Ferolli Domina 80E problem

[nabby68]

I have a Ferrolli Domina 80e combi boiler which is over 10 years old. At the moment I have the thermostat on the boiler for the heating side turned right down to the off position, the other night I found that the heating had come on! not nice in this weather, so I turned the power to the boiler off and left it off overnight. I then turned it back on hoping this had reset the problem but later on in the evening the same thing happened. Could this be a fault on the PCB?
Advice needed please

 

[Boilerman2]

It could be, BUT I would be checking a lot of other things first such as the Diverter Valve!

 

[nabby68]

Thanks for reply
How would I go about checking diverter valve?
And would it be diverter valve as the heating is coming on even when hot water is not called for?

 

[picasso]

Unfortunately your boiler does not have a diverter valve you were probably right with your first guess with the pcb but you will need to get it confirmed before replacing any thing.

 

[nabby68]

ok thanks
how would I check the pcb?

 

[picasso]

You cant

 

[nabby68]

who can then?

 

[picasso]

Registered gas installer

just something for you to note, there are a few things that can cause the heating to come on with no demand other than the pcb, so please dont fit a new board as a hope and see tactic

 

[Boilerman2]

Whoops! thankfully I don't see too many Ferroli's so didn't realise this one had a 4 pipe Hex Sorry OP!