Vokera Linea 24 Combi Boiler not staying lit?

My Vokera combi boiler ignites for a few seconds then goes out and continually repeats the process. The radiators eventually warm up but theres no hot water.
I have taken the differential pressure switch out and blown through it. The relay appears to work ok. When i put it back together it worked fine for 5 mins then went back to reigniting every few seconds.

Does anyone have any other suggestions? Ive heard that maybe its the ignition pcb??