Bosch 6000 gas boiler does not turn on. Heating systems for country and country houses
Gas wall-mounted boilers Buderus
Logamax models U042, U044, GB072, GB172. With open and closed chamber combustion. Repair and service methods, adjustment of operating parameters. Maintenance recommendations. 
Gas heating boilers Vaillant
Models: floor-standing Atmovit exclusiv, wall-mounted condensing Ecotec plus. Service, Maintenance, settings of functional components. Hydraulic diagrams. 
Gas wall boilers Ariston
Clas, Clas Evo, Genus models. Recommendations for repair, maintenance and service. Elimination of errors and malfunctions. Setting and adjustment methods. 
Gas boilers Immergaz
Models Eolo Star, Eolo Mini, Nike Star, Nike Mini, Metos. Repairs and adjustments. Installation, assembly and connection. Operating mode settings and additional equipment. 
Kentatsu Furst boilers
Wall models Nobby Smart. Condensing Smart Condens. Floor standing Sigma, Kobold. Solid fuel Elegant, Vulkan. Malfunctions and error codes. Description and characteristics.
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- Differential pressure switch does not close. Check the fan and wires 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 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 electrical network, electrodes with wires and, if required, 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 flow into 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 for oxidation of the electrodes, 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 need to 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 need to 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. Conduct correct installation coding plug, measure it and replace if required.
C1, C6- Differential pressure switch does not close. Check the fan and wires 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 at 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 the sensor and the connection contacts.
E2- The flow temperature sensor is defective. Check the sensor and the 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 the correct connection of the electrical plug contacts and the starting lines, if necessary replace the electronic board.
F7- The flame is detected when the unit is off. Check electrodes and cables. The flue gas removal 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 is more than 30 seconds). Press the button again less than 30 seconds.
Malfunctions and adjustments of Bosch boilers
Wall mounted 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 settings of the fan stage. 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 a 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 when they installed 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. It helps to get rid of this error by setting the fan step to 5. I had the same thing, and when I asked 5, there was no error for a year now.
Recently flushed heat exchangers gas boiler Bosch 6000. 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 was 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 is a different 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 one. 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 the air with a Mayevsky tap.
The gas wall-mounted boiler Bosch 6000 24 kW often gives an EA error and is often turned on and off. That is, conditionally - set it to at least 40 degrees, literally 5 minutes and turned off, etc. Previously, I warmed it up as it should, 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 radiator diagram and so on. Try to set the pump speed to maximum (value 3) and bleed air into the radiators.
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Borino, ZhMZ, Siberia, Alpha Calor, Thermotechnik.
Adjustment gas automation Eurosit 630. Replacement of thermocouple and maintenance of the ignition burner.
Luna, Luna 3 Comfort, Luna Duo Tec (F / Fi) models. Double-circuit, turbocharged. Recommendations for eliminating errors and malfunctions. Settings and adjustment of operating modes.
Models ZWC, ZSA, ZSC, ZWR, Gaz 5000, Gaz 3000 W ZW, WBN 6000.
Wall-mounted, double-circuit. Repairs, adjustments and malfunctions. Options for setting functions and modes.
Deluxe Coaxial, Deluxe Plus, GA models. Errors and malfunctions.
Work with remote control Xital. System control. Setting work on temperature and pressure.
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 have to find the decryption and start looking for the problem. And we will describe the ways to eliminate it below.
Features of the Bosch gas boiler
The two-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.
There are power regulators on the control panel. Therefore, the heating can be adjusted to the area of the room. How does the equipment switch from one circuit to another? For this, a three-way valve is provided. The operation of the boiler 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. 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 Bosch models 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 out to the flow fuse. | Clean the pipes and chimney from blockages with soot, debris, and 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. | Run diagnostics on all contacts, sensor. |
| b1 | The system does not find the coding plug. |
|
| C1 |
|
|
| C4 | The pressure switch does not work, does not open. | Diagnose and replace the item. When coding C6, additionally check the rotation of the fan. |
| 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:
Measure pressure. |
| d7 | The control valve is out of order. | Diagnose the valve and its wiring. In the event of a 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:
Remove limescale and dirt from the radiator. |
| EA | The flame in the burner is gone. | How to fix the problem:
|
| 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 signal about the presence of a flame. | Inspect the ionization electrode and the serviceability of the shut-off valves. |
| Fd | Accidental keystroke on the panel. | Press the same button and hold for 30 seconds. |
| | | | Fan not adjusted. | Carry out the adjustment. |
| 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 carry out diagnostics of temperature controllers, product relays. Make preventive cleaning of the furnace, burner, nozzles, and 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 limescale. Salt deposits interfere with heat transfer, so the water boils and sizzles. If the plaque is not removed, the unit will overheat and fail.
