Bosch 6000 boiler error er

What does EA error mean?

If the Bosch boiler has no ignition and the corresponding inscription appears on the screen in the form of error EA, then it is necessary to conduct a thorough diagnosis, because the causes can be quite many. All work begins with three main steps:

Important! Only after these three prerequisites are met, you can proceed to diagnosis.

It is necessary to unfold the control panel and remove the decorative cover. You need to arm yourself with a Phillips screwdriver and unscrew the two screws located on the bottom of the boiler. After that, you need to slightly lower the panel down and turn it towards you.

Next, to remove the top decorative cover, you will also need to unscrew the two self-tapping screws. Lift the bottom and take off the cover. The last obstacle before the ignition electrode is the boiler furnace. To do this you need to unscrew all five screws, lower the lid slightly down and pull it toward you.

Boiler output varies from 18 kW to 35 kW. It has a gas burner installed. There is a single ignition electrode on the right hand side of the burner and a flame control electrode on the left hand side.

Key error codes

Like any device, the Bosch gas boiler also sometimes fails and needs repair, let’s take a much more detailed look at its potential breakdowns and ways to fix them.

Error 11 is possible in the Bosch BWC 42, deciphered, also as error E9, indicates a flue gas temperature limiter.

• Check for damage to the flue gas temperature limiter wire, if found broken or melted, replace;
• it is necessary to check the pressure in the device;
• Check the temperature limiter;
• it is necessary to check the correct functioning of the pump when it is started;
• If there is air in the boiler. drain it.

Error 23 is not considered as an error, this code is generated by the settings and indicates the type of gas used

Error 50 appears on Bosch ZWA 24 models when there is no flame.

• The safety cable must be checked. If it is faulty, correct it;
• Open the gas valve to the end;
• It is necessary to check the pressure in the gas line. If it does not correspond to the rated voltage indicated in the appliance certificate, call the gas service;
• check that the power supply voltage is present and correct;
• Look whether the chimney is not clogged. Clean it if necessary;
• Check the minimum and maximum gas adjustments on the gas block, adjust according to the table in the manual;
• Check the relay of electrical gas control. If faulty, change it;
• Check the working capacity of the gas fitting. Do not do it yourself, call a professional;

Error 70 means ignition differential relay failure.

• Failure of the differential relay. If the relay does not match the nominal resistance, it must be replaced;
• Mechanical damage to the contacts and wires to the relay, check and reconnect the wires;
• Smoke evacuation system not working properly. It can get clogged, clean the flue pipe;
• Faulty setting or fan malfunction. Adjust the fan, if defective, replace it.

Error a2 occurs in case of smoke exhaust on the combustion chamber, it means that the heat exchanger is clogged with soot and smoke. For the elimination clean the heat exchanger.

Clean the heat exchanger with compressed air

Error E2. temperature sensor on the supply line is defective. Test the meter for a short circuit or breakage, inspect the connecting wires for a broken circuit or oxidation. Clean or connect wires; if broken, replace with new sensor.

Error e9 means that the temperature limiter has tripped.

Causes and methods of elimination may be as follows:

• check the mechanical connection and oxidation of the wires between the board and the sensor, clean and connect the wires if damaged;
• Pressure drop in the system. Add water;
• it is necessary to check the limiter itself for a short circuit or breakage with a multimeter by connecting its ends to the sensor, if the resistance does not match, change the limiter:
• Check the working capacity of the pump. it may be jammed, if it is faulty and repair is not possible, replace the pump:

The error ea signals the absence of flame on.

If this code occurs it is necessary to check

• If the gas valve is open, it must be open all the way;
• gas pressure. If it is not up to par, call the professionals to fix the problem;
• mains voltage. If it is insufficient, it is necessary to install an autotransformer or electric voltage stabilizer;
• mechanical connection of wires. Check for breakage or oxidation, clean or connect wires;
• the chimney flue is working properly. if it is dirty or clogged, clean the smoke evacuator;

Error er (er) occurs in the case of incorrect operation of the boiler in case of detection of failures in any of the units of the device.

The error c3 appears on Bosch ZWE boiler in case of flue gases on the combustion chamber. You can eliminate the problem by cleaning the heat exchanger as described in the manual.

When the differential pressure switch is closed with the fan switched off, error c4.

If this code appears, you can create the following:

• blow out the tubes. lead from the relay, removing in advance the relay that is located on top of the boiler. If the relay clicks, the problem is solved;
• Use a multimeter to measure the resistance for open or short circuits; if the parameters do not match, the relay must be replaced.

Error c6 means that the differential relay does not switch on when the fan blows.

• check the chimney to see if the flue is operating correctly. Remove the obstructions; in coaxial chimneys sometimes it can be ice or frost.
• Check for condensation on the tubes. from the relay. Dry the tubes with a hair dryer.
• Check the relay for shorts or interruptions and replace it if necessary.

Error ce is considered a very frequent code in Bosch gas boilers (Bosch gaz ) 6000 24 kw and it means insufficient pressure in the heating circuit.

Lack of water in the circuit can be detected with a pressure gauge:

• If the pressure gauge is in the red zone. you need to add water to the system using the make-up faucet, which is under the appliance;
• if the pressure gauge is in the green zone. The pressure gauge should be replaced. The microswitch or the diaphragm fabric in the meter may be defective.

Error f0 indicates an internal malfunction. If it appears it is necessary to check the strength of the connection between the terminals and the wires to the electronic board. If the wires are not oxidized and the connections are not broken, then it is a failure of the board itself, it must be replaced.

The fd error occurs if the button has been pressed for more than 30 seconds. To reset this code, press and hold the button for less than this time.

Fault se signals insufficient filling of the system for heating.

Heat exchanger with scale and after cleaning

• add water:
• the reason of pressure drop can be the leakage or depressurization of heating pipes. If the pipes are hot, it is difficult to detect a breakdown, because water vaporization may occur in the place of the leak. To determine this it is necessary to cool the system, seal the joints at the leaks:
• The heat exchanger may be clogged with limescale, remove and wash it, the procedure is described in the boiler manual.

Bosch boilers error codes. Recommendations for elimination of faults

Error code EA. Indicates that there is a malfunction of the ignition device. The signal is given by the flame control sensor. This element detects the presence of a flame and interrupts the operation of the gas boiler Bosch Gaz during limited combustion of the main gas burner or in cases of gas supply failure.

Operation stops after three failed start-ups. To resume operation, press and hold Reset button.

Gas valve malfunction. The electronic board controls the gas valve. Diagnose this part by determining the voltage and resistance. If it is found that the values do not coincide with the nominal ones, the valve must be replaced.

No gas supply to the system. There is a valve in the gas distribution system that limits the flow of gas fuel. Consequently, a malfunction at the start-up of the unit could be due to a closed valve.

Insufficient contact or signal from flame control sensor not detected.

Problems with the control board. When the ignition process is normal and the appliance extinguishes instantly in any case, the flame can not be detected by the electronic board. Based on this, the valve should be checked.

Error E9. Problem with Bosch 6000 boiler heat exchanger overheating. The machine stops working.

The thermostat on the over-temperature switch. Temperature sensor and overheating thermostat are most often located on the outlet pipe of the primary heat exchanger. Functional task of the thermostat. the appliance protection against excessive temperature. The malfunction is most often caused by problems with the thermostat, temperature sensor, or a malfunction in the primary circuit.

Temperature sensor is out of order. Wrong signal or contact between the sensor and electronic board on the electronic board.

