On Tue, 24 Dec 2019 12:53:34 +0000, "www.GymRatZ.co.uk"
wrote:

snip

Sorry for the long lost but if anyone has any other suggestions to try
before venturing into the realms of changing the main PCB I'm all ears.

Can't answer your question Pete but was chatting to a heating engineer
the other day (just by chance) and he suggested that Vaillant weren't
actually as good as they are hyped up to be?

I'm not sure how reliable yours has been over the entire 16 years but
a mate has a fairly new (3 years) 'system boiler' (no IHW?) but has
just had to have a new main PCB and gas control valve.

Or maybe because of all the eco restrictions, they have just become
more complicated of late and so less reliable?

I wonder just how much more 'eco' a 3 year old boiler is, with the
environmental cost of making then replacing a gas control valve, PCB,
heating engineer diesel van visits etc over my Mums 40 year old (and
bought second hand at that) boiler that may not burn as 'green' but
has hardly had any attention (and certainly no complex parts, maybe a
couple of thermocouples) over all those years?

The HE comments re Vaillant were that they just have good advertising
[1]?

Cheers, T i m

[1] And the warranty is quite restrictive?