Veissman ignition problem

[mazperks]

Hi, been away for two days and came back to no hot water/heating.
F4 fault on display indicating ignition fault. (Vitodens 100)
If its the electrode should I still be hearing clicking from the spark generator, (the boiler is going through its start sequence ok but I dont have the final clicking sound of the ignition.) Or is it the electrode itself that makes the noise, in which case how do I know which is at fault. Or in fact could the problem be at the panel. I can use a meter but dont know what reading to look for at the generator leads.
Cheers for any help Ian.

 

[Phill Peck]

Do u have gas?

Check at another source if possible.

How old it the boiler/ has it been serviced? I work on a lot of these and never had to change electrodes.

 

[mazperks]

Boiler is 7 yrs old, last serviced just over a yr ago, when heat ex changed.
The f4 fault was common on the 100 due to duff electrodes, mine was replaced under warranty. I dont want to replace electrode and spark gen unneccesarily,without testing, if it is a fault further down line.
Sorry to sound tight but I,ve been out of work for some time and every penny counts.
I would like to check the input to the spark unit but dont know what the reading should be.
Gas supply ok.
EDIT-- That should read duff spark generators.

 

[Dan Robinson]

This is not a DIY repair.

You;ll need to call someone in.

 

[mazperks]

As I am getting no voltage reading at all at the spark generator, and there is continuity in all leads to it, am I correct in thinking it can only be the pcb at fault, in which case is there any reg to say I cant change it myself.
It seems to be a straightforward job to pull off all the connectors and replace them on the new board.

 

[DavidLewis]

Viessmann do a fixed-price repair service, which is cheaper than the cost of a new PCB (at least, it was a couple of years ago when I had similar problems). Sounds like this may be your best bet?

 

[mazperks]

Have found out via Viessman help line, reading should be 300 v dc on spark,
which I aint got, so new pcb it is.