Breakage of the overheating thermostat. When a component is fit for use, but real fluid overheating is detected, there is likely a problem with the heating circuit fluid circulation. The primary heat exchanger or the primary circuit filter is blocked (lack of circulation means the heating medium temperature is too high).

Circulation pump failure or blockage from air in the heating system.

CE error code. Is the sign of insufficient pressure in the system.

Possible sources of this problem: low water pressure in the heating circuit. The contact between the electronic board and the pressostat is broken. Minimum pressure switch malfunction.

Check manometer values beforehand. Very often the problem can be solved with a make-up valve, which is designed for the purpose of filling the heating system with liquid.

When the failure occurs again, there appears to be a water leak. Pump, primary heat exchanger, pressure relief valve, worn sealing elements, make-up valve and other parts may be leaking. Leakage can be determined by inspection of hydronic assemblies and components.

Error code C6. Poor draft in the control unit.

For the correct and failure-free operation of the gas boiler, it is recommended to provide a draught for exhaust gases to prevent them from getting into the living space. The exhaust gases are monitored by the automatics, and if there are any problems, the draft sensor will turn on, and the unit will stop working.

Probable sources of draught absence: small diameter of flue duct, wrong construction, blockage, ice on the inner wall. Restriction in the diameter of the outlet conduit results in poor draught.

The maximum chimney length has been exceeded. It is recommended to study carefully the installation manual of the gas boiler and comply with the relevant requirements. Sufficiently long horizontal part of the flue pipe causes weakening of the required draught.

Stem sensor failure. A characteristic “click” may be heard when a vacuum is felt in the supply line. Poor contact between the traction relay sensor and the electronic board, condensation is present, as well as poor connection of the tubes to the pneumatic relay sensor.

Code C7. Fan malfunction. Fan impeller clogged. There is not enough lubricant on the fan shaft, so it does not produce the necessary speed. Contact between electronic board and fan broken.

Fault code A7. Failure of the domestic hot water sensor to detect the temperature.

This code indicates that the hot water temperature sensor is broken or the required temperature has been exceeded.

Main causes preceding this fault: D.H.W.T. sensor damaged. Bad contact between electronic board and DHW temperature sensor. Control board is defective.

If the domestic hot water temperature sensor works and is reliably connected to the electronic board, but the boiler displays an error at this point, the electronic control board is probably not working.

FA error code. Problems with ignition.

This can occur when the ignition fails or the burner flameout occurs.

Check the contacts between the igniter, and the flame sensor, and also between the gas valve and the board. The main reason for flame failure could be insufficient draught.

Error code E2. Temperature sensor for heating system malfunction.

This means that the temperature sensor in the heating system is defective or the operating temperature is exceeded.

Open circuit in the circuit of the thermal sensor for the heating circuit. The malfunction occurs when the temperature sensor and control board are disconnected, or the fluid temperature is colder than recommended.

The Bosch Gaz boiler must return to operation 5 seconds after the fault is detected, if the fault occurred spontaneously. Check that there is no moisture at the sensor connection and the control board connector If there is no moisture, the temperature sensor must be replaced.

The temperature sensor in the heating circuit is short-circuited. This fault occurs when the temperature sensor contacts short-circuits, or the fluid temperature exceeds the recommended value. Resistance measurement of the temperature sensor is required initially.

In case the resistance differs from the standard value, the temperature sensor must be replaced. If the replacement of the temperature sensor does not help, replace the control board.

Bosch 6000 24 kW wall mounted gas boiler in operation. In the last week, almost every day it shows an EA ignition error. After resetting with the reset button the boiler starts well at times, but this happens intermittently. I recently removed the air intake cover plug and it started working better. What could be faulty?

If it starts giving a chimney error, it is necessary to open the protection covers. This facilitates the flow of air from the living space. Then check the flue pipe for ice and, if necessary, clean it. If the fault is caused by a combustion it is necessary to find out whether the gas is supplied to the house.

Boiler constantly shows error code E2. I can’t figure out what the problem is?

This code tells you there is a problem with the temperature sensor in the heating system. Maybe it needs to be replaced.

What is the problem if the Bosch 6000 W boiler stops working?? Also error E9 often lights up. How to fix it?

This malfunction often occurs due to some problems with the thermostat, temperature sensor, or if the main circulation circuit is malfunctioning. The heat exchanger seems to have overheated. If the temperature sensor and thermostat are not damaged, the problem is with the control board. We recommend that you replace it.

Why can’t the unit start and displays error code CE? The pressure in the system is normal, there are no leaks. I disconnect from the power grid, but the problem remains. Please tell me which one it is due to?

The problem usually appears when the water pressure in the heating circuit is low. In this case it is necessary to check the sensor-relay of minimum pressure. It seems to be defective.

The unit malfunction is: DHW is set to 40 degrees. If you turn on the hot water, the gas burner lights up for a few seconds and then extinguishes. This cycle often happens. Is the faucet emptying warm but not hot or cold water? Sometimes the error code E 9. What’s the problem?

This circumstance indicates that the heating medium in the hot water circuit has overheated. Heat exchanger is most likely clogged or the thermostat is not properly adjusted.

The following problem has occurred. During ignition, the appliance displays an FA error code. If you make a restart, it turns on, but the burner is barely ignited, a few clicks occur, and then the error is displayed. Changed the ignition electrode, cleaned the water flow sensor, turned the plug, but no improvement. What happened?

There are several reasons for this malfunction. Broken ignition electrode. Difficulties with the gas supply. Electronics board is damaged.

Appliance shuts down on its own and CE code is displayed. What to do?

There is no water in the appliance or the pressure switch sensor is damaged. First add water to the heating system.

Gas boiler stops working and error code C 6 is displayed. Cleaning and blowing out helped only for a short time. What happened?

This code indicates lack of draught and we advise to check the flue gas exhaust system. Diaphragm may be jammed. Or else call in a specialist to carry out a detailed check on the machine and have it checked.

The wall hung boiler Bosch Gaz WBN 6000 works at home. Error code A7 is displayed. Appliance itself works, water temperature set manually. When you installed it, you must have overheated it because the automatic temperature control mode was on. The outdoor temperature sensor was not installed. What is the cause and how to fix it??

Presumably, the hot water temperature sensor is broken. Sometimes the control board is damaged.

The unit is in operation for about two or three minutes, then the burner goes out and the error code C6 is displayed. It burns for about a minute, the burner restarts, and the device works well for another 5-6 minutes, and so on constantly. This failure, according to the instructions, indicates that the sensor on the draught is working, but the flue duct has no dirt, combustion products are derived well. I can not understand what the problem is?

In a particular case, the main reasons contributing to the lack of draught may be: the failure of the pneumatic relay-draught sensor. Contact between control board and draught diverter is broken. Condensate present and tubes connected to pneumatic air relay incorrectly. Fan functions malfunction. It does not seem to deliver the speed required.

Bosch boiler. Faults and Meaning

A7. D.H.W.W. temperature sensor malfunction. Check sensor and wiring for short circuit or defect. Replace if necessary.

Ad. Unit can’t fix boiler temperature sensor. Inspect boiler thermo sensor and connecting wires if necessary.

С1. The fan rotates with low frequency. Need to check the mains voltage. Also inspect the flue gas exhaust system and if necessary clean or repair it.

С4. No opening of differential pressure switch if fan is disconnected. Need to inspect the diff. Pressure switch.

С6. Differential pressure switch doesn’t close. Check fan and plug wires. Exchange if necessary. Inspect the diff. Pressure switch and flue gas exhaust pipes.

С7. Fan doesn’t work. Check the fan and its cables and plugs. Replace if necessary.

