Problem: “EA error appears on the new BOSCH WBN 6000-24c boiler - no flame detected. The more degrees are set, the less frequent the error. But at low temperatures, it gives an error almost every day. The flame icon disappears before the error occurs. What to do?"

• Check if the protective conductor is connected;
• Make sure the gas cock is open;
• Check gas pressure, correct if necessary;
• Make sure that the connection to the mains is working properly;
• Check electrodes with wires, replace if necessary;
• Check the flue gas outlet system, clean or repair if necessary;
• Check gas regulation, correct if necessary;
• For natural gas: check the gas flow monitor. Replace if necessary;
• When working with combustion air intake from a room, check the air supply to the room and ventilation openings;
• Clean the heat exchanger;
• Check gas valve, replace if necessary.

In 90% of cases, the problem is in the board. The best thing is to immediately contact the service center. There they will be able to provide quality assistance: make diagnostics and repair the boiler.

Hopefully the article " Gas boiler WBN BOSCH 6000-24c EA error"Was useful to you.

Bosch boiler errors - Meaning, causes and remedies

We have such a problem. The Bosch boiler is two-office, we use it for only six months. They turned on hot water, but it does not heat up, knocks out the boiler and shows an error E9. The filter was cleaned, the device started up, but after an hour it turned off again. Shows the error. When we start, the pressure rises immediately and the unit is cut down. Then we turn it on, the fuses immediately burn out and the boiler goes out. So we can't turn it on. Please help in
what could be the reason?

Most likely your pump is jammed. Usually the fuses are lit because of the pump.

Bosch gas 6000w boiler. Was purchased in August this year. As a sharp cold snap came, it turned off and showed an error C6 (the differential pressure switch does not turn on). After removing the front cover, it was found that the tubes that fit this relay were covered with frost. After drying the tubes, the device started up. This situation has been repeated several times already. Is there any way
get rid of this problem?

It is necessary to look at how the smoke exhaust system is made. A split system often leads to such consequences. We recommend replacing it with a coaxial one. If there is no possibility to change the chimney, then the pipes must be insulated.

Wall hung boiler Wbn 6000-24. The gas is natural. The EA error has appeared for a very long time. After reading about the EA error, I decided to find out the firmware of the board and the fan stage settings. If the software version displays "245-03" in the menu and does not seem to raise any questions, then the menu of the fan stages shows the number "17". Horizontal chimney system with concentric pipe. The exit from the boiler is about 2 meters. No fence adapter
I have not installed air from inside the room and the air enters the unit from outside the room. What guided the masters by installing the 17th stage of the fan, although, judging by the instructions, the 2nd stage is needed. Do I need to change the board?

No adapter needed. You have a standard coaxial with outdoor air intake. Setting the fan step to 5 helps to get rid of this error. I had the same thing, and when I asked 5, there was no error for a year.

Tell me, does the burner use modulation only when using a thermostat or in some other cases?

When the temperature of the coolant approaches the set modulation, the boiler turns on in any case, regardless of whether there is a thermostat or not, but since this process takes little time, it is difficult to fix it. If an OT thermostat is used, then modulations start to occur when the room temperature approaches the set one. If an On / Off thermostat is installed, there is no connection.

Private house 70m2 300mm foam block 50 mm mineral wool and facing with ceramic bricks. There are plans to expand the area by another 50-60 sq. m. On the ground floor there is a transformer substation 33m2, heating batteries are installed on both floors. The hot water supply is implemented by a kitchen and a bathroom, and there will be a second bathroom in the next one. I want to supply BKN Dražice 125. Since a riser is installed in my house, I plan to install a wall-mounted gas boiler
coaxial chimney. I am considering different options. The most optimal for the price is the Bosch 6000 (18 kW), but the bosch gaz 7000 has a minimum power of 24 kW, which, I think, is too much for me. Of the important, I need that the boiler has the ability to set the temperature in the boiler and, in the future, it would be possible to mount a room thermostat and an outdoor sensor. Interested in
the difference between the specified models in the composition of components or in the place of assembly? Maybe there are some other fundamental differences?

In your case, the most optimal model will be the bosch gaz wbn6000-18 and wstb 120.

Error codes for Bosch WBN 6000 boilers

Error A7 - Malfunction of the DHW temperature sensor. Inspect the sensor for a defect or short circuit and its wiring. Replace if necessary.

Error Ad - The unit cannot fix the boiler temperature sensor. It is required to inspect the boiler temperature sensor and connecting wires.

