German Buderus boilers are productive, powerful equipment. It is popular not only in private houses and apartments, but also in production. A “smart” control system controls the operation of the heater - in case of problems, a special code is displayed on the display. What do Buderus boiler errors mean? What should I do to restore the operation of the equipment? We will describe in detail how to deal with the problem.
Features of Buderus boilers
The German company Buderus produces boilers that operate on almost any type of fuel - solid fuel, using firewood, coal, briquettes, coke as fuel, liquid fuel, diesel, gas and electric. The most popular are solid fuel and gas.
Solid fuel ones are completely autonomous, can work without additional energy sources (without electricity), using various types of fuel - wood, coal, coke, briquettes, peat. They have a long combustion cycle, thanks to the large loading chamber and ash pan. Buderus solid fuel boilers are used both as an autonomous heating system and in conjunction with units that run on gas or diesel fuel.
Suitable for systems operating with a pump and for systems in which circulation occurs due to the temperature difference between hot and cold water, for open systems or with an expansion tank. They have compact dimensions and can be installed even in small spaces.
Gas boilers are the most common due to the availability and relatively low price of gas. By type of installation they are divided into wall-mounted and floor-mounted, and by type of use into single-circuit and double-circuit. Despite their small dimensions, wall-mounted boilers have a large power range - from 14 to 100 kW, the most popular are Buderus units with a power of 24 kW.
Gas boiler Buderus
Floor-standing boilers can be used in residential premises and in production, and have a large power range of up to 38 mW. Like all gas equipment, Buderus Logomax boilers are equipped with an automatic control system. During operation, the system displays data about errors and malfunctions.
Connection instructions
The Buderus boiler is connected after installation on a solid wall or a special ramp.
All communications are connected:
- Forward and return lines of the heating circuit.
- Water supply.
- Gas pipeline.
- Power supply.
Particular attention is paid to the condition of gas pipeline connections. They should be checked with a soap solution to detect leaks
Then the power supply is connected through a special socket with a grounding electrode.
The boiler starts after the system is filled with water. It is poured using a refill tap, bringing the pressure to approximately 0.8 bar.
This is necessary in order not to exceed the pressure when heating, so the water will expand. After filling the system, the boiler is turned on and the required coolant temperature is set. The burner will start and the boiler will start working.
When starting for the first time after a long period of inactivity, you often have to make several startup attempts due to air locks in the system. When they are all removed, the operation of the unit will be stable and smooth.
The most common error codes and troubleshooting methods
Using the example of one of the company's most popular units - Buderus Logamax U042 24K and Buderus Logamax U072, let's look at the most common error codes for the Buderus boiler.
Error 6a
appears on the display when there is no gas supply. There can be many reasons for this situation. First, you should check whether the gas valve is open. If the tap is open and the system generates an error, check the reliability of the connection of the protective wire, the pressure in the gas line corresponds to the nominal one, and if a drop in pressure is detected, adjust it.
The reason may also be a lack of power supply or a violation of the draft in the chimney - check the draft with a lit match or candle. If the flame does not deviate towards the chimney, it means it is clogged and needs to be cleaned. Check the gas flow control relay; if faulty, replace the relay.
Inspect the connections of the electrodes with the wires; if the contacts are dirty, clean them, connect them if the contacts are broken. If you have not carried out a technical inspection for a long time, your heat exchanger may be dirty, clean it as described in the instructions for the boiler.
The cause of the malfunction may be contamination of the burner jets; they should be cleaned with a brush. The gas block may break down; it is practically beyond repair and will have to be replaced. Sometimes the reason may be the lack of natural ventilation in the room where your unit is installed; open the doors, window or window.
Error 3y
also often appears on Buderus Logomax devices. This malfunction occurs when the differential relay does not operate when the fan is turned off, or the fan operates at too high speeds, you need to check the relay and, if necessary, replace it.
Error 4c
means that the heat exchanger temperature limiter has tripped. This happens when the pressure in the heating line drops - check and adjust the pressure when there is not enough water in the system - note that you can only add water to a cooled boiler so that cracks do not form in the heat exchanger due to temperature differences.
Buderus boiler control system
The thermostat itself may fail, it cannot be repaired, it needs replacement, the connection may burn out or oxidize, clean the contacts and connect them. The cause of the malfunction of the Buderus mounted unit, if code 4c appears on the indicator, may also be a breakdown of the pump; replace it.