CE. Insufficient pressure in heating system. Water refill is required.

d7. Gas system malfunction. Check connection cable. Inspect the gas system and replace if necessary.

E2. Supply line temperature sensor malfunction (breakage). Inspect for possible damage or short circuit of the sensor and its wiring. Replace if necessary.

Е9. Temperature limiter in heat exchanger tripped. Check for possible damage of heat exchanger temperature limiter and connecting wires. Replace if necessary. Check the nominal pressure in the system. Inspect temperature limiter and replace with new if necessary. Check circulation pump start-up and replace if necessary. Check fuses, replace if necessary. Bleed the unit. Check the water circuit in the heat exchanger. If necessary, replace. Check the flue gas temperature limiter for possible damage.

EA. No flame. Check connection of safety wires. Check if the gas cock is open. Test the gas supply pressure reading and, if necessary, correct. Check connection to the power grid, check electrode and conductor connection and replace if necessary. Inspect combustion product exhaust system, clean or make repairs. Check gas adjustment, correct if necessary. For natural gas: Check the relay that controls the gas flow. Change if necessary. While operating with combustion air intake from the room, check the room air intake and ventilation openings. Clean the heat exchanger. Inspect the gas system, replace if necessary.

F7. The boiler detects a flame when turned off. Check electrodes for oxidation, replace if necessary. P Inspect combustion product outlet and clean or repair if necessary. Check the electronic control board for moisture, dry it out if necessary.

FA. Flame detected when gas supply is shut off. Check the gas system, replace if necessary. Inspect the electrodes and connection wires, replace if necessary. Inspect combustion exhaust system, clean or repair.

P. Boiler type can not be detected. Adjust the unit type.

Fd. Incorrect button operation (lasts more than 30 seconds). Press the button again for less than 30 seconds.

A2, C3. Flue gas outlet on combustion chamber. Perform heat exchanger check for blockages.

A3. Flue gas temperature sensor not detected. The sensor and connecting cables should be checked for damages.

A4. Flue gas outlet on flow fuse. Check flue gas outlet.

A6. Combustion chamber temperature sensor not detected. Sensor and connecting cables must be checked for damage.

A7. Hot water temperature sensor malfunction. Check for defects or short circuit of the temperature sensor and its wiring if necessary. Replace.

A8. Contact with the BUS was interrupted. Check contact cable and regulators.

A9. D.H.W. sensor not installed correctly. Check mounting clearances, remove sensor if necessary and reassemble using heat transfer compound.

AC. Module not detected. Module connected incorrectly. Check module, outdoor temperature sensor, remote control and contacts.

Ad. Unit can’t fix boiler temperature sensor. Inspection of boiler thermo sensor and wires need to be done.

b1. Encoder plug not identified. C1, C6 Fan and plug wires must be checked Carry out correct coding plug installation, measure plug and replace if necessary.

C1, C6. Differential pressure switch does not close. Check fan and plug wires. Replace if necessary. Inspect the diff. Pressure switch and combustion products outlet pipe.

C4. Differential. Pressure switch does not open in disconnected position. Carry out a check on the differential pressure switch.

CC. Control can’t find the outdoor temperature sensor. Inspect encoder and catenary cable for breaks.

d3. There is no jumper detected on ST8 161. If jumper is present, insert plug correctly, check external limiter. Otherwise: check if there is a jumper.

d4. Large temperature difference present. Check circulation pump, bypass hose and system pressure.

d5. External temperature sensor defective. Check sensor and connecting pins.

E2. Supply line temperature sensor defective. Check sensor and connecting contacts.

Е9. Restrictor tripped in supply line. Check system pressure, temperature sensors. Check pump and fuse functions on control board, bleed the unit.

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

F0. Internal fault. Check that the electric plug and starter contacts are connected correctly, replace the PCB if necessary.

F7. Flame detected when unit is off. Perform electrode and cable checks. Flue gas evacuation system possibly defective. Check the control board for humidity.

FA. Flame detection after turning off the gas supply. Check ionization electrode. Check the gas system.

Fd. Incorrect button press (duration over 30 seconds). Press the button again for less than 30 seconds.

Troubleshooting and adjustment of Bosch boilers

Wall mounted boiler Wbn 6000-24. Gas. Natural. EA error has been appearing for a very long time. After reading about EA error, I decided to find out the board firmware and fan stage settings. If the menu shows “245-03” and no questions asked, the menu for the fan stages shows “17”. Smoke exhaust system horizontal with concentric tube. Outlet from the boiler about 2 meters. I don’t have any adapter for air intake from inside the room and the air to the unit comes from outside the room. What guided the craftsman, when installing the 17th stage fan, although, judging by the instructions it must be the 2nd stage. Is it necessary to change the board?

No adapter needed. You have a standard coaxial with outside air intake. It helps to get rid of this error by setting the fan stage to 5. I had the same thing, and when I set 5, it’s been a year since the error.

Recently washed the heat exchangers of the gas boiler Bosch 6000. It ran for a month and kept all the time the pressure at 1. Then I was attracted by a strange gurgling sound inside it before the ignition of the burner (in the cooling mode), as if water from one mug to another is poured. Looked at the pressure 0, it should automatically shut off if the pressure in the system to 0.5, but it worked and heated the batteries. The only thing is that a different sound and gurgling appeared. I added the pressure to 1, but the next day the pressure dropped back to 0.5 (i.e. there is a water leak somewhere). Checked the pipes and radiators but couldn’t find a leak anywhere. No dripping from the unit either, but the pressure is still dropping. advise what the problem can be and where to look for it?

I had a similar problem. There was air in the system and after the machine was running, the air was blowing out and the pressure was dropping. Your automatic air vent valve (on top of the pump) is not closed? It must always be ajar. It is better to bring the pressure to 2 atm., so the expansion tank in the boiler also takes up volume and compensates for the air escaping. In the radiators, of course, also bleed air with the Mayevsky valve.

The gas wall hung boiler Bosch 6000 24 kw often gives out an error EA and often switches on and off. That is conditionally. set it to a minimum of 40 degrees, literally 5 minutes and then turned off and t. д. It used to heat properly, but now the first battery is hot, the far ones are barely warm, it does not reach them. Runs according to return temperature, no room thermostat.

EA error can be eliminated by setting the fan stage to 5. If the unit turns off quickly, its minimum capacity is too high for your system. It can’t give less than 8 kilowatts. And you probably have 5 radiators in your system. That’s how it heats up the water and shuts down. And why it heats them so quickly, possible problems are: something is blocked or air is in the air, or you need to balance the first radiators, so that the whole flow did not go through them only. You have to look at the heatsink diagram and so on. Try to set the pump speed to maximum (value 3) and bleed air in the radiators.

How to start the self-diagnosis

The selftest is a permanent function. It is provided by a system of sensors connected to the control board. Each sensor is permanently on and working.

over, if the contacts of any element get oxidized and the sensor gets disconnected, the control board immediately generates an error that alerts about the malfunction of a particular component or part. That’s why you can’t activate the self-diagnostic test on purpose.

However, when starting the boiler, all parts from the control board are interrogated, an express check of the state and performance of the boiler components. Some users call this process self-diagnosis, although, in fact, it is just a quick check of the state of the unit systems.

Recommendations for troubleshooting errors and malfunctions in Bosch boilers

Boiler Bosch Gaz 6000 doesn’t heat the system. When you turn on the water starts the ignition and begins to heat water, but there is no heating and the icon on the battery is not allocated. Batteries are cold and it does not show any error. What to do?

