Decoding error codes in Vailant heating boilers

In this article we will look at the Vaillant TEC series boiler.
These are modern boilers of the premium segment of the famous German brand. The model range is represented by boilers with a power from 20 to 36 kW, single-circuit and combined. Depending on the configuration, the TEC series is available in two modifications: Plus and Pro. Vaillant Pro is a cheaper model, Vaillant Plus has a hot start function in hot water preparation mode, a larger secondary heat exchanger, a larger expansion tank (10 liters), a more informative LCD display and a circulation pump with automatic speed control.

The operation of any gas boiler is permissible only if there is a working fluid in the system - coolant. By the way, Vaillant prohibits the use of antifreeze or corrosion inhibitors. Therefore, prepared water should be used as a coolant.

The presence of the required filling level of the heating system is monitored by a pressure sensor. Vaillant is a fairly technologically advanced boiler, therefore, it uses a pressure sensor that has the ability to measure its digital value. In many other boilers, the pressure in the system is controlled by pressure switches based on microswitches and a conventional mechanical pressure gauge.

The principle of operation of the Vaillant sensor is as follows: in the housing there is a spring-loaded magnet and a Hall sensor. Through the membrane, the coolant pressure in the pipeline acts on the spring and moves the magnet, thereby changing its position relative to the Hall sensor. Depending on the degree of displacement, the voltage value changes on the contacts, which are fixed by the control board and displays a numerical value on the screen to the user, and also controls the permissible value.

That is, the actual pressure value in the system is constantly monitored by the control unit.

The normal pressure in Vaillant TEC series boilers is considered to be in the range from 0.7 to 2.8 bar. When filling the system, it is recommended to ensure a value of at least 1 bar.

If the pressure value recorded by the sensor differs from the normal range, this is considered a malfunction and the diagnostic system will generate an error.

Decoding

Error f26 informs about a malfunction in the functioning of the gas fittings of the Vailant boiler.
The control valve, which meteres the supply of “blue fuel” to the burner, changes position under the influence of the stepper motor drive. The control signal to the stepper motor is supplied from the electronic board in the form of a “series” of pulses: the number is determined by the set Vaillant operating mode. Error F26 is displayed on the control panel of the Vaillant boiler

The EPU, by adjusting the number of steps, determines the degree of opening of the gas channel and the amount of fuel passed through. The movement of the spindle depends on the interaction of the magnetic fields of the coils. Therefore, the cause of error f26 of the Vaillant boiler must be sought in the gas fittings and control unit.

There is no clear recommendation for eliminating the code, so the manufacturer’s instructions advise that if such a malfunction occurs, contact a service organization. The article was written based on the author’s personal experience and analysis of the exchange of opinions of experts and users on solving the problem with error f26, found on thematic forums.

Electronics present the most unexpected surprises: different codes are caused by similar problems. When looking for the cause of the 26th error, before calling a service representative, you should try to fix the defect yourself.

Restart the boiler

Depending on the type of Vaillant, press the RESET, “NETWORK” or “ON” button. If error f26 is false, which appeared after a power surge, will disappear.

Button to reset error F26 for boilers atmoTEC pro, turboTEC pro

Check grounding

The potential on the body of the Vaillant boiler is a common cause of errors. It is detected by touching the metal part of the unit with an indicator screwdriver. Interference (stray currents) lead to malfunctions of the electronic board and false fault codes.

The problem is solved by installing a dielectric coupling on the gas pipe, in front of the boiler.

dielectric coupling

It is not for nothing that users note that error f26 Vaillant appears after a severe thunderstorm. Violations in the functioning of the heating unit are typical when independently arranging grounding without taking into account the requirements of the PUE and the manufacturer’s recommendations.

Inspect the inside of the boiler

The condition of the electrical circuits between the gas valve block and the electronic board and the reliability of the connections are assessed. Melted insulation and condensation initiate short circuits, the signal is “set”, the command to control the Vaillant boiler valve is lost, and error f26 is displayed. Detected defects are easy to eliminate.

Checking the signal lines in the Vaillant boiler

Damage to the EPU is also visually determined. This is indicated by swollen housings of electrolytic capacitors, microcircuits, cracks, chips, and burnt tracks.

Vaillant boiler control board

Perform cleaning

Dust is a likely cause of error f26. Accumulating on the fittings parts, the control board of the Vailant boiler, it gradually absorbs moisture, turning into a conductive layer. Dirt is removed carefully using a cotton swab, without using alcohol-containing or other aggressive liquids. It is recommended to practice regularly, especially for Vailant atmospheric boilers. This minimizes the risk of errors appearing on the unit display.

If you can’t remove the f26 code, contact an authorized service. It is not advisable to independently “pick” the board using advice from the Internet and various kinds of “experts” for a number of reasons.

• EPU is expensive, from 7800 to 14300 rubles. For diagnostics in a workshop at a stand, restoring the functionality of the unit, you will have to pay no more than 1000.
• Replacing the processor may not give any results - depending on the type of Vailant, the year of manufacture, the “firmware” is different.
• The dense arrangement of parts involves spot soldering. Performed on a machine with temperature control. Otherwise, overheating and damage to element housings are inevitable.
• The lack of schematic diagrams forces the user to act “blindly”. As a result, the boiler remains idle for a long time.
• Sometimes the cause of error f26 is a malfunction in the display board (display panel). It cannot be repaired - it can be changed.

When submitting an application, indicate the release date and type of Vaillant. The technician will replace the EPU in a matter of minutes, the problem with error f26 will be solved quickly.