Error C1 - The fan rotates at a low speed. Need to check the mains voltage. Also inspect the flue gas system and, if necessary, clean or repair it.

Error C4 - No opening of the differential pressure switch if the fan is off. It is required to examine the diff. pressure switch.

Error C6 - The differential pressure switch does not close. Check the fan and cables with plugs. Replace if required. Inspect diff. pressure switch and flue gas outlet pipes.

Error C7 - The fan does not work. Check the fan and its wires with plugs. Replace if required.

CE error - There is not enough pressure in the heating system. Water is required.

Error d7 - Malfunction of the gas system. Check the connecting wire. Inspect the gas system and replace if necessary.

Error E2 - Malfunction of the temperature sensor in the supply line (interruption). It is required to check for possible damage or short circuit of the sensor and its wiring. Replace if required.

Error E9 - The temperature limiter in the heat exchanger is triggered. It is required to check for possible damage to the temperature limiter of the heat exchanger and its connecting wires. Replace if necessary. Check the nominal system pressure. Inspect the temperature limiter and replace with a new one if necessary. Check the start of the circulation pump and, if
it is necessary to replace it. Check fuses, replace if necessary. Remove air from the unit. Check the water circuit in the heat exchanger. Replace if necessary. Check the flue gas temperature limiter for possible damage.

EA error - No flame. Check the connection of the protection wires. See if the gas cock is open. Test the supply gas pressure reading and eliminate if necessary. Check the connection to the electrical network, electrodes with wires and, if necessary, replace. Inspect the flue system, clean or repair. Check the gas regulation, eliminate if necessary. For natural gas: Inspect the gas flow switch. Change if necessary. When working with combustion air intake from the room, check the air supply to the room and the ventilation openings. Clean the heat exchanger. Check gas system, replace if necessary.

Error F7 - When switched off, the boiler detects a flame. Check electrodes for oxidation, replace if necessary. Inspect the flue gas system and, if necessary, clean or repair. Check the electronic control board for moisture, dry if necessary.

FA error - A flame is detected when the gas supply is turned off. Check gas system, replace if necessary. Inspect electrodes and connecting wires, replace if necessary. Inspect the flue system, clean or repair.

Error P - The type of boiler is not detected. Set up the unit type.

Fd error

Error codes for boilers Bosch ZWC MFA

Code A2, C3 - Flue gas outlet on the combustion chamber. Check the heat exchanger for clogging.

Code A3 - No flue gas temperature sensor detected. The sensor and connecting cables must be checked for damage.

A4 code - Flue gas outlet at the flow protector. Check the flue gas outlet.

Code A6 - The temperature sensor in the combustion chamber is not detected. The sensor and connecting cables must be checked for damage.

Code A7 - Malfunction of the hot water temperature sensor (DHW). Perform a check to find defects or short circuits of the temperature sensor and its wiring, if necessary, replace.

Code A8 - Contact with the BUS bus interrupted. Check the contact cable and regulators.

Code A9 - Incorrect installation of the DHW sensor. Check the installation distances, if necessary remove the sensor and reinstall it using heat-conducting paste.

AC code - The module is not defined. The module is not connected correctly. Check the module, outside temperature sensor, remote control and contacts.

Ad code - The unit cannot fix the boiler temperature sensor. It is required to inspect the boiler temperature sensor and wire contacts.

Code b1 - No coding plug defined. Correctly insert the coding plug, measure it and replace if required.

Codes C1, C6 - The differential pressure switch does not close. Check the fan and cables with plugs. Replace if required. Inspect diff. pressure switch and flue gas outlet pipes.

Code C4 - Dif. the pressure switch in the off position does not open. Check the differential pressure switch.

CC code - The control unit cannot detect the outside temperature sensor. It is required to inspect the sensor and contact cable for breakage.

D3 code - No jumper 161 was found on ST8. If there is a jumper, insert the plug correctly, check the external stop. Otherwise: check if a jumper is present.

D4 code - There is a large temperature difference. Check the circulation pump, bypass hose and system pressure.

D5 code - The external temperature sensor is damaged. Check sensor and connection contacts.

Code E2 - Defective flow temperature sensor. Check sensor and connection contacts.

E9 code - A limiter has been triggered in the flow line. Check the pressure in the system, temperature sensors. Check the functions of the pumps and the fuse on the control board, bleed the unit.

EA Code - No flame detected. Inspect the gas cock. Check the gas supply pressure, mains connection, ignition electrode with cable and ionisation electrode with cable.

F0 code - Internal problem. Check that the electrical plug contacts and start lines are connected correctly, replace the electronic board if necessary.