If the device works, but the radiators are cold, first of all you should assess the technical condition of the main element. Specifically, to determine whether the circulation pump integrated into the device works. Very often after a long downtime in the summer, the pump can get clogged or covered with a layer of lime scale. As a result, it does not divert the heated coolant from the heat exchanger in a timely manner. The boiler is boiling, but the batteries are cold. If the unit heats the water, but does not heat the battery, then you should also pay attention to the serviceability of the three-way electric valve. It is responsible for switching the bypass from heating circuit service mode to DHW and heating mode.

What kind of a problem with the boiler Bosch, if it began to give out an error code EA? Appliance shuts off suddenly, display shows error code EA. Cleaned the burner, restarted the appliance, but nothing happens. Boiler starts after resetting, burner starts and goes out. After a short time the ignition cycle starts again and an error occurs. How to fix?

Gas valve malfunction. If problems are noticed, change the gas valve. Ionisation electrode is not working properly or has been damaged. Check valve for possible clogging. Adjust gap between gas burner and ionization electrode if necessary. Gas valve defective. Diagnose gas valve coils to fix suspected breakage or short circuit. If a problem is detected, change the gas valve. The gas valve is jammed. Insert a silicone tube into the connection on the front of the valve and increase the pressure. Insufficient ignition power. Perform ignition power adjustment through service menu. Malfunction or failure of the electronic board. Ignition transformer stopped working. Reset the appliance. If the error repeats, the control board must be replaced. Check the ground connection. Housing must be free of charge. Excessive moisture can cause the boiler unit to shut down. The furnace, ionisation electrode and burner unit must be cleaned of moisture. Ionization electrode malfunction. The control board has detected a flame, although there is no combustion. Diagnose ignition electrode wiring. Possible damage and breaks. Check the continuity of the electric circuit from the control board to the ionization electrode for short circuit. The ignition electrode is striking the burner. The electronic board malfunction. It must be replaced.

Why is the water leaking from the boiler?? After turning on the heating mode after a while the device leaked. All summer it worked properly on a mode of hot water, when you turned on the heating and set the temperature to 40 degrees, and it showed 50 and after about 10-15 minutes the water started leaking. What it can be?

There are not really many reasons, why the boiler leaks. First of all, corrosion can be the culprit. What is corrosion is the destruction of metal structure under the influence of the external environment. Internal corrosion of the gas boiler is caused by oxygen in the water, external. by products of combustion. The next cause of leakage can be a low quality of metal from which the heat exchanger is made and the quality of welds of its joints. High pressure in the system, or water hammer also causes leaks. Burning of the heat exchanger walls also causes leaks. In some cases, when water drips from the appliance, it may be condensation from the chimney, which runs down the chimney and gets on the burner. If this situation occurs frequently, you should install a dampener in the chimney. When it is dripping near the circulation pump, the bolt in the center of the pump may have loosened. Tighten the screw.

Bosch Gaz 4000 W when switching from heating to boiler mode makes a terrible noise, quickly catches up with the temperature and stops. What could be broken?

Maybe the 3-way valve is jammed in a position that prevents switching, or a scale got under the circulating pump. Sometimes you just need to adjust the unit and clean the filters.

Why does not the gas boiler Bosch turn on?? No voltage, t.е. no light on the indicator light. There is a voltage, the device is connected via a transformer. Before this fault, the light was switched off 2 times. What is the reason, it is not known yet. Help to understand this malfunction.

There could be several reasons. Fuse, power supply or board. If there is voltage, but the control light does not come on, it may have blown. If the unit is equipped with overheating protection or lockout, it could have tripped during a power outage, and the pumps stopped functioning, the heating medium stopped, and the unit could overheat, as a consequence of the lockout. But if the control light does not turn on, most likely the power is not getting to it, which means you have to start looking at the blown part.

Why does the Bosch gas boiler frequently turns on and off when heating? The unit when adjusting the temperature of the coolant began to work strangely. Suppose the water temperature has dropped to the limit, when the gas mixture supply to the burner is triggered and the water is heated. The heating up time should not exceed thirty seconds, the circulation pump is running. Then the unit stops heating for the same amount of time and restarts when the liquid cools down. This kind of operation of the unit goes on without any interruption at all. Did not change the settings made in the factory. In the old times, the operation mode was different. At first, the liquid circulation was performed without heating, a little later the heating mode was started. The pump circulates for a preset time, but then shuts down and stops working. Now it is no longer there. Please explain what the problem is?

This probably occurs after the heating fluid in the heating circuit warms up. We had a similar situation. It is recommended to flush the heating system and the error should disappear.

How to reset the error and start the boiler WBN 6000-18? Error C6 appeared and could not be reset. Everything checked according to the instructions, everything is in working order: and the diff. the relay and the fan. How to reset the error and start the unit?

Then you need to unplug the device from the socket and take off the control panel (with display). Then you have to take off the front plate, it also has two screws. The differential relay is in the upper left corner. There are two tubes: red and yellow. Take them off one at a time and blast the water out of them. And then you start the machine again. And in general, the condensate in such quantity from that does not have time to heat the incoming air by the outgoing air. Raise the temperature. Error C6 is the result of condensation or lack of oxygen. Recommendations for removal: Press three buttons simultaneously on the panel: return, “” and “-” until L1 appears on the display, then press “” to find L2, press OK, then press “”or “-” to find function 2.b.d, press OK. To change the setting use buttons “” and “-” to set the desired value and press the OK button until [ ] appears. Turn off and on the unit. Actually inspect the unit, which often has this problem. A common cause is a sloping chimney. It may be sufficient to elevate the boiler by 1 cm to change the slope of the knee just slightly.

This morning, a problem was detected on a Bosch boiler. Spontaneous shutdown of the appliance with error code E9. Where to look for the problem?

Error E9: Boiler overheating. The emergency thermostat is heated to at least 104 C. If there are no ignition signals at this time, no error will be detected. The burner goes out due to increased temperature of the main circuit, but the heat exchanger does not stop heating. In the heating phase is 92 C, for the hot water cycle is 96 C. The automation system will stop the boiler if the temperature of the emergency thermostat exceeds 104 degrees within 10 seconds. If the thermostat on overheating detects a temperature higher than 104°C in the heating or anti-freeze cycle, the boiler electronics performs a pause for about half a minute. If during this time the thermostat or the thermostat probe temperature does not decrease to 100 C, the automatics device will indicate an error. The appliance shuts down on request to ignite the gas burner. If the temperature of the emergency thermostat exceeds 104°C during ignition, the boiler waits for ten seconds before triggering an error. The heating line temperature sensor or overheating thermostat shutting down the boiler is triggered. The safety thermostat will start when the temperature rises above 104 degrees F. Wait until it has cooled down and reset by pressing the reset key. Thermostat breakage or malfunction on overheating. You need to change it. Poor water circulation in the heating system. Perform pressure control for the heating circuit. Its values in the cooled system are 1.2bar. There is air in the heating pipes. to bleed from the system the excess air through the air vent. No circulation. Open fully the closing and regulating elements that disturb the correct circulation of the heating medium. Circulation pump malfunctions. The pump doesn’t rotate at a normal speed. Check the parameters and voltages of the power supply. If you notice a voltage drop in the power grid, connect the boiler to the power grid using a stabilizer. Check circulation pump motor stator winding for open or short circuit. The water pump is functioning correctly, but the pressure is weak. Impeller seems to be defective. Pump must be changed if malfunctioning occurs. Pump does not rotate, but delivery is normal. Diagnose the pump; it looks like it is jammed. Unscrew the stopper and turn the rotor shaft of the electric motor. No power to the water circulation pump. Problems with the control board. You must reset the boiler. When failure follows again, replace the control board. Smoke extraction thermostat overheated. We recommend waiting for the thermostat to cool down before restarting.