Check what

Traction control system

In Vailant Turbo series boilers, the volumetric air flow (after ignition - exhaust gases) is determined using several devices that are structurally connected.

Pitot tube ruptured in Vaillant boiler

Complete set of manostat with Vaillant boiler tubes

Vaillant boiler pressure switch

Connect multimeter probes to the terminals to measure resistance. In the initial position, the microswitch contacts are open, therefore, R = ∞. Close the inlet port of the manostat with your lips and take several breaths. When the MF is triggered, characteristic clicks are heard, and the multimeter shows 0. If there are no complaints about the sensor, check the reliability of the connection of the electrical circuits.

Fan

In practice, error f37 indicates low speed. The shaft rotation speed drops for a number of reasons, and troubleshooting should begin with an external inspection of the turbine. The code is called:

Boiler fan vaillant

• impeller contamination. The weight increases, which affects the number of revolutions. Cleaning removes error f37;
• bearing destruction;
• interturn closure of the winding.

If error f37 of the Vaillant boiler does not disappear after removing dirt from the fan, the turbine must be replaced. It is impractical to test, disassemble, or repair it at home.

Chimney

Another error indicates a problem in the smoke exhaust duct. But if the thrust is reduced, the 37th may also appear. The instructions say that the pressure sensor operates in the range of 68–80 Pa. Inspect the pipe outlet, remove icicles, ice crust, clean the filter from dirt - a service technician is not needed for this.

The chimney is clogged

Electronic board

The “brain” of the Vaillant boiler receives signals from sensors, generating corresponding errors. Fault codes are caused by malfunctions of its operation. Testing cannot be carried out without a simulator, but visual diagnostics often help resolve the problem.

Vaillant boiler control board

Reasons for the error

• Board deformation.
• Dark spots are the result of thermal exposure.
• Unreliable contacts.
• Breaks, peeling paths.
• Damaged parts housings.
• Condensate.
• Dust. Gradually gathering on the surface of the boiler board, absorbing moisture, it turns into a conductive layer. Careful cleaning of the EPU eliminates error f37.

Ignition transformer

Failure to start the Vailant boiler is due to the lack of a spark or its insufficient power. If there are no wire defects, the Tr winding is checked with a multimeter: open – R = ∞, short circuit – R = 0. With interturn, the device will show resistance, but if the value does not correspond to the passport data, the spark is weak, insufficient to ignite the burner. Error f29 can be eliminated by replacing the transformer.

Burnt ignition electrode of Vaillant boiler

Control board

Self-repair is possible for a user with specialized education, but it will take time. Error f29 can be eliminated by replacing the Vaillant boiler assembly.

Useful tips

• With an autonomous gas supply, before the start of the cold season, it is advisable to update the thermal insulation of the outdoor cabinet with cylinders and the head of the gas tank. It is naive to hope that insulation lasts forever.
• Connect the Vailant boiler to the network via a UPS. Some errors are caused by voltage problems. The stabilizer helps, but as long as there is no break in the line. The power supply is capable of providing autonomous operation of Vailant for several hours: enough to eliminate a power line failure or problems with a backup power source. The UPS includes a stabilization circuit, a group of batteries, and a charger.
• Clean the heat exchanger housing periodically. Dust accumulation is the cause of error f29. A layer is formed through which combustion products do not completely pass through the fins of the device into the chimney. Partial flow of thermal energy is redirected inside Vailant. In addition to reducing the efficiency of the unit, the temperature under the casing increases. The result is melting of the insulation, deformation of the electronic board, periodic occurrence of errors with an emergency stop of the boiler.

Repeated breakdown

The music didn’t play for long; my favorite Vaillant gas boiler broke down again. At first I got error f33 and again f28, which means a problem with the gas burner. Since the Vailant display was acting up, naturally the fault was on the control board. However, one should not rush to conclusions. Like last time, we act according to a clear plan:

1. Disabling equipment.
2. Removing a gas boiler.
3. Carrying out diagnostics.
4. Analysis of the design.
5. Checking elements.

Since I had previously inspected the unit, I decided to check all the main components. I was interested in the condition of the tap, sensors, and pump. I didn’t want to disassemble the unit often, so I thought about how to fix all the problems at once. In a Vaillant gas boiler, some elements are hidden, so it is difficult to get to them without damaging another element.

We are talking about the control board. It is located at the bottom of the structure, and to get there you will have to tinker with the bolts, in my case everything looks flimsy. Finally, the Valiant boiler is open and you can look around. The control board is a regular element, the same as in a computer. When disassembling a gas boiler, it is recommended not to touch the contacts and connecting elements with your fingers again, since greasy stains remain on them. All this can affect the operation of the automation.

Eliminating the error begins with cleaning the contacts. As you know, there are tracks on the control board, and they can be easily cleaned with ordinary office grout. As for the sensors, I just removed the dust from them. Upon inspection, I noticed that the three-way valve was loose and could possibly fail in the near future. This element is located in the upper part of the structure and is responsible for shutting off the gas.

In the store I picked up a similar three-way product, the most interesting thing was with the control board. Finding a similar variation is problematic, fortunately, the exact product code is indicated on it, so I was able to order it online.

