Repair of electric heating boilers: design, causes of breakdowns, replacement of elements, error 27 Navien, how to check the heating cable for integrity with a multimeter, do-it-yourself electric boiler for heating a house, repair

One of the main conditions for the operation of electric boilers is their reliability and safety during operation. But even the most reliable equipment breaks down over time. The validity period of any components and assemblies is limited - this is natural. However, premature failure of the device causes the owner a feeling of great distress.

Malfunctions that occur during the warranty period can be repaired free of charge at a service workshop. In all other cases, there will be a paid repair of electric heating boilers. Sometimes it is possible to restore the unit yourself.

What is an electric boiler

An electric boiler is a special high-tech equipment designed for heating various types of premises. A distinctive feature of such a unit is the use of a special type of fuel - electrical energy. In many respects, the boiler is superior to equipment operating on other types of fuel: liquid, solid, gas.

Electrical equipment is considered the safest to use. But in order for it to function well, it is necessary to strictly follow the rules of its operation and perform timely technological maintenance.

Watch the video about the operating principle and design of the Protherm Skat electric boiler.

Device

Despite the wide variety of boilers with different operating principles, the design of all models is approximately the same. The main place in the structure is given to the heating element. Depending on the type of heater used and the principle of its operation, there are several types of boiler units.

All heating elements are located in heat exchangers, which are considered the main structural elements of the boiler unit. If they malfunction, heating of the coolant is impossible.

Depending on the design and manufacturer, the equipment may have different configurations.

List of elements:

Electronic control unit. Regulates temperature conditions by turning equipment on and off at the right time.
Circulation pump (heat pump). It is a mandatory component of the system and maintains a stable speed of coolant movement in the circuit. It produces forced circulation of liquid and creates the necessary pressure in the system, while ensuring the most effective heat exchange and heating of the room.
Expansion tank. Not all types of electric boilers with a pump are equipped with an expansion tank. Therefore, if you purchase equipment without a tank, you will need to purchase this part separately and install it by cutting it into the pipe heating circuit.
Filters. They purify and remove various impurities from water.
Safety valves. Protect the system from unwanted deviations in operation.
Safety valve. Connected to the return pipe. Performs emergency water release when the pressure rises above the established norm.
Pressure gauge. This device determines the pressure of liquids and gases inside the boiler and pipes of heating systems; it is necessary for monitoring.
Thermal switch . Shuts down equipment when it overheats. Connected to a temperature sensor located at the top of the electric boiler.
Automatic air valve. It is located above the heating tank and produces an emergency release of air from the tank in case of excess pressure.

Types of electric boilers

Depending on the operating principle of the heater, all electric boilers are divided into three types.

Electric heating elements

The principle of operation is based on simple electrical heating of elements that give off their heat to the liquid. Heating element – heating element. Water or other approved liquids are used as a coolant, in accordance with the operating instructions.

Induction

Their action is based on the principle of electromagnetic induction. The heating element is a coil, inside of which there is a pipeline filled with water. When an electric current passes through the coil under the influence of an electromagnetic field, the coolant heats up.

Ionic

The working element in such structures are electrodes placed in a special aqueous medium, where the process of heating the coolant occurs when alternating current passes through it.

A feature of the use of this type of boiler is the mandatory monitoring of the electrical conductivity of the liquid and the adoption of measures to regulate it. The phenomenon of electrolysis and breakdown should not be allowed. Failure to comply with these requirements may result in equipment failure.

The liquid used cannot be used for domestic purposes. The heat carrier, which circulates through the pipes and enters the working tank of the boiler, comes into direct contact with the electric current. It is not recommended to carry out repair and commissioning work without the involvement of an experienced technician.

Induction boilers

The operating principle of such boilers is based on electromagnetic induction. The dielectric pipe is surrounded by a winding of insulated wire. The current flowing through it forms an electromagnetic field, which helps to heat any ferrimagnetic element inside the pipe.

Induction boilers are small in size. A circulation pump is not required for the operation of such equipment, although there are models with it.

Due to the fact that induction boilers do not have moving elements that break down over time, they last a very long time. But the device may break down - this happens if there is no water inside the device, and electricity continues to flow. These boilers, like equipment with heating elements, can work with any type of coolant - not only water, but also antifreeze, distillate, etc.

Causes of breakdowns

The causes of breakdowns can be established even before the boiler starts operating. These are: errors in the design and calculations for the selection of additional devices (not included in the boiler configuration), switching elements, determination of the type and cross-section of the required installation wires.

