Modern heating installations eliminate the need for the user to contact a service organization if a problem occurs after the warranty expires, wasting time and wasting money. The reasons causing error f22 of the Vaillant boiler can be eliminated independently. The article tells you what to do in this situation.
Photo of error f22 on the Vaillant boiler
How to fix error f28 of a Vaillant gas boiler (Vailant)
1. Display of the current filling pressure of the heating system, heating flow temperature or display of a status code or error. 2. Green indicator lamp for hot water is off: No hot water is being collected. Flashing: Hot water is being collected. 3. Yellow indicator lamp lights up continuously: Burner on. 4. Red indicator lamp lights up continuously: The device is in a fault state and an error code is displayed. German heating systems are available in various modifications. But regardless of the principle of operation or design features of gas boilers, error f28 is typical for all versions of Vaillant, and the reasons that initiate it are identical. Most of them are identified and eliminated on their own, without calling a specialist. The article will help you troubleshoot possible problems and give recommendations on how to restore the functionality of your equipment.
Error interpretation
Code f28 appears on the display after several unsuccessful ignition attempts. The reasons can be divided into four groups:
Successful attempt to ignite the vaillant boiler
Understanding this and knowing the specifics of the gas supply to the facility, it is easy to develop an action plan for troubleshooting. In order to reduce the time to eliminate the f28 Vaillant error, you need to start by testing the most problematic areas of the circuit.
Video about how error code F28 is displayed on the Vailant boiler.
“Troubleshooting” button to reset certain faults. Click it.
First steps
On a note!
The recommendation to “turn the plug over” and reinsert it into the socket in order to eliminate the error is not suitable for Vaillant boilers - the experiment will lead to the circuit breaker turning off or the electronic board burning out.
Gas path diagnostics
When connecting a building to a main pipe
If we are talking about a residential building, and “blue fuel” is chosen as the main energy resource, in the house, in addition to Vaillant, there is a gas stove. After the pipes have been laid, there are no devices in the section of the circuit up to the boiler. Therefore, you can control the flow of gas without leaving the kitchen.
The check comes down to igniting all the burners on the stove at maximum mode. Flames with a characteristic shade will indicate the absence of problems with the fuel supply, and their intensity and stability will indicate the constancy of the pressure and its normal value. If the stove does not light up or does not work correctly, you need to look for a fault in the section between the main line and the place where the gas pipes are laid (the method is described below).
With autonomous gas supply
Check what
Another option is the formation of an ice jam on one of the sections of the highway outside the building. But this defect must be dealt with (and eliminated) by specialists.
Diagnostics Vaillant
Ionization sensor
If ignition occurs (there is a spark), but after a short time error f28 appears and the operation of the Vaillant boiler is blocked, the electrode “does not see” the flame.
Burnt ignition electrode of Vaillant boiler
New Vaillant boiler ignition electrode
Ignition system
Its serviceability can be judged by the spark between the igniter electrodes. If the connected wires are in normal condition and the assembly body is intact (the absence of cracks is determined visually), the cause of error f28 of the Vaillant boiler is in the transformer. It is necessary to test its winding to identify a break: the multimeter should show ∞.
Coil location in Vaillant boiler
Modulation coil for the gas valve of the Vaillant boiler
Gas valve
It is not difficult to disassemble it yourself: you will need an asterisk key. After dismantling the stepper motor and removing the cap, the rod is visible. It is “responsible” for moving the membrane that regulates the gas supply to the burner of the Vaillant boiler. During operation, it becomes dirty, and layers interfere with its free movement. It is enough to wash it in any alcohol-based liquid, put it in place and reassemble in the reverse order.
Vaillant boiler gas valve
Location of the main units in the Vaillant boiler
This is a theory, but in practice everything is much more complicated.
What are the pitfalls?
Other reasons for the error
Useful tips
If you have experience on how to fix error f28 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.
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Most common hardware problems
F20/F22/23/24 (F10|F11) – overheating.
Errors occur when the volume of coolant in the system decreases, a sharp increase in temperature, or an exorbitant difference in temperature at the outlet and inlet to the Vaillant.
Recommendation: fill the circuit with water, bringing the pressure to normal (2±0.5 bar). Reset and start up the boiler. Repeated occurrence of the error is evidence of a problem.
Probable Causes
1. Leak. An autonomous circuit is a closed and closed system: natural evaporation of liquid is excluded. Loss of coolant is possible only in the event of mechanical damage or leakage. It is easy to find the problematic section of the route (device) by inspecting the house for signs of dampness, stains and streaks. Leaks rarely occur in the Vailant boiler itself: more often in the joints of pipes or heating radiators.
