My glowworm ultimate boiler wont fire up?

Boiler was working fine yesterday, This morning the heating was off so i checked to see if the boiler was turned on,It had a leak on the pump so i changed the washer & tightened it back up, no more leaks, the pilot light is on but it wont fire up now, i have bled the system to take the air out but still no luck, can anyone point me in the right direction?