The causes of breakdowns in the future may be:

Poor quality, incorrect installation and connection of the device with deviations from installation requirements.
Violation of the basic rules for using the equipment specified in the instructions.
Failure to comply with the requirements for carrying out routine, preventive and periodic work and inspections.
The presence of a manufacturing defect, which is discovered both during the warranty period and after its completion.
All components and assemblies have a certain service life, and the reason for their failure is natural wear and tear.
In heating element boilers, the heating elements themselves may fail due to low water quality and the formation of salts and scale on their surface.
Failure of most components and assemblies due to large voltage surges exceeding all permissible standards. These tolerances are specified in the operational documentation.

For ion boilers, water compliance with the required standards is of great importance.

Electric boiler installation

It is possible to organize heating of a private house with an electric boiler yourself! Installation of an electric boiler, compared to gas or solid fuel boilers, is quite simple. But you must strictly follow all the rules and requirements.

There is no need to allocate a special room for the equipment. Due to their minimal dimensions, most electric boilers can be installed anywhere. And the modern design of the equipment can fit perfectly into any room interior. If you wish, you can hide the boiler in a special niche.
Special ventilation systems or chimneys may not be used. This equipment does not create waste that threatens human life and needs to be disposed of.
Connecting the equipment is easy.
The heating scheme with an electric boiler is quite simple, so the installation and connection of this type of heating does not require approval and approval from the relevant authorities. Also, in the future, systematic checks, which often bring discomfort and conflicts, will not be carried out.

Heating a private home with an electric boiler is an innovation, but it is gaining popularity every year. Thanks to the availability of various modifications of equipment for heating with electricity, you can find a suitable option for a particular structure. Before purchasing equipment, each home owner needs to calculate the power of the electric boiler for a specific room, taking into account all heat losses. Therefore, you should worry about insulating the building in advance. This will avoid troubles associated with the heating system.

Types of faults

When operating electric boilers, various types of malfunctions arise - from coolant leaks in pipelines and structural elements to automatic malfunctions. If electronics fail, it is recommended to entrust repairs to specialists in this field.

Typical faults include:

violation of the tightness of the system, the presence of leaks and smudges in fuel lines, elements and assemblies;
heating of electrical wires and odor due to electrical insulation failure;
various types of noise in highways and system elements;
there is no or slight heating of the coolant;
when turned on, the boiler does not start;
After heating the coolant, the electric boiler does not turn off.

Design features

Regardless of the type, the design of electric boilers requires the following mandatory elements:

circulation pump;
copper heating unit;
fuse in the form of a thermal switch;
safety valves;
air valve;
pressure gauge;
control panels;
power control systems.

DIY repair

To carry out work on repairing an electric heating boiler with your own hands, you must have a minimum amount of knowledge on the design and installation of electrical equipment, as well as the heating system as a whole.

It is recommended to study the information on operation, installation and comply with all the requirements specified in the instructions. To troubleshoot the operation of the electric boiler, it is necessary to use diagrams.

In case of all types of malfunctions, it is necessary to first turn off the power to the equipment and then conduct a thorough visual inspection of it. You should pay attention to burning, integrity of various types of connections, damage to insulation and other deviations.

Doesn't start

To determine the reasons for the impossibility of starting the boiler unit, it is advisable to use the electrical diagram of the equipment. Check the integrity of the cable and all fuses, and also ensure that the circuit breakers are working properly using a multimeter and other relevant elements on the control panel. All work should be carried out with the equipment de-energized.

To fully turn on the boiler, the starting circuit must be in good working order, which includes, depending on the type of boiler, its own set of elements.

Components:

emergency thermal switch;
pressure meter;
flow switch;
thermostat sensor.

It is necessary to check their serviceability, and if a breakdown is detected, repair or replace them. Otherwise, starting the boiler will be problematic.

The emergency thermal switch is a bimetallic contact that opens when overheated. It is designed to turn off the boiler in case of temperature overload and failure of the main thermostat circuit. When a critical value is reached, the thermal switch opens its contacts and removes voltage from the electrical appliance.

When cooling, the contacts close again and prepare the circuit for the next start. It is worth noting that the reason for the inoperability of an electrical appliance may be the thermal switch itself, the contacts of which remain open. Then starting the boiler will be impossible.

Simple thermal switches are checked using the “diagnosis” method using a tester. In the normal “cold” state the contacts are closed. To check the operation of this element, it is necessary to heat it above the shutdown temperature using the usual action of an open flame or a soldering iron, and then measure the resistance of the contacts.

The heating elements are turned off and on to maintain the required coolant temperature when the thermostat and temperature sensor in the boiler are working properly. If they break down, starting the boiler is impossible.

