the diagnosis alone, the probes will have to be fixed or asked someone to hold them in the correct position for a while.

After that, you need to take a lighter and heat the tip of the temperature sensor. If the thermal relay is triggered, the circuit will open, and the resistance on the tester's scale will sharply go down, then the thermal relay can also be considered serviceable. If the system does not respond to heating, then this element is damaged and needs to be completely replaced.

Occasionally, the water heater can stop working due to a blown thermal fuse as a result of dangerous overheating of the device. It is enough to correctly adjust the operation of the device for it to start working as usual.

If the check showed that both the heating element and the thermostat are in good order, most likely problems have arisen with the control board. It is almost impossible to repair such an element at home.It will have to be replaced with a new one, and you will have to use the help of a specialist who will help you set up the electronic equipment. Most often, you just need to contact the service center, where the required element will be selected and installed correctly.

A tank leak is a serious problem that cannot always be corrected on your own. In some models, either the tank or the entire heater will need to be replaced. Sometimes the leak can be sealed, but care must be taken to restore the integrity of the outer casing and the thermal insulation layer. Usually such measures are insufficient and short-lived, and soon the leak will reoccur.

The water heater tank most often leaks if:

• damage to the internal tank has occurred;
• the heating element has deteriorated;
• leaky gasket.

If water flows at the place where the heating element is attached, it may not be necessary to repair the tank itself. A special gasket is installed in this place, the leak can be caused by its damage. The gasket is replaced and thus the problem is solved.

A water heater tank leak usually occurs due to neglect or untimely maintenance, which also includes the replacement of the magnesium anode. Another common problem is lack of grounding. This can also lead to the development of corrosive processes and the occurrence of leaks.

If you need to replace the gasket or heating element, it is best to first dismantle the faulty element in order to take it with you and find an exact analogue. Obtaining parts by eye can result in unnecessary costs. This replacement is relatively straightforward. But if problems arise with the tank, you will at least have to contact the service center. Immediately it is necessary to find documents for the water heater and clarify the warranty periods and service conditions.

Regardless of the nature of the breakdown, before starting repair work, you first need to turn off the power supply, remove the protective cover, disconnect the wires, pipes and drain the water. Wall-mounted models are usually removed from the brackets. The protective cover that hides the place for connecting the electrical wires and the fastening of the heating elements may have a different position depending on the model.

On horizontal type devices, such an element is usually located on the left, on vertical heaters - at the bottom, and on small models - in front. On some devices, you first need to unscrew the main mounting bolt located in the center. Sometimes this element is hidden under a decorative sticker.

After that, you need to carefully remove the thermostat, and then remove the tubes of the temperature sensor. They must be handled with great care. If the integrity of the thermosensor tube is broken, liquid filler will leak out. As a result, the water heater will simply have to be thrown away and a new device bought.

If there are stickers on the body with the serial number indicated, they must be kept, even if it interferes with the maintenance and repair of the product. This can affect the manufacturer's fulfillment of the warranty obligations, as well as facilitate the work of the service center employees.

The fact that there are problems in the operation of the device may indicate some changes in the mode of its operation. For instance:

• increasing the time for heating water to a predetermined temperature;
• the appearance of unusual sounds accompanying the operation of the device;
• the appearance of impurities in tap water, a change in its color, smell or taste.

If at least one of these signs is observed, the water heater should be cleaned immediately. To do this, you will have to perform the following operations:

1. Disconnect the device from the power supply.
2. Remove the protective cover.
3. Disconnect the contacts of the electric wires.
4. Shut off cold water supply.
5. Remove residual water from the tank using a hose.
6. Unscrew the screws that hold the heating element.
7. Remove the heating element and descale it.
8. Clean the inside of the drive from dirt and scale particles.
9. Rinse the device thoroughly.
10. Check the health of the magnesium anode.
11. If necessary, replace this element immediately.
12. Wait until the cleaned tank is completely dry.
13. Install the heating element in place.
14. Reassemble the device.
15. Check the tightness of all fasteners.
16. Connect the water heater to the power supply.
17. Check for grounding.

The heating element should be removed from the tank carefully, the bolts may be too stubborn, sometimes the heating element is difficult to remove due to too much scale layer. The heating element is cleaned by mechanical or chemical means, as is the removal of contaminants from the tank. If a large amount of scale is found inside the device, you should consider revising the operating mode of the water heater.

This phenomenon is often observed when the device has been operating at maximum power for a long time. It is recommended to set the maximum heating temperature not higher than 60 degrees in order to increase the life of the device and reduce the number of breakdowns. If the body of the heating device shocks, it is possible that the heating element is deformed and ruptured, or there is a breakdown in the control system.

