How to fix errors on boilers Vailant – types of faults

Especially in the winter, when your Vaillant boiler acts up, it can cause chaos throughout your entire home. Vaillant is a well-known boiler brand that is renowned for its dependability and efficiency, but much like any mechanical system, it occasionally has issues. You can save time and money by being aware of the most frequent problems that can arise with these boilers.

Thankfully, it’s possible to diagnose and even fix a lot of boiler problems without having to contact a professional right away. Determining the significance of odd sounds, leaks, or total shutdowns is frequently the first step towards reestablishing the functionality of your heating system. We’ll examine some basic troubleshooting guidelines that you can use to fix the most common Vaillant boiler issues.

But safety is always the first priority. Understanding when to take care of things on your own and when to contact a licensed engineer is essential. The purpose of this guide is to provide you with the information you need to manage the health of your boiler. Thus, let’s begin the process of restoring warmth and coziness to your house with the least amount of disturbance.

Features of operation and diagnostics of boilers "Vailant"

Error diagnostics and adjustment programs are the two levels of information displayed on boilers with installed monitors. Users will require the first, and the service center masters will require the second. Automation records the history of failures, which is helpful for thorough diagnostics, examining recurrences, and precisely identifying the reasons behind the boiler’s inoperable state. Using the "info" and "-" button functions, the operator can view the top ten violations from the past 10 days. It is required to carry out an independent preliminary inspection of the boiler unit in order to determine its operability if the error messages show up on the scoreboard. The boiler’s primary self-diagnostic units are:

1. Check for tightness of all supply and return lines of the boiler: water, gas, electricity, gas path.
2. Check the presence of dirt in the furnace and gas ducts.
3. Check the electrical wiring, connector and plug connections.
4. Check the condensate drain line, if necessary clean the condensate drain trap from salt and limestone deposits.

Crucial! The need for yearly maintenance of the unit is established by the specifications for the safe operation of boilers with comparable heat output. The primary tasks include checking and regularly cleaning the furnace, heat exchangers, gas filters, and tank for excessive network water discharge.

Prevention

Preventive maintenance on the boiler is necessary, just like it is for any other appliance.

Boiler cleaning

Using a soft brush, remove any soot from the boiler’s exterior. Because the boiler plates are made of copper and have an unremovable anti-corrosion coating, hard cleaning is not permitted. The inability of the heat exchanger design to support internal flushing is a drawback, and using antifreeze or hard water to feed the circuit shortens the unit’s service life.

Combating deposits and limescale

Because hard water is constantly flowing through the DHW circuit in secondary DHW boilers, fouling becomes an even more significant issue. This implies that deposits and scale will cause it to become even more clogged. The manufacturer has addressed this issue and established procedures for routinely cleaning the DHW circuit’s heating surfaces. With the addition of particular agents to the coolant in circulation, it can be done with the assistance of a booster.

After that, let the solution run for a few hours to dissolve and remove the scale.

Kindly take note! Furthermore, it’s advised to keep the hot water supply in low temperature mode so that it doesn’t need to be diluted with cold water. This will essentially result in a zero intensity of scale formation, which begins at 60 °C.

Maintenance of the expansion tank

Every year, expansion vessels require maintenance. In order to achieve this, the boiler is filled with water to the system’s working pressure of 1-1.2 bar. Should water emerge from the expansion tank’s control outlet, the tank’s diaphragm seal has been compromised and needs to be replaced.

Burner and filters

The screens that serve as filters on the gas line are removed for maintenance and then cleaned with water. Over time, combustion products clog the gas burner as well. To clean it, use a vacuum and a soft bristle brush.

The most common error codes are

The most common reason for Vaillant functional failures is incorrect equipment installation and adjustment. For instance, a gas analyzer is needed to adjust the burner and gas valve on boilers. Every time the boiler "Vailant" displays error f28 during startup, the same action needs to be taken. Common categories of errors:

• circulation pump malfunction;
• modulation mode stopped;
• clogged heat exchanger tube system.

An incorrect adjustment is a violation of the technological mode specified in the unit’s passport documents by the manufacturer. This approach leads to failure:

• control unit;
• of the motor;
• of the igniter;
• Gas shut-off valve.

Vaillant shows error information on the control panel in the event that a fault is found.

