look just get a metal guard, a piece of aluminum either side or up and over the terminal of the boiler. if your in the middle of a field or other open area then this problem will always happen. The wind blows the flame then it cuts out. always happens.
try looking at the pressure release valve dripping. this is the most likely culprit. happens all the time. Turn the pressure up to 1.5 and turn the boiler on. if it drips then its letting by and dropping the pressure. This is the small 15mm pipe sticking out the wall near the boiler. If it is...