Viessmann · Error codes
Viessmann error codes and alerts
Identical code numbers can mean different things on different controllers, so every entry is tied to the documented series, controller and manual version. A code is never a diagnosis.
If you smell gas
- Stop what you are doing. Do not use phones, switches, matches or anything that can spark inside.
- Go outside and leave the door open behind you.
- Call the FortisBC 24-hour emergency line at 1-800-663-9911 or dial 911.
Only after that, call ROMA about the boiler. Official guidance: FortisBC gas leaks and odour.
Vitodens 100-W B1HE and B1KE combi boilers (HMU-BCU control, manual 6167 818 - 22)
F.5
System operates in normal mode with replacement value. The fault indicates a lead break or short circuit; check plug 33/X6 and the cable, ve…
Details
F.7
No DHW heating. The control reports a lead break in the storage tank temperature sensor circuit; check the sensor at plug 5, wires 3 and 4, …
Details
F.8
No DHW heating. The control reports a short circuit in the storage tank temperature sensor circuit; check the sensor at plug 5, wires 3 and …
Details
F.13
Regulates as if outside temperature were 32°F (0°C). A lead break has occurred in the outside temperature sensor circuit; check the outside …
Details
F.14
Regulates as if outside temperature were 32°F (0°C). A short circuit has occurred in the outside temperature sensor circuit; check the outsi…
Details
F.49
Burner in a fault state. A disconnection of the flue gas temperature sensor has been detected; check the flue gas temperature sensor and res…
Details
F.50
Burner in a fault state. A short circuit of the flue gas temperature sensor has been detected; check the flue gas temperature sensor and res…
Details
F.59
Burner locked out. The burner has locked out due to low voltage in the power supply; check the mains voltage and, if the voltage is correct …
Details
F.62
Burner in a fault state. The high limit safety cut-out has responded; check the heating system fill level, expansion tank pre-charge pressur…
Details
F.63
Burner in a fault state. The flue gas temperature limiter has responded; check the fill level, expansion tank pre-charge pressure, flow rate…
Details
F.67
Burner in a fault state. The ionization current lies outside the permissible range; check the gas supply pressure, the gas solenoid valve an…
Details
F.68
Burner in a fault state. A flame signal was already present at burner start; close the gas shut-off valve, remove the ionization electrode c…
Lockout
F.69
Burner in a fault state. The ionization current lies outside the permissible range; check whether the insulation block touches the electrode…
Details
F.70
Burner in a fault state. An internal error has occurred in the burner control unit; replace the BCU burner control unit.…
Details
F.71
Burner in a fault state. The fan speed is too low; check the fan for blockage and verify the gas type and flue system settings in the commis…
Details
F.72
Burner in a fault state. The fan idle state was not reached; reset the boiler and, if the fault occurs repeatedly, replace the fan unit.…
Details
F.73
Burner in a fault state. An internal communication error has occurred; reset the boiler and, if the fault recurs, replace the BCU burner con…
Details
F.74
Burner locked out, no central heating or DHW heating. The water pressure is too low; top up with water, vent the system and, if the fault re…
Details
F.77
Burner in a fault state. A data memory error has occurred in the burner control unit; reset the boiler and, if the fault recurs, replace the…
Details
F.89
No central heating and no DHW heating. The internal circulation pump is blocked; check the circulation pump and replace it if necessary.…
Details
F.142
Burner in a fault state. A communication error has occurred on the CAN bus; check the fan unit stepper motor reference run with mains ON, th…
Details
F.160
Burner in a fault state. A communication error has occurred on the CAN bus; check the internal CAN bus subscriber connections when a connect…
Details
F.161
Burner in a fault state. A data memory access error has occurred in the BCU burner control unit; reset the boiler and, if the fault recurs, …
Details
F.163
Burner in a fault state. A memory access checksum error has occurred in the BCU burner control unit; reset the boiler and, if the fault recu…
Details
F.182
No DHW heating. A short circuit has occurred in the outlet temperature sensor circuit, where the sensor is installed; check the outlet tempe…
Details
F.183
No DHW heating. A lead break has occurred in the outlet temperature sensor circuit, where the sensor is installed; check the outlet temperat…
Details
F.184
Burner in a fault state. A short circuit has occurred in the common supply temperature sensor or high limit safety cut-out; check the sensor…
Details
F.185
Burner in a fault state. A lead break has occurred in the common supply temperature sensor or high limit safety cut-out; check the sensor, r…
Details
F.299
Time/date incorrect. The real time clock setting is incorrect, which is why the time and date are wrong; set the time and date correctly.…
Details
F.342
No central heating, no DHW heating. A communication error has occurred with the BCU burner control unit; check the connecting cable at plug …
Details
F.345
Burner locked out, automatic enabling after boiler cools down. The temperature limiter has responded; ensure adequate heat transfer by check…
Details
F.346
Burner in a fault state. An ionization current calibration error has occurred; check the gas supply pressure, the gas solenoid valve inlet s…
Details
F.348
Burner in a fault state. A fault has occurred at the gas modulation valve; for boilers connected to a common flue system check the multiple …
Details
F.349
Burner in a fault state. The air mass flow rate was not detected correctly in the fan unit; check for dust contamination in the ventilation …
Details
F.350
Burner in a fault state. The ionization current lies outside the permissible range; replace the BCU burner control unit.…
Details
F.351
Burner in a fault state. The ionization current lies outside the permissible range; replace the BCU burner control unit.…
Details
F.352
Burner in a fault state. The CO limit within the boiler has been exceeded; check the entire flue gas path for flue gas recirculation, leaks,…
Details
F.353
Burner shutdown with restart if demand exists. The gas supply is insufficient, so the burner output has been reduced; check the gas supply a…
Details
F.354
Burner in a fault state. The gas modulation valve tolerance lies outside the permissible range; replace the gas fan unit.…
Details
F.355
Burner in a fault state. The analogue signal reference check found a flame signal already present at burner start; replace the BCU burner co…
Lockout
F.357
Burner in a fault state. The gas supply is insufficient; check that the gas shut-off valve is open and the solenoid valve input-side screen …
Lockout
F.359
Burner in a fault state. No ignition spark is produced; check the ignition electrode insulation and the 120V supply at the ignition module, …
Lockout
F.361
Burner in a fault state. A flame signal is not present or is insufficient at burner start; check the ionization electrode and connecting cab…
Lockout
F.366
Burner in a fault state. The electricity supply to the gas valve does not turn off; replace the BCU burner control unit.…
Details
F.367
Burner in a fault state. The electricity supply to the gas valve does not turn off; replace the BCU burner control unit.…
Details
F.369
Burner in a fault state. The flame is lost immediately after flame formation during the safety time; check the gas supply pressure, the bala…
Details
F.370
Burner in a fault state. The fuel valve or modulation valve will not close; reset the boiler and, if the fault occurs repeatedly, replace th…
Details
F.372
Burner in a fault state. Repeated flame loss has occurred during calibration; check the ionization electrode and connecting cable, the plug-…
Lockout
F.373
Burner in a fault state. Heat transfer during calibration was too low and the temperature limiter shut down; ensure adequate heat transfer b…
Details
F.377
Burner in a fault state. The stabilization conditions for post calibration were not met during processing of the ionization adjustment; chec…
Details
F.378
Burner in a fault state. The flame was lost during the stabilization or operating phase; check the gas supply pressure, flue gas recirculati…
Details
F.379
Burner in a fault state. A flame signal is not present or is insufficient; check the ionization electrode connecting cable for damage and fi…
Lockout
F.380
Burner in a fault state. The flame is lost immediately after flame formation during the safety time; check the gas supply, the balanced flue…
Details
F.381
Burner in a fault state. The flame is lost during the operating phase; check the gas supply pressure, the balanced flue system for flue gas …
Details
F.382
Burner in a fault state. The error counter has exceeded its limit; reset the boiler and work through the fault analysis using the fault hist…
Details
F.383
Burner in a fault state. Possible contamination of the gas line is suspected; check the gas line for contamination.…
Details
F.384
Gas line fault. The fault relates to the gas line; check the gas supply pressure and replace the gas fan if necessary, then reset the boiler…
Details
F.385
Burner in a fault state. Signal 1 of the ionization current is short-circuited and the BCU burner control unit is faulty; check the ionizati…
Details
F.386
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.387
Burner in a fault state. A ground fault exists on the ionization current and the BCU burner control unit is faulty; check the system for con…
Details
F.388
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.395
Burner in a fault state. An IO electrode ground fault is indicated and the BCU burner control unit is faulty; check the ignition electrode f…
Lockout
F.396
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.399
Burner in a fault state. An IO electrode ground fault is indicated and the BCU burner control unit is faulty; check the IO electrode for a g…
Details
F.400
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.401
Burner in a fault state. An IO electrode ground fault is indicated and the BCU burner control unit is faulty; check the IO electrode for a g…
Details
F.402
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.403
Burner in a fault state. An ionization electrode ground fault is indicated and the BCU burner control unit is faulty; check the IO electrode…
Details
F.404
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.405
Burner in a fault state. An ionization electrode ground fault is indicated and the BCU burner control unit is faulty; check the IO electrode…
Details
F.406
Burner in a fault state. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly positioned; replace the BCU…
Details
F.408