F7 code - The flame is detected when the unit is off. Check electrodes and cables. The flue gas system may be defective. Check control board for moisture.

FA code - Flame detection after gas supply shutdown. Inspect the ionization electrode. Check the gas system.

Fd code - Incorrect pressing of the button (duration more than 30 seconds). Press the button again less than 30 seconds.

Malfunctions and adjustments of Bosch boilers

Bosch assures that its heat exchangers are not coated with special protective anti-corrosion paint. Heat exchangers of other companies (Viessmann, Vaillant, Ariston, Baxi) have a protective layer applied, and they have pure copper. And they present it as the advantages of their models. Is this so or is it just a reduction in the cost of the device.

Copper really does not corrode, which is why it is used. But due to its properties, copper burns rather quickly.

As I know, there are two options for connecting the BKN to a double-circuit gas boiler. First, through a three-way valve. Second, through a hydraulic separator. In both cases, it is used as a consumer for the heating system, respectively, it will be heated from the temperature of the heating system. This is clear to me. But I do not understand what to do with the DHW taps, and whether it is possible to simply put plugs on them. At first I
I assumed that I would buy a Bosch 6000 single-circuit boiler, but since it was not available, I was advised to opt for a double-circuit one. And I'm thinking, if I shut off the outputs, will the heat exchanger be damaged (will it burn out without water)? Since I will not keep the unit constantly operating at maximum, let the BKN continue to work. Moreover, I bought ACV Comfort 130, and by design it is a tank in the tank and, in fact, should keep the temperature better than with a coil. Among the disadvantages of such boilers is a maximum pressure of 3 bars, and a safety valve for the same pressure. And knowledgeable people report that if the valve for some reason does not work, the tank will burst. About the double-circuit model - I am afraid that if the boiler fails, I will be left without hot water at all.

Your conclusions are correct only for purified water. For household needs, you can establish a backup line. But in my memory, the cases of failure of ACV boilers have never happened.

In a private house, I organize a separate smoke exhaust for a 24 kW Bosch 6000 gas boiler. In this regard, I have two questions. Exhaust tract. Is it worth going from "trousers" 80-80 through a tee with a condensate drain to a vertical chimney diameter of 100 mm? The cost of pipes of different diameters does not differ much from each other. Chimney heights up to tee 4800 mm. I bring the pipe through the roof
given 10 degrees. Intake tract. I am going to organize the air intake in an unheated and well-ventilated attic. The outer wall is about 4 meters away. Taking air from the room is not a good solution. The distance from the point of intake in the attic room to the upper plane of the unit is about 1050 mm (and inside the boiler room 800 mm of the entire length). In winter, such a solution can create a number of problems,
the main one is that air with outside temperature will be supplied to the device. It is also possible for strong condensation to form on the air duct, which will fall onto the body. But if condensation can be dealt with with thermal insulation, then how to solve the problem of warm air flow is not clear to me. As an option, I considered it to feed the air duct from the chimney of the bath (you will need to weld
water register with a diameter of 300-500mm). Organize circulation in the register in a separate circuit. It is very difficult, but it should work. Tell me, which chimney kit is suitable for installation on wbn 6000-24 c? It is necessary to bring the chimney directly behind the wall with a thickness of 375 mm; further it will not need to be pulled anywhere. Since the prices for branded equipment are very high, I would like to try another manufacturer.
Neva, for example. Will it be possible to reprogram a single-circuit unit if you turn off the DHW flow sensor first?

Not. It will be necessary to replace the control board of a single-circuit boiler and the hydraulic unit from it. And also install a three-way valve additionally.

We recently flushed the heat exchangers of the Bosch 6000 gas boiler. I worked for a month and kept the pressure at 1. Then I attracted a strange babbling sound inside it before igniting the burner (in cooling mode), as if water were being poured from one mug into another. He looked, and the pressure was 0, In theory, it should have turned off automatically when the pressure in the system dropped to 0.5, but it worked and warmed up the batteries.
The only thing that appeared was another sound and murmur. I added the pressure to 1, but the next day the pressure dropped back to 0.5 again (i.e. water is leaking somewhere). I checked pipes and radiators, but found no leaks anywhere. It also does not drip from the unit, but the pressure still drops. Tell me what could be
problem and where to look for it?

I had a similar experience. In the system, the air even after the operation of the apparatus left the air and the pressure dropped. Is the automatic air vent valve (on top of the pump) not closed? It is necessary to always be ajar. It is better to bring the pressure to 2 atm., So that the expansion tank in the boiler also takes the volume and compensates for the outgoing air. In the radiators, of course, also bleed air with a Mayevsky tap.

