Boiler failed

[Plumbers mate]

Hi all, anyone know what the problem could be with a Glow-worm Betacom 30C, it fires as normal & runs for about 10sec it then goes to flame failure lockout. Boiler only 4 months old so I have booked a engineer visit under warranty, however, they can't come out until Tuesday & could do with fixing before then as customer a bit naffed off. Any ideas would be greatly appreciated.

 

[Billy Bob Bob]

check detection lead for continuity,gas pressures,reversed polarity if its firing at normal rate,but not detecting lead or pcb or reversed polarity if its detecting the burners lit measure resistance of the thermistor should be around 11k cold but check mi,s they vary a fair bit