2. Reduced circulation rate. The coolant moves more slowly, and the boiler burner operates in the specified mode. Hence the overheating and Vaillant's error. What is the reason?
- Heat exchanger
- Pipe
Airlock. It is easiest to identify and mitigate such a problem. It is necessary to check all radiators for the degree of heating: a sharp temperature drop in individual sections of the circuit will indicate the “culprit”. Even if there are automatic valves, you should bleed them manually - they often fail due to poor quality water treatment.
Pump. The boiler overheating error is caused by stopping the device or reducing the shaft speed.
Vaillant boiler pump
First of all, the supply voltage and the set speed are checked. Incorrect operation of the Vailant pump may be due to salt deposits on the impeller. It is necessary to dismantle the pumping device, perform partial disassembly and wash it. After starting the boiler, the overheating error disappears.
Heat exchanger. The formation of layers in its cavity is one of the probable reasons. A gradual decrease in the diameter of the channel negatively affects the circulation of liquid, hence the overheating of the Vaillant boiler and the error.
Recommendation: if there is an alternative heat source at the site, the device must be removed and sent for service. Self-cleaning is ineffective, and after starting up, the Vailant boiler may start up again in a month or a month and a half. High-quality maintenance involves filling the cavity of the heat exchange device with an aggressive liquid, leaving it for at least a day, followed by flushing under pressure. This cannot be done on site.
F26 (F07) – problem with gas fittings.
You should ensure the integrity of the wires and the reliability of the contacts. It is not advisable to change it yourself - you also need to configure it correctly.
F27 – flame simulation error.
The probable cause is the ionization sensor: shorted wires, dirty electrode, dampness. If the boiler has been idle for a long time, you need to remove the casing and dry it (with a directed stream of warm air).
F28 (F04) – unsuccessful ignition.
There are many reasons for this error to appear. You can independently check only the flow of gas to the boiler burner, its pressure, the reliability of the signal circuits and grounding. Other defects - in the meter, main filter, Vaillant fittings, transformer, electronic board - must be determined by a specialist.
F29 – boiler malfunction, problem with re-ignition.
Probable causes of errors during autonomous gasification: gearbox failure, icing, LPG production. The remaining faults are identical to F28; they cannot be determined independently.
F33 (F05) – incorrect fan operation.
The error is caused by its breakdown, failure of the flow switch, or a malfunction in the electronic module of the boiler. If the power and signal lines are not damaged, you need to contact a specialist.
F68 – unstable flame.
Probable Causes
- Unstable pressure in the line.
- Air leak. If Vaillant runs on LPG from a cylinder group, check all connections.
- Problem with the boiler ionization sensor. Its contamination may be the cause of error F68: remove carbon deposits.
- Vaillant boiler gas valve is clogged
- Debris in gas valve
Everything else is due to incorrect operation of the gas fittings and boiler burner. You can service the nozzles yourself: a vacuum cleaner, a toothbrush. If after this the Vaillant error does not disappear, call a technician.
– Pressures greater than 50 mbar are not detected.
The Vaillant boiler simply does not turn on
If the boiler display does not light up, and you are absolutely sure that it is reliably connected to the power supply, then most likely the board has failed. Unfortunately, the self-diagnosis program does not record internal errors in the operation of the board, and if damaged, the boiler will simply go out. Quite often, these damages can be seen visually when inspecting the board.
We have everything you need to restore the boards of TEC and MAX series boilers. Here is an example of repairing one such case (the power module on the board burned out):
The repair was completed within a day and the payment was handed over to the satisfied customer.
Vaillant is a high-quality and reliable technology, but electronic breakdowns still happen sometimes. The boiler circuit board is one of its most expensive elements, so by contacting us, clients save an impressive amount of money. We have been doing repairs for a long time and all spare parts are always in stock, and repairs take a minimum of time, which is especially important when a breakdown occurs during the heating season.
Eliminate the cause of the error:
It is strictly recommended to connect heating boilers through a stabilizer (for the boiler) or a UPS; this will save you from unnecessary costs for replacing the control board.
Filling the circuit is done by turning the valve counterclockwise on the cold water line; do not forget to return the tap to its original position (tighten clockwise tightly), otherwise the relief valve will start to operate.
Depending on the boiler model, the make-up tap can be of different designs.