The gas wall-mounted boiler Bosch 6000 24 kW often gives an EA error and often turns on and off. That is, conditionally - set it to at least 40 degrees, literally 5 minutes and turned off, etc. Previously, I warmed up as needed, but now the first batteries are hot, the distant ones are barely warm, they do not reach them. It operates on the return temperature, there is no room thermostat.

The EA error can be eliminated by setting the fan stage to 5. The fact that the unit turns off quickly means that its minimum power is too high for your system. He cannot give less than 8 kW. And you apparently have 5 radiators in the system. Here he heats this water and turns off. And why he heats them up so quickly, the following malfunctions are possible: something is clogged or airy or the first radiators need to be balanced so that the entire flow does not go only through them. Here you need to look at the diagram of radiators and so on. Try setting the pump speed to maximum (value 3) and bleeding air into the radiators.

Tell me who knows about: Wall mounted gas boiler WBN 6000-18C RN. What kind of production tests are performed? Are they being launched?

Everything was fine with me, I don't think it was from the factory, most likely the storage was strange.

Prompt: the wall-mounted Bosch boiler has stopped, the pressure has risen to 3 bar, it has issued an error E9r. I tried to restart it, it worked, after 10 seconds. the pressure jumped to the maximum, I stopped everything, turned it off, released the pressure. I checked the gas pressure is normal, as it was. What could it be?

If the system is new, then the expansion tank is small, if the old one, then the expansion tank is faulty, or the make-up may poison. In your case, a malfunction of the expansion tank is most likely. If this is so, then option 2: pump up the pressure, replace the tank.

After opening the hot water tap and igniting the burner, the Bosch boiler issues an E2 error (the flow temperature sensor is faulty). This happens in 10-15 seconds. After closing the tap, the error is removed by itself, and the boiler continues to work in heating mode. If the tap is opened again, the situation is repeated. To complete the picture: An additional circulation pump is installed in the heating circuit, before its installation
the boiler and in heating mode showed an error E2 for a couple of seconds, and then changed to E9 (the heat exchanger temperature limiter was triggered). The source of water supply is a borehole pump (pressure on the water supply is from 2x to 3x without sudden jumps).

Possible reasons are: its own circulation pump is faulty (if it is only used with DHW mode), the mesh filter is clogged. the sensor probably shouldn't be ruled out.

Boiler zwa 24. The concept has changed, a heat exchanger from zsa, a boiler sensor and a three-way valve are required. The payment, I think, is the same. In general, a single-circuit must be made from a double-circuit.

The manufacturer does not recommend doing such alterations. But if you wish, you need to purchase a heat exchanger. They have the same feed tubes, but different outlet tubes. On the 2-circuit there is a hole for recharge, but on the 1-circuit there is no. There are 2 options. Change the pipe. Figure out how to plug the hole. The control boards are the same.

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Bosch boiler - Errors and their meaning

Error codes for Bosch WBN 6000 boilers

A7 - Malfunction of the DHW temperature sensor. Inspect the sensor for a defect or short circuit and its wiring. Replace if necessary.

Ad - The unit cannot fix the boiler temperature sensor. It is required to inspect the boiler temperature sensor and connecting wires.

C1 - The fan rotates at a low speed. Need to check the mains voltage. Also inspect the flue gas system and, if necessary, clean or repair it.

C4 - No opening of the differential pressure switch if the fan is off. It is required to examine the diff. pressure switch.

C6 - The differential pressure switch does not close. Check the fan and cables with plugs. Replace if required. Inspect diff. pressure switch and flue gas outlet pipes.

C7 - The fan does not work. Check the fan and its wires with plugs. Replace if required.

CE - There is not enough pressure in the heating system. Water is required.

d7 - Malfunction of the gas system. Check the connecting wire. Inspect the gas system and replace if necessary.

E2 - Malfunction of the temperature sensor in the supply line (interruption). It is required to check for possible damage or short circuit of the sensor and its wiring. Replace if required.

E9 - The temperature limiter in the heat exchanger is triggered. It is required to check for possible damage to the temperature limiter of the heat exchanger and its connecting wires. Replace if necessary. Check the nominal system pressure. Inspect the temperature limiter and replace with a new one if necessary. Check the start of the circulation pump and, if necessary, replace it. Check fuses, replace if necessary. Remove air from the unit. Check the water circuit in the heat exchanger. Replace if necessary. Check the flue gas temperature limiter for possible damage.