Hot water does not turn on
If when opening the mixer there is no hot water, 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 does not work 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.
Errors of Bosch Gaz 6000 boilers
Error A7 - The hot water temperature sensor has a malfunction.
Error Ad - Boiler temperature sensor not detected.
Check the boiler sensor and connection wires.
Error C1 - The fan is rotating at a low frequency.
Check the mains voltage.
Check the flue gas outlet. Clean or repair if required.
Error C4 - The differential pressure switch does not open when the fan is not working.
Check diff. pressure switch.
Error C6 - The differential pressure switch does not close.
Check diff. pressure switch, as well as flue gas pipes.
Error C7 - The fan is not functioning.
Check the fan, wire and plug. Replace if required.
CE error - Low pressure to fill the heating system.
Top up with water.
Error d7 - There is a malfunction of the gas fittings of the wall-mounted boiler Bosch 6000.
Check the connection wire.
Error 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 E9 - Activation of the heat exchanger temperature limiter.
Check the temperature limiter of the heat exchanger for a defect, as well as a possible short circuit in its wire. Replace if required.
Verify operating pressure in the heating system.
Check the temperature limiter, replace if necessary.
Check pump start. Replace the pump if required.
Check fuse, replace if necessary.
Remove air from the Bosch 6000 gas boiler.
Check the water circuit of the heat exchanger; if damaged, replace it.
Check the flue gas temperature limiter for a defect and a possible short circuit in its wire. Replace if required.
EA Error - Flame Not Found.
Check the connection of the protection wire.
Check the opening of the gas cock.
Check gas supply pressure. Correct the problem if necessary.
Check the connection to the electrical network.
Check electrodes and wires. Repair if necessary.
Check the flue gas outlet. Clean or repair if required.
Adjust the gas. Repair if necessary.
For natural gas: check the gas flow monitor. Correct the problem if necessary.
When using the combustion air intake from a room, check the air draft into the room and the ventilation openings.
Clean the heat exchanger.
Inspect the gas fittings. Replace if required.
Error codes for gas boilers Bosch ZSC / ZWC 24 MFA
A7 - Hot water temperature sensor defective.
Check for damage or short circuit of the temperature sensor and its wire, replace if necessary.
A8 - BUS connection interrupted.
Check connecting cable and regulators.
A9 - The hot water temperature sensor is incorrectly installed.
Check the installation area, if necessary, dismantle the sensor and reinstall it using heat-conducting paste.
Ad - No boiler sensor detected.
Check boiler sensor and connecting cable.
b1 - Coding plug not found.
Insert the coding plug correctly, measure and replace if necessary.
C1 - During the operation of the device, the differential pressure switch has opened.
Check differential pressure switch, exhaust system and connecting pipes.
C4 - Differential pressure switch in non-operating position does not open.
Check differential pressure switch.
C6 - Differential pressure switch does not close.
Check differential pressure switch and flue pipes.
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?
d4 - Too large temperature difference.
Check pump, bypass hose and system pressure.
E2 - The flow temperature sensor does not work.
Check temperature sensor and connecting cable.
E9 - The limiter in the flow line has worked.
Check the pressure in the system, temperature sensors, check the operation of the pumps and the fuse on the electronic board, remove air from the device.
EA - Bosch ZSC / ZWC boiler does not detect a flame.
Is the gas cock open? Check the pressure in gas network, mains connection, starter electrode with cable and ionisation electrode with cable.
F0 - Internal fault.
Check that the electrical plug contacts and start lines are tightly connected, replace the electronic board if necessary.
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 - Flame detected after gas supply cut off.
Check the ionisation electrode. Check gas valve.
Fd - The button was mistakenly pressed for too long (more than 30 seconds).
Press the button again in less than 30 seconds.
CC - No outside temperature sensor detected.
Check outside temperature sensor and connecting cable for damage.
Malfunctions of gas boilers Bosch
The burner does not start
Check the operation of the emergency switch of the heating system - If necessary, switch it on.
Check operation of the control system start switch - If necessary, switch on.
Inspect the safety breakers - Check their functionality, if necessary, replace the faulty breaker.
Inspect the boiler water temperature regulator - Check and replace the defective part if necessary.
High limit safety cut-out defective - Check, replace if necessary.
An error signal appears from external safety devices (e.g. water quantity safety monitor) - Check heating system, eliminate errors, replace the faulty device if necessary.
