Error codes for a gas boiler Viessmann: methods for troubleshooting and recovery

Autonomous heating has a number of compelling advantages over centralized. These are reasonable prices, profitability and high efficiency. To organize an independent heating system, you need a boiler that can not only work perfectly, but also not create problems.

The next generation models with intelligent control devices and multi-level protection will help eliminate problems. For example, a gas boiler Viessmann "prompts" itself. The smart unit will display on the display an alphanumeric code of a brewing malfunction and a breakdown that has already occurred.

We will tell you how to determine the code in which of the nodes or systems of the unit by the code. We will show you how to find the problem and correct the situation in a timely manner in order to prevent a more serious problem. The owner of the unit will only have to decide whether he will repair or call the master.

Error codes for Vitopend 100-W boilers

The electronic system of the units is configured in such a way that in the event of a malfunction of the Viessmann gas boilers, the breakdown is detected automatically. In this case, the error code is displayed on the display of the device. This allows you not to disassemble the entire boiler, but to specifically diagnose the performance of a particular part.

The decoding of the symbols is given in the detailed instructions for certified electricians and gas workers accredited to perform gas boiler repair this German brand manufacturer.

These boilers are available single-circuit and combined. They can work both on natural gas, and on reduced. They have a closed combustion chamber. The power range is from 10 kW to 34 kW.A modulated burner with a built-in fan allows efficient removal of gaseous fuel processing products from the boiler combustion chamber.

Installing replacement and wearing parts that have not been previously tested by the manufacturer can lead to breakdown, poor performance, and a significant reduction in safety.

The standard value of the efficiency of this boiler model is 85%. A controller with an integrated diagnostic system is integrated in a single module with the unit. The Viessmann Vitopend 100-W gas boiler generates typical error codes on a white backlit digital display.

Trouble Code: 06

When this error code appears, the boiler burner is blocked. This is due to the too low pressure of the water circulating through the heat exchanger, which is heated for the heating circuit. At the inlet to the diaphragm reservoir, the pressure must be at least 0.8 bar.

To solve the problem, you need to check the pressure in the unit, remove excess air from the radiators and replenish the coolant volume through the make-up valve located at the bottom of the case.

Before filling the installed gas boiler, it is necessary to flush the heating circuit connected to it, if it was previously used with another unit

According to the instructions, it is necessary to fill in the installation with fresh water from a centralized water supply system or an individual source. If the water hardness exceeds the manufacturer’s recommended limit of 4.5 mEq / l (milligram equivalent per liter), a filter device should be installed.

The hydrogen pH of the water that can be prepared by a German-made boiler should be in the range of 6.5 to 8.5. The manufacturer may add antifreeze to the water.

Pressure testing is carried out in a cold installation at a temperature in the system of less than 30 ° C. The minimum pressure at the inlet to the membrane expansion tank should be 0.8 bar or 0.08 MPa. The maximum working pressure of the heat carrier plying through the boiler should be 3 bar or 0.3 MPa.

Check the expansion tank as follows. Water from the unit is drained to a pressure indicator in the boiler pressure gauge of 0 bar. If the static pressure of the installation is higher than the pressure in the expansion tank, then nitrogen must be pumped through the nipple at the inlet to a value of 0.1 - 0.2 bar higher than the static pressure.

Trouble Code: 0A

The error 0A on the display is accompanied by a burner lockout, and the cause of its occurrence is a lower value of the dynamic gas pressure. According to the instructions, the value of the dynamic pressure of natural gas should be in the range from 8 to 25 mbar, and the pressure of the reduced gas should be from 27.7 to 57.5 mbar.

It is necessary to connect the pressure gauge to the nipple and measure the pressure in the system. It is practically impossible to find pressure gauges with the scale required to measure the pressure of blue fuel in free sale, so an appeal to the master from the service center is inevitable

Checking the pressure in the system is carried out using a gas manometer with a scale division of 0.1 mbar. If low pressure in the gas pipes is detected, then it is necessary to contact the organization supplying gas in order to find out the reasons.

If the pressure value corresponds to the indicator specified by the manufacturer, then it is necessary to start checking the operability of the pressure control relay built into the boiler. If a relay failure is detected, it is advisable to contact a service center.

You can buy a gas pressure monitoring relay for this boiler model from an official Viessmann parts supplier. However, repairs, installation and replacement must be carried out by certified craftsmen who have been certified and obtained permission from the manufacturer to repair the boilers of this brand.

