Vokera Linea boiler constantly relighting

[kwardor]

Can anyone help please.
I have a vokera linea boiler which in the evening constantly relights every couple of seconds - it still gives hot radiators and usually hot water - the weird thing is that it doesn't happen in the morning!
We had a similar problem with the pilot light going out and not relighting and this was fixed a few months ago by replacing the circuit board - can anyone suggest what the problem might be?
Thanks

 

[adlplumbing]

you may have small leak leading to the cuircuit board or
it needs serviceing

 

[scatmanjohn]

Ignition control unit.