The flue gas relay is tripped - AW 10: unlock the flue gas relay. AW 50: wait a maximum of 15 minutes.
The Bosch boiler will turn on automatically if there is a request for heat. In the event of repeated tripping, check the flue gas path and the function of the flue gas monitor. Replace relay if defective.
The burner ignites and shuts down due to a fault. No ignition spark
An ignition spark is heard when the ignition cable is removed - If not: replace the ignition transformer.
If yes: replace ignition electrode or ignition burner.
The burner ignites and shuts down due to a fault
Is the gas cock open? - Open the gas cock.
The supply pressure of natural gas is higher than 8 mbar - If not: Determine the cause and rectify the fault.
Is the air removed from the gas pipeline? - Remove air until gas ignition is possible.
The burner ignites and shuts down due to a fault. No ionization current
The N and L connections may have been reversed - Eliminate the error.
Check voltage between L and PE - If not: carry out PE grounding, if necessary install an isolation transformer.
Poor ionization wire contact - Correct the error, replace the defective part if necessary.
Ionisation electrode shorted to ground - Burner control defective.
Boiling sounds
Whether there is a lime deposits or limescale build-up in the Bosch boiler?
Purge the boiler water circuit according to the manufacturer's recommendations.
In case of constant water loss, find and eliminate the cause.
If necessary, treat the water and install a dirt trap.
Flat main flame
Are the injectors suitable for the gas supplied? - If not: install the correct nozzles.
Matching holes supply and exhaust ventilation local codes and regulations for the installation of gas equipment?
In case of insufficient air flow, the deficiency must be rectified immediately.
Harsh whistle of the burner
Are the nozzles set to the correct pressure? - Check the set value, correct if necessary.
The burner smokes
Is there any noticeable contamination in the crevices or below the slots of the burner rods? - Carry out damp cleaning of the burner as described in this manual.
Find the source of contamination and protect against further contamination.
Are the air inlet and outlet openings permanently functional? - Are there deposits or fibrous contamination on the surface of the heat exchanger?
Inspect through the cleaning holes and combustion chamber. Carry out a dry and, if required, damp cleaning of the boiler as described in this manual.
Are the burner rods damaged or deformed, are there any deformation of individual slots? - Replace burner rods, identify and eliminate the cause of the malfunction.
Information: Damage or deformation is only caused by at least one of the above faults.
Burner ignition is very loud, with strong combustion noises, you can see the flame on the nozzles
Are the correct nozzles installed? - Switch off the burner, fit a new burner rod and correct the incorrect setting for the type of gas.
Are the nozzles set to the correct pressure? - Smell of flue gases in the room where the boiler is installed.
Is the flue gas coming out of the draft breaker? - Determine the cause of the incorrect flue gas discharge and rectify the fault.
If the elimination of the cause is not immediately possible, then the burner must be turned off.
Is the vacuum in the chimney more than 3 Pa? Blockage in the flue gas path?
Are the dimensions of the chimney correct?
Are exhaust fans operating in the boiler room to remove air from the room?
Automation and malfunctions of Bosch Gaz 6000 W boilers
Control automation for gas boilers Bosch Gaz 6000 W
The control panel for gas convection boilers Bosch 6000 W with Cotronic 3 data bus allows you to control the heating system depending on room temperature.
For these wall-mounted convection gas boilers, two types of Bosch regulators are recommended.
OpenThermTM CR12005 Programmable Room Temperature Controller
Rice. 7. Combination of the OpenThermTM CR12005 programmable room temperature controller with the control panel of the Bosch 6000 gas convection boiler
Purpose and functions:
OpenThermTM programmable thermostat for controlling boilers with Cotronic data bus 3.
Data exchange with the regulator via a two-wire bus.
Two-wire bus technology, reverse polarity protection.
Simple, intuitive settings for temperature control and DHW control.
Preset weekly programs with six switching points. The ability to manually change the program for each day of the week.
LCD display with digital and graphical display of work status.
Display of the current heating and DHW temperature, outside temperature (only in the case of a temperature sensor), indication of the boiler burner operation status and error codes.
Possibility of remote reset of boiler error.
Using the OpenThermTM protocol.
The setting range of the air temperature in the control room is 7 ... 39 ° С with a setting step of 0.5 ° С.
Room temperature controller TRZ 12-2
Fig. 8. Combination of the TRZ 12-2 room temperature controller (on / off) with the control panel of the gas convection boiler Bosch Gaz 6000 W
Description and functions of the regulator
The TRZ 12-2 room temperature controller is recommended for on / off control of the burner flame and control of the circulation pump of gas wall-hung boilers.
