Viessmann Vitodens 100 - No Fault Code but no Ignition...

We have a Viessmann Vitodens 100 that has had some issues over the last few years. This winter we had a Viessmann repairman in to fix an F4 fault and he replaced a number of parts at the same time where they typically see problems on this model.

We now are having more problems - no fault code at this stage but the boiler is not igniting when we turn on the heat or hot water. You can hear it turn on and the sound of ignition but it's not actually happening.

Any thoughts? It's happened a few times but we've managed to get it going - this morning have not been able to at all. Am reluctant to call in another repairman when they've just done so much work on it.

Thanks for your advice.

if you are getting ignition, but no flame, then after 5 seconds the boiler should recyle and retry, most boilers will attempt up to 4 times before shutting down with a lock-out code, the fact that this boiler is not doing this indicates that you will need a RGI who preferably is Viessmann trained, could be a PCB fault, or maybe the tacho on the fan, causing the PCB to be waiting for a signal from the fan that never materialises?? Job for a RGI Engineer, Technician, waller, or whatever the PC brigade insist on calling us at the moment!

are you sure your hearing the ignition/spark??...

i work on these boilers all the time and there are some common faults..

there must a fault code...

how old have you had the boiler. take you have the old 100.to viessmann i give it their due they hold there hands up and admit.they had issues with the old 100.the new ones are excellent.this doesnt though help your situation.if i were you id ring viessmann direct and give them hell.p.s there very helpful people.even out of warrentry explain the hassel youve had.im sure they will listen.