EA - No flame. Check the connection of the protection wires. See if the gas cock is open. Test the supply gas pressure reading and eliminate if necessary. Check the connection to the electrical network, electrodes with wires and, if necessary, replace. Inspect the flue system, clean or repair. Check the gas regulation,
eliminate if needed. For natural gas: Inspect the gas flow switch. Change if necessary. When working with combustion air intake from the room, check the air supply to the room and the ventilation openings. Clean the heat exchanger. Check gas system, replace if necessary.

F7 - When switched off, the boiler detects a flame. Check electrodes for oxidation, replace if necessary. Inspect the flue gas system and, if necessary, clean or repair. Check the electronic control board for moisture, dry if necessary.

FA - A flame is detected when the gas supply is turned off. Check gas system, replace if necessary. Inspect electrodes and connecting wires, replace if necessary. Inspect the flue system, clean or repair.

P - The type of boiler is not detected. Set up the unit type.

Fd

Error codes for boilers Bosch ZWC MFA

A2, C3 - Flue gas outlet on the combustion chamber. Check the heat exchanger for clogging.

A3 - No flue gas temperature sensor detected. The sensor and connecting cables must be checked for damage.

A4 - Flue gas outlet at the flow protector. Check the flue gas outlet.

A6 - The temperature sensor in the combustion chamber is not detected. The sensor and connecting cables must be checked for damage.

A7 - Malfunction of the hot water temperature sensor (DHW). Perform a check to find defects or short circuits of the temperature sensor and its wiring, if necessary, replace.

A8 - The contact with the BUS bus has been interrupted. Check the overhead cable and regulators.

A9 - Incorrect installation of the DHW sensor. Check the installation distances, if necessary remove the sensor and reinstall it using heat-conducting paste.

AC - The module is not defined. The module is not connected correctly. Check the module, outside temperature sensor, remote control and contacts.

Ad - The unit cannot fix the boiler temperature sensor. It is required to inspect the boiler temperature sensor and wire contacts.

b1 - No coding plug defined. Correctly insert the coding plug, measure it and replace if required.

C1, C6 - The differential pressure switch does not close. Check the fan and cables with plugs. Replace if required. Inspect diff. pressure switch and flue gas outlet pipes.

C4 - Dif. the pressure switch in the off position does not open. Check the differential pressure switch.

CC - The control unit cannot detect the outside temperature sensor. It is required to inspect the sensor and contact cable for breakage.

d3 - No jumper 161 was found on ST8. If there is a jumper, insert the plug correctly, check the external stop. Otherwise: check if a jumper is present.

d4 - There is a large temperature difference. Check the circulation pump, bypass hose and system pressure.

d5 - The external temperature sensor is damaged. Check sensor and connection contacts.

E2 - Defective flow temperature sensor. Check sensor and connection contacts.

E9 - A limiter has been triggered in the flow line. Check the pressure in the system, temperature sensors. Check the functions of the pumps and the fuse on the control board, bleed the unit.

EA - No flame detected. Inspect the gas cock. Check the pressure in the gas network, the mains connection, the ignition electrode with cable and the ionization electrode with cable.

F0 - Internal problem. Check that the electrical plug contacts and start lines are connected correctly, replace the electronic board if necessary.

F7 - The flame is detected when the unit is off. Check electrodes and cables. The flue gas system may be defective. Check control board for moisture.

FA - Flame detection after gas supply shutdown. Inspect the ionization electrode. Check the gas system.

Fd - Incorrect pressing of the button (duration more than 30 seconds). Press the button again less than 30 seconds.

Malfunctions and adjustments of Bosch boilers

Wall hung boiler Wbn 6000-24. The gas is natural. The EA error has been appearing for a very long time. After reading about the EA error, I decided to find out the firmware of the board and the fan stage settings. If the software version displays "245-03" in the menu and does not seem to raise any questions, then the fan steps menu shows the number "17". Horizontal chimney system with concentric pipe. The exit from the boiler is about 2 meters. I have not installed any adapter for air intake from inside the room and the air enters the unit from outside the room. What guided the masters by installing the 17th stage of the fan, although, judging by the instructions, the 2nd stage is needed. Do I need to change the board?

No adapter required. You have a standard coaxial with outdoor air intake. Setting the fan step to 5 helps to get rid of this error. I had the same thing, and when I asked 5, there was no error for a year.

