Maintenance and repair of gas boilers "Buderus": methods for dealing with typical breakdowns

Amir Gumarov
Checked by a specialist: Amir Gumarov
Author: Tatyana Zakharova
Last update: December 2019

The popularity of the Buderus technique is well founded. Boilers for 100% cope with the tasks, work out the due time, economically consume fuel. But even the most reliable units sometimes fail for various reasons: due to wear of parts, poor-quality coolant or the fault of users.

We will tell you how to service and repair gas boilers Buderus. We will show you which nodes fail more often. We will analyze in which cases you can fix the unit yourself, and in which you need to call the master from the gas service.

In our article you will find a decryption of the codes laid down by the manufacturer for the rapid detection of violations in work. We have described ways to solve problems. Our recommendations on the operation of the equipment will extend the life of the boilers and reduce the number of calls to repairmen.

Gas boilers "Buderus"

Natural gas remains the cheapest fuel, so the popularity of gas boilers is only growing. Single-circuit gas units are used in heating. Double-circuit floor or wall models easily cope with two functions necessary for a comfortable stay in a private house: heating and hot water heating.

The production of gas household and industrial appliances of the Buderus brand is handled by the well-known company Bosch Thermotechnik GmbH. In addition to gas units, electric, solid fuel and diesel-fired boilers are also manufactured.

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

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

Current gas-powered models can be divided into 4 groups:

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

The choice of model according to the placement method depends on the power of the unit. In the apartments of the old housing stock, the number of storeys up to five, and in small-sized country houses are used wall units. Large private buildings, commercial enterprises, production workshops are equipped, installing floor options.

Design features are not fundamental, but they still exist, but faults are usually the same, as are the ways to eliminate them.

For the good functioning of the gas boiler everything is important: the correct installation of the unit and chimney, regular maintenance, compliance with operating rules, timely cleaning and replacement of parts, high-quality fuel.

If at least one item fails to meet the requirements, damage may occur. The most common of them:

Often, difficulties in operation arise simply by inattention, when the user forgets to turn the gas valve or turn on the electricity. More information about breakdowns and their ways to fix them is below.

Common troubleshooting and repair tips

A malfunction is considered typical if it can occur at the boiler of any modification - these are problems with the burner, combustion chamber, fuel supply, security system, electronics, sensors, etc.

Some problems are solved simply - by cleaning, tightening the contacts or reinstalling the part, you can fix them yourself. If a more serious repair is needed to repair, we recommend contacting a service center.

Burner does not turn on after servicing

Often after repair work, the boiler does not want to turn on, ignition does not occur, while no errors are indicated on the display.

Cladding gas boiler
If you decide to flush the pipeline or change radiators, and for this you turn off the boiler and lower the coolant, then after filling the system with water again, attempts to turn on the boiler may fail

And it's all about the emergency thermostat. We will tell you how to repair and turn on the Buderus gas boiler after a forced shutdown.

Temperature limiter STB
The Logamatic control system has an STB safety temperature limiter. It is located to the left of the water regulator, under the cap. To return the limiter to its working position, it is necessary to remove the cap and press the button, then restart the unit

If after pressing nothing has changed, you need to change the overheating sensor - it is better in the service center, with a guarantee for the work performed.

There are other possible causes of downtime.

What can be done:

  • turn on the start and emergency switches;
  • check the operation of the circuit breakers, in case of malfunction - replace;
  • check if the control system of the combustion products is functioning correctly, after it is blocked, restart it and wait 15 minutes.

Modern devices have a restart button. It is always recommended to use it in case of any kind of malfunction.

Many units do not need intervention and restart themselves.With multiple idle startup, the equipment must be shown to the employees of the service workshop.

No spark and flame when ignited

If the start-up process occurs in the operating mode, but the flame does not appear due to the absence of a spark, it is necessary to disconnect the ignition cable, repeat the inclusion and listen.

The absence of sound, a kind of click, indicates a breakdown of the ignition transformer that needs to be replaced. If there is sound, but the spark does not fly out, replace the ignition burner or electrode.

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

Perhaps the reason is elementary - they just forgot to turn off the gas valve. Open the valve and try starting again.

Air plugs can also prevent ignition. It is recommended to bleed air from radiators and system through Mayevsky cranes, inspect the automatic air vent, then try again to light the burner.

Ionization Current Problems

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

Wires connected to the control board
Perhaps it is a matter of poor contact - during the period of operation, the terminal connections are often loosened, and the wiring falls out. Tighten all connections or replace defective item

Due to damage, a short to ground can occur; damage to the ionization electrode should be repaired. If the ionization current does not reach 1.5 mA, you need to clean - remove dirt from the ceramic part or the core of the ionization electrode. You may need to replace the ignition burner.

