Maintenance And Repair Of Gas Boilers "Buderus": An Overview Of Typical Malfunctions And Ways To Fix Them

The popularity of Buderus technology is well founded. The boilers are 100% up to the task, they work for their due time, they consume fuel economically. But even the most reliable units sometimes fail for different reasons: because of details wear, low-quality coolant or due to users fault.

We will tell you how to service and repair gas boilers Buderus. We will tell you which parts fail more often. We'll understand in which cases you can repair the unit with your own hands, and in which cases you need to call a master from the gas service.

In the article we offer you will find the deciphering of codes, laid down by the manufacturer for the rapid detection of malfunctions. We describe the solutions to the problems. Our recommendations for equipment operation will extend the life of your boilers and reduce the number of visits to the repairmen.

Content of the article:

  • Buderus gas boilers
  • Common malfunctions and repair tips
    • Burner won't turn on after service
    • No spark or flame when ignition
    • Ionization current problems
    • Unusual noises in Appliance problems
  • Error codes and instructions for solving them
  • Boiler maintenance recommendations
  • Conclusions and useful video on the subject

Buderus gas boilers

Natural gas is the cheapest fuel, That's why gas boilers are only growing in popularity. Single-circuit gas units are used for heating. Two-circuit floor-standing or wall-mounted models easily cope with two functions necessary for comfortable living in a private house: heating and hot water heating.

The production of gas household and industrial appliances of the Buderus brand is engaged in the well-known company Bosch Thermotechnik GmbH. Besides gas units, electric, solid fuel and diesel boilers are also produced.

Maintenance and repair of gas boilers

Buderus gas models are the largest group of heating equipment. This is due to the popularity of machinery produced specifically for the climatic conditions of Russia

Boilers are diverse in design and method of installation, come in single- and double-circuit, with an open or closed combustion chamber.

Gas-fired models can be divided into 4 groups:

  • wall condensing;
  • wall traditional;
  • floor condensing;
  • floor cast iron atmospheric.

The choice of the model according to the installation method depends on the boiler capacity. In old apartments, up to 5 storeys, and in small country houses wall mounted units are used. Large private buildings, commercial enterprises, industrial workshops are equipped, installing floor versions.

Features in design are not fundamental, but still there are, but the faults are usually the same, as well as ways to fix them.

For good performance of the gas boiler everything is important: correct installation of the unit and chimney, regular maintenance, observance of operating rules, timely cleaning and replacement of parts, quality fuel.

If at least one item ceases to meet the requirements, breakdowns are possible. The most common ones are:

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Mineral contamination of the heat exchanger

The burner does not light or goes out

Sensor wire contacts disconnected

Faulty electronic control board

Frequently operational difficulties arise simply from inattention, when the user forgets to turn the gas tap or connect the electricity. More details on the breakdowns and how to fix them are below.

Common faults and repair tips

Faults are considered typical if they can occur with any boiler modification - problems with burner, combustion chamber, fuel supply, safety system, electronics, sensors, etc.

Some problems can be solved simply by cleaning, tightening the contacts or reinstalling the part, they can be fixed by yourself. If a more serious repair is needed, we recommend that you contact a service center.

Burner does not turn on after service

It is not unusual that after repair work the boiler does not want to turn on, no ignition occurs, with no errors indicated on the display.

Maintenance and repair of gas boilers

If you decided to flush the piping or change the radiators, and for this purpose you shut down the boiler and drained the heating medium, then after back filling the system with water the attempts to turn on the boiler may end in failure

All this is because of the emergency thermostat. Let's tell you how to repair and turn on the Buderus gas boiler after a forced shutdown.

Maintenance and repair of gas boilers

The Logamatic control system has a safety temperature limiter STB. It is located to the left of the water regulator, under the cap. To reset it, remove the cap and press the button, then restart the appliance

If nothing changes after pressing it, the overheating sensor must be replaced, preferably at a service center, with a guarantee on the work carried out.

Some other reasons for downtime are possible.

What can be done:

  • Break stop and emergency stop;
  • Check breakers; replace if faulty;
  • Check if the flue gas control system is working properly, restart after locking and wait 15 minutes.

The modern appliances have a restart button. It is always recommended to use it when various kinds of malfunctions occur.

Many units do not need intervention and restart themselves. If the appliance has repeatedly started without any spark, it must be taken to a service workshop.

No spark or flame during ignition

If the ignition process is in working order but the flame does not appear because there is no spark, disconnect the ignition cable, switch on again and listen.

The absence of a clicking sound indicates a defective ignition transformer which must be replaced. If there is sound but no spark, replace the ignition burner or the electrode.

Maintenance and repair of gas boilers

Original AE ignition device for gas boiler Buderus. The cost of the new service set is 8,400 rubles. To save money you can buy a Chinese analogue, but the quality will be lower

Maybe the reason is elementary - you just forgot to unscrew the gas valve. Open the valve and try again.

Air congestion may also prevent the ignition. It is recommended to bleed the air from the radiators and the system through the Mayevsky taps, inspect the automatic air vent device, then try again to ignite the burner.

Ionisation current problems

The unit will not work if L and N are accidentally mixed up during connection, or if voltage has set between PE and L. It is recommended to reconnect the wires and check grounding, and if necessary, install an isolation transformer.

