oil fired

Hi all, We installed a second hand Rayburn 600k a couple of years ago - yes, I'm afraid it was a bit of a lifestyle statement but SWMBO wanted one, so there it is. Anyway, a while ago it started misbehaving: it would fire up OK, but once up to temperature, it would switch off - as it should -...

Just had oil delivered after leaving the tank empty for the summer (I know not ideal), asked the guy to bleed it, which he said he did (I had turned it on for him) but noticed after a hour the rads still where not heating (after checking the water wasn't hot either), went to check boiler, seems...