Vokera Flowmatic-electrical problem

[Anderz]

Vokera Flowmatic 24-96 RSE Ignition control box

The one I have is a Brahma with a multi-spade connecter block which houses 8 wires.
6 wires go to a printed circuit board and 2 go directly to a pair of igniters.
The date on the box is Feb,93
the fault manifests itself occasionally, it will fire up on request, run for 8 seconds then cut out leaving only the fan running then when I disconnect and reconnect the terminal block with the power still on it sometimes works normally for days,weeks,and maybe even months.
Its at its worst when I've been away a while and its not been running.
...Q-Is it an intermittent fault in the box or is it elsewhere? Can anyone please shed any light?

Reluctant to replace the box in case the fault lays elsewhere.

Many thanks in advance, Anderz.

 

[Gasinayr]

when it goes to fault, fan only running. check for 240v at terminals at right hand side of pcb, 47 48 49 they should all be live, if no volts at 49 job for a GRI as you have to open combustion chamber

 

[Anderz]

when it goes to fault, fan only running. check for 240v at terminals at right hand side of pcb, 47 48 49 they should all be live, if no volts at 49 job for a GRI as you have to open combustion chamber

Ta much Gasinayr, I'll make these checks the morra!

 

[Anderz]

when it goes to fault, fan only running. check for 240v at terminals at right hand side of pcb, 47 48 49 they should all be live, if no volts at 49 job for a GRI as you have to open combustion chamber

Ta much Gasinayr, I'll make these checks the morra!

Was ready to perform test when,the boiler refused to go to fault (quite Ironic)as this is intermittent and old (93) I have decided to go for a changeout,looking for quotes,I'm in the Greenock area.

 

[Gasinayr]

Sounds like dirt in the flue venturi, good boiler get it serviced