Fault and Error Codes for Viessmann Vitopend, Vitodens Boilers

If the blockage, damage or anomaly persists, contact the services of an ISCIR authorized company.

10 Constant operation. Short circuit to outdoor temperature sensor. Check the outside temperature sensor and cable.
18 Constant operation. Interruption to the outdoor temperature sensor. Check the outside temperature sensor and cable.
30 Burner blocked. Short circuit to boiler temperature sensor. Check the boiler temperature sensor.
38 Burner blocked. Interruption to the boiler temperature sensor. Check the boiler temperature sensor.
50 No domestic hot water is prepared. Short circuit to the domestic hot water temperature sensor in the battery. Check the sensor.
51 No domestic hot water is prepared. Short circuit to the temperature sensor a.c.m. at the exit. Check the sensor.
52 Burner blocked. Volumetric flow sensor short circuit. Check the connections and the cable, replace the sensor if necessary.
58 No domestic hot water is prepared. Interruption to the boiler water temperature sensor. Check the sensor.
59 Do not prepare domestic hot water. Interruption to a.c.m. at the exit. Check the sensor.
5A Burner blocked. Volumetric flow sensor interruption. Check the connections and the cable, replace the sensor if necessary.
A0 Burner blocked Dynamic gas supply pressure too low. Checking the gas pressure and the gas pressure switch.
A3 Burner blocked. The flue gas temperature sensor is not positioned correctly. Install the flue gas temperature sensor correctly.
A9 Controlled automation operation without the influence of an Open Therm unit. Communication error on Open Therm unit. Check the connections and cable, replace the Open Therm unit if necessary.
b0 Burner blocked Short circuit at the flue gas temperature sensor. Check the sensor.
b7 Emergency mode. Ignition error. Disconnect the on-off switch and reconnect.
b8 Burner blocked. Interruption to flue gas temperature sensor. Check the sensor.
0A Burner blocked. Dynamic supply pressure too low. Check gas pressure and gas pressure switch.
0C Burner blocked. The mains voltage is too low. Check the mains supply.
E3 Burner on failure. Error in the circuit of safety elements. Check the temperature limiter and connecting cables.
E5 Burner blocked. Internal error Check ionization electrode and connecting cables.

F0 Burner blocked. Internal error Automation is being replaced.
F1 Burner on damage. Max. of flue gas has been exceeded. Check the filling level of the system. Check the circulation pump. Ventilate the installation.
F2 Burner on damage. Temperature limiter disconnected. Check the filling level of the installation. Check the circulation pump. Ventilate the installation, check the temperature limiter and the connection cables. To unlock the burner, turn the "vitopend 100 wh1d fault indicator" button briefly to the limit to your right and then back (Reset).
F3 Burner on damage. There is already a flame signal when the burner is started. Check the ionization electrode and the connecting cable. Disconnects and reconnects the on-off (or reset) switch.
F4 Burner on damage. There is no flame signal. Check the ignition / ionization electrode and the connecting cable, check the gas pressure, check the valve block, ignition and ignition mode. Disconnects and reconnects the on-off (or reset) switch.
F5 Automatic ignition on failure. The air switch is not open when the burner is started or does not close when the ignition speed is reached. Check the exhaust / air intake system, the hose from the pneumatic switch, the pneumatic switch and the connecting cables. Disconnects and reconnects the on-off (or reset) switch.
F8 Emergency burner. The fuel valve closes late. Check the valve block. Check the two control paths. "Reset" is performed.
F9 Emergency burner. The blower speed when starting the burner is too low. Check blower, blower connection cables, blower power supply, blower control. "Reset" is performed.
F30 Burner blocked. Short circuit to boiler temperature sensor. Check the boiler temperature sensor.
F38 Burner blocked. Interruption to the boiler temperature sensor. Check the boiler temperature sensor.
F50 Do not prepare domestic hot water. Short circuit to the domestic hot water temperature sensor in the battery (only for the wall-mounted gas heating boiler). Check the sensor.
F51 Do not prepare domestic hot water. Short circuit at the outlet temperature sensor (boiler for heating and cooking a.c.m on gas). Check the sensor.
F58 Do not prepare domestic hot water. Interruption to the domestic hot water temperature sensor in the battery (wall-mounted boiler for gas heating). Check the sensor.
F59 Do not prepare domestic hot water. Interruption to the sensor for the outlet temperature (boiler for heating and cooking a.c.m on gas). Check the sensor.
FA Burner on damage. The blower stop point has not been reached. Check blower, blower connection cables, blower power supply, blower control. "Reset" is performed.
FC Burner blocked. Blown electrical control (automation) defective. Check the connection cable to the blower, check the blower, possibly replace or replace the automation.
Fd Burner blocked. Ignition error. Ignition electrodes and connecting cables are checked. Check for a strong disturbing field (EMC) near the unit. "Reset" is performed. If the fault is not repaired, the automation is replaced.
FF Burner blocked. Ignition error. Ignition electrodes and connecting cables are checked. Check for a strong disturbing field (EMC) near the unit. "Reset" is performed. If the fault is not repaired, the automation is replaced.
–– (lightning) Burner blocked Communication error between ignition control and control unit Checking the connection cable. "Reset" is performed. If the disturbance is not remedied, replace the ignition switch or the control unit.