A detailed video on diagnostics of the condition, maintenance and self-repair of domestic water heaters can be viewed here:

It is not so difficult to repair a water heater when it comes to replacing some of its elements. In the event of a serious breakdown, it would be wiser to contact a specialized service center. Correct use of the device and its timely maintenance will save you many problems and costs.

When the hot water supply cannot be called stable, many decide to acquire a domestic water heater, for example, the Thermex electric water heater. However, it can fail quite unexpectedly. This is especially true for inexpensive boiler models. Of course, you can immediately contact the master, or you can try to fix the breakdown yourself.

Thermex is an electric water heater that can easily provide the house with hot water in summer or in the absence of a gas boiler. It should be clarified that Thermex water heaters are produced by the oldest concern in Russia, which first released its products back in 1995. Moreover, all products, including water heaters, fully comply with Russian and international standards.

Thermex boilers are used to heat water if the pressure of cold water in the water supply is not lower than 0.05 MPa and does not exceed 0.6 MPa. The volume of tanks is varied, but most often there are boilers with 50 and 80 liters. The case, depending on the model, can be steel or made of plastic. These materials help to extend the service life of the water heater. The space between the outer casing and the tank is filled with thermal insulation, which allows you to save heat for a long time.

There is often a control panel on the front of the water heater. Less often it happens from the bottom, on the right side. In a tank of any capacity, the ten is capable of heating water to a temperature of 75 degrees.

The thermostat ensures that the water temperature is maintained within a certain range, which makes the boilers very convenient. In cases where the water temperature exceeds 95 degrees, it will be automatically disconnected from the network. The thermal switch is responsible for this.

Modern water heaters are equipped with various additional elements.

For example, some have a silver anode that decontaminates the water.

A safety valve protects the device from a sudden increase in pressure in the tank. This valve has an outlet pipe that must be connected to a sewer drain.This is necessary in order to drain water through it once a month, preventing clogging with lime deposits.

In most models of water heaters, over time, the same elements become faulty. As a result, it is necessary to carry out repair work. At first glance, it is very difficult to repair a water heater with your own hands. However, if you get a little familiar with its structure and the principle of operation, then everything becomes extremely simple and understandable.

When there is a boiler, you need to know at least its key elements and main indicators. Having familiarized yourself with them, the principle of operation becomes clear, as a result, the slightest malfunctions can be quickly eliminated.

The water heater consists of the following main parts:

• The outer casing of the water heater is covered with enamel, which is applied using the powder coating method. This allows you to reliably protect the tank from the outside and make it decorative.
• The bracket allows you to attach the tank to the wall.
• Hot water pipe. Also available in stainless steel with special properties. Possesses high wear resistance and resistance to corrosion.

Boilers Termeks have long established themselves as reliable and unpretentious household appliances. But, like any other technique, they are prone to malfunctions. Some of the breakdowns can be eliminated with your own hands, and in case of other malfunctions, the repair of the Termeks water heater should be done by a master.

Before disassembling the device, you need to have at least a little understanding of its design and principle of operation.

• body material is sheet steel with anti-corrosion coating;
• alloy steel, durable and resistant to corrosion, used for the manufacture of the inner tank;
• the elements of the device (heating element, magnesium anode and thermostat) are installed on a metal flange;
• magnesium anode is a rod covered with a covered magnesium alloy - this part protects the tank from corrosion;
• a drain pipe through which hot water is discharged (the intake takes place at the top of the tank, where the water temperature is higher);
• the space between the outer shell and the tank is filled with polyurethane foam for good thermal insulation - due to this, the liquid in the switched off unit retains the temperature for a long time (like in a thermos);
• heating element is used to heat water;
• when the water heats up to a certain temperature, the heating turns off thermostatlocated at the bottom of the apparatus, it also turns on heating when the liquid cools down;
• a tube is installed at the bottom of the tank through which cold water flows.

The water heater is running by convection principle:

• through the supply pipe, water enters the storage tank;
• the thermostat turns on the heating element to heat the liquid to the temperature set on the thermostat;
• due to the physical law of convection, warm water begins to rise;
• in the upper part of the tank there is an entrance to the pipe for the intake of heated water, which is supplied to the consumer;
• when the hot water is used up and the temperature in the tank drops, the thermostat will turn on the heating again and the process will be repeated.

The design of the water heater is quite simple and there may be several causes of malfunctions. There are breakdowns in which it is possible to repair Termex water heaters with your own hands:

• the device does not heat the liquid;
• the unit heats the water slowly;
• the boiler often turns off or does not turn on;
• water flow from the tank.

When the liquid in the device does not heat up, then a possible cause may be a malfunction of the heating element. Signs of its failure, in addition to the lack of water heating, may be as follows: knocking out the automatics on the dashboard, permanently turning off the RCD (residual current device), receiving an electric shock through the water.

