Viessmann Vitodens 100-W Boiler
60 fault codes documented
Connection error — Displayed on programming unit
A 'Connection error' appears on the display unit, indicating a problem with the communication between the heat management unit and the programming unit.
F.142 — Burner in fault state due to CAN bus communication error
The burner is in a fault state because of a communication error on the CAN bus. This indicates a problem with how different components are communicating.
F.160 — Burner in fault state due to CAN bus communication error
The burner is in a fault state due to a communication error on the CAN bus. This could involve either internal or external communication components.
F.161 — Burner in fault state due to BCU data memory access error
The burner is in a fault state due to an error accessing the data memory of the BCU burner control unit. This prevents the boiler from functioning correctly.
F.163 — Burner in fault state due to BCU memory access checksum error
The burner is in a fault state because of a memory access checksum error in the BCU. This indicates an integrity issue with the control unit's memory.
F.346 — Burner in fault state: Ionization current calibration error
The burner is in a fault state due to an ionization current calibration error. This affects the boiler's ability to accurately detect and maintain a flame.
F.348 — Burner in fault state: Gas modulation valve issue
The burner is in a fault state related to the gas modulation valve. This may occur in systems with multiple boilers or indicate a flue issue.
F.349 — Burner in fault state: Air mass flow rate not correctly detected
The burner is in a fault state because the air mass flow rate is not being detected correctly in the fan unit. This indicates an issue with airflow measurement or components.
F.350, F.351 — Burner in fault state: Ionization current outside permissible range
The burner is in a fault state because the ionization current is outside the permissible range. This indicates an issue with flame detection and safety.
F.352 — Burner in fault state: CO limit exceeded
The burner is in a fault state because the CO (carbon monoxide) limit within the boiler has been exceeded. This is a critical safety issue indicating improper combustion or flue problems.
F.353 — Burner shutdown: Insufficient gas supply, reduced output
The burner has shut down (with potential for restart if demand exists) due to an insufficient gas supply, leading to reduced burner output. This means the boiler isn't getting enough fuel.
F.354 — Burner in fault state: Gas modulation valve tolerance exceeded
The burner is in a fault state because the gas modulation valve tolerance is outside the permissible range. This affects gas flow control and combustion.
F.355 — Burner in fault state: Flame signal present at burner start
The burner is in a fault state because a flame signal was already present at the burner start (analogue signal reference check). This is a safety issue preventing normal ignition.
F.357 — Burner in fault state: Insufficient gas supply
The burner is in a fault state due to an insufficient gas supply. This can be caused by various issues from the gas shut-off valve to the gas line itself.
F.377 — Burner in fault state: Ionization adjustment stabilization not met
The burner is in a fault state because the stabilization conditions for post-calibration of the ionization adjustment were not met. This can be due to incorrect gas type settings.
F.378 — Burner in fault state: Flame loss during operation
The burner is in a fault state due to a flame loss during the stabilization or operating phase. This indicates an issue with maintaining the flame.
F.379 — Burner in fault state: Flame signal not present or insufficient
The burner is in a fault state because the flame signal is either not present or insufficient. This is crucial for safe boiler operation.
F.380 — Burner in fault state: Immediate flame loss after ignition
The burner is in a fault state due to a flame loss immediately after flame formation, during the safety time. This indicates a problem with the ignition process or flame stability.
F.381 — Burner in fault state: Flame loss during operation phase
The burner is in a fault state due to a flame loss during its normal operating phase. This indicates a sustained issue with flame stability.
F.382 — Burner in fault state: Error counter limit exceeded
The burner is in a fault state because an internal error counter has exceeded its limit. This usually means multiple minor faults have occurred, indicating an underlying problem.
F.383, F.384 — Burner in fault state: Possible gas line contamination
The burner is in a fault state, possibly due to contamination in the gas line. This affects the boiler's ability to receive a clean and steady gas supply.
F.385 — Burner in fault state: Short circuit in ionization current signal
The burner is in a fault state due to a short circuit in the ionization current signal. This can also indicate a problem with the BCU burner control unit.
F.386 — Burner in fault state due to control unit error
The burner is in a fault state because the BCU burner control unit is faulty. This error will prevent the boiler from operating.
F.387 — Burner in fault state: Ground fault in ionization current
The burner is in a fault state due to a ground fault in the ionization current, or a faulty BCU burner control unit. Condensate backup can also cause this issue.
F.388 — Burner in fault state due to control unit error
The burner is in a fault state because the BCU burner control unit is faulty. This error will stop the boiler from operating.
F.395 — Burner in fault state due to electrode ground fault
This fault indicates that the burner is in a fault state, likely due to a ground fault with the ignition electrode or a problem with the burner control unit (BCU). The boiler will not operate correctly.
F.396 — Burner in fault state due to control unit error
The burner is in a fault state, indicating an internal error or malfunction within the BCU burner control unit. This prevents normal operation of the boiler.
F.399 — Burner in fault state due to IO electrode ground fault
This fault indicates a problem with the burner, specifically an IO electrode ground fault or an issue with the burner control unit. The boiler will not function as expected.
F.400 — Burner in fault state due to control unit error
The burner is in a fault state because the BCU burner control unit is faulty. This error will stop the boiler from operating.
F.401 — Burner in fault state due to IO electrode ground fault
This fault indicates that the burner is in a fault state, possibly due to a ground fault in the IO electrode or a problem with the burner control unit. Normal boiler operation is interrupted.