Error F28 may also appear due to a gearbox malfunction. The element is responsible for gas pressure and is connected to the meter. When I had suspicions about the gearbox, I initially carried out diagnostics; it was necessary to check the settings. First of all, turn off the gas valve

You need to pay attention to the display. If the error code disappears, it means the element needs to be replaced. It happens that everything is fine with the magnet, but the ignition transformer suffers

Soot often accumulates on it and the gas boiler refuses to work. Checking the pressure is not so easy, since it requires removing the casing. Having reached the distribution box, close the shut-off valve. Inside there are several sealing screws that are fixed to the gas fittings. It is only necessary to loosen them a little; the structure is not as strong as it might seem at first glance

It happens that everything is fine with the magnet, but the ignition transformer suffers. Soot often accumulates on it and the gas boiler refuses to work. Checking the pressure is not so easy, since it requires removing the casing. Having reached the distribution box, close the shut-off valve. Inside there are several sealing screws that are fixed to the gas fittings. They only need to be loosened a little; the structure is not as strong as it might seem at first glance.

A digital tonometer is used to check blood pressure. In the instructions you will find exact indicators of normal pressure depending on the modification.

Advantages and disadvantages

The advantages of products from the German brand include the following:

• The presence of a modulating burner allows you to effectively regulate the power of the device.
• Closed firebox.
• Possibility of automatic transition to maintenance of the hot water supply system without the participation of the owner.
• The primary heat exchanger has undergone major design changes. This made it possible to increase the efficiency to 91 percent.
• The copper heat exchanger is additionally protected by the proprietary “Suplar” coating.
• Availability of a plate flow heat exchanger.
• The equipment independently monitors the status of all components in real time, performs an automatic emergency stop when critical faults are detected, and records error codes in the internal memory.
• The circulation pump supports operation in several modes.
• Integrated expansion tank on some models.

No equipment is without drawbacks, and the Vaillant gas boiler is no exception. Here they are as follows:

The need to connect to the mains. If there is no power supply, the equipment will automatically stop

To get rid of this problem, it is enough to purchase an uninterruptible power supply, first paying attention to its power. High prices. High quality workmanship, the use of durable wear-resistant materials and modern technical solutions could not but affect the cost

On the other hand, this is more of a side effect than a disadvantage. After all, the technological effectiveness of the equipment has a positive effect on the level of energy consumption, thanks to which the user saves additional money.

Why does blood pressure drop?

The pressure drop in the boiler has a single cause - a coolant leak. If, after several attempts to increase the pressure using the supply valve, no positive results appear, you should look for a leak in the boiler itself or in the heating circuit.

Difficulty may arise if the boiler is a condensing boiler and is connected to a floor heating system.

Finding leaks in such conditions is extremely difficult. It may turn out that the fault is hidden in the discharge valve connected to the sewer system.

The optimal way to search for causes is to consistently eliminate possible causes of leaks, so that ultimately only one, the correct one, remains.

NOTE!

Certain information can be obtained if you try to determine the intensity of the leak and analyze the throughput capacity of the boiler elements involved.

Video on the topic

Gas autonomous heating systems are the most common and optimal from an ergonomic point of view today. But due to not the best operating conditions, they are often subject to various breakdowns, regardless of the country of origin and the price of the unit.

For example, a Vaillant boiler, the malfunctions of which are often associated with poor gas purification, may not last even one season, although it costs a lot of money. And this is not the fault of the manufacturers, because the equipment is designed for optimal conditions and cannot always effectively deal with problems arising due to the fault of public utilities.

Doesn't restart

There are many reasons for failure to restart a boiler. It is almost impossible to name them all, since most problems one way or another lead to the installation being blocked, and restarting becomes impossible until the cause is eliminated. However, some possible reasons can be named immediately.

For example, the power plug in the outlet may be upside down. Vaillant gas boilers are phase dependent, i.e. cannot work when the contacts are rephased. If a reconnection occurs during repair work, starting the unit will no longer be possible.

In addition, it is possible that the injectors become clogged with soot, which stops passing gas in the required quantity, resulting in immediate blocking upon startup.

Unit connection diagram

The connection diagram of the unit will depend on several factors, the first and most important, of course, is the type of heating system. There are three types of them:

1. Those that use natural circulation. The movement of heat is ensured by the difference in water pressure that occurs in the line due to the expansion of coolants due to increased temperature. Installation of such a line is cheaper, but you will not be able to regulate the temperature using a radiator; accordingly, the second type is used on higher-quality automation.
2. Forced circulation is carried out by special pumps, so you can freely regulate the amount of heat. Accordingly, the method is the most effective of those on the market, but the connection diagram is much more complicated and installation is more expensive. In addition, the system is completely dependent on electricity, and if it is turned off, the unit simply ceases to perform its functions.
3. Hybrid circulation. Nowadays there are practically no devices with this type of heating on the market, but such a device combines the advantages of both of the above. In the event of a power failure, the boiler freely switches to the mode of natural distillation of water through pipes.

You might be interested >> Gas-independent boilers from Conord

Accordingly, the connection diagram is available depending on the type of heating selected by the user.

Vaillant boiler error F28: how to fix

If you don’t want to understand the reasons and finances allow, of course, you can take the equipment to a service center. However, DIYers recommend not to give up and try to carry out repairs at home.

Please note that we are talking about gas equipment, so precautions must be taken. The unit must be turned off to ensure complete safety.

My actions during a breakdown:

My actions during a breakdown:

1. There is a “reset failure” button.
2. Equipment dismantling.
3. Carrying out diagnostics.
4. Boiler disassembly.

I am familiar with the structure of gas equipment and the first thing I check is the electrodes. My first thought is that the wiring is damaged. If there are exposed contacts, this is the easiest problem to fix. Take a blowtorch, everything falls into place. However, during the first inspection I did not find any problems with the wires; the electrodes are all in place (in theory, the electronic board should receive a signal).

The second point is grounding. It is checked using a tester. The most difficult thing is the valve; according to the instructions, it must withstand a certain pressure. In my case, he was clearly acting up and didn’t even know what to do. I decided to simply replace the element, error f 28 disappeared by itself.