Weekly programming of time intervals.
Three operating modes: "Normal", "Economy", "Automatic".
Vacation function (up to 99 days).
Anti-freeze function.
Date and current time display, automatic summer / winter time change (synchronization with the system).
The room temperature adjustment range is from +5 to +39 ° С.
Malfunctions shown on the display of Bosch 6000 boilers
A7 - Hot water temperature sensor defective.
Check for damage or short circuit of the temperature sensor and its wire, replace if necessary.
Ad - Boiler temperature sensor not recognized.
Check the boiler temperature sensor and the connecting cable
C1 - Low fan speed.
Check the mains voltage.
C4 - Differential pressure switch does not open when the fan is off.
Check differential pressure switch.
C6 - Differential pressure switch does not close.
Check differential pressure switch and flue pipes.
C7 - The fan is not working.
Check the fan and its cable with a plug, replace if necessary.
CE - Insufficient filling pressure of the heating system.
Add water.
d7 - The gas fittings of the wall-mounted Bosch Gaz 6000 W boiler are faulty.
Check the connecting wire.
E2 - Defective flow temperature sensor (open circuit).
Check for damage or short circuit of the temperature sensor and its wire, replace if necessary.
E9 - The heat exchanger temperature limiter has tripped.
Check the heat exchanger temperature limiter and its connecting wire for damage, replace if necessary.
Check the operating pressure in the heating system.
Check temperature limiter, replace if necessary.
Check pump start-up, replace pump if necessary.
Check fuse, replace if necessary.
Remove air from boiler Bosch 6000 W.
Check the water circuit of the heat exchanger, replace if necessary.
Check the flue gas temperature limiter and its connecting wire for damage, replace if necessary.
EA - No flame detected.
Check the protective conductor connection.
Check if the gas cock is open.
Check supply gas pressure, correct if necessary.
Check the electrical connection.
Check electrodes with wires, replace if necessary.
Check the flue gas system, clean or repair if necessary.
Check gas regulation, correct if necessary.
For natural gas: check the gas flow control switch, replace if necessary.
When working with a combustion air intake from a room, check the room air supply and ventilation openings.
Clean the heat exchanger.
Check gas fittings, replace if necessary.
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OPERATION AND REPAIR OF BOILERSProterm Panther Proterm Skat Proterm Bear Proterm Cheetah Evan
Ariston Egis Teplodar Cooper Atem Zhitomir Neva Lux Arderia Nova
Termona Immergaz Electrolux Conord Lemax Galan Mora Aton
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2017-04-29 Evgeny Fomenko
The device and principle of operation of Bosch boilers
The most popular models among the line of Bosch boilers are double-circuit. They are faced with two tasks: the first is to heat the room to a given temperature, the second is to ensure hot water for household needs.
Bosch devices, namely the Bosch Gas 4000 W and Junkers Bosch models, are equipped with two independent heat exchangers, which allows them to perfectly perform two tasks: heating water and providing heat in the room.
In each of the models, it is possible to choose the device power that suits you from 12 to 35 kW; when choosing, the area of the room is taken into account. With regard to heating liquid for household needs, the productivity is about 8-13 liters per minute.
Advantages of a wall-mounted double-circuit boiler:
The boiler can be built into the kitchen wall Disadvantages:
- The first 20-40 seconds after you turn on the hot water tap, cold water flows.
Let's take a closer look at how the device works, using the example of the Bosch Gas 4000 W ZWA 24 model. When the boiler operates in heating mode, use gas burner heat is transferred to the primary heat exchanger, which is a structure of copper tubes and records.
So that they do not deteriorate from exposure high temperatures and water, their surface is covered protective layer... Its main task is to transfer the heat generated during the combustion of the flame to the heating system. The movement of water in the system is provided by a pump.
Also, the design provides a three-way valve, its task is to prevent water from entering the secondary heat exchanger. A secondary heat exchanger is required to heat domestic water. The heated liquid for the heating circuit leaves the device through the heating supply line, and the cooled liquid enters through the heating return line.
When the boiler is set to heat water for consumption, the 3-way valve closes the heating circuit. The heated liquid flows from the primary heat exchanger to the secondary one, and then flows out of the device.
Bosch boiler three-way valve
The plus when using different heat exchangers is obvious. When heating is often used plain water, but it usually contains impurities. When it heats up, impurities begin to form deposits, which negatively affect the heat exchanger, reduce it throughput, prevent water from warming up, shorten its service life.
