Viessmann 100

[PekPek]

Hope someone can point me in the right direction. Getting a F4 fault. Boiler is out of warrenty but Viessmann did send me a new Ignition Zig as a goodwill gesture.

Got my local gas guy (who doesn't "do" Viessmanns) to fit it but still getting F4 fault. Sounds like it is trying to do something, gives up, F4

Does the PCB need replacing ? What do do/try next....also waiting for next gas guy to turn up who does know about them but thought I would jump the gun.

Cheers
Pete

 

[weargas]

I bought one of those for my own house when they first came out. My god I said!! A domestic Viessmann boiler!!!! How can I lose???? Turns out I was to become it's "biatch" and I had to supply the KY. Many, many repairs. I do have to hand it to viessmann though they got it wrong and they know it. They are a helpful lot because of it.
I had an F4 after having the super new improved never ever go wrong again ignition module fitted. It happened after the boiler has been on for a while. The heat inside the casing was causing the rubber condensate pipe to go soft and kink. The condensate backed up into the heat exchanger and bang goes your mangoes you get an F4. How hard would it've been to incorporate a seperate blocked condensate sensor???