Nuances of installation and operation

The installation of boiler equipment is carried out by gas company specialists in accordance with the instructions for the specific model.

Installation features of Vaiilant boilers:

• connection components (holder, fasteners) are included in the delivery set;
• maintain minimal mounting clearances on the sides, top and bottom;
• maintaining additional distances to combustible materials is not required;
• drilling locations are determined using the installation template;
• instead of lubricant, only water or liquid soap is used so as not to damage the seals;
• At the end of the work, the connections are carefully checked for leaks.

The product has two levels of control: user and specialist. The first displays basic information and makes it possible to configure basic system parameters using keys and controls. The second is used for repair and maintenance and is protected by a special code.

Possible faults

There are two groups of problems that arise when using Vailant gas heating appliances. In the first case, the boiler does not work completely, in the second - partially. Possible causes of malfunctions and measures to eliminate them are presented in the table.

When the system is turned on, the display may show error messages. What typical fault codes mean, their causes and methods of elimination can be seen in the table.

Repair of various models

According to the manufacturer's instructions, the Vaillant TurboTEC Pro 28 kW gas boiler cannot be repaired in such a way that changes occur in the boiler itself, in the water or gas supply lines, in the electrical network or in the chimneys. The threads of all connections can only be tightened and loosened using open-type wrenches. Pipe pliers, extension cords and similar equipment should not be used for this purpose.

Check the pressure as follows:

• the shell is removed;
• The distribution box tilts forward;
• the gas valve is closed;
• the screw in is loosened;
• a pressure gauge is connected;
• the gas shut-off valve opens;
• the device is started at full load;
• The connection pressure is measured.

If you cannot resolve the problem on your own, you should perform the following steps:

• the boiler needs to be stopped;
• remove the pressure gauge;
• check the tightness of the screw;
• fold out the distribution box;
• return the casing to its place;
• wait for gas service representatives.

Both single-circuit and double-circuit boilers, which consume a lot of gas and produce an extremely hot smoke stream, do not require repair. It is necessary to clean and wash the upper heat exchanger. If the hydraulic resistance is low, the company recommends tightening the supply valve. If there is no spark at all, there is no need to waste time cleaning the gas valve. The problem is almost 100% likely to be related to the system electronic board. If the AtmoTEC Plus boiler changes pressure sharply when the temperature changes, it is necessary to pump up the expansion tank.

F28: causes of occurrence, corrective actions

• gas sensor malfunction;
• breakdown of the gas pressure switch;
• airing of the gas pipeline;
• low pressure in the gas line;
• breakdown of fittings in the fuel supply unit;
• incorrect feed setting;
• failure of the ignition system – the ignition cable, transformer, plug are damaged;
• improper grounding;
• carbon deposits on the sensor;
• failure of the electronic board, other problems in the electronic unit;
• problems with - low voltage, surges;
• stabilizer fault ();
• fire hydrant activation.

Decoding

Error f36 should be interpreted as follows: traction violation: falls or the channel is completely blocked. The temperature of the exhaust gases rises sharply, which is recorded by a sensor monitoring the chimney. A corresponding signal is sent to the electronic board, code 36 is generated, and the heating unit stops.

Error F36 is displayed on the Vaillant boiler

The situations in which the Vaillant atmospheric boiler shows error f36 are different: initial startup, when the weather changes, only in the evening hours. The article discusses all the probable causes of the problem - the user will definitely find a solution to the problem.

Where to begin

Imported boiler equipment reacts to instability of the supply voltage. Jumps, phase imbalances, increased (lower) Uc values ​​lead to failures in the electronic circuit, and false errors appear. Before you start searching for the cause of the fault code, you need to restart the Vailant boiler. Depending on the modification, press the Reset, “Network”, “On/Off” button. If the appearance of the f36 symbol is associated with problems in power supplies, the error will be removed.

Reset error F36 on the Vaillant boiler control panel

Advice

The UPS helps eliminate the possibility of displaying false codes. Connecting the Vailant boiler to the home network through the unit guarantees stable operation of the unit even in the event of problems with power lines or a backup power source. Autonomy is provided by batteries (built-in or externally attached).

Connection diagram for backup power to the Vailant boiler

First steps

Reset.

This is done with a button on the Vaillant boiler panel or by turning off/on the power. Error F75 caused by power surge disappears.

Heating circuit recharge.

When the pressure in the system is below a critical value, fault code F22 is displayed. But if the coolant level is “on the verge” (minimum permissible), there will not be a difference of 50 bar when the pump starts working. Consequently, error F75 will appear.

Bleeding air.

When bubbles accumulate in the coolant, the channel is not blocked, but the circulation speed decreases. This affects the correct operation of the flow switch, which issues a corresponding signal to the electronic board. And now it generates error F75 and stops the Vaillant boiler. Models of the TEC series are equipped with a special deaeration program (P.0): after its start, the fault code disappears.

The most common malfunctions and their causes

Despite true German quality, like any other equipment, Vailant boilers are subject to various types of failures. If this or that problem does arise, the device informs the owner about it by displaying an alphanumeric code on the LCD display, including a red light, as mentioned above. Each error has its own code.