DTC: 0C

This error code appears on the display if the mains voltage drops significantly. The burner in this case is blocked, and to solve the problem, it is necessary to check the mains voltage and find out the cause of its fall. The network may sag if several electrical appliances are connected at the same time.

If the heating device is filled with water of inadequate quality, scale and corrosion may occur. Also, using the wrong heat carrier can lead to overheating and damage to the gas boiler

Sometimes a decrease in voltage is associated with a violation of the contact connection at the junction of the internal wiring. The problem of a lack of mains voltage can also arise when selecting a cable with a cross section of insufficient size. The owner himself must solve these problems.

Often there is a situation of seasonal undervoltage. When at the same time many users turn on heating equipment, and the voltage in the distribution network is not enough to meet the increased consumption. In such cases, you must contact the organization that provides the supply of electricity.

Problems with a voltage drop in the power supply supplying the volatile devices of Wisman brand boilers are solved by installing stabilizer for gas boiler.

Trouble Code: CC

A CC error indicates a malfunction in the external expansion module. The reason for this error message is the loss of communication between the external expansion module and the device controller. The most common way to troubleshoot is by trivially checking the cable connecting these parts.

If the contact is removed, then the cable just needs to be connected. If the cable is broken or broken, it must be replaced.

Trouble Code: F02

The appearance of the code F02 on the display indicates a burner malfunction. This alphanumeric designation appears when the temperature limiter is activated. First of all, the user should check the fullness of the system with coolant and let out excess air from the circulation pump and radiators.

If after these procedures the error continues to be displayed, then the temperature limiter must be checked for a malfunction. It is also necessary to check the connecting cables.

The diagram shows the location of the temperature limiter and other sensors on the Viessmann Vitopend 100-W gas boiler

Check the limiter as follows:

• Sensor cables are disconnected;
• It is determined whether current flows through the temperature limiter (this is done by a universal measuring device);
• The defective stop must be removed;
• The installation site is lubricated with heat-conducting paste;
• A new limiter is installed;
• Unlocking is carried out by pressing the MODE and OK buttons until the reset symbol flashes on the display;
• Re-ignition is performed.

The temperature limiter is checked in order to make sure that after an emergency shutdown there is no release of the gas furnace when the water temperature in the boiler is below 90 ° C.

DTC: F03

Code F03 indicates that a flame signal appears before the burner starts. Repair of Wismann gas boilers that produce this error consists in checking and repairing the ionization electrode.

Additionally check the connection cables. It is necessary to shut down and restart the mains switch. You can also perform the above reset procedure.

Trouble Code: F04

This error indicates the absence of a flame signal. In most cases, the problem is solved after restarting the boiler or performing a reset. If this method does not help, then you need to check the condition of the two ignition electrodes. Then the ionization electrode is checked. Perhaps they have mechanical damage or have changed their position relative to each other.

Replacement of gas control valves is as follows. Disconnect plugs A, D and hose B. Then unscrew the union nuts E and dismantle the defective C / G fittings. After installing a new valve with a seal F and the installation is carried out in the reverse order

Then check the connection cables. If damage is revealed during inspection, then these parts must be replaced with new ones or repaired. The dismantling of broken products and the installation of new ones must be carried out strictly according to the instructions.

In addition to ignition problems, there may be problems with the gas supply. It is necessary to check the gas pressure, inspect the gas control valves. The next step is to diagnose the ignition and the ignition module. If malfunctions are detected, it is necessary to replace or contact a service center for repair of parts.

DTC: F05

Indicates a malfunction of the furnace. The error appears due to the fact that the air pressure switch does not open when the burner starts. Also, the relay may not close when the ignition load is reached. To determine the cause of the malfunction, it is necessary to inspect the Air / Combustion Products system.

Upon examination, you can find the following problems:

• The chimney is overgrown with ice. Withdrawal of combustion products and entry is difficult. The problem is solved by removing the growth of ice.
• Improperly installed coaxial chimney. Proper installation is required.
• The fan is out of order. In this case, you need to replace the part.
• The fused venturi must be replaced.
• It is required to replace the pressure switch.

After replacing the air pressure switch, the error disappears.

DTC: F08

The error is caused by a solenoid valve relay lock. In this case, the burner of the device does not turn on.

Due to the special design, the solenoid valves fail extremely rarely. Checking their performance is carried out in several ways.

It is necessary to check the functionality of the relay, the valve itself, as well as the connecting cables. The lock may fall after resetting or rebooting the device.