Recently, the heat exchangers of the Bosch 6000 gas boiler were washed. I worked for a month and kept the pressure at 1. Then I attracted a strange babbling sound inside it before lighting the burner (in a cooling mode), as if water were being poured from one mug into another. He looked, and the pressure was 0, In theory, it should have turned off automatically when the pressure in the system dropped to 0.5, but it worked and warmed up the batteries. The only thing that appeared was another sound and murmur. I added the pressure to 1, but the next day the pressure dropped back to 0.5 (i.e. water is leaking somewhere). I checked pipes and radiators, but found no leaks anywhere. It also does not drip from the unit, but the pressure still drops. Tell me what could be
problem and where to look for it?

I had a similar experience. In the system, the air even after the operation of the apparatus left the air, and the pressure dropped. Is the automatic air vent valve (on top of the pump) not closed? It is necessary to always be ajar. It is better to bring the pressure to 2 atm., So that the expansion tank in the boiler also takes the volume and compensates for the outgoing air. In the radiators, of course, also bleed air with a Mayevsky tap.

The gas wall-mounted boiler Bosch 6000 24 kW often gives an EA error and often turns on and off. That is, conditionally - set it to at least 40 degrees, literally 5 minutes and turned off, etc. Previously, I warmed up as needed, but now the first batteries are hot, the distant ones are barely warm, they do not reach them. It operates on the return temperature, there is no room thermostat.

The EA error can be eliminated by setting the fan stage to 5. The fact that the unit shuts down quickly means that its minimum power is too high for your system. He cannot give less than 8 kW. And you apparently have 5 radiators in the system. Here he heats this water and turns off. And why he heats them up so quickly, the following malfunctions are possible: something is clogged or airy, or the first radiators need to be balanced so that the entire flow does not go only through them. Here you need to look at the diagram of radiators and so on. Try to set the pump speed to maximum (value 3) and bleed air into the radiators.

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This article contains all possible malfunctions and options for their elimination, as well as error codes for Bosch 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.

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

You can find out the price and buy heating equipment and related products from us. Write, call and come to one of the shops in your city. Delivery throughout the territory of the Russian Federation and the CIS countries.

Errors of Bosch Gaz 6000 boilers

The list below contains malfunctions specifically for Bosch Gaz 6000 series boilers. Determine the error code and eliminate the malfunctions in a timely manner.

Error code A7 - The hot water temperature sensor has a malfunction

Error code Ad - Boiler temperature sensor not detected

Check the boiler sensor and connection wires.

Error code C1 - Fan rotates at low speed

1. Check the mains voltage.
2. Check the flue gas outlet. If required, clean or repair.

Error code C4 - Differential pressure switch does not open when the fan is not working

Check diff. pressure switch.

Error code C6 - Differential pressure switch does not close

1. Check diff. pressure switch, as well as flue gas pipes.

Error code C7 - Fan not functioning

Check the fan, wire and plug. Replace if required.

CE error code - Low pressure to fill the heating system

Top up with water.

Error code d7 - There is a malfunction of the gas fittings of the wall-mounted boiler Bosch 6000

1. Check the connection wire.

Error code E2 - Malfunction or breakage of the temperature sensor on the supply line

Check the sensor for a defect, as well as a possible short circuit in its wire. Replace if required.

Error code E9 - Heat exchanger temperature limiter intervention

1. Check the temperature limiter of the heat exchanger for a defect, as well as a possible short circuit in its wire. Replace if required.
2. Check the operating pressure in the heating system.
3. Check the temperature limiter, replace if necessary.
4. Check pump start. Replace the pump if required.
5. Check fuse, replace if necessary.
6. Remove air from the Bosch 6000 gas boiler.
7. Check the water circuit of the heat exchanger; if damaged, replace it.
8. Check the flue gas temperature limiter for a defect, as well as a possible short circuit in its wire. Replace if required.

EA Error Code - Flame Not Found

1. Check the connection of the protection wire.
2. Check the opening of the gas cock.
3. Check gas supply pressure. Correct the problem if necessary.
4. Check the connection to the electrical network.
5. Check electrodes and wires. Correct if necessary.
6. Check the flue gas outlet. If required, clean or repair.
7. Adjust the gas. Correct if necessary.
8. For natural gas: check the gas flow monitor. Correct the problem if necessary.
9. When using the combustion air intake from a room, check the air draft into the room and the ventilation openings.
10. Clean the heat exchanger.
11. Inspect the gas fittings. Replace if required.

Error code F7 - Flame detection when the boiler is off

Although the boiler is off, a flame is detected.

1. Check the electrodes for contamination, replace if necessary.
2. Check the humidity of the electronic board, dry if necessary.

Error code FA - Flame detection after gas supply cut off

A flame was detected after the gas supply was cut off.