If you study thematic forums where boiler owners discuss their malfunctions, the most popular queries are:

• error with code F22, indicating the absence of water in the device or its shortage. It is worth checking whether the pump is jammed, whether the pump cables are securely connected to the water pressure sensor, look at the sensor itself or at the power of the pump. Possible still weak water circulation;
• error with code F28, in which the unit does not start at all. The reasons may be different: the zero and phase are incorrectly connected, the gas is oversaturated with air, the gas pressure level is too low, the control board is broken, the boiler is not properly grounded, a cable break or an error in connecting to the gas pipeline. Some problems can be solved by yourself by looking at the instruction manual. For example, check whether the gas tap is open or change the gas pressure in the boiler settings to 5 mbar;

Error F28 on the boiler display

• error with code F29, in which the burner flame constantly goes out, and new attempts to ignite are unsuccessful. The reasons may be: the gas boiler is not grounded correctly, gas supply failures in the gas system itself, problems with the ignition transformer or gas valve. To eliminate this problem, it is worth checking the gas pressure; it may drop too low or see if there is enough air for normal combustion of the fuel;
• error with code F36 (Vailant Atmo), in which combustion products come out. This problem may occur due to poor ventilation in the room or poor draft in the chimney, or the temperature in the room is too high. You should also check whether there is sufficient space between the boiler and the wall;
• error with code F75, in which the boiler pump works, but the pressure does not rise. There may also be several reasons: breakdown of the pump or water pressure sensor, air getting into the heating system, incorrect connection of the expansion tank or insufficient water pressure. To fix the problem, you can try cleaning the water pressure sensor or you will have to purchase more powerful components.

Features of Vailant boilers

The main difference between Vaillant heating units is that engineers have been working on them for almost 145 years. The design and technical characteristics of products are constantly being improved.

Advantages

Gas water heaters VAILLANT (Vailant) have gained the trust and love of customers all over the world thanks to true German quality. Vaillant geysers are distinguished by a high degree of safety, consistently attractive design, reliability and ease of use, and high performance.

But no matter how reliable and durable geysers of this reliable brand are, malfunctions sometimes occur in their operation.

The stable operation of a gas water heater is influenced by many factors and, first of all, it is necessary to systematically carry out maintenance of the gas water heater on time in order to maintain it in good working condition for a long time.

The influence of external factors: dust, dirt, as well as the formation of scale and wear of any parts of the gas water heater, can cause disruptions in its operation. In this case, you need the help of a qualified specialist who can cope with any problem and return the equipment to working condition and you to a good mood.

Therefore, if the following malfunctions of the Vaillant geyser are present:

Malfunction: the column does not light up. Possible reasons: the cause may be poor water pressure, a faulty membrane in the water unit, a faulty reverse draft sensor, a faulty heat exchanger overheat sensor.

Fault: leaking. Possible reasons: rupture of the heat exchanger, wear of gaskets on the connections, rupture of the membrane in the water unit, malfunction of the rod seal in the water unit.

Malfunction: turns on, but does not heat water. Possible reasons: blockage of the heat exchanger, scale deposits on the walls of the heat exchanger tubes, clogging of the heat exchanger radiator with soot, malfunction of the membrane in the water unit.

Malfunction: when the vailant gas water heater is turned on, a bang occurs. Possible reasons: weak electric ignition discharge, insufficient flame on the igniter, faulty solenoid gas valve.

Malfunction: does not go out when the water is turned off. Possible reasons: sticking of the membrane in the water unit, malfunction of the water unit rod, malfunction of the gas valve.

As well as any other problems, you should contact us and call a geyser repair specialist, since only a qualified specialist will be able to accurately determine the existing problem and competently and promptly fix it. If you do not repair VAILLANT geysers on time or do it poorly, the problem may arise again in the near future, but its solution may require more time and financial costs.

We are always happy to help you! Cost of repair of geysers in St. Petersburg

Commissioning sequence for Vaillant boilers

• Before filling, it is necessary to thoroughly rinse the heating system (large particles remaining after installation work can damage the actuators)
• check the condition of the automatic air vent on the circulation pump; if it is closed, unscrew it 1-2 turns
• shut-off valves on heating radiators or thermal heads must be fully open
• fill the heating system to a pressure of at least 1 bar (usually 1.3 – 1.5 bar)
• turn on the boiler and check the pressure, if necessary, recharge the system
• Be sure to check the gas deflector for leaks
• Vaillant requires filling the system with prepared water with a hardness of no more than 20 units according to the German calculation system and prohibits the addition of antifreeze or corrosion inhibitors to the system.

After the system is filled, it is necessary to carry out the P0 air removal program, in which only the pump will operate in a specially designed mode and remove excess air from the heating and domestic hot water circuit

Setup and management

Handling Vaillant boilers involves competently transferring them from one mode to another. The question often arises of how to properly turn off the heating system for the summer so as not to pay extra for gas and not overheat the house. The solution to the problem is to close the heating circuit for a short stroke, using a tap and jumpers.

If the equipment is made according to a scheme with artificial circulation, everything will be even simpler: you should disconnect the circulation pump from the scheme and seal the boiler inlet pipe. Trying to solve the problem by installing additional speakers is impractical and not very economical

It is important to remember that you will have to ensure a stable temperature by normalizing the flow of hot liquid. It is necessary to pump up the expansion tank if the pressure level continuously decreases and increases, changes unpredictably

A steady drop in pressure in the system cannot be easily eliminated; it is imperative to find the place where the coolant is leaking and eliminate the cause of the problem. The search for defects should be carried out on radiator plugs, connecting lines and where fittings and pipes are soldered.

If pumping the tank does not produce results or they last too short a time, you need to inspect the tank. Often its outer shell depressurizes and allows air to pass through. But even more often the performance of the spool valves is disrupted, which also begins to leak.

The pumping of the tank itself is carried out in the following stages:

• turn off the boiler, supply and return valves;
• open the drain fitting until it is completely drained;
• connect the pump unit via a spool, under no circumstances blocking the fitting.