Extraneous noise in the unit

If the sound of boiling is clearly audible, it is necessary to thoroughly clean all components and parts in contact with the coolant. Usually with regular cleaning, which is carried out once a year, this problem does not happen.

Buderus boiler heat exchanger
To a greater extent, pollution by mineral formations occurs in the heat exchanger, where hot water is constantly circulating. Scale is deposited literally on all elements of the site

What should be done:

  • remove the unit lining;
  • dismantle the heat exchanger;
  • to clear all elements of a scum by a special means;
  • put the part in place.

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 water noise is heard during heating, which lasts longer than programmed, check the settings. Perhaps the problem is the pump’s malfunction - you need to check how the turbine functions, adjust the speed.

Error codes and instructions for resolving them

Modern gas boilers are able to inform the user about a malfunction, and some breakdowns can be fixed independently, with the help of a stop and a new start.

Buderus boiler digital display
If the unit cannot cope, and an error is displayed, then proceed according to the instructions, and if necessary, contact the technical service

Error codes are alphanumeric characters that indicate the type of malfunction. Among them there are simple ones that require a reboot or cleaning, but there are also complex ones that make it necessary to diagnose all units of the unit. Consider the most significant and frequently occurring errors.

0Y - temperature increase above the operating settings (at a rate of + 95 ° C). If the boiler does not automatically turn off, turn it off manually, check the health of the sensors and the settings that have been set.

You should also check the pump, connecting it to the main regulator. Adjust the power of the pump.

2P - a sharp increase in hot water temperature.Check that the pressure matches the operating parameters, check the pump, and repair if necessary.

H11 - problems with the hot water sensor. Check the operation of the temperature sensor, as well as the contacts of the connecting wires. Replace defective parts.

3A - the fan does not start. Check contacts, wire connection. If the assembly is defective, replace it.

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

4C - overheating of the heat exchanger. Carefully inspect the loop and sensors, release air from the system, check the pressure in the network. If everything is normal - the problem is in the water unit of the radiator or pump, disassembly and repair are required.

6A - no ignition, no flame. Unscrew the gas valve to the maximum, check the pressure.

Gas boiler draft reminder poster
If there is a suspicion of lack of draft, check if it is in the chimney. You can use a lit match - an even flame indicates contamination of the chimney, fluctuating - a good draft

It is also recommended to diagnose the flow switch, check and, if necessary, strip the contacts of the electrodes, brush off the deposits from the burners, and if the burner malfunctions, install a new assembly.

6C - the system detects a flame when the boiler is off and gas is shut off. Check whether the chimney is working and the contacts are not oxidized. Perhaps due to condensation, moisture appeared on the board, which needs to be dried, and at the same time check the purity of the condensation siphon.

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

After replacing some components - for example, a fan or a pump - the unit must be put into operation. After self-repairing a gas boiler, Buderus does not always succeed in getting it to work properly due to “flown” settings. We advise you to call a wizard who will check the correct connection and reconfigure the unit.

Boiler service recommendations

In addition to proper operation, regular maintenance of gas equipment is necessary. According to our rules, the rights and obligations to conduct inspection and repairs are transferred to the organization with which contract signed for the supply of blue minerals, installation and connection of the boiler.

The master repairs the boiler Buderus
Equipment manufacturer Buderus insists on transferring service rights to a service organization, among whose employees there are masters accredited by the company. This is dictated by the requirements for operational safety and proper maintenance of equipment.

For self-service, the manufacturer's recommendations must be followed.

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

  • Perform thermal disinfection - flushing the hot water system at maximum temperature.
  • Regularly clean the lining - wipe with a damp cloth, without the use of abrasive detergents.
  • Check the operating pressure in the network using a manometer (norm - from 1 to 2 bar).
  • If necessary, add water to the heating circuit.
  • Remove air from the unit if water heating does not occur evenly.
  • Check the exhaust system of the combustion products, and if parts with corrosion are found, replace them.

Cleaning internal components can also be done on their own. But before disassembling the boiler, make sure that the gas valve is closed and the voltage is turned off.

Usually, buderus gas boiler malfunctions such as sensor “sticking” or chimney blockage are usually handled independently.

Conclusions and useful video on the topic

Boiler maintenance - disassembly sequence and inspection:

Dismantling and cleaning parts of the wall model:

Universal variant of washing the heat exchanger:

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

You can independently understand the design, characteristics and functions of the boiler, 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 unit be serviceable and safe, cope with its task and not pose a threat to the residents of the house.

Please leave comments in the feedback box below. Share your own experience in servicing gas boilers. It is possible that your tips will be useful to readers of our site.

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