Burner in a fault state. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly positioned; replace the BCU…
Details
F.410
Burner in a fault state. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly positioned; replace the BCU…
Details
F.416
Burner in a fault state. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly positioned; replace the BCU…
Details
F.417
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.418
Burner in a fault state. The BCU burner control unit is faulty; replace the BCU burner control unit and reset the boiler.…
Details
F.425
System operating normally; calculation not working. Time synchronization has failed; set the time and, if an external time source is used, c…
Details
F.430
Gateway communication error. A communication error has occurred at the gateway; check the gateway module connecting cable and power supply.…
Details
F.446
Burner in a fault state. A deviation has occurred at the boiler supply temperature sensor or high limit safety cut-out; check the sensor, it…
Details
F.447
Burner in a fault state. A deviation has occurred in the ionization current signal; replace the BCU burner control unit and reset the boiler…
Details
F.448
Burner in a fault state. A deviation has occurred in the ionization current signal; replace the BCU burner control unit and reset the boiler…
Details
F.449
Burner in a fault state. An error has occurred in the scheduled program run monitoring or a sequence synchronization error is present; reset…
Details
F.450
Burner in a fault state. An error has occurred in the scheduled program run monitoring or a sequence synchronization error is present; reset…
Details
F.451
Burner in a fault state. An error has occurred in the scheduled program run monitoring or a sequence synchronization error is present; reset…
Details
F.452
Burner in a fault state. An error has occurred in the scheduled program run monitoring or a sequence synchronization error is present; reset…
Details
F.453
Burner in a fault state. An error has occurred in the scheduled program run monitoring or a sequence synchronization error is present; reset…
Details
F.454
Burner in a fault state. An incorrect software version is installed; flash the correct software version for the BCU burner control unit.…
Details
F.455
Burner in a fault state. An error has occurred in program run monitoring; reset the boiler and, if the fault recurs, replace the BCU burner …
Details
F.456
Burner in a fault state. An error has occurred in program run monitoring; reset the boiler, check the fan for sluggishness and replace the f…
Details
F.457
Burner in a fault state. The fan is sluggish or blocked, which has triggered the fault; reset the boiler.…
Details
F.463
Burner in a fault state. Contaminated combustion air or flue gas recirculation is suspected; check the flue system for contamination and flu…
Details
F.464
Burner in a fault state. The ionization current during calibration was too low and the difference compared to the previous value is not plau…
Details
F.467
Insufficient gas supply during calibration or incorrectly sized gas line. The gas supply was insufficient during calibration or the on-site …
Details
F.468
Ionization current too high during calibration. The ionization current is too high during calibration; check the gap between the ionization …
Details
F.471
Sensor lead break or short circuit. A lead break or short circuit is indicated in the sensor circuit; check the lead and plug-in connection …
Details
F.473
HMU heat management unit communication error. A communication error exists between the BCU burner control unit and the HMU heat management u…
Details
F.474
Burner in a fault state. An error has occurred in the scheduled program run monitoring; reset the boiler and, if the fault recurs, replace t…
Details
F.527
Burner in a fault state. An incorrect parameter set is stored in the HMU heat management unit; overwrite (flash) the HMU heat management uni…
Details
F.528
Burner in a fault state. An incorrect parameter set is stored in the BCU burner control unit; overwrite (flash) the BCU burner control unit …
Details
F.540
Burner in a fault state. Condensate has backed up in the heat cell; check the system for condensate backup and check the condensate drain an…
Details
Vitodens 200-W B2HE boilers (HMU/HMI-BCU control, manual 6167 813 - 23)
F.5
System continues in normal mode with replacement value. A lead break or short circuit is detected, so check plug 33/X6 and the cable and ver…
Details
F.7
No DHW heating. A lead break in the storage tank temperature sensor prevents DHW heating, so check the DHW setting in the commissioning assi…
Details
F.8
No DHW heating. A short circuit in the storage tank temperature sensor prevents DHW heating, so check the sensor at plug 5, wires 3 and 4 an…
Details
F.11
No solar DHW heating or central heating backup. A lead break in the collector temperature sensor is present, so check the collector temperat…
Details
F.12
No solar DHW heating. A short circuit in the collector temperature sensor is present, so check the operating mode setting in the commissioni…
Details
F.13
Regulates as if outside temperature were 32 C. A lead break in the outside temperature sensor is present, so check the operating mode settin…
Details
F.14
Regulates as if outside temperature were 32 C. A short circuit in the outside temperature sensor is present, so check the outside temperatur…
Details
F.15
No solar DHW heating or central heating backup. A lead break in the storage tank temperature sensor is detected, so check the storage tank t…
Details
F.16
No solar DHW heating or central heating backup. A short circuit in the storage tank temperature sensor is detected, so check the storage tan…
Details
F.29
Regulates without low loss header supply sensor. A lead break in the low loss header sensor is present, so check the low loss header setting…
Details
F.30
Regulates without low loss header supply sensor. A short circuit in the low loss header sensor is present, so check the supply temperature s…
Details
F.50
Burner in a fault state. A short circuit in the flue gas temperature sensor puts the burner into a fault state, so check the flue gas temper…
Details
F.57
Normal operation without room influence. A lead break in the room temperature sensor is detected, so check the remote control setting in the…
Details
F.58
Normal operation without room influence. A short circuit in the room temperature sensor is detected, so check the plug and cable of the exte…
Details
F.59
Burner locked out. Low voltage in the power supply causes the burner to lock out, so check the mains voltage and replace the fan unit if the…
Details
F.62
Burner in a fault state. The high limit safety cut-out has responded, so check the heating system fill level, pre-charge pressure in the dia…
Details
F.63
Burner in a fault state. The flue gas temperature limiter has responded, so check fill level, expansion tank pre-charge pressure, flow rate …
Details
F.67
Burner in a fault state. The ionization current lies outside the permissible range, so check the gas supply pressure, gas solenoid valve and…
Details
F.68
Burner in a fault state. A flame signal is already present at burner start, so close the gas shut-off valve, remove the connecting cable of …
Lockout
F.69
Burner in a fault state. The ionization current lies outside the permissible range, so check the insulation block against the electrode cera…
Details
F.70
Burner in a fault state. An internal error in the burner control unit has occurred, so replace the BCU burner control unit as described on p…
Details
F.71
Burner in a fault state. The fan speed is too low, so check the fan for blockage, check the gas type and flue system setting in the commissi…
Details
F.72
Burner in a fault state. The fan idle state has not been reached, so reset the appliance and replace the fan unit if the fault occurs repeat…
Details
F.73
Burner in a fault state. An internal communication error has occurred, so reset the appliance and replace the BCU burner control unit if the…
Details
F.74
Burner locked out, no central heating or DHW heating. The water pressure is too low, so top up with water and vent the system, then check th…
Details
F.77
Burner in a fault state. There is a data memory fault in the burner control unit, so reset the appliance and replace the BCU burner control …
Details
F.89
No central heating and no DHW heating. The internal circulation pump is blocked, so check the circulation pump and replace it if necessary.…
Details
F.91
Function of affected extension in emergency mode. There is a communication error with the DIO electronics module, so check the connections t…
Details
F.92
Function of relevant electronics module in emergency mode. There is a communication error with the ADIO electronics module, so check the com…
Details
F.94
Electronics modules connected to PlusBus not functioning. There is a voltage error on the PlusBus, so check the PlusBus power supply on the …
Details
F.100
Electronics modules connected to PlusBus not functioning. There is a voltage error on the PlusBus, so check the PlusBus power supply on the …
Details
F.104
Depends on DIO extension configuration. The external fault message input is active, so check the connected external device.…
Details
F.142
Burner in a fault state. There is a communication error on the CAN bus, so check the fan stepper motor reference run, the plug-in connection…
Details
F.160
Burner in a fault state. There is a communication error on the CAN bus, so check the internal CAN bus subscriber connections if a connection…
Details
F.161
Burner in a fault state. There is a BCU data memory access error, so reset the appliance and replace the BCU burner control unit if the faul…
Details
F.163
Burner in a fault state. There is a memory access checksum error in the BCU, so reset the appliance and replace the BCU burner control unit …
Details
F.180
Burner in a fault state. The gas pressure is too low, so check the gas pressure and notify the gas supply utility if necessary, check the ga…
Details
F.182
No DHW heating. A short circuit in the outlet temperature sensor prevents DHW heating if that sensor is installed, so check the sensor at pl…
Details
F.183
No DHW heating. A lead break in the outlet temperature sensor prevents DHW heating if that sensor is installed, so check the outlet temperat…
Details
F.184
Burner in a fault state. A short circuit in the common supply temperature sensor and high limit safety cut-out has occurred, so check the se…
Details
F.185
Burner in a fault state. A lead break in the common supply temperature sensor and high limit safety cut-out has occurred, so check the senso…
Details
F.299
Time or date incorrect. The real time clock setting is incorrect, so set the time and date correctly.…
Details
F.342
No central heating or DHW heating. There is a communication error with the BCU burner control unit, so check the connecting cable at plug X4…
Details
F.345