The solenoid valve is checked by fire or tool. In the first case, it is necessary to install a new thermocouple. Then light the ignitor and bring the fire to the end of the thermocouple. If the automation is triggered, the valve is working properly. In the second case, it is necessary to dismantle the sensor, insert it into the repair contact and apply voltage. If the valve closes, then the automation is OK.

DTC: F10

When this error occurs, the device continues to operate in continuous mode. Code F10 indicates a short circuit gas boiler sensors. It is necessary to inspect the outdoor temperature sensor and the room temperature sensor.

Connection cable with sensors. The sensor check is carried out as follows. The controller housing opens. Sensor cables are disconnected. Resistance is measured, and indicators are compared with a curve.

If the indicators have a significant deviation, then the sensor should be replaced.

DTC: F18

An error occurs when one of the two sensors opens. A problem is identified when checking the cables of the outdoor temperature sensor and the connections of the room temperature sensor. If the contact is removed, then you need to firmly connect it back. If the cables are damaged, they must be replaced.

DTC: F30

Error F30 occurs when the unit temperature sensor is shorted. When it appears, the user needs to inspect the boiler temperature sensor. If a visual inspection does not reveal a problem, disconnect the cables from the sensor and measure the resistance. If, when comparing the resistance with a curve, a strong deviation is detected, then the part must be replaced.

Trouble Code: F38

This error appears when the boiler temperature sensor breaks.When it appears, it is necessary to inspect the sensor, identify the place of cable breakage, replace or connect the cable.

Trouble Code: F51

Error display F51 indicates that the boiler has stopped heating water. The cause is a short circuit in the sensor.

Checking the sensor that measures the temperature of the outlet water is carried out as follows. The cables are first disconnected. After that, the resistance is measured and its values ​​are compared with the curve. If a significant deviation is detected, the sensor should be replaced.

The outlet water sensor t is located in the water inside the hot water circuit of the gas unit. Therefore, before replacing and checking the device, it is necessary to empty the circuit

The resistance of the cylinder sensor t must also be checked and compared with a curve. Before checking, disconnect the plug from the cable harness located on the controller.

Trouble Code: F59

The cause of error F59 is the opening of the sensors. It is necessary to check the connection of the cable for the water temperature sensor, as well as the connection of the sensor plug t of the DHW cylinder. If a disconnection is detected, carefully plug the plug back in.

Trouble Code: F70

Error code F70 indicates a malfunction of the external module. The error is displayed due to a short circuit in the temperature sensor of the collector S1, which is connected to an external expansion module. When this code appears, you need to check the sensor for a malfunction.

DTC: F78

The error is related to the opening of the sensor t of the collector S1 installed on the external expansion module. Check the condition of the sensor cables and contact density.

Trouble Code: F80

This error also indicates a malfunction in the external expansion module. The cause is a short circuit in temperature sensor S2.

It is necessary to disconnect the sensor cables and check its resistance. If the values ​​deviate from the curve, the sensor must be replaced.

DTC: F88

The error occurs when electrical contact is lost with the lower sensor S2 of the DHW cylinder associated with an external expansion module.

To check the sensors, pull the plug out of the controller. Then the resistance must be measured at the terminals of the sensor with a multimeter

It is necessary to find out the cause of the opening and eliminate it.

DTC: F90

Error F90 indicates a short circuit in the upper temperature sensor S3 of the DHW cylinder installed on the external expansion module.

If a serious deviation from the resistance curve is detected when measuring with an ohmmeter, then the sensor must be repaired or replaced

It is necessary to diagnose the sensor.

Trouble Code: F98

An error indicates an open sensor S3. It is necessary to check the sensor for an open, connect the cables tightly or replace them in case of mechanical damage.

With codes of violations in work and their decoding adopted by the manufacturer of boilers with the Master Gas logo, will acquaint next article, which will be useful to both real and potential owners of units of this brand.

Conclusions and useful video on the topic

Error F05 and ways to resolve it:

Error F02 on the Vitopend 100-W boiler display:

Each malfunction code that appears on the display of the gas boiler indicates a problem in a particular unit of the device. When carrying out repairs, it is imperative to turn off the power to all parts of the heating device. You also need to close the gas valve and stop the gas supply.

Elements that perform protective functions should not be repaired for operational safety reasons.In the event of a breakdown of Viessmann components, their replacement must be carried out only with original branded parts or spare parts authorized for use by an official representative of the manufacturer.

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