Vaillant error decoding

1. F20 – It is quite a rare error and indicates overheating of the boiler equipment, for example, the heat exchanger is clogged with limescale, due to which the water circulation is disturbed and the temperature rises sharply. At this point, the STB temperature indicator is triggered and the boiler will shut down protectively. Causes – can occur with a faulty sensor or weak contact of the NTC.
2. F22 – signals a lack of coolant in the boiler circuit. Failure appears due to a failure of the pressure sensor or malfunction of the pump, which does not create the necessary pressure. The same failure can occur in case of incorrect connection of sensors installed on the supply and return lines or in case of breakage of connecting electric wires. If the cause is insufficient water, you can try adding water to the system. If this does not remove the error signaling, it will be necessary to perform diagnostics of the components – water pressure sensor, pump electric line and electronic board.
3. Vaillant boiler f28 error, the most common when it fails to make the device ignite. Officially it is considered that such an error requires a call to the service center, but practitioners believe that sometimes the device does not work by accident and the failure can be eliminated independently. Problems affecting the error f 28 boiler "Valiant": no gas access to the burner device, broken gas shut-off valve, poor grounding of the circuit, low gas pressure after the gas valve, defective igniter, a problem with the ignition control board.
4. F29 – this code is also related to the burner operation, it appears if there were three unsuccessful ignition attempts, or the flame goes out in the operating mode. Main causes: low gas pressure upstream of the burner, stuck valve or debris clogged orifices, faulty ignition transformer or equipment grounding. Diagnostics is performed by the operator himself.
5. F33 – the error is inherent only for turbo models. The electric signal comes from the pressure switch and is related to a violation of the start-up technology: at the request for ignition, the CU starts the smoke evacuator, which creates a vacuum. When the draught is created, the relay contacts are closed, they transmit a signal to open the valve and the igniter to ignite the burner. If there is no such signal, the screen displays – f33. Main causes: fan/flue gas pump is not working, pressure switch is defective, flue gas circuit installation error, chimney clogging, "sticking" of relay.
6. F36 means the boiler room is gassy due to flue gases entering the boiler room. The sensor is triggered at low draught values. Causes: leakage in the flue gas path, blocked chimney or lack of ventilation. To eliminate the failure, it is necessary to clean the chimney and flue pipe, turn on ventilation in the room and open a window for fresh air access.
7. F37 indicates a deviation of the fan speed limits, the failure may be due to a faulty pressure sensor. Inspection is carried out independently, in case of confirmation of the breakdown call a specialist.
8. Error f75 of boiler "Vailant" means low pressure of circulation water in the pipe, can be due to a blockage of the heating system, poor operation of the pump or water sensor. To eliminate this fault, open the bypass line, it will also be necessary to vent the expansion tank on the return line.

Other possible malfunctions and remedies

Occasionally, the boiler display stops working, making it impossible to log faults. The most likely reason will be a malfunction with the board itself if the user is certain that the boiler control board is receiving power and that it is connected to the network correctly.

Kindly take note! Regretfully, internal board functionality failures cannot be recorded using the boiler software. Sometimes infractions are visible, but the boiler will not be able to operate.

Additional error codes that could exist:

1. F49 – bus voltage drop on eBUS due to short circuit.
2. F63 – EEPROM, failure of electronic control unit. If a failure occurs, pressurize the medium to check the correct operation of the circulation pump and the condition of the expansion tank.
3. F64 – electronics does not work due to a short circuit of the pressure sensor on the supply or return pipe.
4. F65 – overheating of electronic boards. In case of failure or poor operation of electronic equipment test the software, check the state of contact groups, the operating parameters of the electrical network, the functionality of the stabilizer.
5. F67 – violation of burner flame control signal. In case of alarms from the burner unit or from the draught indicator in the furnace, first of all clean the chimney and the condensate drain, which may be clogged with lime scale buildup.

Kindly take note! You can independently press the "Failure removal" button, which has the image of "fire with a cross," before contacting the service center. It is worthwhile to contact a qualified specialist if the unit is not functioning, particularly if the boiler is still covered by warranty.

It will be necessary to disassemble the boiler in order for the arriving specialists to diagnose all boiler equipment. The state of the electrodes and wiring feeding the electronic board will then be examined, along with the ground loop’s dependability, the pressure of the gas fuel, and the functionality of the valve on the gas line upstream of the boiler. The electronic board of the boiler control unit will need to be checked, repaired, or replaced if these units pass inspection and testing without displaying any problems.

Correcting problems with Vaillant boilers is essential to keeping your home’s heating system dependable and effective. Knowing the common types of faults, like thermostat malfunctions, pressure issues, and ignition failures, gives homeowners the ability to recognize early warning indicators of problems. By taking preventative measures, you not only prolong the boiler’s lifespan but also improve the general security and comfort of your home.

It’s critical to distinguish between straightforward solutions that homeowners can safely perform on their own and more complicated issues that call for expert assistance when dealing with boiler problems. Some people may be able to perform tasks like checking the pressure or resetting the boiler. Still, it is definitely best to leave handling internal component failures and problems with the gas supply to qualified technicians. This complies with warranty requirements and safety regulations in addition to guaranteeing a proper fix.

It becomes clear that preventive maintenance is essential to avoiding most boiler malfunctions. Setting up yearly examinations with a licensed specialist aids in identifying possible problems before they develop into serious defects. Furthermore, by keeping the boiler operating efficiently, these maintenance procedures can lower energy costs and lessen their negative effects on the environment. It’s a tiny investment that yields significant benefits in terms of dependability and comfort.

The ultimate objective is to guarantee that your Vaillant boiler runs efficiently for the duration of its life, giving you hot water and steady heat when you need it. Homeowners can enjoy a warm, comfortable home even in the coldest months by knowing how to handle common mistakes and when to call in experts. The efficiency and safety of home heating practices are ensured by this balance of professional support and knowledge.

Homeowners who have Vaillant boilers frequently deal with a range of typical issues that can impair heating comfort and efficiency. This post will walk you through the process of locating and resolving these common errors, which can range in complexity from more intricate issues like display error codes or ignition failures to more straightforward ones like pressure drops or thermostat malfunctions. It is possible to prevent expensive professional repairs and ensure your boiler functions dependably and efficiently by being aware of the signs and fixes for these problems.

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