A level sensor (coolant presence) is installed in the upper part of the unit body; it ensures that the power to the electric boiler is turned off if there is no liquid in the tank. In this case, the “dry” type electrode must be in water. In this case, the corresponding relay is activated, and the circuit is prepared to start the boiler. The flow switch is designed to turn off equipment in the absence of coolant circulation in the system, which helps prevent overheating of the liquid.

Doesn't turn off

If the boiler does not turn off when it overheats, it means that the emergency thermal switch is not working, if there is no water in the boiler, the level sensor is faulty, and so on.

To turn off the boiler, it is necessary to break the starting circuit, which includes the corresponding automation elements. It is necessary to check the serviceability of all components that are present in this type of boiler and determine why this or that device does not turn off. The same search methods using a multimeter are used. Do not forget about de-energizing and completely shutting down the boiler if necessary.

Makes noises

When any electric boiler unit operates, there is always a certain background and noise. This is a typical and natural phenomenon. But the nature of the noise can be different, and some sounds can be used to judge the technical condition of the boiler. During operation, the types and nature of noise change somewhat over time. It all depends on the quality of equipment installation, installation, configuration, physical wear and tear of components and assemblies, as well as operating conditions.

A low noise level in the system indicates the high quality of the electric boiler used. A uniform, monophonic sound of operation indicates normal functioning, and the source of noise is, like in a kettle, heated water. The volume of sounds depends on the degree of oxygen saturation of the liquid. This process does not have any negative impact on the condition of the boiler and system.

If an uneven noise is heard, accompanied by a crackling sound, this is due to the formation of lime deposits on the walls of the heat exchanger. Over time, their number increases, and gradually they begin to flake off and enter the system.

Depending on the amount of deposits, sounds of different volume and timbre are heard; with a significant increase, a crackling sound is heard. To eliminate this phenomenon, it is recommended to flush the heat exchanger elements. In addition, the temperature of the internal walls of this device also increases, and this affects the wear resistance and durability of the equipment.

Doesn't heat water

The lack of heating of water, provided that the rest of the equipment circuit is in good working order and operable, can be due to two reasons: insufficient voltage at the terminals of the heating elements or problems in the elements themselves and their connections.

The integrity of heating elements can be determined by checking the resistance using a tester or similar device. Each component of the device must be tested separately. To do this, you need to disconnect them to gain access. If a malfunction is detected, the heating elements should be replaced.

Replacing the heating element

Depending on the type of boiler, appropriate heating elements are installed in them. These can be heating elements or electrodes. If they cannot be repaired, they must be replaced.

Procedure:

Shut off the water supply to the unit.
Drain the fluid from the system.
Disconnect the equipment from the power supply.
Make sure there is no voltage.
To access the heating elements, dismantle the necessary equipment and its elements.
Disconnect the wires from the heating elements. To facilitate installation work, it is advisable to first sketch or photograph the connection diagram.
After unscrewing the fasteners and removing them, remove the faulty element.
Install a new heating element corresponding to this boiler.
Install a new waterproofing gasket and secure the heating component.
Connect the appropriate wires to the contacts of the element and check the result obtained with the previously sketched diagram.
Check the correct installation.
Fill the system with water and start the boiler in accordance with the operating instructions.

Prices for heating elements for boilers

Heating element boiler spare part

Restoring the performance of electrode and induction boilers

Unlike heating element boilers, in electrode-type heaters, faulty electrodes are replaced. The same approach is used here as in the case of repairing heating elements units. The requirements for replacing heaters in electrode boilers are higher.

Boilers on heating elements

This equipment is designed as follows. Inside a container filled with running water are several simple tubular heaters. Circulation is ensured by a pump. The device also includes an expansion tank.

The power is adjusted in steps by turning on one or several 1.5 kW or 2 kW heaters at once. You can set the maximum power of the electric boiler, and during operation it will be able to change the level of power consumption within acceptable limits.

Boilers of this type have many disadvantages. Among them:

When water leaks, heating elements overheat and, as a result, burn out. In theory, they should turn off automatically, but this does not always happen.
Over time, scale builds up on tubular heaters, which reduces the power of the equipment and increases the likelihood of heating elements overheating. But at the same time, since the water circulates in a closed loop, there is not so much lime in it that scale becomes a serious problem.
Boilers with heating elements are not suitable for small rooms, since they have significant dimensions.

Prevention and recommendations for use

Compliance with operating rules, together with the implementation of timely preventive measures, extends the period of trouble-free operation of the unit. It is preferable to carry out preventive maintenance during the lowest load of the boiler, in the summer.