The heating element can come out of the three if:

• the unit was turned on without water and the overheating protection did not work;
• The heating element was “overgrown” with a thick layer of scale and was out of order due to overheating;
• there was a sharp jump in the voltage in the network;
• the heater has expired.

To check the heating element for damage, you need use a tester (with a special measuring device). If the device, switched to resistance mode, shows infinity, it means that the heater coil has burned out. If zero is displayed on the device, a short circuit has occurred. In both cases, the heater must be replaced.

Heater Replacement Procedure in a 50 liter Termex boiler is not difficult, but requires patience and attention.

1. Before draining water from a failed Termeks water heater, the unit should be de-energized. After that, release water from the container of the device, and unscrew all hoses or pipes from the nozzles.
2. Remove the device from the wall and turn it over.
   

Carefully, using a screwdriver, pry up the decorative plugs and remove them.

It should be noted that a screw is hidden under the sticker, often due to which craftsmen, when trying to disassemble the unit, break the cover.

In order not to confuse the location of all wires in the future during assembly, they must be marked with construction tape (by signing them), or photographed.

Now you need to unscrew the nuts holding the flange. In this model of the unit, there are 4 of them on each heating element.

Remove the retainer washer. If it is stuck, you can use a screwdriver.

Remove the heating element. It also often sticks to the body and requires a slight pry with a screwdriver to detach it.

The second flange contains more wires. They all need to be disconnected.

After disconnecting the wires, unscrew all nuts, remove the washer and remove the heater.

Now you need to completely unscrew the entire electrical part, which is held by 4 screws.

There is also a screw hidden under the board, which must be unscrewed.

After that, the decorative cover can be easily removed.

The method of replacing heaters in the 80 liter Termex boiler is not much different from the above.

This is a fairly common malfunction that appears during prolonged operation of the device without preventive cleaning. If you hear noises coming from the tank when the boiler is on, and the water heats up for a long time, this means that the heating elements are “overgrown” with scale. Its thick layer interferes with the full transfer of heat from the heater to the surrounding liquid. This can cause the cell to overheat and burn out. With such a problem, it will be easy to make repairs with your own hands.

Read also:  DIY wood table repair

How to disassemble a water heater to replace heating elements has been mentioned above. In a situation when the heating elements are in good order, but they have a large layer of scale, then it must be removed from the heaters. Mechanical cleaning (with a file, sharp objects and sandpaper) is not recommended due to possible damage to the heating element housing.

For safe descaling, you can use chemicals specially designed for this. You can buy them at a household chemicals store or service center.

For descaling, prepare a container, the depth of which will be slightly deeper than the heater itself, for example, a bucket.

1. It is necessary to dilute the descaler (which is acid) in a bucket, observing the percentage of concentration, which is indicated in the instructions. If the concentration is less, then the cleansing will be ineffective.
2. Dip the heating element in the acid solution and time it. Dissolution may take from several minutes to 2 or more hours. The cleaning time depends on the thickness of the formed layer and the properties of the solution.

It is important to follow the instructions for the descaler and not to overexpose the heaters in acid. After cleaning the heating elements, it is enough to rinse it with running water.

The reason that the Termeks water heater turns off without reaching the desired temperature, or does not turn on at all, may be faulty thermostat... It is checked with a resistance tester. If it is missing, the part should be replaced. To do this, just remove the bottom cover of the device, disconnect the wires and replace the thermostat.

If a leak is detected from the container, the problem is solved by replacing it. Here you should calculate how much it will cost you to replace or repair the tank, and what is the price of a new unit. It is recommended not to spend money on repairs, but to purchase a new boiler.

If you nevertheless decide on an independent repair of the Termeks boiler tank, then the following difficulties should be taken into account:

• when dismantling the tank from the outer casing, you will certainly damage the shell;
• if the device has a plastic reservoir, it cannot be restored.
• if the material of the container is copper or stainless steel, then you can try to solder it, but it will be problematic to do it efficiently without a special tool at home.

Some models of water heaters have glass enamel coated containers. When you try to repair such a tank by brazing, you will inevitably damage this layer, after which it will be impossible to repair it.

In a situation where water seeps out from under the flange, the problem may lie in rubber gasketthat has worn out. To replace it, you need to de-energize the unit, drain the water, disassemble the device according to the above instructions and replace the gasket.

Some types of malfunctions of the Termex boiler can only be eliminated by a master, and it is highly discouraged to make repairs on your own in such cases. Problems that can only be solved by a specialist:

• incorrect operation and emergency shutdowns of new equipment for which the warranty service has not expired;
• the settings on the electronic thermostat are reset;
• RCD often turns off the unit;
• a tank leak, although the effectiveness of such a repair is questionable - it will be cheaper to purchase a new device.

But before calling the service, make sure that in the line through which cold water is supplied, there is a pressure... There are models of units that turn off the boiler in the absence of pressure in the supply line.