If, after some time after replenishing the system, the pressure drops, then there is a leak in the system (pipes in the boiler suitable for the heat exchanger, the connection points of the supply and return pipes, the connection points of the batteries.)
— If the pump impeller is dirty, mechanical cleaning and flushing will help.
— Unreliable contact: burning, oxidation of the lamellas leads to instability of the supply voltage.
— Deformation of the shaft or impeller, destruction of the bearing, contamination of the internal air removal channel
Inspect the board for damage (oxidation, dark areas, moisture, characteristic smell of burnt tracks and modules, remove excess dust); all operations with the board must be carried out using antistatic gloves.
Any diagnostics and repair of the boiler must be carried out by a certified specialist with a valid certificate issued by Rostekhnadzor.
Source
How to fix error F29 of a Vaillant gas boiler (Vailant)
When following the manufacturer's recommendations for the installation and operation of household heating systems, they rarely fail. According to repair statistics, some problems are a consequence of illiterate user actions or the influence of external factors. This article will help you resolve error f29 yourself.
Decoding the code
Error f29 appears while Vaillant is running. It is confused with the 28th, the code of which indicates unsuccessful attempts at ignition. There is no point in immediately dealing with the boiler or calling a technician if the equipment is under warranty. The malfunction is a consequence of a short-term interruption in the gas supply.
First steps
Press button number 8 on the control panel of the Vailant boiler.
This algorithm of actions saves time in troubleshooting problems with heating equipment. A negative result is a reason to look for the reason for the shutdown of the Vailant boiler.
On a note! The instructions for gas equipment contain scant information on faults. The manufacturer, taking into account the complexity of the devices and their danger in terms of ignition (explosion), does not rely on repairs by the user - only a certified technician. A number of Vailant boiler errors are caused by identical factors.
Check what
Gas main
Blockage of the path, pressure drop cause error f29. In a facility with a gas stove, it can be used to test the system by igniting all burners. Based on the height of the flames, their stability, and color, it is easy to determine whether “blue fuel” is flowing through the pipe, whether the pressure is reduced, or whether air is leaking.
Simple gas flow check
The stove consumes more gas when igniting than Vaillant. In practice, after turning it on, the boiler error f29 disappears. If this is observed, the reason is in the counter. Its mechanical part sometimes jams, and increased fuel consumption contributes to a “breakdown”: the meter will have to be changed.
Probable Causes
Air supply channel
The procedure is determined by the specific installation of the heating installation.
Coaxial chimney with protection from the external environment Recommendation . If code 29 appears during periods of change in wind direction, you should change the air duct laying scheme: take the pipe to a different place, cover the head - there are many options. The main thing is that it doesn’t blow.
Ionization sensor
Provides a signal to the Vailant boiler control module about the presence and stability of the flame. As a result of partial contamination (carbon deposits, dust), the electrode loses sensitivity. Error f29 can be eliminated by cleaning the wire.
Clean the Vaillant boiler
When repairing a Vailant boiler, the integrity of the signal circuits is checked. The harness is disassembled, but at the end of the work the tie is not put back in place. It is possible that the ionization sensor wire is adjacent to a metal part and, when the insulation is worn out, periodically shorts out. Hence the error f29.
Gas valve
It must be taken into account that it is adjusted by pressure. Therefore, with error f29, no disassembly of the fittings or adjustments are carried out, only cleaning. After dismantling the Vailant boiler assembly, remove the cap covering the damper control rod. It is electromechanical, movement is provided by a magnet. The smallest fractions, clogging the gap between it and the gasket, prevent the free movement of the rod. The entire cavity to which there is access is also cleaned. Removing dirt and dust eliminates error f29.
Vaillant boiler gas valve
It is also caused by mechanical damage. A typical malfunction is a defect in the gearbox: the unit is replaced.
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
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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:
- Disabling equipment.
- Removing a gas boiler.
- Carrying out diagnostics.
- Analysis of the design.
- 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.
What checks are carried out before the first start-up of the boiler?
For further normal and safe operation, as well as maintaining the warranty, any equipment requires compliance with a number of conditions:
The installation manual also requires installing a coarse filter on the cold water supply to the boiler and on the return pipe of the heating system, as well as a gas filter.
It is better to study the commissioning process in more detail in the instructions for a specific boiler model.
The selection of the test program (airing, filling the system) is started by turning on the boiler and simultaneously holding the “+” button for 5 seconds. The selected program is activated with the “i” button. For TEC series boilers, five programs are preinstalled.
