I have a Vaillant EcoTec 831 (2013 so '2nd generation). I see online that this model has a bad reputation for PCBs, and mine had to be replaced.
As it was out of warranty, I found a local plumbing engineering to do this. I don't know where he bought the replacement - and since issues, I've realised that the market has generic parts so am wondering whether that is the root-cause and if so what can be done.
We first we had F70 "Invalid device specific number (DSN)" error but he's fixed that by reviewing the DSN setting (essentially telling the PCB that it is a particular type, in our case "10").
We've also noticed that the Divertor is 'clawing' like a crow. Neither of us remember this happening before yet it would seem to be unrelated (?)
Now our boiler is quite intermittent. Fortunately, it works 90% of the time but sometimes just refuses - ie with either or both DHW & CH demanding to be fed, it just does not respond and the display reflects a low temperature.
Other times, it responds to DWH and/or CH but then exceeds the max temps set for those: going past 58 degrees to over 70 !
And finally: at times when it's not being demanded to supply, the display reflects a fairly high temp, eg 40-50 degrees. Yet it is silent and can do that for no reason (I don't mean a few minutes after being used).
Obviously time will tell whether this becomes too problematic, but one of us has had to miss a shower once per week so it's already annoying!
When I had the F70 error, I felt I had a diagnosis for which I could hold the plumber to account. But now the problem is more intermittent, and I've not seen any error messages, I do not know what to do. Suggestions welcome please, thanks.
Mike, Manchester.
As it was out of warranty, I found a local plumbing engineering to do this. I don't know where he bought the replacement - and since issues, I've realised that the market has generic parts so am wondering whether that is the root-cause and if so what can be done.
We first we had F70 "Invalid device specific number (DSN)" error but he's fixed that by reviewing the DSN setting (essentially telling the PCB that it is a particular type, in our case "10").
We've also noticed that the Divertor is 'clawing' like a crow. Neither of us remember this happening before yet it would seem to be unrelated (?)
Now our boiler is quite intermittent. Fortunately, it works 90% of the time but sometimes just refuses - ie with either or both DHW & CH demanding to be fed, it just does not respond and the display reflects a low temperature.
Other times, it responds to DWH and/or CH but then exceeds the max temps set for those: going past 58 degrees to over 70 !
And finally: at times when it's not being demanded to supply, the display reflects a fairly high temp, eg 40-50 degrees. Yet it is silent and can do that for no reason (I don't mean a few minutes after being used).
Obviously time will tell whether this becomes too problematic, but one of us has had to miss a shower once per week so it's already annoying!
When I had the F70 error, I felt I had a diagnosis for which I could hold the plumber to account. But now the problem is more intermittent, and I've not seen any error messages, I do not know what to do. Suggestions welcome please, thanks.
Mike, Manchester.