Burner locked out, automatic restart after cool down. The temperature limiter has responded, so ensure adequate heat transfer, check fill le…
Details
F.346
Burner in a fault state. There is an ionization current calibration error, so check the gas supply pressure, gas solenoid valve strainer, io…
Details
F.348
Burner in a fault state. There is a fault with the gas modulation valve, so check whether multiple connections is set in the commissioning a…
Details
F.349
Burner in a fault state. The air mass flow rate is not detected correctly in the fan unit, so check the ventilation air for dust contaminati…
Details
F.350
Burner in a fault state. The ionization current lies outside the permissible range, so replace the BCU burner control unit as described on p…
Details
F.351
Burner in a fault state. The ionization current lies outside the permissible range, so replace the BCU burner control unit as described on p…
Details
F.352
Burner in a fault state. The CO limit within the appliance has been exceeded, so check the entire flue gas path for flue gas recirculation, …
Details
F.353
Burner shutdown with restart if demand exists. The gas supply is insufficient and burner output is reduced, so check the gas supply, visuall…
Details
F.354
Burner in a fault state. The gas modulation valve tolerance lies outside the permissible range, so replace the gas fan unit.…
Details
F.355
Burner in a fault state. The analogue signal reference check shows that a flame signal is already present at burner start, so replace the BC…
Lockout
F.357
Burner in a fault state. The gas supply is insufficient, so check the gas shut-off valve, the solenoid valve screen, static and flow gas pre…
Lockout
F.359
Burner in a fault state. There is no ignition spark, so check the ignition electrode insulation and the 120 V supply at the ignition module …
Lockout
F.361
Burner in a fault state. The flame signal is not present or is insufficient at burner start, so check the ionization electrode and cable, pl…
Lockout
F.366
Burner in a fault state. The electricity supply to the gas valve does not turn off, so replace the BCU burner control unit as described on p…
Details
F.367
Burner in a fault state. The electricity supply to the gas valve does not turn off, so replace the BCU burner control unit as described on p…
Details
F.369
Burner in a fault state. Flame loss occurs immediately after flame formation during the safety time, so check the gas supply pressure, the b…
Lockout
F.370
Burner in a fault state. The fuel valve or modulation valve will not close, so reset the appliance and replace the fan unit if the fault occ…
Details
F.372
Burner in a fault state. Repeated flame loss occurs during calibration, so check the ionization electrode and cable, plug connections, flue …
Lockout
F.373
Burner in a fault state. Heat transfer is too low during calibration and the temperature limiter has shut down, so ensure adequate heat tran…
Details
F.377
Burner in a fault state. The stabilization conditions for post calibration are not met, so check the gas type setting, replace the BCU burne…
Details
F.378
Burner in a fault state. Flame loss occurs during the stabilization or operating phase, so check the gas supply pressure, flue gas recircula…
Lockout
F.379
Burner in a fault state. The flame signal is not present or is insufficient, so check the ionization electrode connecting cable for damage a…
Lockout
F.380
Burner in a fault state. Flame loss occurs immediately after flame formation during the safety time, so check the gas supply pressure, flue …
Lockout
F.381
Burner in a fault state. Flame loss occurs during the operating phase, so check the gas supply pressure, the balanced flue system for recirc…
Lockout
F.382
Burner in a fault state. The error counter has exceeded its limit, so reset the appliance and work through the fault analysis using the faul…
Details
F.383
Burner in a fault state. There is possible contamination, so check the gas line for contamination.…
Details
F.384
The fault concerns the gas line, so check the gas supply pressure, replace the gas fan if necessary and reset the appliance.…
Details
F.385
Burner in a fault state. There is a short circuit on signal 1 of the ionization current, so check the ionization electrode and connecting ca…
Details
F.386
Burner in a fault state. The BCU burner control unit is faulty, so replace the BCU burner control unit as described on page 61 and reset the…
Details
F.387
Burner in a fault state. There is a ground fault in the ionization current and the BCU burner control unit is faulty, so check the ionizatio…
Details
F.388
Burner in a fault state. The BCU burner control unit is faulty, so replace the BCU burner control unit as described on page 61 and reset the…
Details
F.395
Burner in a fault state. There is an IO electrode ground fault and the BCU burner control unit is faulty, so check the ignition electrode fo…
Lockout
F.396
Burner in a fault state. The BCU burner control unit is faulty, so replace the BCU burner control unit as described on page 61 and reset the…
Details
F.399
Burner in a fault state. There is an IO electrode ground fault and the BCU burner control unit is faulty, so check the IO electrode for grou…
Details
F.400
Burner in a fault state. The BCU burner control unit is faulty, so replace the BCU burner control unit as described on page 61 and reset the…
Details
F.401
Burner in a fault state. There is an IO electrode ground fault and the BCU burner control unit is faulty, so check the IO electrode for grou…
Details
F.402
Burner in a fault state. The BCU burner control unit is faulty, so replace the BCU burner control unit as described on page 61 and reset the…
Details
F.403
Burner in a fault state. There is an ionization electrode ground fault and the BCU burner control unit is faulty, so check the IO electrode …
Details
F.404
Burner in a fault state. The BCU burner control unit is faulty, so replace the BCU burner control unit as described on page 61 and reset the…
Details
F.405
Burner in a fault state. There is an ionization electrode ground fault and the BCU burner control unit is faulty, so check the IO electrode …
Details
F.406
Burner in a fault state, burner locked out. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly position…
Details
F.408
Burner in a fault state, burner locked out. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly position…
Details
F.410
Burner in a fault state, burner locked out. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly position…
Details
F.416
Burner in a fault state, burner locked out. The BCU burner control unit is faulty or the flue gas temperature sensor is incorrectly position…
Details
F.425
System operating normally, calculation not working. The time synchronization failed, so set the time and check parameters 1504 and 508 if ex…
Details
F.430
Normal operation in line with boiler target values. There is a communication error with the gateway, so check the gateway module connecting …
Details
F.446
Burner in a fault state. There is a deviation in the boiler supply temperature sensor or high limit safety cut-out, so check the sensor, its…
Details
F.447
Burner in a fault state. There is a deviation in the ionization current signal, so replace the BCU burner control unit as described on page …
Details
F.448
Burner in a fault state. There is a deviation in the ionization current signal, so replace the BCU burner control unit as described on page …
Details
F.449
Burner in a fault state. There is an error in the scheduled program run monitoring or a synchronization error in the sequence, so reset the …
Details
F.450
Burner in a fault state. There is an error in the scheduled program run monitoring or a synchronization error in the sequence, so reset the …
Details
F.451
Burner in a fault state. There is an error in the scheduled program run monitoring or a synchronization error in the sequence, so reset the …
Details
F.452
Burner in a fault state. There is an error in the scheduled program run monitoring or a synchronization error in the sequence, so reset the …
Details
F.453
Burner in a fault state. There is an error in the scheduled program run monitoring or a synchronization error in the sequence, so reset the …
Details
F.454
Burner in a fault state. The BCU software version is incorrect, so flash the correct software version onto the BCU burner control unit.…
Details
F.455
Burner in a fault state. There is an error in the program run, so reset the appliance.…
Details
F.456
This concerns program run monitoring, and if the fault recurs the BCU burner control unit must be replaced as described on page 61.…
Details
F.457
Burner in a fault state. The fan is sluggish or blocked, so reset the appliance, check the fan for sluggishness and replace the fan unit in …
Details
F.458
Burner in a fault state. The safety-relevant reset sequence is faulty, so reset the appliance.…
Details
F.463
Burner in a fault state. The combustion air is contaminated or flue gas recirculation is occurring, so check and clean the flue system, chec…
Details
F.464
Burner in a fault state. The ionization current is too low during calibration and the difference compared to the previous value is not plaus…
Details
F.467
Burner in a fault state. The gas supply is insufficient during calibration, possibly due to a contaminated or incorrectly sized gas line, so…
Details
F.468
Burner in a fault state. The ionization current is too high during calibration, so check the gap between the ionization electrode and the fl…
Details
F.471
No call for heat. A lead break or short circuit is present, so check the lead and plug-in connection and measure to see whether the supply v…
Details
F.473
No call for heat. There is a communication error with the HMU heat management unit, so check the connecting cable between the BCU burner con…
Details
F.474
Burner in a fault state. There is an error in the scheduled program run monitoring, so reset the appliance and replace the BCU burner contro…
Details
F.477
Limited solar thermal system functionality. The differential temperature monitoring for the solar system has detected an issue, so check the…
Details
F.517
Normal operation, remote control unit not functioning. There is a lead break in the PlusBus cable or an incorrect appliance address is set, …
Details
F.527
Burner in a fault state. An incorrect parameter set is stored in the HMU heat management unit, so overwrite or flash the HMU heat management…
Details
F.528
Burner in a fault state. An incorrect parameter set is stored in the BCU burner control unit, so overwrite or flash the BCU burner control u…
Details
F.530
Solar function limited. A sensor value is not available, a sensor lead is broken or one or more sensors are missing, so check the sensors or…
Details
F.538
No solar central heating backup with SDIO. There is a lead break in the system return temperature sensor, so check the sensors or connect mi…
Details
F.540
