Features of Buderus boilers

The German company Buderus produces boilers that operate on almost any type of fuel - solid fuel, using wood, coal, briquettes, coke, liquid fuel, diesel, gas and electric as fuel. The most popular are solid fuel and gas.

Solid fuel completely autonomous, can work without additional energy sources (without electricity), on various types fuel - wood, coal, coke, briquettes, peat. They have a long burning cycle, thanks to a large loading chamber and an ash pan. Solid fuel boilers Buderus are used both as an autonomous system for heating, and in conjunction with units that run on gas or diesel fuel.

Suitable for systems operated by a pump and for systems in which circulation occurs due to the temperature difference between hot and cold water, for open systems or with expansion tank. They are compact and can be installed even in small spaces.

Gas boilers are the most common, due to the availability and relatively low price of gas. According to the type of installation, they are divided into wall and floor, according to the 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 capacity of 24 kW.

Gas boiler Buderus

Floor boilers can be used in residential premises and in production, have a wide power range up to 38 mW. Like all gas equipment, Buderus Logomax boilers are equipped with automatic system control. During operation, the system displays data on errors and malfunctions on the display.

Most Common Error Codes and Troubleshooting

Using the example of one of the company's most popular units - Buderus Logamax U042 24K and Buderus Logamax U072, let's consider the most common Buderus boiler error codes.

Error 6a

appears on the display if there is no gas supply. There can be many reasons for such a situation. First, you should check if the gas valve is open. If the valve is open and the system gives an error, check the reliability of the protective wire connection, the compliance of the pressure in the gas line with the nominal one, if a pressure drop is detected, adjust it.

Also, the cause may be a lack of power, a violation of draft in the chimney - check the draft with a lit match or candle. If the flame does not deviate towards the chimney, then it is clogged and needs to be cleaned. Check the gas flow control switch, if defective, replace the switch.

Inspect the connections of the electrodes to the wires, if the contacts are dirty, clean them, connect in case of broken contacts. If you have not carried out a technical inspection for a long time, you may have a dirty heat exchanger, clean it according to the description 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. There may be a breakdown of the gas block, it is practically beyond repair, you will have to replace it. Sometimes the reason may be the lack of natural ventilation in the room where your unit is installed, open the door, window or window.

Error 3y

also appears frequently on Buderus Logomax devices. This fault occurs when the differential relay does not work when the fan is turned off, or the fan is running at too high a speed, you need to check the relay and replace it if necessary.

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 - keep in mind 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, a replacement is needed, the connection may burn out or oxidize, clean the contacts and connect them. The reason for the failure of the mounted Buderus unit in the event of the appearance of code 4c on the indicator may be a breakdown of the pump, replace it.

When airing the boiler, bleed the air from it, the procedure is described in the instructions for the device. Check temperature sensor flue gases and its connection to the wires, if you notice a malfunction, oxidation or rupture, eliminate it. The error also occurs when the fuse burns out, replace it and if the integrity of the water heat exchanger is violated, either soldering it or replacing it will be required.

1n (1h)

Error 1h or error 1h appears on the display when the flue gas temperature is exceeded. The gas burner is switched off due to the high temperature of the combustion products, possibly due to boiler contamination.

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 first turned on, this may also indicate an incorrectly designed, too narrow chimney.

2e

Indicates a malfunction on the boilers Buderus Logomax u042 24k when the temperature on the supply stream 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 happened? To eliminate it, you should check the water pressure in the system, if necessary, top it up. The second reason may be the blockage of the pump, eliminate it.

2p

Error 2p - indicates an excessively rapid increase in temperature in the heating circuit. To eliminate it, open the service taps, check the water pressure in the system, clean the filters, check the operation of the pump, the pump connection.

3a

Error 3a means that the fan is not working. The cause of a malfunction in the boilers Buderus Logomax u042 24k and Buderus Logamax U072 may be the sticking of the contacts of the differential relay, check the relay, if repair is not possible, replace it. It is possible that the contacts in the electrical wiring are broken or the connecting hoses have come off.

It is possible that the fan itself has broken - repair or replace it. The error appears on the display and when the draft in the chimney is broken, check the tightness of the connection using a probe with an annular gap, clean the chimney pipes if they are clogged.

3c

The causes of the malfunction in the event of error 3c are similar to the causes for error 3a, as well as the ways to eliminate them. Another factor, in the event that this code appears on the indicator, can sometimes be the formation of condensate on the differential relay. To eliminate it, remove the relay, dry it with a hair dryer and install it in place.

3y

When the fan starts to run too fast, error 3y appears on the display. Check fan and exhaust system.

4c

The reasons for the appearance of the code 4c on the display and the troubleshooting methods are described above in the most common errors.

6a

Code 6a is also one of common mistakes Why it appears and how to fix it is described above.

def

Error def means burner error, lack of flame ionization, may 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

If the button is pressed for more than 30 seconds, the error fd appears on the Buderus Logomax u072 display. To eliminate it, you need to press the button again for a time less than 30 seconds.

Before proceeding with the 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 the temperature values ​​appear on the indication. And if only the failure repeats, proceed to find and fix the problem.

Other breakdowns

In addition to those described above, automation can also signal other malfunctions on gas boilers:

1. Code 4Y appears on the display after a drop in the temperature of the coolant, for example, after a power outage.
2. Code CL means sensor failure hot water. The reason may be a short circuit of the sensor and the wire, in which case you will have to change the sensor.
3. The value 9C lights up on the display if the DIP switches are set incorrectly (there are 8 of them on the Buderus Logomax u042 24k model). Carry out the settings according to the table in the instructions for the device.
4. 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.
5. Code d7 indicates a malfunction of the gas valve. Check the gas connection and the operation of the gas block, if the block is faulty, it will have to be changed.
6. Code C7 reports a fan failure. Check the condition of the fan, its wires and plug.

There are problems that the display does not fix. For example, if a loud water noise is heard or the water takes too long to heat up, the pump speed should be adjusted. If the outlet water temperature is insufficient, check the turbine and replace it if necessary.

In case of problems with ignition, you need to check the gas pressure, if the electricity is turned off, see if the electrode connections with wires are oxidized, if the chimney is clogged and tight, if the burner is clogged.

boilervdom.ru

Boiler errors Buderus Logamax U072

Publication date 03.10.2014

In this article, we will take a closer look at the errors, their possible reasons and ways to eliminate boiler equipment Logamax U072.

2E - insufficient filling pressure of the heating system, it is required to add water.

3A - low fan speed. Check mains voltage, flue gas system.

3C - the differential pressure switch does not close. First of all, check the fan and its cable with plug, as well as the differential pressure switch and the flue gas pipes.

3Y - when the fan is turned off, the differential pressure switch does not open. Check the latter for performance.

4C - the heat exchanger temperature limiter has tripped. In this case, first check for damage to the temperature limiter of the heat exchanger and its connecting cable. Check the working pressure in heating system, as well as a temperature limiter, a pump, a fuse, a heat exchanger water circuit.

4Y - failure of the flow temperature sensor. In this case, check the temperature sensor and its wires for damage or short circuit, and replace it if necessary.

6A - no flame. Check if the protective conductor is connected, open gas valve. Check supply pressure. Check if the device is connected to the mains. Inspect the flue gas system and clean or repair if necessary. Clean the heat exchanger. Inspect the gas fittings, replace if necessary.

6C - Flame detected after shutting off the gas supply. If this error occurs, check the gas fittings, electrodes and wires, the flue gas exhaust system, if necessary, replace them.

C7 - fan malfunction. Check fan and plug, replace if necessary.

CL - failure of the hot water temperature sensor. Inspect the sensor for damage or short circuit, if necessary, replace the defective device.

SR - the temperature sensor of the boiler is not recognized. Check the boiler sensor and connecting wire.

D7 - gas fittings are faulty. In this case, check the connecting wire and the gas fitting.

FD - the button was pressed too long (more than 30 seconds). Press the button again (at least 30 seconds).

P - the type of boiler is not defined. Set boiler type.

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Possible errors, their codes and malfunctions of Buderus boilers (Buderus)

This article contains all possible malfunctions and options for their elimination, as well as error codes for Buderus boilers. All information is read in the following order: code - name - possible malfunction. If you have any additional questions, please leave them in the comments to this article.