And when the liquid that flows through the primary heat exchanger, it is in a closed circuit, does not change its chemical properties, minimizes negative consequences.
The liquid that flows through the secondary heat exchanger will build up deposits over time and over time the heat exchanger will need to be replaced or cleaned. If the malfunction occurs on winter period, your boiler will be able to operate smoothly in heating mode using the primary radiator.
Major error codes
Like any device, the Bosch gas boiler also sometimes fails and needs repair, let's take a closer look at it possible malfunctions and ways to eliminate them.
11
Error 11 is possible in the Bosch BWC 42 device, it stands, in the same way as error E9, signals that the flue gas temperature limiter has been triggered.
Flue gas temperature limiter
You need to do the following:
- check for subject wire damage flue gas temperature limiter, if you find rupture or melting, replace;
- check pressure in the device;
- check temperature limiter;
- check serviceability of the pump when it starts;
- if air has accumulated in the boiler, drain it.
23
Error 23 is not an error, this code appears during settings and indicates the type of natural gas used
50
Error 50 appears on Bosch ZWA 24 models when there is no flame.
Boiler Bosch ZWA 24
How to fix it:
70
Error 70 means a malfunction of the differential relay during ignition.
Reasons and ways to eliminate it:
- differential relay failure, you can determine by measuring its resistance, if it does not correspond to the nominal, the relay will be replaced;
- mechanical breakdown of contacts and wires suitable for the relay, check and connect the wires;
- poor chimney performance, it may become clogged, clean the chimney;
- incorrect setting or breakdown of the fan, adjust the operation of the fan, if it is faulty, replace it.
a2
Error a2 appears when exhaust flue gases exit on the combustion chamber, indicating that the heat exchanger is clogged with soot and fumes. To eliminate, clean the heat exchanger.
Cleaning the heat exchanger with compressed air
e2
Error e2 - the flow temperature sensor is faulty. Ring the sensor for a short or open circuit, and inspect the connecting wires for a broken circuit or oxidation. Strip or connect the wires, in case of sensor failure, replace with a new one.
e9
Error e9 means the temperature limiter has been triggered.
The reasons for the appearance and methods of elimination may be as follows:
ea
Error ea signals the absence of a flame in the on state.
When this code appears, you should check:
er
Error er (ep) appears in case of incorrect operation of the boiler in the event of malfunctions in any of the device blocks.
c3
Error c3 appears on the Bosch ZWE boiler in the event of the appearance of exhaust gases on the combustion chamber. This problem can be eliminated by cleaning the heat exchanger in accordance with the instructions in the instructions.
c4
When the differential pressure switch is closed and the fan is off, error c4 appears.
Differential relay
When this code appears, you can do the following:
- blow out the pipes coming from the relay, after removing the relay, which is located in the upper part of the boiler. If the relay clicks, the problem is eliminated;
- measure resistance with a multimeter on a cliff or short circuit, if the parameters are inappropriate, the relay must be changed.
c6
Error c6 means that the differential relay does not turn on when the fan is turned on.
What to do when this code appears:
- check the chimney, eliminate interference, in coaxial chimneys sometimes it can be ice or frost.
- see if there is condensation on the tubes coming from the relay. Dry the tubes with a hair dryer.
- check relay for short circuit or open, replace the relay if necessary.
ce
The ce error is a fairly often repeated code in Bosch gas boilers (bosch gaz) 6000 24 kW and means insufficient pressure in the heating circuit.
Bosch boiler gas 6000 24 kW
The lack of water in the circuit is determined by the pressure gauge:
- if the pressure gauge is in the red zone, it is necessary to add water to the system using the make-up tap, which is located under the device;
- if the pressure gauge is in the green zone, change the pressure sensor. The sensor may have a defective microswitch or diaphragm.
f0
Error f0 means an internal fault. When it appears, you need to check the reliability of the connection of the terminals and wires to the electronic board. If the wires are not oxidized, the connections are not broken, then this is a malfunction of the board itself, it should be replaced.
fd
The fd error appears 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.
se
The se error signals an insufficient filling of the heating system.
Heat exchanger with scale and after cleaning
What should be done:
- add water:
- the reason why the pressure drops can be a leak or depressurization of heating pipes. If the pipes are hot, it is difficult to detect a malfunction, as water can evaporate at the leak. To determine, cool the system, seal the joints in the places of leakage:
- the heat exchanger may be clogged with scale, remove and rinse it, the procedure is described in the instructions for the boiler.
Other malfunctions
The above were the most common error codes, let's look at other possible malfunctions.
Sometimes there are such problems:
