Calling any heating engineers or knowledgeable persons

[rustyrider]

I moved into a house with oil CH last year.  The previous occupiers had drained the tank dry so I had to get some oil first.  Then found that it didn't work.  After blowing the crap out of the pipe with an air compressor, I started to get a reasonable flow arriving at the boiler as my tank is slightly higher than the boiler (but by no more than a foot or so).  Even then, the boiler locked out 3 or 4 times with air in the pipe before it started to work reliably.

Then some thieving towrag came along one day when I was at work, unscrewed the filler on top of the tank and pumped about 150 litres out of it!