Burner in a fault state. There is condensate backup in the heat cell, so check the condensate drain and siphon trap, replace insulation bloc…
Details
F.544
Mixing valve closes, heating circuit pump operational. There is a lead break in the common supply temperature sensor of heating circuit 2 wi…
Details
F.545
Mixing valve closes, heating circuit pump operational. There is a short circuit in the common supply temperature sensor for heating circuit …
Details
F.546
Mixing valve closes, heating circuit pump operational. There is a lead break in the common supply temperature sensor of heating circuit 3 wi…
Details
F.547
Mixing valve closes, heating circuit pump operational. There is a short circuit in the common supply temperature sensor for heating circuit …
Details
F.548
Mixing valve closes, heating circuit pump operational. There is a short circuit in the common supply temperature sensor for heating circuit …
Details
F.549
Mixing valve closes, heating circuit pump operational. There is a short circuit in the common supply temperature sensor for heating circuit …
Details
F.574
Room temperature. Normal operation is indicated, so check the external room temperature sensor as instructed in the measures.…
Details
F.666
Lead break in DHW preheating sensor TS3. No solar function with preheating is available, so the second storage tank and the solar transfer p…
Details
F.667
Short circuit in DHW preheating sensor TS3. No solar function with preheating is available, so the second storage tank and the solar transfe…
Details
F.668
Lead break in DHW reheating sensor TS4. No solar function with preheating is available, so the second storage tank and the solar transfer pu…
Details
F.669
Short circuit in DHW reheating sensor TS4. No solar function with preheating is available, so the second storage tank and the solar transfer…
Details
F.670
Lead break in buffer temperature sensor TS3. No solar central heating backup is available, so temperature sensor TS3 should be checked.…
Details
F.671
Short circuit in buffer temperature sensor TS3. No solar central heating backup is available, so temperature sensor TS3 should be checked.…
Details
F.672
Lead break in thermostat function temperature sensor TS3. No solar function with thermostat function is available and the solar transfer pum…
Details
F.673
Short circuit in thermostat function temperature sensor TS3. No solar function with thermostat function is available and the solar transfer …
Details
F.691
Burner in a fault state. Feedback from the combustion air supply is missing, so check the connection at the CAI and the operation of the pro…
Details
F.762
System in a fault state. The system pressure is too low, so top up with water and vent the system, then check the minimum pressure switch, e…
Details
F.763
System in a fault state. The gas pressure is too high, so check the gas supply pressure.…
Details
F.764
System in a fault state. The lag boiler reports a fault, so check the lag boiler fault as stated in the measures.…
Details
F.765
System in a fault state. There is a communication error with the lead boiler, so check the lead boiler fault as stated in the measures.…
Details
Vitodens 200-W B2HA large-input boilers (Vitotronic control, B2HA service manuals 5683 702/5685 828/5683 710)
0F
Service required. Code 0F is only displayed in the fault history and service is required, so after servicing select code “24:0”. The table c…
Details
10
Short circuit on outdoor temperature sensor. A short circuit on the outdoor temperature sensor has occurred, so the boiler operates based on…
Details
18
Outdoor temperature sensor cable broken. The outdoor temperature sensor cable is broken, so the boiler operates based on the outdoor tempera…
Details
1A
Flow sensor 1 faulty. Flow sensor 1 is faulty, which blocks the burner; replace the sensor. The table classifies it as Blocking.…
Details
1B
Flow sensor 2 faulty. Flow sensor 2 is faulty, which blocks the burner; replace the sensor. The table classifies it as Blocking.…
Details
1F
Differential flow rate too large. The differential flow rate is too large, which blocks the burner; clean the heat exchanger by flushing. Th…
Details
20
Short circuit on system flow temperature sensor (low-loss header). A short circuit on the system flow temperature sensor has occurred, so th…
Details
28
System supply temperature sensor cable broken (low-loss header). The system supply temperature sensor cable is broken, so the boiler regulat…
Details
30 140
Short circuit on boiler water temperature sensor. A short circuit on the boiler water temperature sensor has occurred, which blocks the burn…
Details
38 140
Boiler water temperature sensor cable broken. The boiler water temperature sensor cable is broken, which blocks the burner; check the boiler…
Details
40
Short circuit on supply temperature sensor (heating circuit 2 with mixing valve). A short circuit on the supply temperature sensor of heatin…
Details
44
Short circuit on flow temperature sensor (heating circuit 3 with mixing valve). A short circuit on the flow temperature sensor of heating ci…
Details
48
Supply temperature sensor cable broken (heating circuit 2 with mixing valve). The supply temperature sensor cable of heating circuit 2 with …
Details
4C
Flow temperature sensor cable broken (circuit 3 with mixing valve). The flow temperature sensor cable of circuit 3 with mixing valve is brok…
Details
50
Short circuit on DHW tank temperature sensor. A short circuit on the DHW tank temperature sensor has occurred, so there is no DHW heating; c…
Details
51
Short circuit on DHW tank temperature sensor 2 (tank loading system). A short circuit on DHW tank temperature sensor 2 has occurred; with a …
Details
58
DHW tank temperature sensor cable broken. The DHW tank temperature sensor cable is broken, so there is no DHW heating; check the DHW sensor.…
Details
59
Lead break on DHW tank temperature sensor 2 (tank loading system). A lead break on DHW tank temperature sensor 2 has occurred; with a tank l…
Details
90
Short circuit on temperature sensor (solar). A short circuit on the temperature sensor on the solar control module has occurred, so the syst…
Details
91
Short circuit on temperature sensor (solar). A short circuit on a temperature sensor has occurred, so the system remains in control mode; ch…
Details
92
Short circuit on collector temperature sensor (solar). A short circuit on the collector temperature sensor has occurred, so there is no sola…
Details
93
Short circuit on collector temperature sensor (solar). A short circuit on the collector temperature sensor has occurred, so the system remai…
Details
94
Short circuit on tank temperature sensor (solar). A short circuit on the tank temperature sensor has occurred, so there is no solar DHW heat…
Details
98
Tank temperature sensor cable broken (solar). The tank temperature sensor cable is broken, so the system remains in control mode; check the …
Details
99
Temperature sensor cable broken (solar). A temperature sensor cable is broken, so the system remains in control mode; check the sensor on th…
Details
9A
Collector temperature sensor cable broken (solar). The collector temperature sensor cable is broken, so there is no solar DHW heating; check…
Details
9B
Tank temperature sensor cable broken (Vitosolic S3). The tank temperature sensor cable is broken, so the system remains in control mode; che…
Details
9C
Tank temperature sensor cable broken (solar DHW). The tank temperature sensor cable is broken, so there is no solar DHW heating; check the t…
Details
9E
No flow rate in collector circuit or flow rate too low or temperature limiter has responded. There is no flow rate in the collector circuit …
Details
9F
Solar control module faulty. The solar control module is faulty, so the system remains in control mode; replace the solar control module. Th…
Details
A3
Flue gas temperature sensor not properly positioned. The flue gas temperature sensor is not properly positioned, which blocks the burner; pr…
Details
A4
Max. system pressure exceeded. The maximum system pressure has been exceeded, so the system remains in control mode; check the system pressu…
Details
A7
Faulty programming unit. The programming unit is faulty, so the system stays in control mode at the factory default setting; replace the pro…
Details
B0 141
Flue gas temperature sensor shorted out. The flue gas temperature sensor is shorted out, which blocks the burner; check the flue gas tempera…
Details
B1
Communication fault; programming unit (internal). There is a communication fault with the programming unit (internal), so the system stays i…
Details
B5
Internal fault. An internal fault has occurred, so the system is in control mode at the factory default setting; replace the control unit. T…
Details
B7
Boiler coding card missing, faulty or incorrect. The boiler coding card is missing, faulty or incorrect, which blocks the burner; plug in th…
Details
B8 141
Flue gas temperature sensor cable broken. The flue gas temperature sensor cable is broken, which blocks the burner; check the flue gas tempe…
Details
BA
Communication fault - accessory kit for heating circuit 2 with mixing valve. There is a communication fault with the accessory kit for heati…
Details
BB
Communication error, extension kit for heating circuit 3 (with mixing valve). There is a communication error with the extension kit for heat…
Details
BC
Communication error, remote control Vitotrol, heating circuit 1 (without mixing valve). There is a communication error with the remote contr…
Details
BD
Communication error, remote control Vitotrol, heating circuit 2 (with mixing valve). There is a communication error with the remote control …
Details
BE
Communication error, remote control Vitotrol, heating circuit 3 (with mixing valve). There is a communication error with the remote control …
Details
BF
Incorrect LON communication module. The LON communication module is incorrect, so the system remains in control mode; replace the LON commun…
Details
C1
Communication fault, extension EA1. There is a communication fault with extension EA1, so the system remains in control mode; check the conn…
Details
C2
Communication fault - solar control unit or Vitosolic. There is a communication fault with the solar control unit or Vitosolic, so the syste…
Details
C3
Extension AM1 communication fault. There is a communication fault with extension AM1, so the system remains in control mode; check the conne…
Details
C4
Communication fault, Open Therm extension. There is a communication fault with the Open Therm extension, so the system remains in control mo…
Details
C5
Communication error, variable speed internal pump. There is a communication error with the variable speed internal pump, so the system is in…
Details
CD
Communication fault, Vitocom 100 (KM-BUS). There is a communication fault with the Vitocom 100 (KM-BUS), so the system remains in control mo…
Details
CF
Communication fault - LON communication module. There is a communication fault with the LON communication module, so the system remains in c…