Any type of pump is useful for the job; You can take a car gauge and a pressure gauge from the car too. The air pump is pumped until water flows out of the outlet fitting. Next, release the air and repeat its introduction, continuously monitoring the pressure gauge readings. It should show 1.1–1.3 bar; more precise information is provided in the technical documentation. Now you can close the pouring fitting, open all the previously closed taps, feed the boiler in the normal way to 1.2–1.5 bar, and then start warming up.

It is especially important to monitor internal pressure if the house or other structure is visited only periodically. It is no secret that the stability of power supply is now far from ideal.

And if the power stops, the boiler stops working, so the pressure inside the tank can drop due to cooling below what is required for the boiler to operate. Even after the power supply is restored, the boiler cannot warm up the house, because soon the uncontrolled house presents a sad sight - pipes and radiators torn from ice everywhere. Therefore, the pressure in the expansion tank must be constantly monitored. No less bad is the situation in which the pressure level continuously increases. Of course, a well-chosen and correctly installed safety valve corrects the matter to some extent, but it is better not to rely on it, since this is still more of an emergency measure. It is always worth remembering that pressure control deserves increased attention.

Error F.75

Error f75 of the Vaillant boiler means that after starting the pump five times, the pressure does not rise, but remains below 50 mbar. How to resolve error F75 Vaillant? What to do:

Check the water pressure sensor and pump. Air may have entered the heating system. Check water pressure and expansion tank.

If your Vaillant boiler gives an error, please contact our staff. We will make an accurate diagnosis and... All work is guaranteed!

Error F22 on the display indicates that the water is not heated to the temperature specified in the program. It may arise during the process, and the washing will continue, although it cannot be called high-quality. Most often, the heating problem is critical, so the machine will stop completely.

If your model does not have a display, pay attention to the RPM lights. In the described case, three will light up at once: 1000, 800 and 600 (or 800, 600 and 400), that is, all except one:. If there is no error, other signs may indicate problems with temperature conditions

So, after finishing the program, the laundry is still dirty or smells unpleasant. It is worth noting that sometimes this case is misdiagnosed, believing that the cold laundry you take out of the drum after washing is already a problem. But since rinsing always takes place in cold water, in this case there is no reason to panic

If there is no error, other signs may indicate problems with the temperature regime. So, after finishing the program, the laundry is still dirty or smells unpleasant. It is worth noting that sometimes this case is misdiagnosed, believing that the cold laundry you take out of the drum after washing is already a problem. But since rinsing always takes place in cold water, in this case there is no reason to panic.

Practical recommendations

It is advisable to order and install a new German sensor of a new modification in the Vaillant boiler (article 0020023721). The price is quite high (around 11,500 rubles), but the warranty on it is 5 years, and the problem with the appearance of error f75 due to the “whims” of the flow switch will be solved forever. It is made in such a way that debris is excluded: special membrane material, polymer filling of voids in the sensor body.

If you have experience and methods on how to fix error f75 of a Vaillant boiler or what needs to be done based on your experience, write in the comments to this article, we will try to consider your option and analyze it in detail in this article or one of the following articles. You can also send photos and videos with comments and descriptions.

Source

List of first level problems

Let’s first consider what the owner can “fight” on his own, without fear of the product becoming completely unsuitable and voiding the warranty.

The list of situations available for correction includes two options:

• The boiler doesn't work at all. Those. the device does not heat the coolant if it is a single-circuit model, and does not heat either the coolant or sanitary water if it is a double-circuit model.
• The boiler heats sanitary water, but does not heat the coolant. This problem is typical only for dual-circuit units.

Both of these positions have a number of completely removable reasons and several solutions that a prudent owner should familiarize himself with. However, before a detailed study of the situation, you should check whether the boiler is connected to the network at all and whether one of the functions is disabled: heating or DHW.

Now let’s look at the typical causes and methods for eliminating them in the case when the boiler does not heat at all:

• The gas valve is closed. Both shut-off devices installed by gas workers on the inlet gas pipe must be opened.
• The supply of cold water is cut off. This can be solved by opening the shut-off valve on the water pipe.
• Power supply disruptions. The heating unit will stop operating if there is no power supply. If the electricity supply is restored, the boiler will start itself.
• Temperature set too low. The owner of the boiler corrects an oversight made when making settings by simply switching the unit to the required temperature regime.
• Water pressure drop (F22). The encoding will indicate a lack of pressure in the system for normal operation of the boiler. Its appearance means that you need to bleed the air from the batteries and open the make-up valve located at the bottom of the device.
• Refusal to ignite (F28). If the third attempt to ignite the gas heating equipment does not lead to the desired result, you need to find the fault reset button on the control panel, press it and hold the position for at least a second. Failure again? Call the gas workers.
• Chimney fault (F48). This signal indicates an increase in the temperature of the exhaust flue gases. They could have stagnated and overheated due to a clogged external chimney that needs to be cleaned.

Note that a drop in pressure will also be signaled by the S76 indicator. This code is from the boiler condition monitoring group. However, to restore operation, the same actions will be required as when fixing error F22.

For the sake of his own safety, health and the safety of his household, the boiler owner is obliged to monitor the smoke removal system. Complete removal of gases is necessary, since the products of blue fuel processing are extremely toxic

The second type of violation, determined by the operation of only the hot water supply without heating the coolant, is most often associated with errors made by the technician during the settings. You can change the temperature yourself. The manual supplied with the boiler describes in detail how to perform this operation.