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

Error code P - Boiler type not defined

Set the boiler type.

Error code Fd - The button was mistakenly pressed for too long (more than 30 seconds)

Error codes for gas boilers Bosch ZSC / ZWC 24 MFA

Below is a list of faults specifically for Bosch boilers of the ZSC / ZWC 24 MFA series. Determine the error code and fix problems in a timely manner.

Error code A7 - Hot water temperature sensor defective

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

Error code A8 - BUS connection interrupted

Check connecting cable and controls.

Error code A9 - Hot water temperature sensor incorrectly installed

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

Error code Ad - No boiler sensor detected

Check boiler sensor and connecting cable.

Error code b1 - Coding plug not found

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

Error code C1 - Differential pressure switch tripped during instrument operation

Check differential pressure switch, exhaust system and connecting pipes.

Error code C4 - Differential pressure switch in the inoperative position does not open

Check differential pressure switch.

Error code C6 - Differential pressure switch does not close

Check differential pressure switch and flue gas pipes.

Error code d3 - No jumper detected on ST8 161

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

Error code d4 - Temperature difference too large

Check pump, bypass hose and system pressure.

Error code E2 - Flow temperature sensor does not work

Check temperature sensor and connecting cable.

Error code E9 - Flow limiter tripped

Check the system pressure, temperature sensors, check the operation of the pumps and the fuse on the electronic board, remove air from the device.

Error code EA - Bosch ZSC / ZWC boiler does not detect a flame

Is the gas cock open? Check gas supply pressure, mains connection, starter electrode with cable and ionisation electrode with cable.

Error code F0 - Internal malfunction

Check that the electrical plug contacts and start lines are properly connected, replace the electronic board if necessary.

Error code F7 - Although the boiler is off, a flame is detected

Check electrodes and cable. If the flue gas outlet works, check the electronic board for moisture.

FA error code - Flame detected after gas cut

Check the ionisation electrode. Check gas valve.

Error code Fd - The button was mistakenly pressed for too long (more than 30 seconds)

Press the button again in less than 30 seconds.

CC error code - Outside temperature sensor not detected

Check outside temperature sensor and connecting cable for damage.

Any equipment can break down. The main thing is to quickly and effectively eliminate the breakdown. To facilitate the task, the Bosch gas boiler generates errors on the display. These symbols indicate the cause of the malfunction. You just need to find the decryption and start looking for the problem. We will describe the ways to eliminate it below.

Features of the Bosch gas boiler

The double-circuit device is the most popular among users. It simultaneously operates for hot water supply (DHW) and heating. Some models are equipped with two heat exchangers to ensure smooth operation of the system.

The control panel contains power regulators. Therefore, the heating can be adjusted to the area of \u200b\u200bthe room. How does the equipment switch from one circuit to another? A three-way valve is provided for this. Boiler operation is focused on the main circuit - heating. When the mixer is opened, the valve switches the flow to the DHW system.

The circulation of the coolant is provided by a pump. The sensors control the device and, in case of deviations in operation, send a signal to the control module. As a result, error codes appear.

Errors and malfunctions

The table contains error codes that correspond to the Bosch WBN 6000-24C, Bosch ZSC 24-3 (35-3) MFA, ZWC 24-3 (28-3, 35-3) MFA, Bosch ZWE 24-4 (28- 4), ZSE 24-4 MFA, Bosch ZWE 24-5 MFK, Bosch ZWE 24-4 (ZSE) MF.