During the current heating season, it is advisable to pay attention to problems and deviations that arise during operation. In the warm season, it is recommended to replace all unstable elements and troubleshoot problems. Then carry out a preliminary launch and check the functionality of the boiler equipment and systems.

Preventive measures include: cosmetic repairs, cleaning of various systems and equipment elements. Particular attention must be paid to fastening and connecting elements, which can significantly affect the functionality of the equipment.

Timely, regular implementation of preventive measures along with high-quality installation and proper operation will allow heating equipment to operate trouble-free for decades.

To extend the service life of the heating unit, it is necessary to clean the heating elements from scale. However, you can prevent the problem by pouring distilled or soft water into the heating system. If ordinary water was used before, then the heating elements are cleaned using special powders that are sold in hardware or auto stores.

The powder is diluted in water, the resulting mixture is poured into the heating system, which is turned on at full power. After 30-40 minutes, the entire solution (it will be rusty in color) is drained into the sewer system. Now you can be sure that the entire system will again receive its normal 100% power. A less effective option is to install devices for filtering the working fluid.

The reliability of the electrical system in the home is of particular importance. Outdated wiring is one of the most common causes of electrical equipment failure. It is advisable to replace the aluminum wire with a copper wire with a larger cross-section.

A feature of the use of this type of equipment is the mandatory monitoring of the electrical conductivity of the liquid and the adoption of measures to regulate it. The phenomenon of electrolysis and breakdown should not be allowed. You can find out how to cook in a Pompeii oven by following the link.

Thermostat is not installed where it should be

For proper operation of the boiler room, it is very important to adhere to the diagram for connecting the thermostat to the gas boiler. Using a thermostat provides a short delay after reaching the set temperature, which can significantly reduce the number of boiler starts and stops, save resources and reduce equipment wear.

To connect the thermostat to a boiler with a Dry Contact circuit, two conductors are connected, and the cable length should be no more than 50 meters. In this case, the thermostat should not be installed next to the boiler. It is also unacceptable to install a thermostat in an unheated room.

Replacing faulty electric heating elements

So, first you need to visit a store that sells spare parts for electric boilers and select the model of electric heating element we need. You can find out which model is needed in the technical data sheet of the electric boiler. Please note that the electric heating element must exactly match the element specified in the passport. If the characteristics do not match, the entire system may fail! Therefore, be responsible when choosing the necessary spare parts.

Let's consider how to replace the heating element in an electric boiler and the correct procedure for carrying out the work.

It is necessary to disconnect the boiler from the power supply to avoid electric shock.
Drain all liquid from the heating system.
If access to the heating element mounting is difficult, it is necessary to dismantle the electric boiler.
We disconnect the wires from the heating element, having previously marked or written down the order of fastening the wires (phase and zero).
Let's start dismantling the heating element. To do this, unscrew the fastening bolts or nuts and remove the faulty heating element.
We insert and fasten the new heating element. When attaching a new heating element, be sure to change the waterproofing gasket, since if you want to use the old one, it will most likely leak soon.
Next, we perform the same actions as in points 1, 2, 3 and 4, only in reverse order.
We turn on the boiler and see if everything works correctly and reliably.

When replacing electrodes in an electrode boiler, the procedure is the same.

Since even a slight inaccuracy in assembly in an electrode boiler, unlike a heating element, the probability of electric shock is much greater. Therefore, you should not risk your life, as well as the health of your loved ones. It is better to contact a workshop specializing in the repair of electrical equipment.

Noise in the middle of the tank

If the boiler is making noise, then you need to listen to the sounds.

The noise is uniform and monotonous.
The noise is uneven. Cods are heard.

If the boiler makes noise evenly and monotonously, then there are no problems with its operation. The source of noise is the heating of water. This noise can be weak, or it can be loud. It all depends on whether the heating system is open or closed. If it is open, the boiler makes louder noise. The reason is the presence of air in the coolant .

You can get rid of noise by converting an open system to a closed one.

When the boiler makes uneven noise and crackles are heard, this is a breakdown. The cause may be scale on the heating element. The high temperature of the heating element causes the scale to heat up, which is accompanied by increased noise. Uneven sound and crackling occurs due to the fact that the thickness of the scale in individual areas of the heating element is different. The noise is generated like this:

First, thin deposits of limestone are heated. They don't make too much noise.
Thicker deposits are then heated. They take longer to heat up. That's why they hum louder than fine deposits.
The cracking sounds are very thick. This sound can also be created by plaque, which has begun to lag behind the heating element.

You can get rid of noise by regularly cleaning the heating element from scale.