Prevention
Like any other equipment, the boiler requires timely prevention.
Cleaning the boiler
Cleaning of soot from the boiler is carried out with a soft brush from the outside. The use of harsh cleaning is unacceptable, since the boiler plates are made of copper, with an anti-corrosion coating that cannot be removed. The disadvantage of the heat exchanger design is that it cannot be internally washed, and the use of antifreeze or feeding the circuit with hard water shortens the service life of the unit.
Fighting deposits and scale
The problem of deposits is even more important when operating secondary hot water boilers, due to the constant circulation of hard water through its circuit. This means that it becomes even more clogged with deposits and scale. The manufacturer took care of this situation and created conditions for periodic washing of the heating surfaces of the DHW circuit. This can be done using a booster with the addition of special agents to the circulation coolant.
Next, the solution is run for several hours, dissolving and washing away the scale.
Note! In addition, it is recommended to maintain a low temperature for hot water supply, which does not require dilution with cold water. In this case, the intensity of scale formation, which begins at 60 °C, will be practically reduced to zero.
Expansion tank maintenance
Expansion tanks are subject to annual maintenance. To do this, the boiler is filled with water to the operating level in the system of 1–1.2 bar. If water appears from the control output of the expander, then the tightness of the tank membrane is broken and it will need to be replaced.
Burner and filters
The filters on the gas line are made in the form of a mesh; for maintenance they are removed and washed with water. The gas burner also becomes clogged with combustion products over time; it should be cleaned with a soft bristle brush and a vacuum cleaner.
What to do with error F20 on a Vaillant gas boiler (Vailant)
The diagnostic function of heating installations in automatic mode allows the user to solve almost all problems without contacting service. For Vaillant gas boilers, error f20 is a rare occurrence. Understanding the reasons why it is caused, it is easy to identify the problem and fix it on your own.
Decoding the code
Recommendations for eliminating the f20 Vaillant error found on forums and thematic sites are different. It appears when the boiler overheats, and there are several reasons for this. The nuance is that the instructions indicate different codes for them: f0 (high supply temperature), f22 (sharp drop in coolant pressure) and a number of others.
Error f20 is displayed on the control panel of the Vaillant boiler
Not everyone understands the difference between Vaillant boiler sensors. Devices installed on the forward and return lines monitor the current temperature. The overheating thermostat is activated at a value of t˃ 95 0C at the output of the heat exchanger and turns off the heating installation upon an alarm signal with error f20. Therefore, it is necessary to deal with it.
Procedure
Step 1
Perform a reset by pressing the button on the Vaillant control panel. Imported boilers are sensitive to the supply voltage, and if the network is unstable, they malfunction with an indication of some error. If it is false, it is easily reset.
Button 8 “Troubleshooting” for resetting specific faults
Step 2
Bring the thermostat into working position. In Vaillant boilers, it is “cocked” manually by pressing the rod (painted red). If error f20 is caused by a pump malfunction or other reason, it will disappear. To access the overheating thermostat, you need to fold back the front panel - in most Vaillant models, a protective device (fuse) is installed at the heat exchanger outlet, under the NTC sensor.
Location of the NTC sensor of the Vailant boiler
Step 3 – diagnostics of signal circuits. Defects are determined visually: line break, insulation melting, short circuit - the causes of error f20 and emergency stop of the Vaillant boiler. The reliability of the contacts and the absence of oxides are checked.
Step 4 – testing the overheat sensor. It is easy to determine serviceability with a multimeter by measuring the resistance. In the initial state, the contacts of the working device are closed, R = 0. The protective thermostat cannot be repaired - it is replaced.
The last reason that causes error f20 is the electronic board of the Vaillant boiler. It generates a fault code based on a signal from the overheating sensor. It will not be possible to identify a defect on your own without diagrams, experience, or appropriate equipment. If the measures taken to eliminate error f20 are unsuccessful, you need to contact a service center. After replacing the board, the boiler's performance will be restored.
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Bosch machine repair and parts replacement
If you are unable to fix the problem yourself, contact the service center for the services of a technician. It is not possible to determine the location of the breakdown on your own; professional diagnostics are needed. At risk:
Pressure and water supply sensor
If the pressure sensor (pressostat) fails, the failure cannot be corrected: the part needs to be replaced. A breakdown can result in an endless cycle of draining and filling water.
