viessmann vitodens 100 compact reliability

[xray1]

Thanks for reading this post
I had a vitodens 100 compact 18kw installed eighteen months ago and so far its its failed 3 times with the same fault F4.
The first failure was within 2 days and I accepted this as what we call infantile failures
A complete control panel was fitted and that worked OK for 12 months then one morning F4 again.
New control fitted and working fine again.
Well its happend again f4,tries to fire the igniter-no spark and then of course no ionisation current.
Does anyone no if they have an issue with the control boards on this model.
While its under warranty I,m Ok,in a few months its another problem.

Regards

 

[Gasguru]

Does anyone no if they have an issue with the control boards on this model.

They certainly did and it generated much discussion on the trade forums.

Sometimes it was due to faulty ignition modules though.

I assumed they had cured the problem but others more familiar will have a better insight.

 

[simond]

It is true the Viessmann 100 series - particularly the combi, have had a bad reliability record. It is fair to say that the budget 100 series has damaged the brand.

F4 could describe a multitude of potential faults. Earlier PCBs were being modified and changed. In the last 6 months Viessmann have identified an interference related fault from the spark generator on the side of the heat exchanger. Because it was interference, I'm assuming RF, it was not consistent and affected some of the installed base more than others.

Changing this to a modified (black, assumed to be shielded) unit has in most cases cured the reliability.

We have now resumed fitting the compact, because apart from the F4 (now sorted) it is one of the few reasonably well made small open vent compatible boilers. Broag Remeha 18v being another. Both can be fitted with weather compensation (late models of Viessmann 100 only).