I have the same problem with the same boiler. I'm told that there may be a blockage in the filter and/or pipe, as the crud from the bottom of the tank would have been stirred up when filled from empty. Also the 'nozzle' probably needs changing. Found the following from another website which i'm gonna try.....
If you have sludge in the filter, AND you have had your boiler serviced annually, get someone else to service it. If your service guy (assuming you had one) is OFTEC registered, OFTEC would be pleased to hear from you, and they will then inspect his work. Tank and filter checks are on the list of service items.
Once you have cleaned the strainers at the tank end, Turn off the oil at the boiler, and put a shallow tray under the burner. Switch off the power to the boiler, and unplug the cable that goes to the burner. Disconnect the pipe that goes into the pump, normally a 15mm spanner. Put the end of the pipe into a pot and open the oil valve. Run a couple of litres into a container. It should flow freely. Turn off the valve and reconnect the pipe, plug in the burner, turn on the power and try the burner.
Wipe the pipe joint with a piece of paper towel and check in about 15 mins for leaks.
If the oil didn't flow freely you need to find a way of pushing the oil back up the pipe to dislodge debris that is probably blocking the pipe.
Bear, December 2008