But if a blockage occurs, then the pressure switch simply needs to be cleaned. There is no need to disassemble the machine, just disconnect the tube from the pressure switch and rinse thoroughly under running water. This part is located in the central part of the left side wall.
The flow sensor monitors the throughput of the machine. If water does not enter the tank, do the following:
Inlet (fill) valve
If there is a malfunction, the valve must be replaced. Open the top cover of the machine. There are two hoses connected to the fill valve - disconnect them. Then you should disconnect the wires from the burnt valve and remove it. After this, you can install a new one.
On a note! When replacing any valves in a washing machine, you should first turn off the water supply in the water supply, otherwise it will flow onto the floor.
A malfunction of the fill valve can lead to flooding of the neighbors below if the Aqua Stop is missing or is faulty in the machine.
Water intake sensor
If the electronic module is broken, the sensor does not detect the liquid intake. Because of this, the machine cannot start washing. If the sensor completely fails, it is cheaper to buy a new washing machine. In other cases, the technician can help with repairs.
Other malfunctions and solutions
If the reverse draft diode blinks, then either it is faulty, or the combustion products are not completely removed but enter the room. The repair instructions in this case are as follows: first you should clean the chimney, then check the quality of ventilation.
After this, you can replace the backdraft sensor. Initially, during installation, it is important to comply with all safety requirements. Quite often the gas burner becomes clogged and soot is deposited on it. It should be cleaned regularly to ensure full control of the flame level.
Fault codes, malfunctions and errors of Vailant boilers
Error F28 appeared on the Vailant boiler, what should I do? First of all, if such malfunctions occur, you should not immediately start to panic. Not everyone knows that absolutely every boiler from a German company is equipped with its own diagnostic system, which is part of the electronic unit.
All necessary data on the operation of the system can also be obtained on the liquid crystal display of the unit.
You can also perform independent diagnostic measures. First you need to evaluate how efficient the device is. To do this, first of all, the outlet and inlet connections are checked. It is necessary to make sure that the carbon monoxide, hot water and condensate outlets are completely sealed
You also need to pay attention to ensure that there is no serious contamination in the pressure reduction chamber.
The next step is to check all electrical wiring. To do this, you need to make sure that the connectors and plugs fit tightly and do not dangle. Salt or limestone deposits may accumulate in the condensate drain and siphon, which can also affect the performance of the unit. If such contaminants appear, it is imperative to get rid of them.
Sometimes the gas burner of the unit becomes clogged with carbon deposits. In this case, it must be cleaned, as well as the internal walls of all working chambers and the chimney must be treated.
Decoding
Error f33 is generated by the electronic board of the Vaillant boiler. After starting the unit, the fan (turbine) is turned on by command from the ECU, and a vacuum is created in the chimney. This is detected by the sensor, and with normal flow through the exhaust channel of volatile combustion products, the relay contacts close the signal line. The ECU “sees” that there are no problems with the path, and gives permission to operate the gas valve and ignite the Vailant boiler. Accordingly, if the differential relay does not open the electrical circuit when the turbine stops, error f33 appears on the display.
Error F33 is displayed on the Vaillant control panel
The time indicated in the fault table (30 minutes) is approximate. In the Vaillant boiler, a timer is not included in this signal line. The delay in automatic operation is determined by the operating mode of the heating unit, weather conditions and a number of other factors.
Where to begin
Restart the unit. There is a Reset (or “On/Off”) button on the Vaillant boiler panel that clears the failure. Press for 5 seconds, release. If the cause of error f33 is voltage instability, the code will be cleared.
Button to reset error F33 for boilers atmoTEC pro, turboTEC pro
Advice
Powering the Vailant boiler from a UPS eliminates the appearance of false fault symbols. The unit, unlike a traditional stabilizer, provides autonomous power to the heating unit, and breaks on power lines or problems with the backup generator will not cause an emergency stop for the Vaillant.
Boiler stabilization scheme
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.
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
First steps
Press button number 8 on the Vaillant boiler control panel
This algorithm of actions saves time in troubleshooting problems with heating equipment. A negative result is a reason to look for the reason for the shutdown of the Vailant boiler.
On a note! The instructions for gas equipment contain scant information on faults. The manufacturer, taking into account the complexity of the devices and their danger in terms of ignition (explosion), does not rely on repairs by the user - only a certified technician. A number of Vailant boiler errors are caused by identical factors.
What to repair?