Details
D6
Input DE1 reports a fault at extension EA1. Input DE1 reports a fault at extension EA1, so the system remains in control mode; remove the fa…
Details
D7
Input DE2 reports a fault at extension EA1. Input DE2 reports a fault at extension EA1, so the system remains in control mode; remove the fa…
Details
D8
Input DE3 reports a fault at extension EA1. Input DE3 reports a fault at extension EA1, so the system remains in control mode; remove the fa…
Details
DA
Short circuit on room temperature sensor (heating circuit 1 without mixing valve). A short circuit on the room temperature sensor of heating…
Details
DB
Room temperature sensor shorted out (heating circuit 2 with mixing valve). The room temperature sensor of heating circuit 2 with mixing valv…
Details
DC
Short circuit on room temperature sensor (heating circuit 3 with mixing valve). A short circuit on the room temperature sensor of heating ci…
Details
DD
Room temperature sensor cable broken (heating circuit 1 without mixing valve). The room temperature sensor cable of heating circuit 1 withou…
Details
DE
Room temperature sensor cable broken (heating circuit 2 with mixing valve). The room temperature sensor cable of heating circuit 2 with mixi…
Details
DF
Room temperature sensor cable broken (heating circuit 3 with mixing valve). The room temperature sensor cable of heating circuit 3 with mixi…
Details
E0
Fault, external LON participant. There is a fault with an external LON participant, so the system remains in control mode; check the connect…
Details
E1 202
Ionization current too high during calibration. The ionization current is too high during calibration, so the burner is in a fault mode; che…
Details
E2 201
Heating water flow rate too low during calibration. The heating water flow rate is too low during calibration, so the burner is in a fault m…
Details
E3 204
Heat transfer too low during calibration; temperature limiter caused shutdown. The heat transfer is too low during calibration and the tempe…
Details
E4
Fault, supply voltage 24 V. There is a fault with the 24 V supply voltage, which blocks the burner; replace the control unit. The table clas…
Details
E5 226
Fault, flame amplifier. There is a fault with the flame amplifier, which blocks the burner; replace the control unit. The table classifies i…
Details
E7 192
Ionization current too low during calibration. The ionization current is too low during calibration, so the burner is in a fault mode; check…
Details
E8 189
Ionization current lies outside the permissible range. The ionization current lies outside the permissible range, so the burner is in a faul…
Details
EA 193
Ionization current outside the permissible range during calibration (deviation from previous level too great). The ionization current lies o…
Details
EB 194
Repeated flame loss during calibration. Flame loss has occurred repeatedly during calibration, so the burner is in a fault mode; check the g…
Lockout
EC 67 or 195
Parameter fault during calibration. A parameter fault has occurred during calibration, so the burner is in a fault mode; press reset button …
Details
ED 191
Internal fault. An internal fault has occurred, so the burner is in a fault mode; replace the control unit. The table classifies it as Locki…
Details
EE 132
At burner start, flame signal is missing or too weak. At burner start the flame signal is missing or too weak, so the burner is in a fault m…
Lockout
EF 138
Flame is lost immediately after it has built (during the safety time). The flame is lost immediately after it has built during the safety ti…
Details
F0
Internal fault. An internal fault has occurred, which blocks the burner; replace the control unit. The table classifies it as Blocking.…
Details
F1 135
Maximum flue gas temperature exceeded the 230ºF (110ºC) limit. The maximum flue gas temperature has exceeded the 230ºF (110ºC) limit, so the…
Details
F2 129
Fixed high limit switch open (activated). The fixed high limit switch is open (activated), so the burner is in fault mode; check the heating…
Details
F3 139
Flame signal already present at burner start. A flame signal is already present at burner start, so the burner is in fault mode; check the i…
Lockout
F6
Boiler water temperature sensor temperature values vary too widely from one another. The boiler water temperature sensor temperature values …
Details
F8 148
Gas valve closes too late. The gas valve closes too late, so the burner is in fault mode; check the gas valve, check both control wiring and…
Details
F9 151 or 152
Fan speed too low during burner start. The fan speed is too low during burner start, so the burner is in fault mode; check the fan, the fan …
Details
FA 154
Fan not at standstill. The fan is not at standstill, so the burner is in fault mode; check the fan, the fan connecting cables and the fan co…
Details
FC 190
Gas valve faulty or faulty modulation valve control, or vent system blocked. The gas valve is faulty or the modulation valve control is faul…
Details
FD 227
Boiler coding card is missing. The boiler coding card is missing, so the burner is in a fault state and the additional fault B7 is displayed…
Details
FD -
Fault, burner control unit. There is a fault with the burner control unit, so the burner is in a fault state; check the ignition electrodes …
Lockout
FE 158, 159, 162 or 225
Damaged or incorrect boiler coding card or main PCB. The boiler coding card is damaged or incorrect or the main PCB is damaged or incorrect,…
Details
FF 224
Internal fault or reset button R blocked. An internal fault has occurred or the reset button R is blocked, so the burner is in fault mode; r…
Details
N/A 2
Gas supply - no/low gas pressure detected. No or low gas supply pressure is detected, so the burner is in a hold or wait state and the boile…
Details
N/A 3
No boiler water circulation detected. No boiler water circulation is detected, so the burner is in a hold or wait state and the boiler is no…
Details
N/A 5
Flame failure during stabilization. Flame failure during stabilization has occurred, so the burner is in a hold or wait state and the boiler…
Lockout
N/A 6
Boiler temperature has exceeded the monitoring limit. The boiler temperature has exceeded the monitoring limit, so the burner is in a hold o…
Details
N/A 8
Flue gas temperature has exceeded the monitoring limit. The flue gas temperature has exceeded the monitoring limit, so the burner is in a ho…
Details
N/A 29
Open circuit at terminals 1 and L on the Multi terminal of the power pump module. There is an open circuit at terminals 1 and L on the Multi…
Details
N/A 33
Power supply voltage below minimal operation level or internal fuse failure. The power supply voltage is below the minimal operation level o…
Details
Vitocrossal 300 CU3A floor boilers (Vitotronic 200 control, service manual 5673 649 - 20)
10
Boiler operates based on outdoor temperature of 32°F (0°C). A short circuit on the outdoor temperature sensor makes the boiler operate at 32…
Details
18
Boiler operates based on outdoor temperature of 32°F (0°C). The outdoor temperature sensor cable is broken, so the boiler operates at 32°F (…
Details
30
Burner blocked. There is a short circuit on the boiler water temperature sensor, which blocks the burner; check the boiler water temperature…
Details
38
Burner blocked. The boiler water temperature sensor cable is broken, which blocks the burner; check the boiler water temperature sensor. The…
Details
40
Mixing valve closes. The supply temperature sensor of heating circuit 2 with mixing valve has a short circuit, causing the mixing valve to c…
Details
44
Mixing valve closes. The supply temperature sensor of heating circuit 3 with mixing valve has a short circuit, causing the mixing valve to c…
Details
48
Mixing valve closes. The supply temperature sensor cable is broken on heating circuit 2 with mixing valve, causing the mixing valve to close…
Details
4C
Mixing valve closes. The supply temperature sensor cable is broken on circuit 3 with mixing valve, causing the mixing valve to close; check …
Details
50
No DHW heating. There is a short circuit on the DHW tank temperature sensor, which stops DHW heating; check the DHW sensor.…
Details
58
No DHW heating. The tank temperature sensor cable is broken, which stops DHW heating; check the sensor.…
Details
90
Control mode. A temperature sensor connected to the solar control module has a short circuit, so the boiler remains operational; check the s…
Details
91
Control mode. A temperature sensor connected to the solar control module has a short circuit, so the boiler remains operational; check senso…
Details
92
No solar DHW heating. There is a short circuit on the collector temperature sensor, which stops solar DHW heating; check the temperature sen…
Details
93
Control mode. There is a short circuit on the tank temperature sensor, so the boiler remains operational; check the temperature sensor at co…
Details
94
No solar DHW heating. There is a short circuit on the tank temperature sensor, which stops solar DHW heating; check the temperature sensor o…
Details
98
Control mode. A temperature sensor connected to the solar control module has a lead break, so the boiler remains operational; check the sens…
Details
99
Control mode. A temperature sensor connected to the solar control module has a lead break, so the boiler remains operational; check sensor a…
Details
9A
No solar DHW heating. The collector temperature sensor cable is broken, which stops solar DHW heating; check the sensor at the solar control…
Details
9B
Control mode. The tank temperature sensor cable is broken, so the boiler remains operational; check the temperature sensor at connection S3 …
Details
9C
No solar DHW heating. The tank temperature sensor cable is broken, which stops solar DHW heating; check the temperature sensor on the solar …
Details
9E
Control mode. There is no supply rate in the collector circuit, the flow rate is too low, or the temperature limiter has responded; check th…
Details
9F
Control mode. The solar control module is faulty, so the boiler remains operational; replace the solar control module. The table classifies …
Details
A7
Control mode (stays in factory default setting). The programming unit is faulty, so the boiler control stays in the factory default setting;…
Details
B0
Burner blocked. The flue gas temperature sensor is shorted out, which blocks the burner; check the flue gas temperature sensor. The table cl…
Details
B1
Control mode (stays in factory default setting). There is a communication fault with the internal programming unit, so the boiler control st…
Details
B5
Control mode (factory default setting). There is an internal fault, so the boiler control runs in the factory default setting; replace the c…
Details
B7
Burner blocked. The boiler coding card is missing, faulty or incorrect, which blocks the burner; plug in the boiler coding card or replace i…
Details
B8