Boiler Bosch 6000 18 kW has been working for less than a month, the heating has stopped several times and shows error EA. Started by specialists, the stabilizer was replaced by another one. Stops are still occurring, you were told to replace the AVR. I had another one installed, it had stopped three times in two weekends. Tell me what to do?

Error EA means no flame detected. This error occurs most often when the temperature is low. If the temperature is set higher, then this malfunction occurs less often. If so, in most cases the problem is with the electronic board. The stabilizer has nothing to do with it. To solve this problem, check if the protective conductor is connected. Check that the gas valve is open. Check the gas pressure, correct if necessary. Make sure that the connection to the mains is working properly. Check electrodes and wires, replace if necessary. Check the flue gas exhaust system, clean or repair if necessary. Check gas adjustment, correct if necessary. For natural gas: check the gas flow switch. Replace if necessary. When working with combustion air intake from the room, check the room air supply and ventilation openings. Clean the heat exchanger. Check the gas fitting, replace if necessary. It is better to contact a service center to check the board and replace it in case of malfunction.

There is a big problem with heating the domestic water in a Bosch W6000 wall mounted gas boiler. Informant recommended to replace the heat exchanger.

Plate secondary heat exchanger is often clogged with limescale, but this is quite removable. Dismantle the assembly, soak it in citric acid for 24 hours, then rinse. If the heat exchanger has already been flushed by acid 1-2 times during the operation it is better not to risk further and a new unit should be installed.

What is the problem with the Bosch boiler if it shows error code C6 and then switches off?? If it suddenly switches on, it works unstable. Sometimes it will turn on and work for an hour and a half, two hours or less than 5 minutes, but often can not start, rebooting does not help much. How to fix it?

Error code C6: No draught. In order to ensure the safe and reliable operation of the gas appliance, it is necessary to create a draught for the exhaust of combustion products so that they do not get into the living space. Gas extraction is monitored electronically, and in case of any malfunction, the draught sensor is activated, and the gas appliance will stop working. The main sources of no draught: the limited diameter of the chimney duct improper installation, clogging, ice on the inner wall. Reduction in outlet duct size causes insufficient draught. The maximum chimney length is exceeded It is recommended to study carefully the instructions for installation of the gas boiler and check whether all the necessary requirements have been met. Sufficiently long horizontal part of the flue pipe causes weakening of the draught. Pressostat. draught sensor is broken. If you create vacuum in the supply pipe, you can hear a characteristic “click. Lack of contact between electronic board and draught sensor, presence of condensate, as well as incorrect connection of tubes with pneumatic relay. Damage to the fan components. Clogged fan impeller. Lack of sufficient lubrication of the fan shaft, so it does not build up the necessary revolutions. No contact between control board and fan.

Help to understand the boiler. When switching on it gives EA error (no flame detected), the wick burns. Cleaned the electrodes from the fouling. The gas pressure is normal. The heat exchanger is not very burnt. The boiler has been in service since 2016.

Error EA is quite common. It usually goes away on its own and does not appear in warmer times. The owners don’t risk reloading the unit in sub-zero temperatures and wait for warming. And when it gets a little warmer outside, they want to call a handyman, and there is no error. But it often appears again when cold weather arrives. In any case, you need to look for the cause, and it is better if this is done by specialists. It may be recommended to try to work out a few ways to solve: Adjust the min pressure of the gas valve. Put not 1.2 as in the manual, but 2mbar, but this is best done by a service. Check the soft black insulation, which is placed when connecting the chimney. If not properly installed, it can eventually block the hole and interfere with air intake from the street. If gas pressure is ok, try swapping ionization and ignition electrodes, sometimes it helps. If not, you will most likely need to replace the circuit board or re-flash it.

Why the Bosch gas boiler is noisy and warm? In addition the safety valve is leaking. What kind of problem?

If you can be sure that the boiler has been installed according to the instructions, you should first examine the expansion tank. It is likely that it is preferable to move it to another place. In addition, the settings of the boiler unit are made. In particular, the flow of liquid is inspected or the gas valve is adjusted, since its insufficient adjustment is the source of such difficulties in operation.

Why does the pressure in the Bosch gas boiler decreases?? After a year and a half of trouble-free operation the pressure in the boiler began to decrease. The heating medium has been drained from the expansion tank, followed by pumping of air and water make-up. Everything was carried out strictly according to the instructions, but literally after a short period of pressure is reduced again. No leaks anywhere to be found. Planned to replace the nipple, but we can’t. Why is the unit unable to hold a correct pressure? How to service and adjust the expansion tank?

There is no need to take the liquid out of the heating line. Switching the device off. Then disconnect the nipple that is located at the top of the expansion tank. In the case of water leakage it is advisable to change the tank. When air began to escape, close the filler cock and open the drain cock, which will begin to remove water from the boiler. When the liquid finishes pouring, connect a pump with a manometer to the nipple and pump the pressure specified in the passport. Perform the operation several times, because often a little liquid escapes during pumping and, therefore, the pressure is relieved. Inflate until the pressure is relieved and the water runs out. Then screw on the cap, turn on the taps and feed the system. We start the device and using the air vent to remove the air from the system.

What is the reason for the blinking of the indicator on the Bosch boiler?? The unit doesn’t turn on and there is no hot water. How to fix the problem?

First. Power supply voltage fluctuations. Second possibility. an assembly error. For example, the wrong throttle washer on the coaxial chimney. And the third. Cleaning the ionization electrodes. There is another option. Apparently the power relay that controls the turbine burned out. It is on the board. On the same board, next to it is a similar relay the power winding of which is connected to the connector which is not used in this model. So, if you swap these relays, most likely the device will work as before.

How to reduce the pressure in a Bosch boiler? Can anyone help how to relieve the pressure? And whether it is possible to reduce the gas pressure? There is a regulator in the appliance that corrects the gas pressure or there is no need to make any adjustments?

The regulator can adjust the pressure of the gas supplied to the unit. When it is sufficiently reduced, the burner unit will not ignite, but if it is increased, you can trace the separation of the flame from the wick, and the gas burner will go out immediately after ignition. Here are the manipulations for the adjustment. Warm up the boiler considerably. Fully open the flue outlet. Set the main burner to maximum, at this time the light is yellow-blue. Close the tap of the incoming gas mixture, which cuts off the yellow light. After a short time, check the boiler unit’s operation in various modes.

The Bosch gas boiler does not start after a sudden power outage. The pressure in the system is normal. What else would you advise to pay attention to?

Power surge often causes a phase change in the network, which is very important for most power-dependent models. Turn the plug in the socket. If you don’t see any lights on the panel, check the fuses on the control board and replace the blown ones. Next you need to check the gas pressure, the sensors of overheating and draft overturning, the chimney condition and the coolant circulation in the system.

We have the same problem. Bosch boiler is a two-circuit, we have used it for only six months. We turned on the hot water, and it does not warm, knocked out the boiler and error E9 shows. Cleaned the filter, the unit kicked in, but shut down again an hour later. It’s showing an error. When we start it, the pressure rises and the unit shuts down. Then turn on, the fuses burn out and the boiler extinguishes. We still can’t turn it on. Please help me, what could be the reason?

Most likely your pump is jammed. Usually, the fuses burn out because of the pump.

Boiler Bosch gas 6000w. Was purchased in August of this year. As a sharp cold snap came, it shut down and showed error C6 (differential pressure switch does not turn on). After removing the front cover it was found that the pipes that lead to this relay are covered with frost. After drying the tubes the appliance started. This situation has repeated itself several times. Is there any way to get rid of this problem?