Actually a review. Reliability

Vaillant has no problems with reliability. It has been working for me for a couple of years now and has never required repair. By the way, before the start of the new heating season, do not forget to call a specialist to carry out preventive work (this winter - the second in a row since the installation - we first postponed everything until later, and then completely forgot to carry out scheduled maintenance, but there were no deviations in the operation of the boiler noticed. We are ashamed of the “German”, we will definitely call a specialist by next winter).

Not everything went as smoothly for the neighbor. But here, it seems, the installers are at fault: according to the old woman, they filled the stabilizer with water (the same as mine), and Vaillant worked without it. For the time being. This time came in the spring, in the form of a thunderstorm. It made the Turbo TecPro electronic components fly away. The case was not covered by warranty, and the part cost the grandmother 2,500 rubles. Otherwise, the boiler still works to this day without any complaints.

Features of the operating algorithm

The Turbo Tec Pro boiler operates in three alternating cycles:

• the gas is burning and the pump is running, pumping heated water;
• the gas goes out, and the pump continues to pump water for some time;
• the boiler seems to be resting (and the lower you set the temperature of the heating circuit, the longer it will “smoke” between operating cycles);
• everything went anew.

Since the boiler is a double-circuit boiler, both circuits (heating and water heating) must somehow “be friends” (communicate with heat) with each other. But something in the boiler operation algorithm seemed illogical to me:

Somewhat surprising

If, while the boiler is running to heat the batteries, you start to draw hot water, the gas will first go out, and then, after a dozen or so seconds, it will flare up again. The question is: why extinguish it?

if, when the boiler is operating to heat the house, we reduce the temperature (of the heating circuit, not the hot water), the boiler tries to use “free” energy, that is, as it considers, excess energy, to slightly heat its supply of hot water: gas (yellow light ), as mentioned above, goes out and the green indicator lights up. It would seem like a reasonable idea, but... the green light burns for literally ONE SECOND. Will you be able to heat the water circuit even a fraction of a degree in such a time?

Pleases

What’s also nice about the “German” is the possibility of additionally installing all sorts of “goodies” (for example, a two-zone temperature sensor that controls it in one of the rooms and simultaneously outside; based on the data received, it commands the boiler to heat further or pause - the device is designed to save gas) .

Of course, the engineers thought about the safety and durability of the boiler: if the water pressure in the heating circuit drops below normal, Vaillant will stop working and display an error code on its black and white LCD display (simultaneously with the red indicator). The same thing will happen if the gas pressure in the line drops, only the error number will be different. In my first winter (more precisely, already in March, at temperatures above zero), the boiler often “stopped” due to a gas error, because... handicraft in Russia is incurable - when laying a highway in a microdistrict, they were either lazy or forgot... to blow it thoroughly. Result: there was a lot of water (condensate) in the gas. In winter, it froze on the walls of the pipes, but when the heat appeared, it went into the gearbox and clogged it.

It's just infuriating

If you decide to use Vaillant TurboTec Pro for bathtub attraction, this paragraph is for you:

For some reason, Turbo Tek Pro cannot heat water “in real time” (serve as a flow-through heater). It only heats the small container of water that is located in its depths. When (quite quickly when taking a shower / filling a bath) this volume is used up, almost cold water begins to flow from the tap... AND NOW IMAGINE THAT YOU ARE STANDING UNDER THIS TAP!!! I even know what will come out of your mouth: YourBunnyWrote “№!%*? etc. After this (first... and so far last) bath/shower, you will probably think about an indirect heating boiler. It is designed to accumulate a large volume of water in advance, heating it from the heating circuit.

Summary

The Vaillant Turbo Tec Pro gas boiler is generally good and reliable. Consumes less energy than a refrigerator. Yes, there are a couple of moments in it to make fun of (like one of your careless relatives), but what you can’t take away is German reliability.

PS I have not used any other gas boilers, so I have nothing to compare with. Perhaps the above-mentioned shortcomings also occur on other models - I don’t know. I will be glad to publish your comments, remarks, clarifications.

Basic error codes (f28, f75) and their brief explanation

There are a lot of codes for various errors or malfunctions.

Let's look at the most common of them:

IMPORTANT!

In addition to error codes marked with the letter F, there are status codes marked with the letter S. They inform about the ongoing process and are not errors.

What causes an emergency stop

Chimney

• Clogging of the channel, blocking - this is often associated with error f36 of the Vaillant boiler. Ice on the inner walls and head, a layer of dust, debris, cobwebs on the filter grille - the draft decreases, the heating unit is blocked by an emergency signal.
• Illiterate design, violation of installation rules. The manufacturer gives comprehensive recommendations for arranging a chimney for a Vailant boiler: pipe cross-section, length of route and vertical section, elevation above the roof, slope and a number of others. A discrepancy in one of the parameters has a negative impact on traction and initiates blocking of the unit with error f36. During operation, miscalculations appear when the wind direction changes, strong gusts (draft overturning - the boiler “blows out”), precipitation (liquid overflows from the drainage system into the chimney pipe).
• The condensate collector is not installed in the channel or the location for the storage tank is incorrectly selected.
• The hood is calculated based on the characteristics of the heating unit and power. Owners who, in order to save money, connect Vailant to a chimney previously installed for another boiler often encounter error f36. The manufacturer also warns about possible problems - only the air duct/gas outlet of the Vaillant brand (instructions, section 5.5).

Blown air supply to the vaillant boiler through the external wall

• Violation of tightness. Unreliable knee joints and air leaks worsen traction.
• Damage (lack) of thermal insulation. A drop in temperature reduces the flow rate of volatile combustion products through the channel - the cause of error f36. It can be removed by insulating the chimney.