F.402 — Burner in fault state due to control unit error
The burner is in a fault state, indicating an internal error or malfunction within the BCU burner control unit. This will prevent the boiler from functioning.
F.403 — Burner in fault state due to ionization electrode ground fault
This fault indicates that the burner is in a fault state, likely caused by a ground fault with the ionization electrode or a problem with the BCU burner control unit. The boiler's operation is halted.
F.404 — Burner in fault state due to control unit error
The burner is in a fault state because the BCU burner control unit is faulty. This error prevents the boiler from starting or operating.
F.405 — Burner in fault state due to ionization electrode ground fault
This fault indicates that the burner is in a fault state, possibly due to a ground fault in the ionization electrode or an issue with the burner control unit. The boiler will not operate as intended.
F.406, F.408, F.410 — Burner in fault state due to control unit error
The burner is in a fault state because the BCU burner control unit is faulty. These errors will prevent the boiler from running.
F.416 — Burner locked out due to flue gas temperature sensor positioning
The burner is locked out because the flue gas temperature sensor is incorrectly positioned. This is a safety measure to prevent improper operation.
F.417, F.418 — Burner in fault state due to control unit error
The burner is in a fault state, indicating an internal error or malfunction within the BCU burner control unit. These errors will stop the boiler from functioning.
F.425 — Time synchronization failed, normal operation with calculation error
The system is operating normally, but a calculation function is not working because time synchronization failed. This may affect scheduling or data logging.
F.430 — Communication error with gateway
The boiler is operating normally according to target values, but there is a communication error with the gateway module. This can affect remote monitoring or control.
F.446 — Burner in fault state due to temperature sensor deviation
The burner is in a fault state due to a deviation in the boiler supply temperature sensor or an issue with the high limit safety cutout. This is a safety measure.
F.447, F.448 — Burner in fault state: Deviation in ionization current signal
The burner is in a fault state due to a deviation in the ionization current signal. This indicates a problem with how the boiler detects the flame.
F.449, F.450, F.451, F.452 — Burner in fault state: Error in program run monitoring
The burner is in a fault state due to an error in the scheduled program run monitoring. This indicates a general problem with the boiler's internal programming or operation.
F.453 — Burner in fault state: Synchronization error in sequence
The burner is in a fault state due to a synchronization error in its operational sequence. This indicates a timing or coordination problem within the boiler's control system.
F.454 — Burner in fault state: Incorrect software version
The burner is in a fault state because the BCU burner control unit has an incorrect software version. This needs to be corrected for proper boiler operation.
F.455 — Burner in fault state: Error in program run monitoring
The burner is in a fault state due to an error in the program run monitoring. This indicates a general problem with the boiler's internal programming or operation.
F.456 — Burner in fault state: Error in program run monitoring with fan issue
The burner is in a fault state due to an error in program run monitoring, potentially linked to a sluggish or blocked fan. This affects combustion and safe operation.
F.457 — Burner in fault state: Fan sluggish or blocked
The burner is in a fault state because the fan is sluggish or blocked. This issue can prevent proper airflow for combustion, leading to boiler shutdown.
F.463 — Burner in fault state: Contaminated combustion air or flue gas recirculation
The burner is in a fault state due to contaminated combustion air or flue gas recirculation. Foreign bodies or deposits can interfere with the combustion process.
F.464 — Burner in fault state: Low ionization current during calibration
The burner is in a fault state because the ionization current was too low during calibration, or the reading was implausible. This can affect flame detection and safety.
F.467 - Burner in a fault state due to insufficient gas supply
The boiler's burner has entered a fault state because the gas supply was not sufficient during calibration. This can be caused by problems with the gas line or internal components being contaminated.
F.468 - Burner in a fault state due to high ionization current
The boiler's burner has entered a fault state because the ionization current was too high during calibration. This can be caused by issues with the ionization electrode, or excessive dust in the ventilation air leading to deposits.
F.471 - No call for heat due to lead break or short circuit
The boiler is not receiving a call for heat, indicating a problem with a sensor or its connection. This is often caused by a broken wire or a short circuit in the system.
F.473 - Heat Management Unit (HMU) communication error
There is a communication error between the BCU burner control unit and the HMU heat management unit. This usually points to a problem with the connecting cable between these two components.
F.70 — Burner in fault state due to internal control unit error
The burner is in a fault state due to an internal error within the burner control unit. This critical error will prevent the boiler from operating.
F.71 — Burner in fault state: Fan speed too low
The burner is in a fault state because the fan speed is too low. This can indicate a physical obstruction or an incorrect setting.
F.72 — Burner in fault state: Fan idle state not reached
The burner is in a fault state because the fan unit did not reach its idle state. This can prevent the boiler from operating safely.
F.73 — Burner in fault state due to internal communication error
The burner is in a fault state due to an internal communication error. This suggests a problem within the boiler's control system.
F.74 — Burner locked out: Low water pressure, no heating or hot water
The burner is locked out, and there is no central heating or domestic hot water (DHW) heating because the water pressure is too low. The internal circulation pump is also off.
F.77 — Burner in fault state due to data memory error
The burner is in a fault state due to an error in the data memory of the burner control unit. This can prevent the boiler from operating correctly.
F.89 — No heating or hot water: Internal circulation pump blocked
There is no central heating or domestic hot water (DHW) heating because the internal circulation pump is blocked. This prevents water from circulating in the system.