You need to look at how the smoke evacuation system is made. Separate system often leads to these consequences. We recommend replacing with a coaxial system. If there is no possibility to change the chimney, the pipes must be insulated.

Wall mounted boiler Wbn 6000-24. Gas. natural. EA error has been appearing for a very long time. After reading about the EA error I decided to find out the board firmware and fan stage settings. If the menu gives the software version “245-03” and no questions asked, the fan stage menu showed a number “17”. The chimney system is horizontal with a concentric tube. Outlet from the boiler about 2 meters. I don’t have any adapter for the air intake from inside the room and the air is supplied to the unit from outside the room. What guided craftsmen, setting the 17th stage fan, although, judging by the instructions should be the 2nd stage. Do you need to change the board??

No adapter is needed. You have a standard coaxial with outside air intake. It helps to get rid of this error by setting the fan stage to 5. I had the same thing, and when I set 5, I haven’t had an error for a year.

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

When the fluid temperature approaches the set temperature, the boiler switches on in either case, regardless of whether there is a thermostat or not, but as this process takes very little time, it is difficult to detect it. If using an OT thermostat, the modulation starts when the room temperature approaches the set temperature. If there is an “On/Off” thermostat, there is no connection.

A private house 70m2 300mm cellular concrete 50mm mineral wool and ceramic brick cladding. I plan to add another 50-60 sq. ft. м. On the first floor there are 33 m2 of TP, the radiators are mounted on both floors. DHW is implemented kitchen and bathroom, in the future will be a second bathroom. I want to put BKN Drazice 125. Since my house is mounted riser, I plan to install a wall mounted gas boiler with coaxial chimney. I consider different variants. The best price is the Bosch 6000 (18 kW), but the Bosch gaz 7000 has a minimum capacity of 24 kW, which for me, I think, too much. Of the important, I want the boiler to be able to set the temperature in the boiler and, in the future, you can mount a room thermostat and an outdoor sensor. Interested in the difference between these models in the composition of components or the place of assembly? Maybe there are some other differences in principle?

In your case, the best model would be Bosch gaz wbn6000-18 and wstb 120.

Error codes of Bosch WBN 6000 boilers

Fault A7. Defective temperature sensor for DHW. Check sensor and wiring for defects or short circuits. Replace if necessary.

Error Ad. The unit can’t detect the boiler temperature sensor. Inspection of water heater temperature sensor and connection wires is required.

Error C1. Fan rotates with low frequency. Check for line voltage. Also check the flue gas exhaust system and if necessary clean or repair it.

Error C4. No opening of differential pressure switch if fan is switched off. Inspection of diff. Pressure switch.

Fault C6. Differential pressure switch does not close. Check fan and plug wires. Replace if necessary. Inspect the diff. Pressure switch and flue gas exhaust pipe.

Error C7. Fan doesn’t work. Carry out a check on the fan and its wires with connectors. Replace if necessary.

Error CE. Insufficient pressure in the heating system. Water must be filled in.

Error d7. Malfunction of the gas system. Check connection cable. Inspect the gas system and replace if necessary.

Error E2. Failure of temperature sensor on supply line (breakage). Check for possible damage or short circuit of the sensor and its wiring. Replace if necessary.

Error E9. Temperature limiter in the heat exchanger is tripped. Check for possible damage to the temperature limiter on the heat exchanger and its connection cables. Error d7 Replace if necessary. Check the nominal pressure in the system. Inspect temperature limiter and replace with new one if necessary. Perform start-up check of circulation pump and replace if necessary. Check the fuses and replace if necessary. Bleed the appliance. Check the water circuit in the heat exchanger. Replace if necessary. Check the flue gas temperature limiter for possible damage.

Error EA. No flame. Check connection of safety wires. Check that the gas valve is open. Test the gas pressure reading and correct if necessary. Check the connection to the power grid, electrodes with wires and, if necessary, replace. Inspect the combustion products venting system, clean or repair. Check the gas adjustment and correct if necessary. For natural gas: Inspect relay controlling gas flow. Replace if necessary. When operating with combustion air intake from the room check the air intake and ventilation openings. Clean heat exchanger. Check the gas system, replace if necessary.

Error F7. Boiler detects flame when switched off. Check for oxidation of electrodes, replace if necessary. Inspect the combustion product outlet and clean or repair if necessary. Check the electronic control board for humidity, dry it if necessary.

FA error. Flame detected when the gas supply is shut off. Check the gas system, replace if necessary. Inspect electrodes and connection wires, replace if necessary. Visually inspect the flue gas exhaust system, clean or repair.

Error P. Boiler type not detected. Adjust the unit type.

Fd error. Incorrect button operation (duration over 30 seconds). Press button again for less than 30 seconds.

Error codes of Bosch ZWC MFA boilers

Code A2, C3. Flue gas outlet on the combustion chamber. Perform a heat exchanger check for clogging.

Code A3. Flue gas temperature sensor not detected. Check sensor and connecting cables for damage.

A4 Code. Flue gas outlet on flow fuse. Check flue gas outlet.

Code A6. Sensor in the combustion chamber is not detected. The sensor and connection cables must be checked for damage.

Code A7. Sensor defective on hot water temperature sensor. Check for defects or short circuit of the temperature sensor and its wiring, if necessary. Replace.

Code A8. Contact to the BUS has been interrupted. Check contact cable and regulators.

Code A9. Wrong assembly of DHW sensor. Check the mounting distances, if necessary remove the sensor and reassemble it using heat transfer paste.

AC code. Module is not detected. Incorrectly connected module. Check the module, outdoor temperature sensor, remote control and contacts.

Ad code. The unit cannot lock the boiler temperature sensor. Inspection of boiler temperature sensor and cable contacts is required.

Code b1. Coding plug not defined. Install coding plug correctly, measure it and replace if necessary.

C1, C6 codes. Differential pressure switch does not close. Check the fan and plug wires. Replace if necessary. Inspect diff. Pressure switch and combustion products outlet pipe.

Code C4. Differential. Pressure switch does not open in disconnected position. Test the differential pressure switch.

Code CC. Control Unit cannot detect outdoor temperature sensor. Sensor and contact cable need to be inspected for breakage.

Code d3. Jumper not detected on ST8 161. If jumper is present, insert plug correctly, check external limiter. Otherwise: check that connectors are in place.

Code d4. High temperature difference present. Check the circulating pump, the by-pass hose and the system pressure.

Code d5. External temperature sensor defective. Check sensor and connecting contacts.

Code E2. Supply line temperature sensor defective. Check sensor and connection pins.

Code E9. Restrictor tripped in the supply line. Check the system pressure, check the temperature sensors. Check pump and fuse functions on control board, bleed the unit.

EA code. No flame detected. Check the gas valve. Check the gas pressure, mains connection, ignition electrode with wire and ionization electrode with cable.

Code F0. Internal malfunction. Check the correct connection of the electric plug pins and start lines, replace the PCB if necessary.

Code F7. The flame is detected when the unit is switched off. Check the electrodes and cables. Maybe the flue gas evacuation system is defective. Check the control board for moisture.

FA code. Flame detection after the gas supply is turned off. Inspect the ionisation electrode. Check the gas system.

Fd code. Incorrect button operation (lasts more than 30 seconds). Press the button again for less than 30 seconds.

Troubleshooting and adjustments to Bosch boilers

Bosch company assures that its heat exchangers are not coated with a special protective anti-corrosion paint. The heat exchangers of other companies (Viessmann, Vaillant, Ariston, Baxi) have a protective layer, but theirs is pure copper. And they put it as an advantage of their models. Is it true or is it just a cheapening of the unit price.