When the boiler becomes airy, bleed the air from it; the procedure is described in the instructions for the device. Check the flue gas temperature sensor and its connection to the wires; if you notice a malfunction, oxidation or break, repair it. The error also occurs when the fuse burns out; replace it; and if the integrity of the water heat exchanger is damaged, it will either need to be soldered or replaced.
1н (1h)
Error 1h or error 1h appears on the display when the flue gas temperature is exceeded. The gas burner turns off due to the high temperature of the combustion products, possibly due to contamination of the boiler.
It is necessary to clean the boiler; detailed recommendations for this procedure can be found in the instructions. The flue gas sensor may be faulty, replace it. If such a situation occurs when the unit is turned on for the first time, this may also indicate an incorrectly designed, too narrow chimney.
2e
Signals a malfunction on Buderus Logomax u042 24k boilers when the temperature in the supply flow rises too quickly. When error 2e appears on the display, water heating stops for 2 minutes.
Boiler panel Buderus Logamax U042-24K
What to do if this happens? To eliminate this, check the water pressure in the system and top it up if necessary. The second reason may be pump blockage; eliminate it.
2p
Error 2p - signals an excessively rapid increase in temperature in the heating circuit. To eliminate it, you should open the service taps, check the water pressure in the system, clean the filters, check the functionality of the pump, and check the pump connection.
3a
Error 3a means that the fan is not working. The cause of the malfunction in the Buderus Logomax u042 24k and Buderus Logamax U072 boilers may be sticking contacts of the differential relay; check the relay; if repair is impossible, replace it. Perhaps the contacts in the electrical wiring are broken or the connecting hoses have come loose.
It is possible that the fan itself has broken down - repair or replace it. The error appears on the display and then, when the draft in the chimney is broken, check the tightness of the connection using a probe with an annular slot, clean the chimney pipes if they are clogged.
3c
The causes of the malfunction in the event of error 3c are similar to the reasons for error 3a, as well as the methods for eliminating them. Another factor, if this code appears on the indicator, can sometimes be the formation of condensation on the differential relay. To fix it, remove the relay, dry it with a hairdryer and reinstall it.
3y
When the fan starts running too fast, error 3y appears on the display. Check the fan and exhaust system.
4c
The reasons for the appearance of code 4c on the display and troubleshooting methods are described above, in the most frequently repeated errors.
6a
Code 6a is also one of the most common errors; why it appears and how to fix it is described above.
def
Error def means burner error, lack of flame ionization, can occur after the gas is turned off or when the gas pressure in the system does not match the nominal one. In this case, you should call specialists from the gas service to measure the pressure in the system and adjust it.
fd
When you press the button for more than 30 seconds, error fd appears on the Buderus Logomax u072 display. To eliminate it, you need to press the button again for less than 30 seconds.
Before proceeding with inspection and repair, in the event of a malfunction, it is necessary to reset the error by pressing and holding the “Reset” button for 5 seconds, when the indication stops flashing and temperature values appear on the display. And if the failure continues, proceed to find and fix the problem.
Error 2E (the first three indicators blink)
The logic of the error is that the supply temperature rises too quickly, i.e. The coolant at the outlet of the heat exchanger heats up too quickly and to prevent emergency overheating, the operation of the boiler is blocked for two minutes. The main reason for this behavior of the boiler may be poor coolant circulation. Poor circulation can most often be caused by:
- circulation pump malfunction or insufficient performance
- heat exchanger clogged with dirt or scale
- air in the heating system
In this article we looked at the most common malfunctions of Buderus gas boilers. A complete list of errors is contained in the equipment operating manual. Modern gas engines are designed so that the elements are as accessible as possible for ease of service. The user can eliminate some errors independently, for example, refill the boiler or inspect the chimney for blockages.
Any actions for self-diagnosis should be taken only in case of urgent need and in compliance with precautions and safety measures. If you do not have an idea of the operating principles and design of a gas boiler, it is better to call a qualified specialist. The Buderus company posts educational videos in which a specialist talks, including about boiler errors that occur.
Sources
- https://www.tproekt.com/gazovyj-dvuhkonturnyj-kotel-buderus/
- https://thermo-lider.ru/gazovye-kotly/oshibki-gazovykh-kotlov/oshibki-gazovykh-kotlov-buderus/buderus-kotel-oshibka-6a/
- https://boilervdom.ru/kotly/kody-oshibok/kody-oshibok-kotla-buderus-buderus-chto-delat-v-konkretnoj-situacii.html
- https://cosmo-frost.ru/gazovye-kolonki-i-kotly/neispravnosti-gazovye-kolonki-i-kotly/kody-oshibok-i-neispravnosti-gazovogo-kotla-buderus/
- https://teploservice-ovk.ru/kod-oshibki-kotla-buderus-logamax-u072/post/chto-delat-kogda-kotel-buderus-logamax-u072-vydaet-oshibku-6a
- https://zen.yandex.com/media/bosch_climate/oshibka-6a-kotla-buderus-kak-borotsia-5e7cc025b0d2c37f5d219d0b
Other breakdowns
In addition to those described above, automation can also give signals about other malfunctions on gas boilers:
- Code 4Y appears on the display after a drop in coolant temperature, for example, after a power outage.