Maintenance and repair of gas boilers

This may be a loose contact - terminal connections often become loose and wires fall out during use. Tighten all connections or replace the defective element

If there is a ground fault, the ionization electrode must be repaired. If the ionization current does not reach 1.5 mA, the ceramic part or the core of the ionization electrode must be cleaned. It may be necessary to replace the ignition burner.

Unit noises

If you can clearly hear boiling sounds, it is necessary to thoroughly clean all units and parts that are in contact with the coolant. Usually with regular cleaning, which is done once a year, this problem does not occur.

Maintenance and repair of gas boilers

More contamination by mineral formations occurs in the heat exchanger, where hot water is constantly circulating. Scale builds up on literally all elements of the unit

What to do:

  • dismantle the unit liner;
  • dismantle the heat exchanger;
  • clean all elements from scale with a special agent;
  • replace the part.

In order to reduce the amount of deposits to a minimum, we recommend installing filters that reduce the concentration of salts in the water.

If you hear water noise when heating for longer than programmed, you should check the settings. It may be that the pump is not working properly - check the functioning of the turbine and adjust the speed.

Error codes and troubleshooting instructions

Modern gas boilers are able to inform the user about the malfunction and some malfunctions can be solved by themselves, by stopping and restarting.

Maintenance and repair of gas boilers

If the unit fails and an error is displayed, act according to the instructions and, if necessary, contact the technical service

The error codes are alphanumeric symbols indicating the type of fault. Among them, there are simple ones that require resetting or cleaning, but there are also complex ones that make it necessary to diagnose all units of the unit. Let's consider the most significant and frequent errors.

0Y - temperature increase above the working settings (at normal +95°C). If the boiler does not shut off automatically, switch it off manually, check the sensors and the settings are correct.

You should also check the pump, its connection to the main regulator. Adjust the capacity of the pump.

2P - sudden increase in DHW temperature. Check that pressure is within operating parameters, check pump operation, repair if necessary.

H11 - Hot water sensor malfunction. Check the operation of the temperature sensor as well as the contacts of the connecting wires. Replace defective parts.

3A - Fan does not start. Check contacts, wire connections. If the unit is defective, replace it.

3U - The fan speed is too high. Check the operation of the flue duct, clean if necessary.

4C - The heat exchanger has overheated. Carefully inspect the loop and sensors, bleed the system, check the mains pressure. If all is normal, the problem is in the radiator water assembly or pump, disassembly and repair required.

6A - no ignition, no flame. Turn the gas cock to the maximum, check the pressure.

Maintenance and repair of gas boilers

If you suspect there is no draft, check if it is in the chimney. You can use a lit match - a steady flame indicates a dirty chimney, a fluctuating flame indicates good draft

It is also recommended to diagnose the flow switch, check and if necessary clean the electrode contacts, brush away any deposits from the burners, and if the burner is faulty, install a new unit.

CThe system detects a flame when the boiler is off and the gas is shut off. You should check if the chimney is working and if the contacts are oxidized. Condensation may have caused moisture on the board which needs to be dried and the condensation trap cleaned.

9L - gas fitting malfunction. A thorough check of the fittings and wiring, repair and replacement is required.

After replacing some parts - such as the fan or pump - the unit needs to be put back into operation. After self-repair of the gas boiler Buderus is not always possible to make it work properly because of \"lost\" settings. It is advisable to call a service technician who will check the correct connection and re-set the appliance.

Boiler maintenance recommendations

Besides proper operation, it is necessary to service the gas equipment regularly. According to the rules in force in our country, the rights and obligations to carry out servicing and repairs are transferred to the organisation with which the boiler is contracted for the supply, installation and connection.

Maintenance and repair of gas boilers

Buderus equipment manufacturer insists on transferring the maintenance rights to a service organisation whose employees have been accredited by the company. This is dictated by the requirements of operational safety and proper maintenance of the appliances

If you do the maintenance yourself, you must follow the manufacturer's recommendations.

What can you do with your own hands, without involving gas workers?

  • Do the thermal disinfection - flushing the DHW system at maximum temperature.
  • Clean the liner regularly - wipe with a damp cloth, without abrasive detergents.
  • Check the operating pressure in the network using a manometer (normal 1 to 2 bar).
  • If necessary add water to the heating circuit.
  • Remove air from the unit if water heating is uneven.
  • Check the exhaust system and replace it if corroded.

Cleaning the internal parts can also be done by yourself. But before disassembling the boiler, make sure that the gas valve is closed and the voltage is disconnected.

Usually malfunctions of Buderus gas boilers such as a \"sticking\" sensor or a clogged flue pipe are handled by yourself.

Conclusions and useful video on the topic

Boiler maintenance - disassembly and inspection sequence:

Disassembly and cleaning of wall-mounted model parts:

Universal option of heat exchanger flushing:

Buderus gas boilers, due to their power, efficient operation and maintainability, are ideal for the equipment of heating systems in private homes. But they, like any other serious equipment, need regular maintenance.

You can understand the design, characteristics and functions of the boiler yourself, learn how to clean the heat exchanger and change spare parts, or you can conclude a contract with a service organization. The main thing is that the boiler must work properly, be safe, cope with its task and not endanger the residents of the house.

Leave your comments in the box below for feedback. Share your own experiences in servicing gas boilers. It is possible that your advice will be useful to the readers of our website.


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