Copper is really not susceptible to corrosion, which is why it is used. But because of its properties copper burns quite quickly.

As I know, there are two options for connecting the BCH to a two-circuit gas boiler. The first, through the three-way valve. The second, through the 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. That makes sense to me. But I do not understand what I should do with the DHW outlets, and can I just put plugs on them. Initially, I assumed that I would buy a Bosch 6000 single boiler, but since it was not available, I was recommended to opt for a two-circuit. And I wonder if I shut off the outputs, will not suffer heat exchanger (will not burn without water)? Since keep the unit constantly running at maximum, I will not, let the BKN continue to work. Especially since I bought an ACV Comfort 130, and it is by design a tank in the tank and should essentially hold the temperature better than with a coil. The disadvantages of such boilers is the maximum pressure of 3 bar and a safety valve for the same pressure. And knowledgeable people say that if the valve for some reason will not work, the tank will break. About the two-circuit model. I fear that if the boiler fails, I will have no hot water at all.

Your conclusions are only correct for treated water. For domestic needs, you can set up a backup line. But in my memory no ACV boiler failure has ever happened.

I am in a private home organizing separate flue for the Bosch 6000 gas boiler at 24 kW. In this regard I have two questions. Exhaust duct. Is it worth changing from the “pants” 80-80 through the tee with a condensate drain to a vertical flue diameter of 100 mm? The cost of pipes of different diameters is not very different from each other. The height of the chimney to the tee is 4800 mm. I take the pipe out through the roof, taking into account the 10 degrees. Fume extraction duct. The air intake is going to organize in the room is not heated and well-ventilated attic. To the outer wall of about 4 meters. To take the air from the room is not a good solution. Distance from the intake point in the attic space to the top plane of the unit. 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 thing is that the device will be fed to the air with the outside temperature. It is also possible formation of strong condensation on the duct, which will sink to the housing. But if you can fight condensation with insulation, then how to solve the problem of warm air flow I do not understand. As an option, considered to feed the duct from the chimney of the bath (will need to weld a water register with a diameter of 300-500mm). Circulation in the register to organize a separate circuit. It is very difficult, but it should give results. Can you advise which set of chimney will be suitable for installation on the wbn 6000-24 c? The flue pipe should be lead out beyond the wall thickness of 375 mm, you do not need to pull it further. Since the of branded equipment is very high, I would like to try another manufacturer. Neva, for example. Will it be possible to reprogram the single circuit unit if the DHW flow sensor is disconnected first?

No. It will be necessary to replace the control board of a single-circuit boiler and hydraulic unit from it. And also additionally install a three-way valve.

Recently was washed the heat exchangers of the gas boiler Bosch 6000. Worked for a month and kept all the time the pressure at 1. Then attracted a strange murmuring sound inside it before ignition of the burner (in the cooling mode), as if the water from one mug to another poured. Looked, and the pressure is 0, in theory, it should automatically shut off if the pressure in the system to 0.5, but it worked and heated the batteries. The only thing is that a different sound and murmur appeared. I added pressure to 1, but the next day the pressure dropped back to 0.5 (i.e. there is a water leak somewhere). Checked the pipes and radiators but could not find any leaks. It’s not dripping from the unit either, but the pressure’s still dropping. Please advise what the problem may be and where to look for it?

I had a similar. There was air in the system, and after the device worked, the air was coming out and the pressure was dropping. You have an automatic air vent valve (on top of the pump) is not closed? You want it to be ajar all the time. It is better to bring the pressure to 2 atm., so that the expansion tank in the boiler would also take up volume and compensate for the air escaping. In the radiators, of course, also bleed air with a cocks Maevsky.

Wall mounted gas boiler Bosch 6000 24 kW often gives error EA and often turns on and off. That is, conditionally. Set it to a minimum of 40 degrees, literally 5 minutes and turned off and t. д. It used to heat as it should, but now the first batteries are hot, the distant ones are barely warm, it does not reach them. Works on the return temperature, no room thermostat.

Error EA 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. It cannot give less than 8 kW. And you probably have 5 radiators in the system. This is how it heats up the water and shuts down. And why it heats them so quickly, possible faults: clogged or blown out or balancing the first radiators, so that the whole flow did not go only through them. You have to look at the diagram of radiators and so on. Try to set pump speed to maximum (value 3) and air bleed in radiators.

Please advise who knows about: Wall hung gas boiler WBN 6000-18C RN. What kind of tests are made at the factory? Do they start?

I was fine, I don’t think it’s from the factory, it’s more likely that the storage was strange.

Can you advise: stopped Bosch wall hung boiler, pressure rose to 3 bar, error E9r. I tried restarting it, it worked after 10 seconds. Pressure jumped to the maximum, I stopped everything, shut off, depressurized. Checked the gas pressure, it’s fine as it was. What could it be??

If the system is new, the expansion tank is small, if it is old, the expansion tank is defective or the make-up water may be leaking. In your case, the expansion tank is the most likely fault. If this is the case, there are two options: pressurize it, replace the tank.

After opening the hot water tap and igniting the burner, the Bosch boiler generates error E2 (supply line temperature sensor defective). It happens in 10-15 seconds. After closing the tap, the error clears itself and the boiler continues to work in heating mode. If you open the tap again, the situation repeats. To complete the picture: In the heating circuit is installed additional circulating pump, before its installation the boiler and in the heating mode showed error E2 for a couple of seconds, and then changed to E9 (triggered temperature limiter heat exchanger). The source of water supply well pump (water supply pressure of 2x to 3x without sudden jumps).

Possible causes are: defective own circulation pump (if it is only involved in DHW mode), clogged strainer. The sensor probably should not be excluded.

Boiler zwa 24. Changed the concept, you need a heat exchanger from zsa, boiler sensor and three-way valve. I think the board is the same. In general, the two-planimetric should make a single-circuit.

The manufacturer does not recommend doing such modifications. But if there is a desire, you need to buy a heat exchanger. Supply pipes are the same, but the outlet is different. At the 2-circuit has a hole for makeup, and the 1-circuit is not. There are two options. Change the tube. To figure out how to close the hole. Control boards are the same.

Heating systems for summer and country houses. Boilers, gas heaters, water heaters. Repair, service, maintenance. Mounting and installation recommendations.

The control panel for Bosch 6000 W gas convection boilers with Cotronic 3 enables room-temperature dependent control of the heating system.

For these wall convection gas boilers, we recommend two types of Bosch regulators.

Programmable OpenThermTM CR12005 room temperature controller

TRZ 12-2 room temperature controller

Faults shown on Bosch 6000 boilers display

A7. Hot water temperature sensor defective.

Ad. Boiler temperature sensor not recognized.

C1. Fan speed too low.

C4. Differential pressure switch does not open when the fan is switched off.

C6. Differential pressure switch does not close.

CE. Insufficient filling pressure in the heating system.

d7. Gas fitting of the wall hung boiler Bosch Gaz 6000 W defective.

E2. Supply line temperature sensor defective (breakage).

E9. Exchanger temperature limiter activated.

What are the errors that occur during the operation of gas boilers Bosch

The temperature sensor for the DHW circuit is not functioning properly. This indicates that the temperature sensor in the DHW circuit is defective or the permissible temperature has been exceeded. Probable causes of this malfunction: the temperature sensor on the hot water supply is defective. The contact between the hot water temperature sensor and the control board is broken. The electronic board is defective. If the D.H.W. temperature probe is intact and properly wired to the control board, but the unit still displays an error, the control board appears to be defective.

