Bosch gas boiler. Error C4. Eliminate by yourself

An error code such as C4 can be annoying if you depend on your Bosch gas boiler to heat your house during the cold months. You can save time and money, though, if you know how to troubleshoot and fix this issue on your own. We’ll walk you through the process in this post to get rid of the C4 error code and get your boiler working again.

First and foremost, it’s critical to understand what the C4 error means. When a Bosch gas boiler encounters the C4 error, an ignition issue is usually the cause. This could indicate that your home isn’t heating at all because the boiler is having trouble lighting the gas to generate heat. Although this error can be alarming, it’s usually fixable with some simple troubleshooting.

Make sure safety comes first before attempting to fix the C4 error. If the boiler has been running, turn off the electricity and let it cool. To avoid mishaps or more harm, become acquainted with the boiler’s safety instructions and handbook as well. After implementing these safety measures, you can start debugging the C4 error.

Begin by inspecting the boiler’s gas supply. Verify that the gas valve is open and that the gas line is free of obstructions and leaks. Verifying the gas supply is a sensible first step because the C4 error can occasionally be caused by a straightforward problem like a closed gas valve. Proceed to inspect the ignition system if the gas supply appears to be operating without any issues.

The igniter, flame sensor, and control board are some of the parts that make up your Bosch gas boiler’s ignition system. Examine these parts for any indications of wear, rust, or accumulation that might be impeding correct ignition. Take extra care to clean the igniter and flame sensor to make sure no dirt or debris is interfering with their operation. To fix the C4 error, think about replacing any damaged parts that you find.

Indication "C4"

The control panel display displaying the error "C4" typically indicates a problem with the heating medium ventilation system. The primary cause of this error in the case of the Bosch WBN 6000 – 18C RN boiler is the malfunction of the pressostat or differential smoke relay sensor, which controls the fan operation. Consequently, Bosch will assist in installing a new, defective part in order to resolve this issue with the boiler brand. Particularly, a pressostat. Nonetheless, a heating system diagnostic procedure must be used prior to beginning any repair work. In this instance, take these steps:

• Disconnect the Bosch water heater using the center button located on the front panel;
• Disconnect the device from the power supply;
• Stop gas supply with the help of a tap.

Following these steps, it is essential to move on to the water heater’s body part removal.

Disassembly of the boiler drum Bosch Gaz WBN 6000 – 18C RN

Removing the front cover

The Bosch boiler’s front decorative cover needs to be removed first. A Phillips screwdriver is the only tool needed for this easy process. You must unfold the control panel and take the front cover apart in order to accomplish this. Two screws in the lower part of the fastener need to be undone with a Phillips screwdriver. The front panel is lowered and unfolded towards itself after the self-tapping screws have been removed. The upper ornamental cover can then be removed, which is the next step that can be done.

Removing the upper decorative cover

The Bosch boiler’s upper decorative panel has two self-tapping screws located at its base. To remove this part, a Phillips screwdriver will be necessary once more. Subsequently, the boiler’s upper decorative cover can be removed by following the same procedure used to remove the front cover: gently pull the housing portion downward and remove it. It won’t be necessary to disassemble any more Bosch boiler trim panels afterwards.

After that, you can begin utilizing the coolant system’s internal device.

Checking the operation of the Bosch boiler pressostat

Pressure-switching gas boiler. It can be found on the boiler’s upper cover.

A closer look at the internal device of the Bosch boiler you can notice a small pressostat, located in the upper left corner of the device. It is used to control the operation of the smoke extraction system fan. The mechanism of starting the heating equipment is as follows: when the device is turned on, the first fan starts, which leads to automatic switching of the pressostat. In case of malfunction of this part, the fan will not function in the correct mode and may cause smoke in the room. For this reason, the next step of repair works is diagnostics of the pressostat operability with the help of multimeter. In normal state the contacts of the pressostat should be opened. Otherwise this part will be faulty and the error "C4" will be eliminated after replacing this part. The order of actions for realization of diagnostic works is as follows:

• Disconnect the connectors of this sensor;
• Turn on the pre-prepared multimeter;
• Set the multimeter to the circuit test mode;
• Check the contacts.