Burner blocked. The flue gas temperature sensor cable is broken, which blocks the burner; check the flue gas temperature sensor. The table c…
Details
BA
Mixing valve regulates to a supply temperature of 68°F (20°C). There is a communication fault with the accessory kit for heating circuit 2 w…
Details
BB
Mixing valve regulates to a supply temperature of 68°F (20°C). There is a communication error with the extension kit for heating circuit 3 w…
Details
BC
Control mode without remote control. There is a communication error with the remote control Vitotrol of heating circuit 1 without mixing val…
Details
BD
Control mode without remote control. There is a communication error with the remote control Vitotrol of heating circuit 2 with mixing valve;…
Details
BE
Control mode without remote control. There is a communication error with the remote control Vitotrol of heating circuit 3 with mixing valve;…
Details
BF
Control mode. The LON communication module is incorrect, so the boiler remains operational; replace the LON communication module. The table …
Details
C1
Control mode. There is a communication fault with extension EA1, so the boiler remains operational; check the connections and, without exten…
Details
C2
Control mode. There is a communication fault with the solar control unit or Vitosolic, so the boiler remains operational; check the solar co…
Details
C4
Control mode. There is a communication fault with the Open Therm extension, so the boiler remains operational; check the Open Therm extensio…
Details
C7
Control mode, max. pump speed. There is a communication fault with the variable speed circulation pump of the heating circuit without mixing…
Details
C8
Control mode, max. pump speed. There is a communication error with the external variable speed heating circuit pump of heating circuit 3 wit…
Details
CD
Control mode. There is a communication fault with the Vitocom 100 on the KM-BUS, so the boiler remains operational; check the connections an…
Details
CF
Control mode. There is a communication fault with the LON communication module, so the boiler remains operational; replace the LON communica…
Details
D6
Control mode. Input DE1 reports a fault at extension EA1, so the boiler remains operational; remove the fault at the appliance concerned. Th…
Details
D7
Control mode. Input DE2 reports a fault at extension EA1, so the boiler remains operational; remove the fault at the appliance concerned. Th…
Details
D8
Control mode. Input DE3 reports a fault at extension EA1, so the boiler remains operational; remove the fault at the appliance concerned. Th…
Details
DA
Control mode without room influence. There is a short circuit on the room temperature sensor of heating circuit 1 without mixing valve; chec…
Details
DB
Control mode without room influence. The room temperature sensor of heating circuit 2 with mixing valve is shorted out; check the room tempe…
Details
DC
Control mode without room influence. There is a short circuit on the room temperature sensor of heating circuit 3 with mixing valve; check t…
Details
DD
Control mode without room influence. The room temperature sensor cable is broken in heating circuit 1 without mixing valve; check the room t…
Details
DE
Control mode without room influence. The room temperature sensor cable is broken in heating circuit 2 with mixing valve; check the room temp…
Details
DF
Control mode without room influence. The room temperature sensor cable is broken in heating circuit 3 with mixing valve; check the room temp…
Details
E0
Control mode. There is a fault on an external LON participant, so the boiler remains operational; check the connections and the LON particip…
Details
E1
Burner in a fault mode. The ionization current is too high during calibration, so the burner is in a fault mode; check the gap between the i…
Details
E3
Burner in a fault mode. Heat transfer is too low during calibration and the temperature limiter caused shutdown, so the burner is in a fault…
Details
E4
Burner blocked. There is a fault in the 24V supply voltage, which blocks the burner; replace the control unit. The table classifies it as Bu…
Details
E5
Burner blocked. There is a fault in the flame amplifier, which blocks the burner; replace the control unit. The table classifies it as Burne…
Details
E7
Burner in a fault mode. The ionization current is too low during calibration, so the burner is in a fault mode; check the ionization electro…
Details
E8
Burner in a fault mode. The ionization current lies outside the permissible range, so the burner is in a fault mode; check the gas supply, g…
Details
EA
Burner in a fault mode. The ionization current during calibration deviates too greatly from the previous level, so the burner is in a fault …
Details
EB
Burner in a fault mode. There is repeated flame loss during calibration, so the burner is in a fault mode; check the ionization electrode ga…
Lockout
EC
Burner in a fault mode. There is a parameter fault during calibration, so the burner is in a fault mode; press reset button R or replace the…
Details
ED
Burner in a fault mode. There is an internal fault, so the burner is in a fault mode; replace the control unit. The table classifies it as B…
Details
EE
Burner in a fault mode. At burner start the flame signal is missing or too weak, so the burner is in a fault mode; check the gas supply, gas…
Lockout
EF
Burner in a fault mode. The flame is lost immediately after it has built during the safety time, so the burner is in a fault mode; check the…
Details
F0
Burner blocked. There is an internal fault, which blocks the burner; replace the control unit. The table classifies it as Burner blocked.…
Details
F1
Burner in a fault mode. The maximum flue gas temperature of 230ºF (110ºC) has been exceeded, so the burner is in a fault mode; check the fil…
Details
F2
Burner in fault mode. The fixed high limit switch is open (activated), so the burner is in fault mode; check the fill level and circulation …
Details
F3
Burner in fault mode. A flame signal was already present at burner start, so the burner is in fault mode; check the ionization electrode and…
Lockout
F8
Burner in fault mode. The gas valve closes too late, so the burner is in fault mode; check the gas valve and both control wiring connections…
Details
F9
Burner in fault mode. The fan speed is too low during burner start, so the burner is in fault mode; check the fan, the fan cables, the power…
Details
FA
Burner in fault mode. The fan is not at standstill, so the burner is in fault mode; check the fan, the fan connecting cables and the fan con…
Details
FC
Burner in fault mode. The gas valve or modulation valve control is faulty, or the vent system is blocked, so the burner is in fault mode; ch…
Details
FD
Burner in a fault state and additional fault B7 is displayed. The boiler coding card is missing, so the burner is in a fault state and fault…
Details
FD
Burner in a fault state. There is a fault in the burner control unit, so the burner is in a fault state; check the ignition electrodes and c…
Lockout
FE
Burner in fault mode. The boiler coding card or the main PCB is damaged or incorrect, so the burner is in fault mode; press reset button R a…
Details
FF
Burner in fault mode. There is an internal fault or the reset button R is blocked, so the burner is in fault mode; restart the equipment and…
Details
Vitocrossal 200 CI2 commercial condensing boilers (fault codes, SI 6175 797 - 23)
F.7
No DHW heating. Lead break, tank temperature sensor. Check DHW setting in the commissioning assistant and correct if necessary. Check tank t…
Details
F.8
No DHW heating. Short circuit, tank temperature sensor. Check tank temperature sensor. Replace faulty component if necessary.…
Details
F.13
Regulates as if the outside temperature were 32\u00b0F (0\u00b0C). Lead break, outside temperature sensor. Check the operating mode setting …
Details
F.14
Regulates as if the outside temperature were 32\u00b0F (0\u00b0C). Short circuit, outside temperature sensor. Check outside temperature sens…
Details
F.29
Regulates without supply temperature sensor for low loss header. Lead break, low loss header sensor. Check low loss header setting in the co…
Details
F.30
Regulates without supply temperature sensor for low loss header. Short circuit, low loss header sensor. Check supply temperature sensor, low…
Details
F.49
Burner in a fault state. Lead break, flue gas temperature sensor. Check flue gas temperature sensor. Reset the boiler.…
Details
F.50
Burner in a fault state. Short circuit, flue gas temperature sensor. Check flue gas temperature sensor. Reset the boiler.…
Details
F.57
Normal operation without room influence. Lead break, room temperature sensor. Check remote control setting in the commissioning assistant an…
Details
F.58
Normal operation without room influence. Short circuit, room temperature sensor. Check plug and cable of external room temperature sensor, h…
Details
F.59
Burner locked out. Power supply, low voltage. Check mains voltage. If voltage is correct and the fault occurs repeatedly, replace the fan un…
Details
F.62
Burner in a fault state. High limit safety cut-out has responded. Check heating system fill level. Check pre-charge pressure in diaphragm ex…
Details
F.63
Burner in a fault state. Flue gas temperature limiter has responded. Check heating system fill level. Check pre-charge pressure in diaphragm…
Details
F.64
Normal operation; burner restarts. Flame loss during stabilization or operating phase. Check ionization electrode (replace if necessary): Ch…
Lockout
F.65
Burner in a fault state. Flame signal is not present or insufficient at burner start. Check ventilation air/flue system and condensate drain…
Lockout
F.67
Burner in a fault state. Ionization current lies outside the permissible range. Check gas supply (gas pressure), check gas solenoid valve an…
Details
F.69
Burner in a fault state. Ionization current lies outside the permissible range. Check ionization electrode: Check whether insulation block i…
Details
F.71
Burner in a fault state. Fan speed too low. Check fan for blockage. Check the gas type and flue system setting in the commissioning assistan…
Details
F.72
Burner in a fault state. Fan idle state not reached. Reset the boiler. If fault occurs repeatedly, replace fan unit.…
Details
F.74
Burner locked out. Internal circulation pump off. No central heating and no DHW heating. System pressure too low. Top up with water. Vent th…
Details
F.77
Burner in a fault state. Data memory burner control unit. Reset the boiler. If the fault recurs, replace the BCU burner control unit.…
Details
F.87
Burner in a fault state. Water pressure too high. Replace the water pressure sensor. Replace the safety assembly. Open BDF valves. Check exp…
Details
F.89
No central heating and no DHW heating. Circulation pump blocked. Check circulation pump. Replace if necessary.…
Details
F.91
Function of affected extension in emergency mode. DIO electronics module communication error. Check connections to DIO electronics module an…