Ignition is not possible. This situation can occur if there is no ignition or the flame bursts. You need to check the connections between the ignition unit and flame sensor as well as between the gas valve and the board. Main factor of the flame failure is the lack of draught.

Failure of temperature sensor in the heating system. This code indicates a failure of the temperature sensor in the heating circuit or the recommended temperature has risen. Breakage in the circuit of the temperature sensor in the heating circuit. This fault can occur when the contact between the temperature sensor and electronics board is broken, or the temperature value is much lower than required. Five seconds after the fault is detected, the Bosch Gas boiler must resume normal operation if the fault occurred spontaneously. Check that there is no moisture at the sensor connector and at the controller connector. If there is no humidity, the sensor must be changed. Short circuit of the temperature sensor in the heating circuit. This malfunction occurs due to a short circuit in the temperature sensor circuit or the water temperature value is much higher than required. First it is recommended to perform resistance measurement of the sensor. If the resistance differs from the nominal, the temperature sensor should be replaced. If installing a faulty sensor does not bring results, replace the control board.

It means there is no ignition. Fault is reported by the flame ionisation sensor that controls the ignition. This element analyzes the presence of the flame and suspends the operation of the boiler Bosch when the main burner burns weakly or in case of gas supply problems. Blockage occurs after 3 unsuccessful starts. To return to operation, it is recommended to keep the reset button pressed. Gas valve malfunction. Gas valve is controlled by electronic board. Check this element by measuring voltage and resistance. If it is found that the values deviate from the nominal parameters, it is recommended to replace the valve. No gas flowing into the appliance. There is a valve in the gas distribution unit that is restricting the gas supply. Therefore, a malfunction when starting the appliance may be due to a blocked faucet. Improper contact or missing pulse from the flame ionisation probe. The electronic board is defective. When the ignition cycle is normal and the unit sharply extinguishes anyway, the electronics possibly do not detect the flame. Therefore, it must be diagnosed.

Boiler overheating Bosch Gaz. The appliance stops. The overheat thermostat activated. Temperature sensor and over-temperature thermostat are most often located on the outlet pipe of the main heat exchanger. The main purpose of the thermostat. is to protect the machine from excessive temperature. An alarm situation could be caused by a problem with the thermostat or the temperature sensor, or if the main circulation circuit is broken. Damage to the temperature sensor. Electronic board receives incorrect signal or contact between control board and sensor is broken. Damage to the overheating thermostat. If the component is functional, but real fluid overheating has occurred, there is likely a problem with the primary circuit coolant circulation. Primary heat exchanger or primary circuit filter element is blocked (low circulation gives increased temperature of coolant heating). Circulation pump malfunction or air blockage in the heating system.

Indicates that there is low pressure inside the system. Probable causes that influence the formation of this malfunction: Low fluid pressure in the heating system. The contact between the electronic board and the pressostat is broken. Pressostat malfunction. Pressure gauge reading is required beforehand. In many cases the problem can be eliminated by using a make-up valve, which is needed to add coolant to the heating system. In the case where there is a repetition of failure, then most likely there is a leakage of coolant. Leaking can be a hydraulic pump, main heat exchanger, relief valve, worn sealing elements, make-up valve and other components. Leaks are detected visually by inspecting hydraulic connections and components.

Как устранить ошибку ЕА котла Бош. Краткий обзор котла.

Lack of traction. For the correct and failure-free operation of the gas appliance it is necessary to ensure the draught for flue gases evacuation, so they don’t penetrate into the living space. This is monitored by the automatics, and if there are some problems, the traction sensor will activate and the gas appliance will stop working. The main factors of no draught: small size of the chimney duct inaccurate installation, clogging, ice on the walls. Narrowing of the chimney duct diameter leads to a weak draft. Smoke exhaust pipes are too long. You need to study the manual of the boiler carefully and check that all the necessary requirements are met. Horizontal part of the chimney is too long, which reduces the required draught. Breakdown of the pneumatic draught sensor. When there is a vacuum in the inlet tube, you will notice a faint click. Improper contact between traction sensor-relay and electronic board, condensation in tubes or incorrect connection of tubes to pneumatic air relay.

Fan operation stopped. Fan impeller is clogged. There is no grease on the fan shaft, accordingly it can not develop the necessary speed. Loss of contact between electronic board and fan.

Gas boiler Bosch 6000 in operation. EA ignition error has been on almost nonstop lately. After resetting with the reset button the appliance occasionally switches on normally, but this happens infrequently. A few days ago I removed the air intake plug and it is doing much better. What could be faulty?

If the error on smoke evacuation appears, it is necessary to open the safety covers. This will help to remove air from the room. Then examine the chimney pipe for the presence of ice and, if present, clean it. If the failure is due to a flame out, it is advisable to check if there is a gas supply to the room.

Often the boiler displays error E2. Can anyone explain what it signals?

This code indicates damage to the heating system temperature sensor. You probably need to change it.

What is the reason why the boiler Bosch Gaz 6000 stops working?? The error E9 is often displayed. What to do?

Such failure is usually caused by various problems with thermostat, temperature sensor or main circulation circuit malfunction. Most likely there is an overheating of the liquid in the heat exchanger. If the temperature sensor and thermostat are functional, there is a problem with the electronic board. We need to replace it.

Why the appliance won’t start and shows error CE? Maintains normal pressure, no leaks. I unplug, but the problem persists. Please tell me what the reason is?

This situation can occur if the pressure in the heating system is too low. In this case you need to check the sensor-pressostat. It is most likely faulty.

The appliance has the following problem: DHW is on at forty-five degrees. At the moment when the hot water tap is opened, the burner lights up and then goes out. This cycle occurs frequently. Cold and warm water alternately flows from the faucet. Repeatedly displays error E 9. What could be the reason?

This fault indicates that the heating medium in the hot water circuit has overheated. Apparently the heat exchanger is blocked or the thermostat is not properly set.

We have such a fault. During ignition, the boiler goes into FA error. If you reset the boiler, it switches on normally, but the burner lights up, strange clicks are heard and the error is displayed again. I replaced the ignition electrode, washed the flow sensor, turned the plug, but no improvement. Has anyone else had this problem??

There are three possible causes for this problem. The flame control electrode is defective. Incorrect gas supply. The electronic board is malfunctioning.

The boiler has interrupted autonomously and the CE code is displayed. What to do?

There is no water in the appliance or the pressure switch sensor is damaged. Fill heating system first.

Gas boiler shuts down and error C 6 is displayed. Cleaned and blown out. no result. What to do?

This situation indicates a weak draft and the chimney system should be checked. Diaphragm may be jammed. In other cases, you need to call a specialist for a thorough diagnosis of the appliance with subsequent.

At home we use a Bosch 6000 gas boiler. Error A7 began to appear. The device itself is functioning, the temperature of the liquid is set manually. During the installation there must have been some overheating, because the automatic temperature mode was activated. The outdoor temperature sensor has not been installed. What is the problem?

Supposedly there is a problem with the temperature sensor of hot water. In another case, the electronic board fails.

The unit operates for about a few minutes, then the burner switches off and error C6 appears. It glows for no more than a minute, the burner starts again and the unit runs continuously for another 5-6 minutes, and so many times. This failure, according to the instructions, indicates that the sensor on the draught, but the chimney is not soiled, flue gases are removed normally. Could you please tell me what is the cause of this problem??

In your case, the main reasons contributing to the lack of draught are: damage to the draught sensor. Broken contact between control board and draught sensor. Condensation in the tubes or incorrect connection of the tubes to the pressostat. The fan is damaged. It is probably running on low speed.