Adviсe

• There are many recommendations on the Internet for solving the problem with code 36 of the Vailant boiler. Some are useful, and some are simply harmful. Some of the “experts” suggest how to remove error f36: replace the temperature sensor with a response limit of t = 65 with a similar device designed for 95 (the temperature values ​​​​are indicated on the case). Unprofessional intervention in the design of the Vailant boiler is prohibited! We are talking about removing carbon monoxide from the premises. There is no need to explain what its accumulation in the room leads to due to the delay in the thermostat response.
• A decrease in the draft of an atmospheric boiler is caused by an exhaust device operating nearby. It is prohibited to use technical equipment of this category near Atmo series units.

Violation of recommendations for installation of the unit

The instructions set out the requirements for the premises and mounting of the Vailant. Unprofessional installation of the boiler causes error f36.

Causes

• Inconsistency between Vaillant power room dimensions.
• Increased room temperature.
• Insufficient natural ventilation. It’s easy to verify by opening the window and door sashes. Additional air flow will remove error f36.
• Wrong choice of location. A small interval between the Vailant boiler and surfaces (walls, floors, ceilings), household appliances that emit thermal energy (gas stove) leads to overheating of structural elements. Minimum distances are specified in the manual. If they are not met, conditions are created for the temperature sensor to operate, and error f36 is displayed.

Heat exchanger contamination

A layer of dust on the body of the device, in the intercostal space, prevents air from entering the Vaillant boiler from the room. Traction drops, emergency stop with error f36. It can be removed by cleaning the combustion chamber and heat exchanger surface.

Reduced circulation rate

Sensor problem

Other errors indicate a malfunction of the device (AtmoGuard), but the “behavior” of the electronics is unpredictable: anything can happen. Code 36 is caused by a breakdown or incorrect operation of the traction sensor. In Vailant boilers, the chimney control system is “cunningly” designed. The difference from heating installations from other manufacturers is that the removal of volatile combustion products is monitored by 2 sensors. Their precise location in the channel guarantees a quick response to the slightest change in flow.

Vaillant boiler draft sensor

One part of the sensor (sensor) controls the gases escaping into the chimney, the other (external) controls their penetration into the room. If this is observed, the electronics turns off the supply of “blue fuel” to the burner after two minutes. After 15–20 minutes (when the sensor has cooled down), the Vaillant boiler automatically starts working. The heating unit is blocked with error f36 provided that this situation is repeated 2 more times.

The instructions do not contain recommendations for “deep” testing of the sensor. Only the test method for operation is described: close the chimney, start the Vailant boiler. Next, observe the actions of the electronics: emergency shutdown (2 minutes), re-ignition (15–20).

Types of boilers produced

Vaillant produces gas and electrical equipment. Electric boilers are limited to one EloBLOCK model in several power options.

Gas appliances are presented in a more diverse range.

Among them:

• traditional (throw away some of the useful heat along with smoke);
• condensation (use additional energy from exhaust gases);
• single-circuit VU;
• dual-circuit VUW;
• atmospheric Atmo (uses air from the room for combustion, and a standard chimney for exhaust);
• turbocharged Turbo (allows you to arrange an underwater and outlet path through the wall);
• mounted;
• floor

Single-circuit

Boilers with one circuit are designed to heat only the coolant of the heating system. For water treatment, you can connect an external boiler.

In dual-circuit models, water is prepared separately for heating and for domestic household needs.

Wall mounted

Wall mounted boilers are mounted using fasteners on the wall. Save space due to small dimensions. Household installations of low and medium power are manufactured in wall-mounted versions.

Floor-standing

Powerful domestic and industrial boilers are installed permanently on the floor. They have significant weight and dimensions. In some cases, they require a separate room - a boiler room.

Gas boiler double-circuit Vailant error F75

The Vailant double-circuit gas boiler provides heating of the house and supply of hot water. Experts recommend these boilers because of their efficiency in use, operational safety, ease of installation and affordable price.

Which boiler to choose?

Vailant gas boilers can be floor-mounted or wall-mounted. Floor-mounted ones are more powerful and durable. Wall-mounted ones take up less space.

The Vailant double-circuit wall-mounted gas boiler can be selected from a large model range. One of the main indicators is the power of its power. You need to calculate how much hot water your family spends on average. Based on this, you can choose a boiler.

The Vailant double-circuit gas boiler can operate on natural and liquefied gas. The consumption of liquefied gas is less than natural gas. The device is converted to another type of gas by readjustment.

How to run self-diagnosis

The self-diagnosis system is a complex of sensors consisting of NTC elements (thermistors) or software products.

All of them operate in continuous mode, monitoring the status of connected elements from the moment the boiler is turned on.

Therefore, the self-diagnosis system does not need to be started - it is always on and operates in constant mode, monitoring the operating mode of components and parts, immediately signaling the occurrence of problems.

In the event of an emergency, a special code will appear on the display indicating the problematic structural element. The user is only required to react appropriately when an error occurs.

Diagnostics and boiler failures

It should be noted that Vaillant equipment is one of the safest among all others. The number of settings, parameters, and checks here is significantly greater than in boilers of other brands. Boilers with displays can display status codes, diagnostics (two levels), faults and setup programs. The average user will only be interested in error codes, so everything else is mainly intended for service specialists.

The Vailant automation also stores a history of all errors, this makes it very convenient to diagnose and troubleshoot the boiler. At any time you can view the last 10 errors that occurred on the boiler (use the “info” and “-” buttons to display the list).

Next, we will consider the most common errors of Vaillant boilers and recommendations for eliminating them.