In order to fix the error "C4", Bosch boiler will assist in replacing the pressostat if the contacts are closed, which indicates that the pressostat is stuck.

In this article, we"ll tackle a common issue with Bosch gas boilers: Error C4. If you"re experiencing this error, don"t panic! We"ll guide you through how to resolve it yourself, saving you time and money on technician visits. Understanding the nature of Error C4 is the first step. It often indicates a problem with the ignition or combustion process, potentially caused by issues like blocked air vents, faulty ignition components, or gas supply interruptions. We"ll walk you through a step-by-step troubleshooting process to identify and fix the problem. From checking for obstructions in the air vents to ensuring proper gas supply, we"ll cover all the bases. By following our simple instructions, you"ll be able to get your Bosch gas boiler back up and running efficiently in no time, ensuring your home stays warm and comfortable during the colder months.

Pressostat removal

The replacement of a pressostat is a simple, quick, and labor-light process. Disassembling the faulty sensor is the first step in the repair process. It takes little effort to remove the jammed pressostat in a Bosch boiler, and the procedure is as follows:

• Disconnect the two impulse tubes located at the bottom of the pressostat;
• Release the two clips located in the upper part of the sensor;
• Pull the pressostat towards yourself and remove it from the boiler.

Once the inappropriate pressostat has been disassembled, a new part must be bought and installed. It can be purchased online as well as in typical building supply stores. Such spare parts for Bosch boiler repairs typically cost between 500 and 1000 Russian rubles.

Installation and connection of the new pressostat

A new pressostat is very easy to install and won’t take much time at all. Naturally, it is executed in accordance with the plan in reverse order of disassembly:

• It is necessary to return the pressostat to its original place;
• Clamp the two clips located in the upper part of the sensor;
• Connect the two impulse tubes located at the bottom of the pressostat.

The Bosch boiler can be put back together after these procedures. The return of the upper decorative cover that was previously disassembled should mark the beginning of this procedure. That portion of the trim is secured in place using a Phillips screwdriver and two self-tapping screws. Subsequently, the boiler control panel is raised and positioned. A Phillips screwdriver and two screws are also used to secure it in place.

Once the Bosch boiler has been assembled and finished, and the new pressostat has been installed in the heating equipment system, a diagnostic of its serviceability must be performed. The following steps must be taken in order to achieve this goal:

• Connect the heating equipment to the power supply network;
• Open the gas supply by means of a tap;
• Start the Bosch Gaz WBN 6000 – 18C RN boiler using the switch on button on the control panel;

The last phase of the repair process will involve verifying that the device is operational and that the new part is connected correctly.

Functionality check

The boiler’s control check and the operability of the new pressostat constitute the final step in eradicating the error "C4" associated with the Bosch boiler brand. Following startup, the heat carrier’s pump and fan will operate sequentially. The gas burner will then start up on its own, signaling that the boiler is in good operating condition and prepared for more use. Following all adjustments, the display will no longer show the error code "C4" and instead show the temperature indicator for the water heating process.

Don’t panic if your Bosch gas boiler has the dreaded C4 error code on it. There are steps you can take to troubleshoot and possibly resolve the issue on your own, even though it can be frustrating.

Check the fundamentals first. Verify that the gas supply is turned on and that the boiler is receiving power. Simple mistakes can occasionally result in error codes like C4.

Next, examine the pressure gauge on the boiler. The C4 error code may be brought on by low pressure. You can try repressurizing the system by according to the manufacturer’s instructions if the pressure is lower than the advised range.

If pressure isn’t the problem, further investigation is warranted. Examine any obvious indications of obstructions or damage on the boiler’s parts, including the burner, heat exchanger, and flue. Errors can be fixed by removing any barriers.

You can also try to clear the error code by resetting the boiler, if you feel comfortable doing so. The manual for your boiler will provide detailed instructions on how to reset the system safely.

If attempting these do-it-yourself solutions doesn’t fix the C4 error, it might be time to hire an expert. A skilled technician can diagnose the problem more thoroughly and fix any underlying problems that are causing the error code.

Always remember that the most important thing when using gas appliances is safety. Never be afraid to ask a qualified professional for help if you have any questions or feel uneasy performing any troubleshooting steps.

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