Error code A - Chimney sweep mode

The device is in the "chimney sweep" mode. After 15 minutes, the chimney sweep mode is automatically deactivated.

Error code H - Heating mode

The Buderus boiler is in heating mode.

Error code (=) H - DHW mode

The device is in DHW mode.

Error Code 0A - Blocking

Cyclic blocking active: the delay time between switching off and switching on the burner has not yet expired (service function 2.3b).

Error code 0A for GB072-24K

Keep warm duration: The keep warm time has not yet expired (service function 2.3F).

Error Code 0C - Burner

The burner turns on.

Error Code 0E - On-Off Mode

The heat demand is less than the minimum heat output of the boiler. The boiler operates in on-off mode.

Error code 0H - Heat demand

The device is in the ready state, there is no need for heat.

Error Code 0L - Delay

The gas valve opens, the first delay time.

Error Code 0U - Startup

The boiler starts up.

Error code 0Y - The temperature is higher than the set one

The actual flow temperature is higher than the set temperature. The boiler is switched off.

Error code 2E - Air removal

Error: Ventilation function is active.

Error code 2H - Pump protection

Anti-jamming protection for the heating circuit pump and three-way valve is active.

Error code 2P - Temperature increase

Limitation of gradients: temperature increase too fast in domestic hot water mode.

1. Open service taps.

Error code 5H - System test

Boiler test by control system.

Error code h21 - Temperature sensor

Sensor damage DHW temperature(GB072-24K).

1. Remove temperature sensor.
2. Check the connecting cable for breaks and short circuits, replace if damaged.

Error code 0Y - The temperature at the flow sensor is more than 95 C

This message may appear in the absence of a malfunction, if all the valves on the radiators suddenly close or after hot water is drawn from the GB072-24K.

1. Check the operating pressure in the heating system.
2. Open service taps.
3. Complete electrical connection heating circuit pump to the main controller BC20.
4. Check or replace the heating circuit pump.
5. Correctly set the pump power or its characteristic and adjust to the maximum power.
6. Check for damage or short circuit in the flow temperature sensor and its wires, replace if necessary.

Error code 0Y - High temperature on the hot water temperature sensor

1. Check the correct position of the sensor.
2. Check it, and if it is defective, replace it.

Error code 3A - Fan does not work

Check it, and if it is defective, replace it.

Error Code 3F - Business Interruption

The burner and fan have been running for 24 hours without interruption and turn off for a short time for security.

Error Code 4C - Blocking

The heat exchanger temperature limiter or the flue gas temperature limiter of the Buderus boiler has tripped. If a blocking fault exists long time, then it passes into the locking one.

Flow temperature sensor defective (short circuit). If the fault exists for a long time, the display will show fault code 4U and run code 222.

Error code 4Y - Temperature sensor

Flow temperature sensor defective (break). If the fault exists for a long time, the display will show fault code 4Y and operating code 223.

Error code 6A - Flame not detected

After the 4th ignition attempt, the blocking fault turns into a locking one.

Error code 6L - No ionization signal during burner operation

The burner restarts. If the ignition fails, a blocking error 6A will be displayed, after the 4th ignition attempt, the blocking fault goes into failure.

Error code 8Y - Temperature control relay AT90 has tripped

1. Check the adjustment of the temperature control relay AT90.
2. Check the heating control setting.

Error code 8Y - Faulty temperature control relay AT90

Error code 8Y - There is no jumper between the terminals of a separate AT90 temperature control relay

If no temperature control relay is connected, install a jumper.

Error code 8Y - Temperature control relay blocked

1. Unlock the temperature control relay.
2. Check the condensate drain.
3. The condensate pump does not work - replace the condensate pump.

EL error code

Faulty main regulator BC20 - replace.

Error code 3C - Fan operation error

Check the fan and its cable with plug, replace if necessary.

Error code 3L - Fan turned off during the delay time

Error code 3P - Fan is running too slow

Check and, if necessary, replace.

Error code 3Y - The fan is running too fast

1. Check and, if necessary, replace.

Error code 4C - Temperature limiter

Error in the heat exchanger temperature limiter or flue gas temperature limiter.

1. Check: for damage to the heat exchanger / flue gas temperature limiter and its connecting cable, replace if necessary, operating pressure in the heating system, temperature limiter, replace if necessary, pump pressure, replace pump if necessary, fuse, replace if necessary.
2. Remove air from the boiler.
3. Check the water circuit of the heat exchanger, replace if necessary.
4. For Buderus boilers with a divider in the heat exchanger, check whether the divider is installed.

Error code 4U - Temperature sensor

Flow temperature sensor defective (short circuit).

Check for damage or short circuit in the temperature sensor and its wire, replace if necessary.

Error code 4Y - Faulty flow temperature sensor (break)

Check for damage or breakage of the temperature sensor and its wire, replace if necessary.

Error code 6A - Error: flame not found

1. Check: protective conductor connection, whether the gas cock is open, gas supply pressure, electrical connection, electrodes with wires, flue gas system, clean or repair if necessary.
2. Check the gas-air ratio, correct if necessary.
3. For natural gas: check gas flow switch, replace if necessary.
4. When operating with combustion air intake from a room, check the air supply to the room and ventilation holes.
5. Clean the drain of the condensate siphon.
6. Remove the membrane in the fan mixing device, check for cracks and dirt on it.
7. Clean the heat exchanger of the Buderus boiler.
8. Insert KIM correctly, replace if necessary.
9. Two-phase network (IT): install a resistance of 2 ohms between PE and N on the connection of the electronic board to the mains.

Error code 6C - In shutdown mode, the boiler registers a flame

1. Check the contamination of the electrodes, replace if necessary.
2. Check the flue gas system, clean or repair if necessary.
3. Check the moisture content of the electronic board, dry if necessary.

1. Check gas fittings, replace if necessary.
2. Clean the condensate siphon.
3. Check electrodes and connecting wires, replace if necessary.
4. Check the flue gas system, clean or repair if necessary.

Error code 7L - Time error at first delay time

Error code 7L - Time error when trying to restart

Replace BC20 main regulator.

Error code 9L - Faulty gas valve

The coil or connecting wire of the gas fitting is defective.

1. Check wires, replace if necessary.
2. Replace gas valve.

Error code 9P - KIM not recognized

Insert KIM correctly, replace if necessary.

Error code EL - Faulty KIM or main regulator BC20

Replace KIM. Replace BC20 main regulator.

Error codes for gas wall-mounted boilers Buderus Logamax

Error code 1A - Exhaust gas outlet at flow fuse

Check gas path.

Error code 1L - Exhaust gas outlet on the combustion chamber

Check the heat exchanger for contamination.

Error code 1Y - Exhaust gas temperature sensor not detected

Check flue gas temperature sensor and connecting cable for damage.

Error code 2E - Insufficient filling pressure of the heating system

Check filling pressure, increase it if necessary.

Error code 2P - Temperature difference too high

Check pump and bypass line.

Error code 4C - The limiter in the supply line has tripped

Check the system pressure, temperature sensors, check the operation of the pumps and the fuse for printed circuit board, remove air from the device.

Error code 4E - The temperature sensor in the burner chamber is not detected

Check the temperature sensor in the burner chamber and the connecting cable for damage.

Error code 4Y - Flow temperature sensor not working

Check temperature sensor and connecting cable.

Error code 5H - EMS communication interrupted

Check connecting cable and regulators.

Error code 6A - Flame not detected

Is the gas cock open? Check the pressure in the gas network, mains connection, trigger electrode with cable and ionizing electrode with cable.

Error code 6C - Flame detected after shutting off gas supply

Check ionizing electrode. Check gas fittings.

Error code 8Y - No jumper found on ST8 161

If there is a jumper, insert the plug correctly, check the external limiter. Otherwise: is there a jumper?

Error code 9C - Coding plug not found

Insert the coding plug correctly, measure it and replace if necessary.

Error code CL - Hot water temperature sensor defective

Logamax U054-24K

• Check temperature sensor and connecting cable for damage or short circuit;
• The hot water temperature sensor is incorrectly installed.

Logamax U054-24K

• Check the installation area, if necessary, dismantle the sensor and reinstall it using heat-conducting paste.

Error code CP - Boiler sensor not found

Check boiler sensor and connecting cable.

EC Error Code - Internal Fault

Check the tightness of the connection of electrical plug contacts and jumper lines, if necessary, replace the printed circuit board.

Error code EL - Wrong reference voltage

Replace printed circuit board.

Error code EP - By mistake, the fault message reset button was held down too long (more than 30 seconds)

1. Press the reset button again and hold it down for less than 30 seconds.
2. Outside temperature sensor not found. Check the outside temperature sensor and connecting cable for damage.

Malfunctions of Buderus boilers

If you are not 100% sure what exactly the problem is and that you can solve it - immediately contact service center for troubleshooting and troubleshooting.

The burner does not turn on

The emergency switch of the heating system is in the off - on position.

Start switch of the control system in the off position - enable.

The circuit breakers are faulty - check their operability, if necessary, replace the defective circuit breaker.

Boiler water temperature controller damaged - check and, if necessary, replace defective parts.

Safety temperature limiter damaged - check and, if necessary, replace defective parts.

Error message from external safety devices (for example, from a water level safety device) - the user must check the Buderus boiler, eliminate the malfunction and, if necessary, replace the element.

The flue gas control system has been triggered:

• AW 10 - unlock the flue gas control system;
• AW 50 - Wait a maximum of 15 minutes.

The boiler will turn on automatically if there is a demand for heat. If triggered repeatedly, check the flue gas path and check the function of the flue gas monitoring system. If there is a defect, then replace.

The burner starts and switches to fault. No spark on ignition

Is there a sound when an ignition spark is generated with the ignition cable removed?

• If not, then - replace the ignition transformer;
• If so, replace the ignition electrode or ignition burner.

Burner starts and switches to fault

All gas shut-off valves are closed - open the gas shut-off valves.

Natural gas supply pressure greater than 8 mbar - if not, find the cause and rectify the problem.

Has air been removed from the pipeline? Remove air until the gas can be ignited.

The burner of the Buderus boiler starts and switches to fault. No ionization current

If the N and L connections are reversed, fix the error.

Is there voltage between L and PE? If not, ground the PE, in this case install an isolating transformer.

Poor contact of the ionization wire - eliminate the error, in this case, replace the defective part.

Short to ground on the ionization electrode - fix the damage.

Defective burner control - replace the element.

The burner starts and switches to fault. Ionization current less than 1.5 mA

The core or ceramic of the ionization electrode is dirty - clean the ionization electrode, if necessary, replace the ignition burner.

Boiling sounds

Lime deposits or scale build-up in the boiler - clean the water circuit of the heating boiler in accordance with the manufacturer's recommendations.

With constant loss of water, determine and eliminate the cause. If required, carry out water treatment and install a dirt trap.

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Errors and malfunctions of gas boilers Buderus

Buderus boiler error codes

A - The machine is in "chimney sweep" mode. After 15 minutes, the "chimney sweep" mode is automatically deactivated

H - The Buderus boiler is in heating mode.

(=) H - Appliance in DHW mode

0A - Cyclic blocking active: the delay time between switching off and switching on the burner has not yet expired (service function 2.3b).

0A - Keep warm duration for GB072-24K: Keep warm time interval has not yet expired (service function 2.3F).

0C - Burner turns on

0E - The heat demand is less than the minimum heat output of the boiler. The boiler operates in on-off mode.

0H - The device is in the ready state, there is no need for heat.

0L - Gas valve opens, first delay time.

0U - The boiler starts up.

0Y - The actual flow temperature is higher than the set one. The boiler is switched off.

2E - Error: Ventilation function is active.

2H - Anti-jamming protection for the heating circuit pump and three-way valve is active.

2P - Gradient limitation: temperature increase too fast in domestic hot water mode.

5H - Boiler test by control system

H11 - Damage to the DHW temperature sensor (GB072-24K)

Remove temperature sensor.

Check the connecting cable for breaks and short circuits, replace if damaged.

0Y - The temperature at the flow sensor is more than 95 C.

This message may appear in the absence of a malfunction, if all the valves on the radiators suddenly close or after hot water is drawn from the GB072-24K.




Check for damage or short circuit in the flow temperature sensor and its wires, replace if necessary.

0Y - High temperature on the hot water temperature sensor

Check the correct position of the sensor.
Check it and if it is defective, replace it
Insert KIM correctly, replace if necessary

2P - Limitation of gradients: temperature increase too fast in heating mode

Check the operating pressure in the heating system. Open service taps.
Connect the heating circuit pump electrically to the BC20 master controller.
Check or replace the heating circuit pump.
Correctly set the pump power or its characteristic and adjust to the maximum power.

3A - The fan does not work. Check it and if it is defective, replace it

3F - The burner and fan have been running for 24 hours without interruption and are switched off for a short time for safety reasons.

4C - The heat exchanger temperature limiter or the flue gas temperature limiter of the Buderus boiler has tripped. If a blocking fault exists for a long time, then it turns into a locking one.

4U - Faulty flow temperature sensor (short circuit). If the fault exists for a long time, the display will show fault code 4U and operation code 222

4Y - Faulty flow temperature sensor (break). If the fault exists for a long time, the display will show fault code 4Y and operating code 223

6A - No flame detected. After the 4th ignition attempt, the blocking fault turns into a locking one.

6L - No ionization signal during burner operation. The burner restarts. If the ignition fails, a blocking error 6A will be shown, after the 4th ignition attempt, the blocking fault goes into a fault

8Y - The AT90 temperature control relay has tripped. Check the adjustment of the temperature control relay AT90. Check the heating control setting.

8Y - Faulty temperature control relay AT90. Check for damage or short circuit in the temperature sensor and its wire, replace if necessary.

8Y - There is no jumper between the terminals of the separate AT90 temperature control relay.
If a temperature control relay is not connected, install a jumper

8Y - Temperature control relay blocked
Unlock the temperature control relay. Check the condensate drain.
Condensate pump not working - Replace condensate pump.

EL - Faulty main regulator BC20 - Replace

3C - Fan operation error. Check the fan and its cable with plug, replace if necessary.

3L - The fan has turned off during the delay time. Check and, if necessary, replace.

3P - The fan is running too slowly. Check and, if necessary, replace.

3Y - The fan is running too fast. Check and, if necessary, replace. Check the flue gas system, clean or repair if necessary.

4C - Error of the heat exchanger temperature limiter or flue gas temperature limiter.
Check: for damage to the heat exchanger / flue gas temperature limiter and its connecting cable, replace if necessary, operating pressure in the heating system, temperature limiter, replace if necessary, pump pressure, replace pump if necessary, fuse, replace if necessary.
Remove air from the boiler. Check the water circuit of the heat exchanger, replace if necessary.
For Buderus boilers with a divider in the heat exchanger, check whether the divider is installed.

4U - Faulty flow temperature sensor (short circuit). Check for damage or short circuit in the temperature sensor and its wire, replace if necessary.

4Y - Faulty flow temperature sensor (break). Check for damage or breakage of the temperature sensor and its wire, replace if necessary.

6A - Error: Flame not found.
Check: PE connection, gas cock open, gas supply pressure, electrical connection, electrodes with wires, flue gas system, clean or repair if necessary. Check the gas-air ratio, correct if necessary. For natural gas: check gas flow switch, replace if necessary. When working with combustion air intake from a room, check the air supply to the room and the ventilation openings.
Clean the drain of the condensate siphon. Remove the membrane in the fan mixing device, check for cracks and dirt on it. Clean the heat exchanger of the Buderus boiler.
Check gas fittings, replace if necessary. Insert KIM correctly, replace if necessary. Two-phase network (IT): install a resistance of 2 ohms between PE and N on the connection of the electronic board to the mains.

6C - In shutdown mode, the boiler registers a flame.
Check the contamination of the electrodes, replace if necessary.

Check the moisture content of the electronic board, dry if necessary.

6C - Flame detected after shutting off gas supply.
Check gas fittings, replace if necessary. Clean the condensate siphon.
Check electrodes and connecting wires, replace if necessary.
Check the flue gas system, clean or repair if necessary.

7L - Time error at the first delay time. Replace BC20 main regulator.

7L - Time error when trying to restart. Replace BC20 main regulator.

9L - Defective coil or connecting wire of the gas valve

9L - Faulty gas valve
Check wires, replace if necessary. Replace gas valve.

9P - KIM is not recognized. Insert KIM correctly, replace if necessary.

EL - Faulty KIM or main regulator BC20. Replace KIM. Replace BC20 main regulator.

Malfunctions of Buderus boilers

1. The burner does not turn on

The emergency switch of the heating system is in the Off - On position.
Start switch of the control system in the Off - Enable position.
Faulty circuit breakers - Check their functionality, if necessary, replace the defective circuit breaker. Boiler temperature controller damaged - Check and, if necessary, replace defective parts. Safety temperature limiter damaged - Check and, if necessary, replace defective parts.

Error message from external safety devices (for example, from a water level safety device) - The user must check the Buderus boiler, eliminate the malfunction and, if necessary, replace the element

The flue gas control system has been triggered - AW 10: Reset the flue gas control system. AW 50: Wait a maximum of 15 minutes. The boiler will turn on automatically if there is a demand for heat. If triggered repeatedly, check the flue gas path and check the function of the flue gas monitoring system. If there is a defect, then replace.

2. Burner starts and switches to fault. No spark on ignition.

Is there a sound when an ignition spark is generated with the ignition cable removed? - If not, then: replace the ignition transformer. If so, replace the ignition electrode or ignition burner.

3. Burner starts and switches to fault.

All gas shut-off valves are closed - Open the gas shut-off valves.
Natural gas supply pressure greater than 8 mbar - If not, then: find the cause and rectify the fault. Has air been removed from the pipeline? - Remove air until the gas can be ignited.

4. Buderus boiler burner starts and switches to fault. No ionization current.

If connections N and L are reversed - Eliminate the error.
Is there voltage between L and PE? - If not, then: Ground the PE, in this case install an isolating transformer. Poor contact of the ionization wire - Eliminate the error, in this case, replace the defective part. Short to ground on the ionization electrode - Repair the damage. Burner control defective - Replace element.

5. Burner starts and switches to fault. The ionization current is less than 1.5 mA.

The core or ceramic of the ionization electrode is dirty - Clean the ionization electrode, if necessary replace the ignition burner.

6. Boiling sounds

Lime deposits or scale build-up in the boiler - Clean the water circuit of the boiler according to the manufacturer's recommendations. With constant loss of water, determine and eliminate the cause. If required, carry out water treatment and install a dirt trap.

Buderus Logamatic control system

Logamatic 2107 modes and operating parameters

By turning the rotary selector it is possible to display the measured values ​​from all connected temperature sensors as well as the operating hours of the burner.

The following parameters will be displayed in sequence:

Boiler water temperature.
- Hot water temperature.
- Outside temperature (current value, excluding building insulation).
- Flow temperature, heating circuit 2 (if mixer module FM 241 is present).
- Temperature solar collector(if there is a solar module FM 244).
- Hot water temperature from the solar collector (if there is a solar module FM 244).
- Room temperature, heating circuit 1 (if a control panel is connected remote control).
- Room temperature, heating circuit 2 (if a remote control is connected).
- Flue gas temperature (if a flue gas temperature sensor is connected).
- Burner operating hours.
- Operating hours of the 2nd stage burner (if the 2nd stage module FM 242 is present).
- Operating hours of the solar collector pump (if there is a solar collector module FM 244).

The buttons on the Buderus Logamatic 2107 control system have the same functions as the buttons on the remote control. On the remote control, you can set the operating mode for heating circuits that are equipped with such a remote control. Buttons for setting the operating mode to
the control system is then left "without functions", although the LEDs will show the set mode.

If there are two heating circuits, the operating mode buttons and LEDs work:

For both heating circuits at the same time, if no remote control is installed,
- for a heating circuit without remote control, if a remote control is installed on another heating circuit,
- for none of the heating circuits, if remote controls are installed for two circuits (the LEDs then show the operating mode of the last heating circuit or domestic hot water circuit that was serviced).

On the control system, you can set: automatic mode / manual mode.

Auto mode

The heating system operates according to the heating program preset at the factory. This means that the house will be heated and hot water will be prepared at a certain time. Normally, at night, the heating operates at a lower temperature than during the day.

With the Buderus Logamatic 2107 control system, there is no need to close the thermostatic regulators every evening and open them again in the morning. Switching between normal (day) mode and setback mode (night mode) occurs automatically.

The point in time at which the heating system switches from normal (day) mode to setback mode (night mode) is factory set in the standard program. If desired, this setting can be changed by you or the heating system operator.

Manual mode

If, for example, you want the heating to run longer in the evening and turn on later in the morning, you must manually select the normal (day) heating mode or the reduced temperature mode (night mode). The selected operating mode will work continuously.

Automatic mode selection

Along with the green LED above the "AUT" button, the LED above the "Day mode" or "Night mode" button also lights up, depending on which heating mode is currently on. The change from normal mode to low temperature mode occurs automatically at the time specified in the program.

If there are two heating circuits and only one of them has a remote control, then the LED indication on the control unit is valid for the heating circuit without remote control. Press "AUT" button to select auto mode. The heating system works according to the heating program preset at the factory, which means that the house will be heated and hot water will be prepared at a certain time.

Operating modes Buderus Logamatic 4211

Setting the room temperature for other heating circuits

The heating system can operate with several circuits. If you want to change the room temperature for a heating circuit other than the last selected one, the desired circuit is selected first.

Depending on the equipment of the heating system, the following circuits can be selected:

– MEC OUT.LOOP
– HEATING CIRCUIT 0 – 8

If several heating circuits are assigned to MEC2, they can only be controlled together. Otherwise, the error message "SETTING IMPOSSIBLE MEC FROM LOOP SELECT" appears. In this case, select "MEC FROM. LOOP."

Open the lid. Hold down the "heating circuit" button and select the required circuit with the rotary selector. Release the "heating circuit" button. The displayed heating circuit is selected. As soon as a heating circuit is selected, the screen switches to a permanent display. Keep the "Temperature" button pressed. First, the heating circuit appears, for which the temperature is to be set.

After about 2 seconds, the screen will show the current set temperature and operating mode. On the Buderus Logamatic 4211 control unit, set the desired temperature (here: "21C") for the heating circuit. Release the button to save the entered value. Now daytime
room temperature is set to 21C. After that, a permanent indication will appear.

Heating circuits with MEC2 control panel

During installation, the heating company's specialists specify which heating circuits are to be controlled from the MEC2 control unit. These heating circuits are called "MEC FROM. CIRCUIT."

The following settings are made on the MEC2 simultaneously for all MEC heating circuits:

– room temperature setting.
– summer/winter changeover setting.
– selection of the operating mode.
– Activate the vacation function.
– Activate the break function.

If one heating circuit assigned to MEC2 is selected and then one of the above settings is made, the error message "SETTING IMPOSSIBLE MEC FROM CIRCUIT SEL" appears. Select "MEC FROM. LOOP." to program these settings.

Individual heating circuits

The following control settings can only be made separately for each heating circuit:

– selection of the standard program.
– changing the standard program by shifting the switching points.
– adding or deleting switching points.
– merging or deleting heating periods.
– creation of new heating programs, DHW or circulation pump.

If "MEC OUT. LOOP" is selected and then one of the above settings is performed, the error message "HEBO3 TIMER OUT. OUT. LOOP SEL" appears. Program these settings separately for each heating circuit.

Setting the circulation mode for the Buderus Logamatic 4211

The circulation pump provides an almost immediate supply of hot water to the taps. To do this, twice an hour, the circulation pump is switched on for three minutes and supplies hot water through a separate circulation line.

This interval can be changed by the heating contractor at the service level.

The circulation mode can be changed as follows:

Open the lid.
Hold down the "heating circuit" button and turn the dial to "CIRCULATION".
Release the "heating circuit" button.
The permanent display reappears on the screen.

Select one of the following operating modes for the circulation pump:

"DC LOAD"
The circulation pump operates independently of the heating circuits at a set interval.
Press the "Day mode" button to select the permanent operation mode.

"MACHINE."
The circulation starts at a set interval 30 minutes before the first heating circuit is switched on and stops when the last heating circuit is switched off (factory setting).
You can also enter your own program for the circulation pump.
Press the "AUT" button to select automatic mode.
After about 3 seconds, the permanent display will reappear on the screen.

"WHEN LOADING HW"
The circulation pump does not turn on.
By pressing the "Hot water" button, the circulation pump will turn on only for the duration of a single load.
Press the "Night mode" button to turn off the circulation.
After about 3 seconds, the permanent display will reappear on the screen.

Fault indication Buderus Logamatic

Strategic flow sensor

All available steps are required.
System flow sensor not connected, connected incorrectly or defective.

Check the connection of the flow sensor.
Replace system flow sensor or FM 447 module.

Outside temperature sensor

Transmits the minimum outside temperature.
Outside temperature sensor incorrectly connected or defective, e.g. not connected to the controller with address 1 in a multi-boiler system.

Interrupted communication with control system with address 1.
Check whether the outside temperature sensor is connected to the correct control system.
Check communication with address 1.
Replace outside temperature sensor or boiler module ZM 432.

Flow sensor 1-8

The mixer is fully open.
If an actuator/mixer has been selected in MEC 2, the control system requests the corresponding flow sensor. Faulty FM 441/FM 442 module or control system. Check sensor connection.
If the faulty heating circuit is to be operated as a circuit without mixer, then check whether MEC 2 / Service level / Heating circuit - Actuator is set to "no".
Replace FM 441/FM 442 module.

Hot water sensor

There is no water heating. Sensor not connected, connected incorrectly or defective.

Check sensor connection. Replace sensor or FM 441 module.

The water stays cold

Constant attempts to load the storage tank at low boiler flow temperature.

The sensor is incorrectly connected or defective. The sensor is incorrectly positioned.
Loading pump incorrectly connected or defective.
Faulty FM 441 module or control system.

Check the operation of the sensor and the loading pump. Replace FM 441 module.
Check the location of the sensor on the water heater tank.

Thermal disinfection

Thermal disinfection interrupted.
The heating capacity of the boiler is not enough, because, for example, during thermal disinfection, there is a request for heat from other consumers (heating circuits).
The sensor is incorrectly connected or defective. Loading pump incorrectly connected or defective.
Faulty FM 441 module or control system.
Choose to perform thermal disinfection at a time when there is no additional demand for heat from the consumers. Check the operation of the sensor and the loading pump and, if necessary, replace them. Replace FM 441 module.

Remote control 1-8

Since the actual temperature in the room is not measured, the programs for temperature correction, on-off optimization and auto do not work. adaptation.
The control system works according to the last parameters set on the remote control.
Remote control connected incorrectly or defective.
Check the operation/connection of the remote control. In this case, the addressing of the remote control must be checked. Replace remote control/function module.

Communication with the heating circuit OK 1-8

Incorrect remote control addressing.
Remote control wired incorrectly.
Remote control defective. Faulty control system.
Check the operation/connection of the remote control.
Replace remote control/function module.

Boiler connection 2-3

Boiler stages 2 or 3 are requested.
The control system with address 2 or 3 was not found on CAN-BUS, although it is set in MEC 2 in the Strategy menu.
FM 447 policy module or control system defective.
Check the addressing of the control systems. Check connection to CAN-BUS.
Wrong strategy setting on MEC 2, check the number of boilers.
Replace strategy module FM 447.

Boiler water temperature sensor

The boiler is operating at maximum power.
Emergency operation possible via temperature controller.


Replace boiler water temperature sensor or boiler module ZM 432.

Additional boiler sensor

Mixers open fully. Ecostream regulation not possible.

Sensor not connected, connected incorrectly or defective.
Boiler module ZM 432 or control system defective. Check sensor connection.
Replace additional boiler sensor or boiler module ZM 432.

The boiler is cold

Boiler protection (antifreeze and condensate protection) cannot be guaranteed.
The boiler turns on at maximum power.
The temperature control or switch is not set to the "AUT" position.
No fuel supply. The sensor is incorrectly positioned.
Boiler water temperature sensor defective.
Check that the temperature controller or switch is set to the "AUT" position.
Check the presence and supply of fuel. Check sensor location.
Replace the boiler water temperature sensor.

Burner

Boiler protection (frost protection) cannot be guaranteed. No hot water.
The burner is defective and therefore a 230 V fault signal is sent to terminal BR 9.
Boiler module ZM 432 or control system defective.
Eliminate the fault in accordance with the instructions in the documentation for the heating boiler or burner.
Check the fault signal from the burner to terminal BR 9 (230 V).
If there is a signal: check the operation of the burner. If there is no signal: replace the ZM 432 module.

Safety chain

Boiler protection (frost protection) cannot be guaranteed.
The safety temperature limiter STB has tripped.
Faulty control system.
Find the cause of the STB triggering and then unlock the STB by pressing the jamming button.
Check if an external STB is connected.

Boiler external interference (KS)

Fault input of the boiler module ZM 432 is connected incorrectly.
External components are faulty or defective.
Check operation of external components and, if necessary, repair/replace them.

flue gas sensor

It is not possible to find the boundary flue gas temperature.
The sensor is not connected or connected incorrectly.
The sensor or control system is defective.
Check sensor connection.

Flue gas boundary

No response to regulation. There is a lot of soot in the boiler.
Flue gas sensor defective.
The boiler needs to be cleaned.
Check the connection and operation of the sensor.

External pump interference 1-8

No response to regulation.
Fault input WF 1/2 of the FM 441/FM 442 function module is open.
The externally connected heating circuit pump is defective or defective.
Check the function of the connected heating circuit pump.
Replace the corresponding module.

ECO-BUS reception

No response to regulation. Incorrect addressing of the coding switch located behind the MEC 2 in the controller module CM 431 of the control system.
Error example: Installation with control system and coding switch position greater than 0.
Check the setting of the coding switch:
Position 0: There is only one bus member.
Position 1: Master control system (other BUS participants are expected!).
Position greater than 0: other bus participants.

Supply line configuration

The operating conditions of the boiler cannot be maintained.
When configuring the supply line (Strategy) were set Various types boilers.
With Ecostream control via heating circuit actuators, all boilers must have the same settings.

No Master

Boiler protection cannot be guaranteed.
Priority DHW heating is not possible.
The minimum outside temperature is taken into account.
Main system master control (address 1) is switched off or there is no control system with address 1.
Check the addresses of the bus participants. The master control system must have address 1.
Check bus connection to address 1.

Return line sensor

Return temperature control not possible.
Sensor not connected, connected incorrectly or defective.
The sensor or control system is defective. Check sensor connection.

inert anode

There is no impact. There is voltage at the external input WF 1/2.
The module or control system is defective. Replace inert anode.
Replace the FM 441 module in the control system.

The differential pressure switch does not close.

In this article, we will consider in detail the errors, their possible causes and ways to eliminate Buderus boiler equipment.

Insufficient filling pressure of the heating system, it is necessary to add water,low fan speed. Check mains voltage, flue gas system,differential pressure switch does not close. First of all, check the fan and its cable with plug, as well as the differential pressure switch and the flue gas pipes, and so on...

Error codes for wall-mounted heating boilers Buderus Logamax

The code Fault	Working code	Description
-A	208	The boiler is in the "chimney sweep" mode. After 15 minutes, the "chimney sweep" mode is automatically deactivated
-H	200	The boiler is in heating mode.
=H	201	Boiler in DHW mode
0A	202	Cyclic interlock active: the delay time between switching off and switching on the burner has not yet expired (service function 2.3b).
0A	305	Keep warm duration for GB072-24K: keep warm interval hot water has not yet been exhausted (service function 2.3F).
0C	283	The burner turns on
0E	265	The heat demand is less than the minimum heat output of the boiler. The boiler is in operation on-off.
0H	203	The boiler is in a state of readiness, there is no need for heat.
0L	284	The gas valve opens, the first delay time.
0U	270	The boiler starts up.
0Y	204	The actual flow temperature is higher than the set temperature. The boiler is switched off.
2E	357	The venting function is active.
2H	358	Anti-jamming protection for the heating circuit pump and three-way valve is active.
2P	342	Limitation of gradients: temperature increase too fast in domestic hot water mode.
5H	268	Boiler test by control system
H11		Defective hot water temperature sensor (GB072-24K)	Disconnect the temperature sensor. Check temperature sensor, replace if defective Check connecting cable for breakage and short circuit, replace if defective.
0Y	276	Temperature at flow sensor > 95 °C.	This message may appear without a malfunction if all the valves on the radiators suddenly close or after hot water is drawn from the GB072-24K. Open service taps. Check for damage or short circuit in the flow temperature sensor and its wires, replace if necessary.
0Y	359	High temperature on the hot water temperature sensor	Check the correct position of the temperature sensor Insert KIM correctly, replace if necessary
2P	341	Limitation of gradients: temperature increase too fast in heating mode	Check the operating pressure in the heating system. Open service taps. Connect the heating circuit pump electrically to the BC20 master controller. Check or replace the heating circuit pump. Correctly set the pump power or its characteristic and adjust to the maximum power.
3A	264	Fan not working
3F	273	The burner and fan have been running for 24 hours without interruption and are switched off for a short time for safety reasons.
4C	224	The heat exchanger temperature limiter or the flue gas temperature limiter has tripped	If a blocking fault is present for a long time, then it turns into a locking fault.
4U	350		If the fault is present for a long time, the display will show fault code 4U and operating code 222
4Y	351		If the fault is present for a long time, the display will show fault code 4Y and operating code 223
6A	227	The flame was not detected.	After the 4th ignition attempt, the blocking fault turns into a locking one.
6L	229	No ionisation signal during burner operation.	The burner restarts. If ignition fails, a 6A blocking fault will be displayed, after the 4th ignition attempt, the blocking fault changes to rapier
8Y	232	The temperature control relay has tripped AT90.	Check the adjustment of the temperature control relay AT90. Check the heating control setting.
8Y	232	Faulty monitoring relay temperature AT90	Check for damage or short circuit in the temperature sensor and its wire, replace if necessary.
8Y	232	There is no jumper between the terminals of a separate monitoring relay temperature AT90.	If a temperature control relay is not connected, then install jumper.
8Y	232	Temperature control relay blocked The condensate pump is not working.	Unlock the temperature control relay. Check the condensate drain. Replace condensate pump.
EL	290	Faulty main regulator BC20
3C	217	The fan is not working.	Check the fan and its cable with plug, replace if necessary.
3L	214	The fan has turned off during the delay time.	Check the fan and its cable with plug, replace if necessary.
3P	216	The fan is running too slowly.	Check the fan and its cable with plug, replace if necessary.
3Y	215	The fan is running too fast.	Check the fan and its cable with plug, replace if necessary.
4C	224	The heat exchanger temperature limiter or the flue gas temperature limiter has tripped.	Check for damage to the heat exchanger temperature limiter and its connecting wire, replace if necessary. Check the flue gas temperature limiter and its connecting wire for damage, replace if necessary. Check the operating pressure in the heating system. Check temperature limiter, replace if necessary. Check pump head, replace pump if necessary. Check fuse, replace if necessary. Remove air from the boiler. Check the water circuit of the heat exchanger, if replace if necessary. For boilers with a divider in the heat exchanger, check whether a divider is installed.
4U	222	Flow temperature sensor defective (short circuit).	Check for damage or short circuit in the temperature sensor and its wire, replace if necessary.
4Y	223	Flow temperature sensor defective (break).	Check for damage or breakage of the temperature sensor and its wire, replace if necessary.
6A	227	The flame was not detected.	Check the protective conductor connection. Check if the gas cock is open. Check gas supply pressure Check the electrical connection. Check electrodes with wires, replace if necessary. Check the flue gas system, clean or repair if necessary. Check the gas-air ratio, correct at need. For natural gas: check gas flow switch, replace if necessary. When working with combustion air intake from a room, check the air supply to the room and the ventilation openings. Clean the drain of the condensate siphon Dismantle the membrane in the fan mixing device, check for cracks and dirt on it Clean heat exchanger Two-phase network (IT): install a resistance of 2 ohms between PE and N on the connection of the electronic board to the mains.
6C	228	Although the boiler is switched off, a flame is detected.	Check the contamination of the electrodes, replace if necessary. Check the flue gas system, clean or repair if necessary. Check the moisture content of the electronic board, dry if necessary.
6C	306	After turning off the gas supply, a flame was detected.	Check gas fittings, replace if necessary. Clean the condensate siphon. Check electrodes and connecting wires, replace if necessary. Check the flue gas system, clean or repair if necessary.
7L	261	Time error at first delay time	Replace BC20 main regulator.
7L	280	Time error when trying to restart	Replace BC20 main regulator.
9L	234	Faulty coil or connecting wire of the gas fitting	Replace gas valve.
9L	238	Faulty gas valve	Check wires, replace if necessary. Replace gas valve.
9P	239	KIM is not recognized.	Insert KIM correctly, replace if necessary.
EL	259	Faulty KIM or BC20 master regulator.	Replace KIM. Replace BC20 main regulator.

Fault codes for gas boilers Buderus

Malfunction
The burner does not turn on		Turn on
		Turn on
	Are the circuit breakers ok?
		Check and, if necessary, replace defective parts.
	Natural gas supply pressure > 8 mbar?
		Eliminate the error.
	Defective burner control?
< 1,5 мA.
Boiling sounds	Limescale deposits or scale formation in the boiler?

Fault codes for combined boilers Buderus Logano

Fault code	Possible causes of malfunction
The burner does not turn on	Is the heating emergency switch in the On position?	Turn on
	Is the control system start switch in the On position?	Turn on
	Are the circuit breakers ok?	Check their performance, if necessary, replace the defective machine.
	Is the boiler water temperature controller connected?	Check and, if necessary, replace defective parts.
	Safety temperature limiter connected?	Check and, if necessary, replace defective parts.
	Error message from external safety devices (e.g. water level safety device)?	The user must check the heating system, rectify the fault and, if necessary, replace the defective device.
	Was the flue gas control system activated?	AW 10: Reset the flue gas control system. AW 50: Wait a maximum of 15 minutes. The boiler will turn on automatically if there is a demand for heat. If triggered repeatedly, check the flue gas path and check the function of the flue gas monitoring system. If there is a defect, then replace.
The burner starts and switches to fault. No spark on ignition.	Is there a sound when an ignition spark is generated when the ignition cable is removed?	If not, then: replace the ignition transformer. If yes, then: Replace ignition electrode or ignition burner.
Burner starts and switches to fault.	Are all gas shut-off valves open?	Open gas shut-off valves.
	Natural gas supply pressure > 8 mbar?	If not, then: find the cause and rectify the fault.
	Has the air been removed from the pipeline?	Remove air until ignition of the gas is possible.
The burner starts and switches to fault. No ionization current.	N and L connections reversed?	Eliminate the error.
	Is there voltage between L and PE?	If not, then: Ground the PE, in this case install an isolating transformer.
	Poor contact of the ionization wire?	Eliminate the error, in this case, replace the defective part.
	Short to ground on the ionization electrode?
	Defective burner control?
The burner starts and switches to fault. Ionization current< 1,5 мA.	Is the core or ceramic of the ionization electrode dirty?	Clean the ionization electrode, if necessary replace the pilot burner.
Boiling sounds	Lime deposits or lime scale in the boiler?	Clean the water circuit of the heating boiler in accordance with the manufacturer's recommendations. With constant loss of water, determine and eliminate the cause. If required, carry out water treatment and install a dirt trap

05.11.2017

Buderus boiler error 6a

Wall-mounted gas boilers Buderus

Buderus has been part of the Bosch Group since 2003. Wall mounted boilers of this brand are represented by three model series Logamax U072, Logamax U052 and Logamax U044.

The company provides a wide range of boilers of various technical equipment.

The series and model of the boiler is usually indicated on a special plate, which is located on the boiler. For example, Logamax U072 - 24K stands for:

U- gas heater with circulation pump

0 – gas-burner with premix

7 – boiler series

2 - type of combustion chamber (2 - closed, 4 - open)

24 - rated power of the boiler

K - double-circuit model

If problems occur, this information will be useful in diagnosing the nature of the problem.

The seventh series of Logamax U072 boilers is represented by the widest model range in the power range from 12 to 35 kilowatts. Boilers of this series are widely used for apartment heating and heating of small private houses.

Distinctive features:

low noise level - the boilers really work very quietly

variable speed fan

stylish design and convenient management

Boiler with modern technical equipment, compact size and affordable price.

Boiler Buderus malfunction

Like any other wall-mounted boiler, the Buderus is equipped with a protection system and in the event of an emergency, the operation will be stopped and the user will receive an error message that indicates which system of the unit has a malfunction.

Some devices are equipped with a liquid crystal display, and the user will see an error code. If the boiler is not equipped with a display, the fault will be indicated by flashing the temperature indicators. For example, if the temperature indicator 80 flashes, this means a 3C error that would appear on a similar boiler with a display.

Full list error codes reflected by the blinking of the indicators can be seen in the figure. Next, consider the most common errors and recommendations for their elimination.

Boiler Buderus error 6a

Error buderus 6a (second indicator flashes) occurs when the boiler does not detect a flame on the burner. Flame control is one of the most important functions of a safety system. To control the flame, there is a special electrode on the burner through which a small current flows during combustion. The control board constantly captures this current. If for some reason the current on the ionization electrode disappears, error 6a occurs. The same thing will happen, for example, after several unsuccessful attempts to ignite the boiler - this is the most common situation.

The reasons are standard for all boilers:

incorrect adjustment of the gas valve (insufficient network gas pressure)

poor contact or no signal from the flame ionization sensor

flame control sensor malfunction (dirty, broken)

failure of the control board (required)

incorrect electrical connection of the boiler (lack of grounding)

lack of air for proper combustion (lack of draft, clogging of the intake pipe)

The buderus 6a error is classified as critical, which means that after the occurrence of such a malfunction, the boiler will not start on its own - the error must be reset!

There are two options for resetting the error:

keep the OK button pressed until the fault signs disappear, the boiler starts working again and the display shows the flow temperature.

Turn the boiler on and off

Buderus boiler error 6a how to fix

First of all, you need to exclude the accidental occurrence of an error and simply reset it. If the error occurs again and the boiler does not start, then the problem needs to be addressed. The ignition problem in most cases can only be fixed by a qualified technician. The simplest thing to do is to inspect the combustion chamber and electrodes for contamination and clean if necessary.

If the boiler makes unsuccessful attempts to ignite, visually check that the spark breaks through the burner, and not somewhere else. If a crackling sound is heard, but there is no spark between the electrode and the burner, the electrode insulation is probably damaged somewhere and it needs to be replaced.

The adjustment of the gas valve may only be carried out by a specialist. Checking for proper mains gas pressure can be done via gas stove. If you light all the burners on the stove at the same time, they should work without interruption. If this is not the case, it can be assumed that the incoming pressure is not enough and you need to call the gas service.

In our practice, there was a case when a crack in the viewing window of the combustion chamber was the cause of the malfunction.

If the boiler ignites, but after a while it goes out, this may be due to a malfunction of the electronic board. You can check by replacing the board with a known good one.

Buderus error 3s (fourth indicator 80 flashes)

If such an error occurs, the boiler control board does not receive a signal from the differential pressure switch, that is, its contacts do not close after the fan starts. The pressure switch is used to determine necessary conditions removal of combustion products.

The procedure for starting the boiler into operation is as follows:

The control unit gives a signal to start the fan

The fan creates the necessary vacuum in the exhaust pipe

The differential relay registers vacuum and the microswitch contacts close

The board gives a signal to open the gas valve and ignite

Therefore, in order to understand the problem, it is necessary to determine at what specific moment the boiler goes into error. If the fan starts, but the relay does not click, it is tedious to inspect the supply pipes, perhaps there is a blockage or condensate, or there is actually a blockage in the chimney itself.

If the fan does not start, you need to check if voltage is applied to it. A faulty electronic board may be the reason why the fan does not start.

If the fan is running, there are no problems with the chimney and pneumatic relay tubes, you need to check the pneumatic relay itself by creating a vacuum yourself and checking for a characteristic click.

Permanently closed relay contacts or their opening during burner operation will also be regarded by the security system as a malfunction.

Buderus boilers can be equipped with a variable speed fan, which is electronically controlled and equipped with a sensor.

Error 4C (first indicator flashes)

The error occurs either when there is insufficient pressure in the heating system, or when the temperature at the outlet of the primary heat exchanger is too high. You need to check the pressure gauge. If the pressure in the system is not enough - less than 0.5 bar, it is necessary to feed the boiler. Too high temperature on the heat exchanger can also be caused by problems with the circulation of the coolant or an air lock. The source of the error is either a hydraulic pressure switch or a boiler water temperature limiter - a thermostat, which is located immediately at the outlet of the heat exchanger.

Error 4Y (the first two indicators flash)

Flow temperature sensor defective. For diagnostics, you need to measure the resistance at the sensor contacts. At room temperature it must be within 10 kOhm, the sensor connection must be reliable, because in case of a break, there will also be an error. The CL error logic is the same, only for the DHW temperature sensor. If the temperature sensor fails, the operation of the boiler is blocked, only the circulation pump remains in operation to prevent freezing. If the DHW temperature sensor is damaged, the operation of the boiler will not be blocked.

Error 2E (the first three indicators flash)

The logic of the error is that the flow temperature rises too fast, 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 circulation of the coolant. The most common causes of poor circulation are:

malfunction of the circulation pump or insufficient performance

heat exchanger clogged with dirt or scale

air in the heating system

In this article, we examined the most common malfunctions of Buderus gas boilers. A complete list of errors is contained in the equipment manual. Modern gas systems are designed so that the elements are as accessible as possible for ease of service. Some errors can be corrected by the user himself, for example, make up the boiler or inspect the chimney for blockages.

Doing any self-diagnosis should only be done when it is absolutely necessary to comply with precautionary and safety measures. If you do not have an idea about the principles of operation and device gas boiler- It is better to call a qualified specialist. The Buderus company posts informative videos in which the specialist talks, among other things, about the boiler errors that occur.

The device is in the "chimney sweep" mode. After 15 minutes, the chimney sweep mode is automatically deactivated.

Check price and buy heating equipment and related products you can from us. Write, call and come to one of the stores in your city. Delivery across all territory of the Russian Federation and the CIS countries.

Error code H - Heating mode

The Buderus boiler is in heating mode.

Error code (=) H - DHW mode

The device is in DHW mode.

Error Code 0A - Blocking

Cyclic blocking active: the delay time between switching off and switching on the burner has not yet expired (service function 2.3b).

Error code 0A for GB072-24K

Keep warm duration: The keep warm time has not yet expired (service function 2.3F).

Error Code 0C - Burner

The burner turns on.

Error Code 0E - On-Off Mode

Heat demand less than minimum heat output boiler. The boiler operates in on-off mode.

Error code 0H - Heat demand

The device is in the ready state, there is no need for heat.

Error Code 0L - Delay

The gas valve opens, the first delay time.

Error Code 0U - Startup

The boiler starts up.

Error code 0Y - Temperature above the set

The actual flow temperature is higher than the set temperature. The boiler is switched off.

Error code 2E - Air removal

Error: Ventilation function is active.

Error code 2H - Pump protection

Anti-jamming protection for the heating circuit pump and three-way valve is active.

Error code 2P - Temperature rise

Limitation of gradients: temperature increase too fast in domestic hot water mode.

1. Open service taps.

Error Code 5H - System Test

Boiler test by control system.

Error code H11 - Temperature sensor

Damage to the DHW temperature sensor (GB072-24K).

1. Remove temperature sensor.
2. Check the connecting cable for breaks and short circuits, replace if damaged.

Error code 0Y - The temperature at the flow sensor is more than 95 C

This message may appear in the absence of a malfunction, if all the valves on the radiators suddenly close or after hot water is drawn from the GB072-24K.

1. Check the operating pressure in the heating system.
2. Open service taps.
3. Connect the heating circuit pump electrically to the BC20 master controller.
4. Check or replace the heating circuit pump.
5. Correctly set the pump power or its characteristic and adjust to the maximum power.
6. Check for damage or short circuit in the flow temperature sensor and its wires, replace if necessary.

Error code 0Y - High temperature on the hot water temperature sensor

1. Check the correct position of the sensor.
2. Check it, and if it is defective, replace it.

Error code 3A - Fan does not work

Check it, and if it is defective, replace it.

Error code 3F - Business interruption

The burner and fan have been running for 24 hours without interruption and are switched off for a short time for safety reasons.

Error code 4C - Blockage

The heat exchanger temperature limiter or the flue gas temperature limiter of the Buderus boiler has tripped. If a blocking fault exists for a long time, then it turns into a locking one.

Flow temperature sensor defective (short circuit). If the fault exists for a long time, the display will show fault code 4U and run code 222.