- The CL code means the hot water sensor is faulty. The reason may be a short circuit between the sensor and the wire, in which case the sensor will have to be replaced.
- The value 9C lights up on the display if the DIP switches are incorrectly set (there are 8 of them on the Buderus Logomax u042 24k model). Conduct the settings according to the table in the device instructions.
- The CP code is displayed when the automation does not see the temperature sensor. In this case, you should check the sensor connection contacts and its serviceability. The sensor cannot be repaired, only replaced.
- Code d7 indicates a malfunction of the gas fittings. Check the gas connection and the functionality of the gas block; if the block is faulty, it will have to be replaced.
- Code C7 indicates a fan malfunction. Check the serviceability of the fan, its wires and plug.
There are problems that the display does not detect. For example, if you hear loud water noise or the water takes too long to heat up, you should adjust the pump speed. If the outlet water temperature is insufficient, check the turbine and replace it if necessary.
If you have problems with ignition, you need to check the gas pressure, whether the electricity is turned off, see if the connections of the electrodes with the wires are oxidized, if the chimney is clogged and sealed, and if the burner is clogged.
Problems not shown on the display
When they occur, the Buderus error is not displayed, but a number of signs indicate incorrect operation of the boiler or the entire heating system.
Adjusting the circulation pump
1. Slow heating of batteries; noise of fluid circulating along the circuit. The main reason is the incorrectly set pump speed. The switch is located on its body.
2. “Difficult” ignition, boiler efficiency is lower than declared. There are several options: from poor burner performance to the use of gas with characteristics that do not meet the manufacturer’s requirements.
Recommendation : carry out Buderus service, check the set parameters.
The article provides explanations for all problems that can be resolved independently. It’s better not to go deeper - the boiler is expensive, and unprofessional intervention in its operation will not lead to anything good.
Kinds
Buderus double-circuit boilers are predominantly wall-mounted.
All floor-standing installations are single-circuit, but have the ability to connect an external indirect heating boiler, which allows you to obtain a full-fledged hot water circuit. There are different design options for dual-circuit installations.
According to the type of thermal energy transfer, they are:
- Convection. Heating is carried out in the usual way, in the flame of a gas burner.
- Condensation. A new technology that makes it possible to use thermal energy obtained by condensing water vapor contained in flue gases. The coolant is preheated in the condensation chamber, due to which it enters the primary heat exchanger already prepared. As a result, it becomes possible to reduce the intensity of the main heating, reduce gas consumption and achieve an efficiency of 108%.
NOTE! From a theoretical point of view, such efficiency is impossible. This is a common marketing ploy designed to increase demand. However, condensing boilers can only operate effectively under appropriate conditions - if the indoor temperature is +20°, then the temperature outside should not be below 0°, otherwise the boiler will work like a regular convection unit
However, condensing boilers can only operate effectively under appropriate conditions - if the indoor temperature is +20°, then the temperature outside should not be below 0°, otherwise the boiler will work like a regular convection unit.
According to the type of combustion chamber there are:
- Open (atmospheric). Air enters the boiler directly from the room, and smoke is removed using natural draft.
- Closed (turbocharged), the air supply and smoke exhaust are produced by a turbocharging fan.
For use in private houses or apartments, turbocharged boilers are more convenient, which are capable of providing stable draft that is independent of external conditions.
Removing the sensor
The water sensor is secured by a small bracket; to remove it, you need to lift it and remove the sensor itself from the hydraulic group. After replacing the sensor, the installation procedures must be repeated in the reverse order, not forgetting to secure it with a bracket and connect the power connectors.
After replacement, you need to check the functionality of the sensor and whether error 2e will be displayed again on the information panel. To assemble, you need to install the front panel in reverse order, attach it to two self-tapping screws and install the information panel.
To turn on the boiler, you need to open the water supply tap to the heating system, then open the system feed tap and raise the water pressure in the boiler to 1.5 bar. After which you can connect the boiler to the power supply system and turn it on.