If the above steps do not help, there is likely a problem with the heating or control elements. It could be:
- heating element. Its failure causes scale. To avoid this, carefully select the washing powder or liquid or clean the heating element from time to time by running the washing machine idle with special products;
- Temperature sensor or NTC sensor. Replacing one or both of these parts will most likely solve the problem;
- Control block. Failures in the module can also block the heater. Sometimes a flashing is enough, in some cases a deeper repair or replacement is needed.
Self-diagnosis systems in modern heating boilers make it possible to quickly detect malfunctions, notifying users about this. They are present in equipment from almost all brands, including those from Vailant. In this review, we will analyze the typical errors of Vailant boilers and their numerical designations, and give instructions for further actions.
Decoding
Error f64 is displayed when the heating unit is turned on or during operation. Informs about a boiler electronics failure. Appears, as a rule, after strong power surges in the network, lightning, or emergency situations. It is not advisable to immediately change the EPU - error f64 has several causes.
How to proceed
It does not help to get rid of error f64 - diagnose the unit.
Check what
Coolant temperature sensor
Boiler temperature sensor Vailant
Both are submersible types (for units of the atmo/ turboTEC series - overhead). They are constantly in an aggressive environment, which leads to metal destruction, short circuits, reading failures, and error f64. They are installed by screwing in; there is no need to dismantle them to check. The measurement is carried out relative to the body of the Vaillant boiler.
If, with the signal line open, the multimeter shows R = 0 (internal breakdown), the NTC is faulty and is rejected. After replacing the device, error f64 from the display of the Vailant boiler will disappear.
Flue gas temperature sensor
Flue gas temperature sensor in the Vailant boiler
Checking for short circuit is identical to the method described above (for NTC). In Vailant boilers of the atmoTEC series, the sensor has an original design (AtmoGuard control system). The device contains 2 sensor devices, the location of which (one closer to the burner, the other at the end of the chimney pipe) ensures low response inertia. Short circuit of the sensitive element, short circuit on the line causes error f64. Check the condition, eliminate the defect, and the fault code will be cleared.
Electronic board
Diagnostics of EPU is the prerogative of the service technician. A preliminary performance assessment is performed on site by entering the menu to the 2nd level. To fully test and identify the cause of error f64 of the Vailant boiler, a test on a simulation stand in a hospital setting is necessary. But a number of defects that cause fault codes can be determined independently, and some can be eliminated.
Check the Vaillant boiler control board
What to do
Inspect the board for defects: cracks, chips, damaged tracks, dark spots (burnouts), melted housings of radio components. Each factor causes a Vailant boiler error.
Remove dirt, dust, condensation from the surface. They cause short circuits and the appearance of the f64 code.
Advice
There is no need to carry out a more “deep” diagnosis yourself. There are a lot of recommendations on the Internet, exchanges of opinions on the experience of eliminating the f64 error of the Vailant boiler “on the table”. At the same time, it is overlooked that the circuit diagrams of electronic boards and the design of units are different (depending on the model and year of manufacture). If you couldn't solve the problem, call a service technician.
Practical recommendations
• The Vaillant boiler should not be connected to the network directly, but through a UPS. A unit is a complex device consisting of a group of batteries, their charging and voltage stabilization circuits. Even if the power line is disconnected or the backup electric generator breaks down, the heating installation will continue to function for several hours (depending on the total battery capacity).
• The “weak link” of the pressure sensors of any imported boiler, and Vaillant is no exception, is the sensitive element (membrane). Foreign developers focus on their customers, without taking into account our specifics. This concerns the quality of the water filling the heating circuit. Over time, with increased rigidity of the coolant, the rubber rubber becomes “oaky” and loses sensitivity to changes in the pressure of the circulating liquid. In fact, the sensor (flow switch) is working, but boiler error F75 appears periodically. The reason is that the membrane does not respond to slight changes in pressure.
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 for 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.
Adjustment features
Boilers from this manufacturer are easy to control. However, this does not mean that every person can cope with such a task on their own. It is best to make adjustments together, when one person turns the tap and the other monitors the position of the pressure arrow. To adjust the water or heating temperature, you can use special valves located on the control panel. In this case, how hot the water is will be displayed on the display. Thanks to this, you can increase or decrease the temperature by turning the tap to the desired position.
Also, the fact that the time has come to figure out how to eliminate error F28 in the Vailant boiler can be signaled by special light sensors on the device panel. The green light comes on when heated water is being used. A yellow indicator indicates that gas is burning. If the red LED lights up, this indicates a problem with the system
It is also worth paying attention that only water is poured into the boiler. There is no point in experimenting
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.