Error code 4Y - Temperature sensor

Flow temperature sensor defective (break). If the fault exists for a long time, the display will show fault code 4Y and operating code 223.

Error code 6A - Flame not detected

After the 4th ignition attempt, the blocking fault turns into a locking one.

Error code 6L - No ionization signal during burner operation

The burner restarts. If the ignition fails, a blocking error 6A will be displayed, after the 4th ignition attempt, the blocking fault goes into failure.

Error code 8Y - The AT90 temperature control relay has tripped

1. Check the adjustment of the temperature control relay AT90.
2. Check the heating control setting.

Error code 8Y - Faulty temperature control relay AT90

Error code 8Y - There is no jumper between the terminals of a separate AT90 temperature control relay

If no temperature control relay is connected, install a jumper.

Error code 8Y - Temperature control relay blocked

1. Unlock the temperature control relay.
2. Check the condensate drain.
3. Condensate pump not working - replace condensate pump.

EL error code

BC20 main regulator defective - replace.

Error code 3C - Fan operation error

Check the fan and its cable with plug, replace if necessary.

Error code 3L - Fan turned off during the delay time

Error code 3P - Fan running too slow

Check and, if necessary, replace.

Error code 3Y - Fan is running too fast

1. Check and, if necessary, replace.

Error code 4C - Temperature limiter

Error in the heat exchanger temperature limiter or flue gas temperature limiter.

1. Check: for damage to the heat exchanger / flue gas temperature limiter and its connecting cable, replace if necessary, operating pressure in the heating system, temperature limiter, replace if necessary, pump pressure, replace pump if necessary, fuse, replace if necessary.
2. Remove air from the boiler.
3. Check the water circuit of the heat exchanger, replace if necessary.
4. For Buderus boilers with a divider in the heat exchanger, check whether the divider is installed.

Error Code 4U - Temperature Sensor

Flow temperature sensor defective (short circuit).

Check for damage or short circuit in the temperature sensor and its wire, replace if necessary.

Error code 4Y - Faulty flow temperature sensor (break)

Check for damage or breakage of the temperature sensor and its wire, replace if necessary.

Error code 6A - Error: flame not found

1. Check: PE connection, gas cock open, gas supply pressure, electrical connection, electrodes with wires, flue gas system, clean or repair if necessary.
2. Check the gas-air ratio, correct if necessary.
3. For natural gas: check gas flow switch, replace if necessary.
4. When working with combustion air intake from a room, check the air supply to the room and the ventilation openings.
5. Clean the drain of the condensate siphon.
6. Remove the membrane in the fan mixing device, check for cracks and dirt on it.
7. Clean the heat exchanger of the Buderus boiler.
8. Insert KIM correctly, replace if necessary.
9. Two-phase network (IT): install a resistance of 2 ohms between PE and N on the connection of the electronic board to the mains.

Error code 6C - In shutdown mode, the boiler registers a flame

1. Check the contamination of the electrodes, replace if necessary.
2. Check the flue gas system, clean or repair if necessary.
3. Check the moisture content of the electronic board, dry if necessary.

Error Code 6C - Flame Detected After Gas Shutoff

1. Check gas fittings, replace if necessary.
2. Clean the condensate siphon.
3. Check electrodes and connecting wires, replace if necessary.
4. Check the flue gas system, clean or repair if necessary.

Error code 7L - Time error at first delay time

Error code 7L - Time error when trying to restart

Replace BC20 main regulator.

Error code 9L - Faulty gas valve

The coil or connecting wire of the gas fitting is defective.

1. Check wires, replace if necessary.
2. Replace gas valve.

Error code 9P - KIM not recognized

Insert KIM correctly, replace if necessary.

Error code EL - Faulty KIM or main regulator BC20

Replace KIM. Replace BC20 main regulator.

Error codes for gas wall-mounted boilers Buderus Logamax

Error code 1A - Exhaust gas outlet at flow fuse

Check gas path.

Error code 1L - Exhaust gas outlet on the combustion chamber

Check the heat exchanger for contamination.

Error code 1Y - Exhaust gas temperature sensor not detected

Check flue gas temperature sensor and connecting cable for damage.

Error code 2E - Insufficient filling pressure of the heating system

Check filling pressure, increase it if necessary.

Error code 2P - Temperature difference too high

Check pump and bypass line.

Error code 4C - The limiter in the supply line has tripped

Check the pressure in the system, check the temperature sensors, check the operation of the pumps and the fuse on the printed circuit board, bleed the air from the device.

Error code 4E - The temperature sensor in the burner chamber is not detected

Check the temperature sensor in the burner chamber and the connecting cable for damage.

Error code 4Y - Flow temperature sensor not working

Check temperature sensor and connecting cable.

Error code 5H - EMS communication interrupted

Check connecting cable and regulators.

Error code 6A - Flame not detected

Is the gas cock open? Check the pressure in the gas network, mains connection, trigger electrode with cable and ionizing electrode with cable.

Error code 6C - Flame detected after shutting off gas supply

Check ionizing electrode. Check gas fittings.

Error code 8Y - No jumper found on ST8 161

If there is a jumper, insert the plug correctly, check the external limiter. Otherwise: is there a jumper?

Error code 9C - Coding plug not found

Insert the coding plug correctly, measure it and replace if necessary.

Error code CL - Hot water temperature sensor defective

Logamax U054-24K

• Check temperature sensor and connecting cable for damage or short circuit;
• The hot water temperature sensor is incorrectly installed.

Logamax U054-24K

• Check the installation area, if necessary, dismantle the sensor and reinstall it using heat-conducting paste.

Error code CP - Boiler sensor not found

Check boiler sensor and connecting cable.

EC Error Code - Internal Fault

Check the tightness of the connection of electrical plug contacts and jumper lines, if necessary, replace the printed circuit board.

Error code EL - Wrong reference voltage

Replace printed circuit board.

Error code EP - By mistake, the fault message reset button was held down too long (more than 30 seconds)

1. Press the reset button again and hold it down for less than 30 seconds.
2. Outside temperature sensor not found. Check the outside temperature sensor and connecting cable for damage.

Malfunctions of Buderus boilers

If you are not 100% sure what exactly the problem is and that you can solve it, immediately contact the service center to diagnose and fix the problem.

The burner does not turn on

The emergency switch of the heating system is in the off-on position.

Start switch of the control system in the off position - enable.

The circuit breakers are faulty - check their operability, if necessary, replace the defective circuit breaker.

Damaged boiler water temperature controller - check and, if necessary, replace defective parts.

Safety temperature limiter damaged - check and, if necessary, replace defective parts.

Error message from external safety devices (for example, from a water level safety device) - the user must check the Buderus boiler, eliminate the malfunction and, if necessary, replace the element.

The flue gas control system has been triggered:

• AW 10 - unlock the flue gas control system;
• AW 50 - Wait a maximum of 15 minutes.

The boiler will turn on automatically if there is a demand for heat. If triggered repeatedly, check the flue gas path and check the function of the flue gas monitoring system. If there is a defect, then replace.

The burner starts and switches to fault. No spark on ignition

Is there a sound when an ignition spark is generated with the ignition cable removed?

• If not, then replace the ignition transformer;
• If so, replace the ignition electrode or ignition burner.

Burner starts and switches to fault

All gas shut-off valves are closed - open the gas shut-off valves.

Natural gas supply pressure greater than 8 mbar - if not, find the cause and correct the problem.

Has air been removed from the pipeline? Remove air until the gas can be ignited.

The burner of the Buderus boiler starts and switches to fault. No ionization current

If N and L connections are reversed, correct the error.

Is there voltage between L and PE? If not, ground the PE, in this case install an isolating transformer.

Poor contact of the ionization wire - eliminate the error, in this case, replace the defective part.

Short to ground on the ionization electrode - repair the damage.

Defective burner control - replace element.

The burner starts and switches to fault. Ionization current less than 1.5 mA

The core or ceramic of the ionization electrode is dirty - clean the ionization electrode, if necessary, replace the ignition burner.

Boiling sounds

Lime deposits or scale formation in the boiler - clean the water circuit of the heating boiler in accordance with the manufacturer's recommendations.

With constant loss of water, determine and eliminate the cause. If required, carry out water treatment and install a dirt trap.