How do I fix my burner on my Glow worm Micron?

I have a 4 year old glow worm Micron and the burner goes out on a regular basis. I am unable to restart the boiler immediately -So, I leave it switched off for a period ( aprox 1 hour) and then try again and it then re-ignites. When the burner light goes out - I do not hear any fan noise it is completely dead.