Details
F.92
Function of the relevant electronics module in emergency mode. ADIO electronics module communication error. Check setting in the commissioni…
Details
F.94
Function of the relevant electronics module in emergency mode. Function of the relevant electronics module in emergency mode. Check setting …
Details
F.99
Electronics modules connected to PlusBus not functioning. Communication error PlusBus. Check setting in the commissioning assistant and corr…
Details
F.100
Electronics modules connected to PlusBus not functioning. Voltage error PlusBus. Check whether the PlusBus power supply on the HMU heat mana…
Details
F.104
Depending on configuration of EM-EA1 extension (DIO electronics module). External fault message input active. Check connected external devic…
Details
F.142
Burner in a fault state. Communication error CAN bus. Check the fan unit for correct function. For this, check the stepper motor of the fan …
Details
F.160
Burner in a fault state. Communication error CAN bus. If \u201cConnection error\u201d is displayed, check the internal CAN bus subscriber co…
Details
F.180
Burner in a fault state. Gas pressure too low. Check gas pressure. Notify the gas supply utility if necessary. Check whether the gas pressur…
Details
F.182
No DHW heating. Short circuit, outlet temperature sensor (if installed). Check outlet temperature sensor (plug X1, cores 13 and 14). Measure…
Details
F.183
No DHW heating. Lead break, outlet temperature sensor (if installed). Check the outlet temperature sensor.…
Details
F.184
Burner in a fault state. Short circuit, supply temperature sensor. Check supply temperature sensor. Check plug-in connection and lead to sen…
Details
F.185
Burner in a fault state. Lead break, supply temperature sensor/high limit safety cut-out. Check the supply temperature sensor/ high limit sa…
Details
F.299
Time/date incorrect. Real time clock setting incorrect. Set the time and date.…
Details
F.342
No central heating, no DHW heating. Communication error, BCU burner control unit. Check connecting cable to the burner control unit plug X4 …
Details
F.343
Regulates without return temperature sensor for low loss header. Short circuit of the common return sensor. Check the low loss header settin…
Details
F.344
Regulates without return temperature sensor for low loss header. Lead break of the common return sensor. Check return temperature sensor for…
Details
F.347
Safety shutdown / restart. Oxygen content has fallen below 0%. O2 sensor readings out of range. Check combustion air and flue system for pos…
Details
F.348
Burner in a fault state. Gas modulation valve. If several boilers are connected to a common flue system: Check whether \u201cMultiple connec…
Details
F.353
Burner shutdown with restart if demand exists. Insufficient gas supply, burner output reduced. Check the gas supply. Optically check input-s…
Details
F.354
Burner in a fault state. Gas modulation valve tolerance outside permissible range. Replace the burner fan.…
Details
F.364
Burner in a fault state. Internal system fault. Replace the BCU burner control unit.…
Details
F.365
Burner in a fault state. Gas fitting relay monitoring has responded. Start the burner several times; replace the burner control unit if nece…
Details
F.369
Burner in a fault state. Flame is lost immediately after flame formation (during safety time). Check gas supply (gas pressure and gas flow s…
Details
F.370
Burner in a fault state. Fuel valve or modulation valve will not close. Reset the boiler. If fault occurs repeatedly, replace fan unit.…
Details
F.371
Safety shutdown/restart. Fan speed not reached, reported fan speed below minimum speed. Check exhaust length setting. Check the fan for bloc…
Details
F.378
Burner in a fault state. Flame loss during stabilization or operating phase. Check gas supply (gas pressure and gas flow switch). Check bala…
Lockout
F.379
Burner in a fault state. Flame signal not present or insufficient. Check ionization electrode connecting cable for damage and firm seating. …
Lockout
F.380
Burner in a fault state. Flame loss immediately after flame formation (during safety time). Check gas supply (gas pressure). Check balanced …
Lockout
F.381
Burner in a fault state. Flame is lost immediately after flame formation. Check gas supply (gas pressure and gas flow switch). Check balance…
Details
F.382
Boiler locked out. System fault counter has exceeded its limit value (30). Fault as a consequence of too many non-lockout faults in successi…
Details
F.383
Burner in a fault state. Fuel valve does not close. Check gas line for contamination. Check the gas supply pressure. Replace gas fan if nece…
Details
F.416
Burner locked out. Flue gas temperature sensor incorrectly positioned. Fit flue gas temperature sensor correctly. See \u201cRepairs\u201d. C…
Details
F.425
System operating normally; calculation not working. Time synchronization failed. Set the time. If external time is used, check parameters 15…
Details
F.430
Normal operation in line with target values of boiler. Communication error gateway. Check gateway module connecting cable and power supply.…
Details
F.446
Burner in a fault state. Fault in boiler supply temperature sensor. Check supply temperature sensor. Check plug-in connection and lead to se…
Details
F.453
Burner in a fault state. Error in scheduled program run monitoring. Control unit in fault state. Notify contractor. Reset the boiler. If the…
Details
F.454
Burner in a fault state. Wrong software or version. Control unit in fault state. Notify contractor. Check version of operating software for …
Details
F.457
Burner in a fault state. Fan sluggish or blocked. Reset the boiler. Check fan for sluggishness. In the case of severe contamination or grind…
Details
F.473
No call for heat. Communication error, heat management unit (HMU). Check connecting cable between burner control unit (BCU) and HMU.…
Details
F.517
Normal operation, remote control unit not functioning. Lead break, PlusBus cable, incorrect boiler address set, remote control faulty. Check…
Details
F.519
Communication with the building management system is not possible. External control is not possible. The boiler returns to the internal cont…
Details
F.520
Communication with the building management system is not possible. External control is not possible. The boiler returns to the internal cont…
Details
F.527
Burner in a fault state. Incorrect parameter set, HMU heat management unit. Overwrite (flash) the HMU heat management unit with the correct …
Details
F.528
Burner in a fault state. Incorrect parameter set, BCU burner control unit. Overwrite (flash) the BCU burner control unit with the correct pa…
Details
F.541
Burner in a fault state, fan in ventilation mode. No feedback: Flue gas damper closed. Check the cable and function of the flue gas damper.…
Details
F.542
Emergency function operating mode is activated for heating circuit 1: Heating circuit pump is switched on Heating circuit mixing valve is mo…
Details
F.543
Emergency function operating mode is activated for heating circuit 1: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.544
Mixing valve closes. Heating circuit pump is operational. Lead break, supply temperature sensor, heating circuit 2 with mixing valve Incorre…
Details
F.545
Mixing valve closes. Heating circuit pump is operational. Short circuit, supply temperature sensor for heating circuit 2 with mixing valve. …
Details
F.546
Mixing valve closes. Heating circuit pump is operational. Lead break, supply temperature sensor, heating circuit 3 with mixing valve. Check …
Details
F.547
Mixing valve closes. Heating circuit pump is operational. Short circuit, supply temperature sensor for heating circuit 3 with mixing valve. …
Details
F.548
Mixing valve closes. Heating circuit pump is operational. Short circuit, supply temperature sensor for heating circuit 4 with mixing valve. …
Details
F.549
Mixing valve closes. Heating circuit pump is operational. Short circuit, supply temperature sensor for heating circuit 4 with mixing valve. …
Details
F.574
Room temperature sensor for heating circuit 1 not available. Normal operation without room influence. Check external room temperature sensor…
Details
F.575
Normal operation without room influence. Lead break, room temperature sensor, heating circuit 1. Check external room temperature sensor for …
Details
F.576
Normal operation without room influence. Short circuit, room temperature sensor, heating circuit 1. Check external room temperature sensor f…
Details
F.577
Normal operation without room influence. Room temperature sensor for heating circuit 2 not available. Check external room temperature sensor…
Details
F.578
Normal operation without room influence. Lead break, room temperature sensor, heating circuit 2. Check external room temperature sensor for …
Details
F.579
Normal operation without room influence. Short circuit, room temperature sensor, heating circuit 2. Check external room temperature sensor f…
Details
F.580
Normal operation without room influence. Room temperature sensor for heating circuit 3 not available. Check external room temperature sensor…
Details
F.581
Normal operation without room influence. Lead break, room temperature sensor, heating circuit 3. Check external room temperature sensor for …
Details
F.582
Normal operation without room influence. Short circuit, room temperature sensor, heating circuit 3. Check external room temperature sensor f…
Details
F.583
Normal operation without room influence. Room temperature sensor for heating circuit 4 not available. Check external room temperature sensor…
Details
F.584
Normal operation without room influence. Lead break, room temperature sensor, heating circuit 4. Check external room temperature sensor for …
Details
F.585
Normal operation without room influence. Short circuit, room temperature sensor, heating circuit 4. Check external room temperature sensor f…
Details
F.623
Emergency function operating mode is activated for heating circuit 1: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.624
Emergency function operating mode is activated for heating circuit 1: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.625
Emergency function operating mode is activated for heating circuit 2: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.626
Emergency function operating mode is activated for heating circuit 2: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.627
Emergency function operating mode is activated for heating circuit 3: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.628
Emergency function operating mode is activated for heating circuit 3: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.629
Emergency function operating mode is activated for heating circuit 4: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.630
Emergency function operating mode is activated for heating circuit 4: Heating circuit pump is switched on. Heating circuit mixing valve is m…