Error code	What does	How to fix it yourself
A2	The combustion chamber is smoking. The heat exchanger is clogged with soot and scale.	Clean the radiator. Remove soot with a brush. Scale is removed with reagents or citric acid solution.
A3	No signal from the flue gas sensor.	Inspect sensor wiring, tighten contacts. Replace the defective part.
A4	Carbon monoxide goes to the flow fuse.	Clean the pipes and chimney from clogging with soot, debris, foreign objects. Make sure there is traction.
A6	There is no contact with the temperature sensor of the burner.	Diagnose the connections and the sensor itself.
A7	The water thermistor is out of order.
A8	There is no contact with the BUS bus.	Tighten the connections from the bus to the Control Unit. Replace cable
A9	Incorrect connection of the DHW temperature sensor.	Make sure the connection is wrong. Install the element correctly using heat transfer paste.
AS	The module is not recognized.	Inspect the wiring between the module and the display, information panel. As well as connections, outdoor thermometer.
Ad	There is no connection to the water heater thermistor.	Diagnose all contacts, sensor.
b1	The system does not find the coding plug.	Insert the plug more tightly into the jack. Examine his contacts.
C1	Fan blades rotate too slowly (Bosch WBN 6000-24C). Pressure switch short circuit (Bosch ZWE 24-5 MFA, Bosch ZWE 24-4 (28-4), ZSE 24-4 MFA, Bosch ZSC 24-3 (35-3) MFA, ZWC 24-3 (28-3, 35-3) MFA).	Make sure there is sufficient mains voltage. Clean fan blades, flue gas duct. Check the piping to the relay. Install a working part.
C4	The pressure switch does not work, does not open.	Diagnose and replace the item. When coding C6, additionally check the fan rotation.
C6	The relay does not close.
C7	Fan defective.	Reconnect the plug, repair the fan.
CE	The pressure in the heating system has dropped.	Open the make-up tap. Add water until the readings are correct.
SS / d5	The system “does not see” the external temperature sensor.	Connect the cable more tightly, make sure the part is working properly.
d3	Jumper 161 on ST8 is not fixed.	If the jumper is in place, connect the plug correctly. Contact the service center.
d4	Temperature difference exceeded.	Inspect: pump; bypass. Measure pressure.
d7	The control valve is out of order.	Diagnose the valve and its wiring. In case of malfunction, install a new part.
E0	There is a problem with the circuit board.	Reconnect pins or install a work board.
E2	The flow thermistor is out of order.	Ring the element for open circuit, short circuit. Check connectors for oxidation, clean and replace parts.
E9 (11)	Signal from the heat exchanger temperature sensor.	What to do? Check: Connections and wires for breakage, damage, oxidation. Heating circuit pressure. If it falls below the mark, turn on the make-up. Thermal sensor for short circuit, open circuit. Blockage pump. Unlock and repair. Electronic control module. Air in the system. Bleed the air with Mayevsky's taps. Remove scale and dirt from the radiator.
EA	The flame in the burner is gone.	How to fix the problem: Open the gas valve as far as it will go. If the pressure in the system drops, contact the gas service. Voltage drops in the network - if there are frequent surges, connect the stabilizer. Tighten connections. Remove soot from the flue gas vent. Resume cravings. Clean the ignition electrode, refit it when displaced. Diagnose the gas controller. Inspect and, if found, remove deposits from the walls of the heat exchanger. Call a specialist to check the gas fittings and control board.
er	A signal about the failure of one of the nodes.	Perform complete boiler diagnostics.
F0	Internal problem.	Inspect and reconnect the terminals and wires to the control module. Make sure they are intact. If everything is ok, change the module.
F7	The technique does not function, but the flame is detected.	Check if the flue gas vent is working properly. Confirm the presence of traction. Diagnose sensors, electrodes, cables.
FA	The fuel supply is shut off but there is a flame signal.	Inspect the ionization electrode and the serviceability of the shut-off valves.
Fd	Accidental key press on the panel.	Press the same button and hold for 30 seconds.
| |	Fan not adjusted.	Make adjustments.
P	The boiler type is not defined.	Set the type.
23	The type of fuel is indicated.

Other malfunctions

There are malfunctions in boilers "" that are not displayed as an error.

Burner does not work

Check the condition and turn on the emergency and start switches. If one of the safety breakers is defective, repair it or replace it with a serviceable device.

Also diagnose temperature controllers, product relays. Make preventive cleaning of the firebox, burner, nozzles, exhaust pipes.

No spark, no ignition

Look for the problem in:

• Ignition electrode. Strip it, place it closer to the burner.
• Burner.
• Ignition transformer.

Noise and hum when turning on the boiler

Clean the parts, including the heat exchanger, from scale. Salt deposits interfere with heat transfer, so the water boils and hisses. If the plaque is not removed, the unit will overheat and fail.

Hot water does not turn on

If there is no hot water when opening the faucet, inspect the 3-way valve. If it breaks down, you need to change it. Also, make sure the mixer is in good working order, clean pipes and filters from blockages.

Whistle when igniting the burner

The size of the nozzles does not match the pressure in the gas line. Change them.

Black smoke and soot

The ignition unit needs cleaning. Parts and holes are clogged with dust and dirt.

Pops, noise during ignition

What could have happened:

• Gas supply incorrectly set.
• Incorrectly sized nozzles.
• The chimney is clogged.
• Incorrect structure of the chimney shaft.
• Ventilation in the room is not working well.

We hope that after reading the article, you will determine the cause of the breakdown. You can make repairs yourself if you understand the technique. However, remember: before starting work, it is imperative to shut off the gas and water supply.