Details
F.688
Function of the relevant electronics module in emergency mode. Communication error MZIO. Check setting in the commissioning assistant and co…
Details
F.691
System in a fault state. No feedback, ventilation air supply preventing burner start. Check plug connection, check for blockages of the vent…
Details
F.692
System in a fault state. Burner ventilation air supply interrupted. Check plug connection, check for blockages of the ventilation air damper…
Details
F.694
Burner in a fault state. Fault in heat generator supply temperature sensor. Check supply temperature sensor. Check plug-in connection and le…
Details
F.762
System in a fault state. System pressure too low. Top up with water. Vent the system. If the fault recurs: Check Low water cutoff on termina…
Details
F.764
System in a fault state. Lag boiler reports a fault. Check the lag boiler fault.…
Details
F.765
System in a fault state. Communication error lag boiler. Check communication of lag boiler.…
Details
F.875
System in a fault state. Communication error lead boiler. Check communication of lead boiler.…
Details
F.882
Burner/system in a fault state. Gas outlet pressure too high (GDW3). Check gas pressure switch 3 and the gas outlet pressure (GDW3). If nece…
Details
F.883
Burner/system in a fault state. Gas valve test malfunction: Electronic fault with gas fitting or CAN bus commu- nication error. Restart the …
Details
F.884
Burner/system in a fault state. Gas valve test malfunction: VPS pressure (GDW 2) does not increase during filling. Check gas inlet pressure.…
Details
F.885
Burner/system in a fault state. Gas valve test faulty, valve seat V2 faulty. Replace the gas fitting.…
Details
F.886
System in a fault state. Gas valve test malfunction: VPS pressure (GDW 2) does not drop during VPS test. Restart the burner several times. I…
Details
F.887
System in a fault state. Gas valve test faulty, valve seat V1 faulty. Replace the gas fitting.…
Details
F.888
System in a fault state. Communication error with Lambda probe controller (burner control unit internal error). Replace burner control unit.…
Details
F.889
System in a fault state. O2 probe malfunction: cyclic probe check failed. If the fault occurs directly after installation or after changing …
Details
F.890
System in a fault state. O2 probe malfunction: cyclic probe check failed. Check for internal and external flue gas recirculation, possible c…
Details
F.891
System in a fault state. O2 probe malfunction: probe not ready for operation in pre/post purge. Check the electric connection to the O2 prob…
Details
F.892
Burner in a fault state. O2 probe malfunction: calibration failed. Check for internal and external flue gas recirculation, contamination of …
Details
F.893
Burner in a fault state. O2 probe malfunction: calibration failed. Check for internal and external flue gas recirculation, contamination of …
Details
F.894
Burner in a fault state. O2 probe malfunction: Probe heating. Check Lambda probe plug and replace if necessary. Replace burner control unit.…
Details
F.895
Burner in a fault state. O2 probe malfunction: Wear. Check Lambda probe plug and replace if necessary.…
Details
F.896
System in a fault state. Safety chain 1 has responded. Check the hydraulic minimum pressure switch.…
Details
F.897
System in a fault state. Safety chain 2 has responded. Check low water indicator.…
Details
F.920
System in a fault state. MZIO function fault, digital input 1. Check external setup.…
Details
F.921
System in a fault state. MZIO function fault, digital input 2. Check external setup.…
Details
F.922
System in a fault state. MZIO function fault, digital input 3. Check external setup.…
Details
F.971
Burner in a fault state. When the gas fitting was replaced, the calibration value was not entered. Replace the CV2 calibration value (see la…
Details
F.982
No heating, no DHW heating. Circulation pump heating circuit 1 running dry. Check diaphragm expansion tank, check pump.…
Details
F.986
System in a fault state. Parameter plausibility check between burner 1 and burner 2 failed. Restart the boiler.…
Details
F.1001
Burner in a fault state. Burner control unit not calibrated. Replace the burner control unit.…
Details
F.1002
Burner in a fault state. Burner control unit not calibrated. Replace the burner control unit.…
Details
F.1004
System in a fault state. Reverse flow of flue gas in \u201cdry mode\u201d (partial load range with CI2 1500/2000 MBtu/h). Check flue system …
Details
F.1061
Burner in a fault state. Faulty burner control unit or faulty lead from O2 probe to burner control unit. Replace faulty parts.…
Details
F.1062
Burner in a fault state. Discrepancy between value measured on O2 controller and comparative measurement on burner control unit. Check plug/…
Details
Vitocrossal 200 CM2 commercial condensing boilers (GW6B control, SI 5584 109 - 16 / 5546 489 - 15)
F 80
Burner control unit in a fault state; system cools down; burner control unit locked out. Short circuit, boiler water temperature sensor, bur…
Details
F 81
Burner control unit in a fault state. Sensor drift, boiler water temperature sensor, burner control unit. Check lead and dual sensor; replac…
Details
F 88
Burner control unit in a fault state. Lead break, boiler water temperature sensor, burner control unit. Check lead and dual sensor; replace …
Details
F B7
Burner control unit in a fault state; system cools down; burner control unit locked out. Coding card not inserted in the burner control unit…
Details
F B7
Type of coding card. Coding card does not match burner control unit. Replace coding card or burner control unit…
Details
F E1
Gas pressure switch GDW2 activated (closed on pressure rise). 1st gas valve seat leaking / GDW2, gas pressure switch activated / burner test…
Details
F E2
Gas pressure switch GDW2 did not close during control self diagnostics. Gas pressure switch/GDW2 electrical connection open (switch did not …
Details
F E2
Gas pressure switch GDW2 did not close during control self diagnostics. Gas valve does not open or is leaking; gas pressure switch faulty. C…
Details
F E4
Burner shuts down. Multiple detection of under voltage. Check the power supply…
Details
F E5
Burner control unit in a fault state. Internal fault of the burner control unit and during test of ionization input. Replace burner control …
Details
F EE
Burner control unit in a fault state. Internal error in feedback from gas safety valves; output relay does not respond. Reset burner control…
Details
F EF
Burner control unit in a fault state. Internal error in feedback from gas safety valves; output relay does not respond. Reset burner control…
Details
F F0
Emergency operation according to internal default. Communication error KM BUS burner control unit. Check the KM BUS cable plug for firm seat…
Details
F F1
Burner control unit in a fault state; system cools down. Flue gas excess temperature; excessive gas throughput. Wait until temperature falls…
Details
F F2
Burner control unit in a fault state; system cools down. Excessive boiler water temperature. Wait until temperature falls below the permissi…
Details
F F3
Ionization flame monitor reports faulty flame signal during start-up or after the post-purge. Gas valve leaking (flame present); incorrect c…
Lockout
F F4
No flame formation during safety time; ionization flame monitor reports no flame signal. Ionization electrode incorrectly adjusted; ionizati…
Lockout
F F4
No flame formation during safety time; ionization flame monitor reports no flame signal. Ignition electrode not set correctly; earth leakage…
Lockout
F F4
No flame formation during safety time; ionization flame monitor reports no flame signal. Insulation body of ignition or ionization electrode…
Lockout
F F4
Poor start-up characteristics, rotary damper does not close, solenoid valve does not switch. Servomotor faulty, servomotor connecting cable …
Details
F F4
No flame builds during safety time; ionization flame monitor reports no signal. Incorrect gas type selected. Adjust gas type…
Lockout
F F4
No flame builds during safety time; ionization flame monitor reports no signal. Gas valve does not open. Check the connecting cable; check t…
Lockout
F F4
No flame builds during safety time; ionization flame monitor reports no signal. Combustion characteristics not ideal. Adjust the burner…
Lockout
F F5
Air pressure switch 1 shows no air pressure, fan does not operate. Air pressure switch 1 faulty, incorrectly connected or incorrectly set. R…
Details
F F5
Air pressure switch 1 switches off during operation. Flue gas back pressure; condensate built up; air pressure switch 1 hose faulty; connect…
Details
F F6
Gas pressure switch shows no gas pressure. Gas shut-off valve closed; gas pressure switch faulty; multiple problems with gas supply. Open ga…
Details
F F7
Fan pressure is created during the idle state check of air pressure switch 1. Wind influence on fan. Check flue outlet or chimney…
Details
F F7
Contact of air pressure switch 1 not closed in idle state. Air pressure switch 1 faulty. Replace air pressure switch 1…
Details
F F8
Flame extinguishes during operation. Incorrect gas type selected. Adjust gas type…
Details
F F8
Flame extinguishes during operation. Burner gauze assembly faulty. Check burner gauze assembly; replace if damaged…
Details
F F8
Flame extinguishes during operation. Combustion characteristics not ideal. Adjust burner…
Details
F F9
Fan not running; fan speed not reached. Fan faulty; cables are faulty or broken. Check cables; replace fan if required…
Details
F F9
Status duration too long, fan ramp-up. Internal fault; fan cannot reach its set value. Replace fan or burner control unit…
Details
F F9
Varying fan speed. Fan faulty, cable “a-ÖA” faulty or broken. Check cable; replace cable “a-ÖA” or fan if required…
Details
F F9
No fan feedback. Fan faulty; external power supply to fan not connected or faulty; cable “a-ÖA” faulty or broken; fan blocked (possibly by a…
Details
F FA
Fan runs without demand; burner control unit in a fault state. Fan has not stopped; cable “a-ÖA” faulty; fan faulty; burner control unit fau…
Details
F Fb
Burner not starting. Combustion chamber pressure too high; burner control unit in a fault state. Flue gas path or condensate path blocked of…
Details
FD
Fault within burner control unit. No gas, exhaust recirculation, fan not operating, air pressure sensor defective. Check each component, res…
Details
F EC
Fault around burner control unit. Internal system fault and EMC. Reset burner control unit. Replace the burner control unit if the fault per…
Details
F ED
Fault around burner control unit. Internal system fault and EMC. Reset burner control unit. Replace the burner control unit if the fault per…
Details
F FF
Fault around burner control unit. Internal system fault and EMC. Reset burner control unit. Replace the burner control unit if the fault per…
Details
Talk to a boiler technician
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.